內核中file_operations源碼 linux-2.6.22.6

/include/linux/fs.h 具體內容在最后

//code from : linux2.6.22.6 /** NOTE:* read, write, poll, fsync, readv, writev, unlocked_ioctl and compat_ioctl* can be called without the big kernel lock held in all filesystems.*/ struct file_operations {struct module *owner;loff_t (*llseek) (struct file *, loff_t, int);ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);int (*readdir) (struct file *, void *, filldir_t);unsigned int (*poll) (struct file *, struct poll_table_struct *);int (*ioctl) (struct inode *, struct file *, unsigned int, unsigned long);long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);long (*compat_ioctl) (struct file *, unsigned int, unsigned long);int (*mmap) (struct file *, struct vm_area_struct *);int (*open) (struct inode *, struct file *);int (*flush) (struct file *, fl_owner_t id);int (*release) (struct inode *, struct file *);int (*fsync) (struct file *, struct dentry *, int datasync);int (*aio_fsync) (struct kiocb *, int datasync);int (*fasync) (int, struct file *, int);int (*lock) (struct file *, int, struct file_lock *);ssize_t (*sendfile) (struct file *, loff_t *, size_t, read_actor_t, void *);ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);int (*check_flags)(int);int (*dir_notify)(struct file *filp, unsigned long arg);int (*flock) (struct file *, int, struct file_lock *);ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int); };

1.struct module *owner

第一個file_operations?成員根本不是一個操作;它是一個指向擁有這個結構的模塊的指針.這

個成員用來在它的操作還在被使用時阻止模塊被卸載.幾乎所有時間中,它被簡單初始化為

THIS_MODULE,?一個在<linux/module.h>?中定義的宏.

struct module {struct module *next;const char *name;int gpl_compatible;struct symbol *unres;int seen;int skip;int has_init;int has_cleanup;struct buffer dev_table_buf;char srcversion[25]; };

struct module *owner

? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct symbol

struct symbol {struct symbol *hash_next;const char *name;enum symbol_type type;struct string_list *defn;struct symbol *expansion_trail;struct symbol *visited;int is_extern; };

instance analysis1:

#include <linux/module.h>MODULE_LICENSE("Dual BSD/GPL");static int hello_init(void) {unsigned int cpu = get_cpu();struct module *mod;printk(KERN_ALERT "this module: %p==%p/n", &__this_module, THIS_MODULE );printk(KERN_ALERT "module state: %d/n", THIS_MODULE->state );printk(KERN_ALERT "module name: %s/n", THIS_MODULE->name );list_for_each_entry(mod, *(&THIS_MODULE->list.prev), list )printk(KERN_ALERT "module name: %s/n", mod->name );return 0; }static void hello_exit(void) {printk(KERN_ALERT "module state: %d/n", THIS_MODULE->state ); }module_init(hello_init); module_exit(hello_exit);

?有興趣的同學可以練練手看看

2.loff_t (*llseek) (struct file *, loff_t, int);

llseek?方法用作改變文件中的當前讀/寫位置,并且新位置作為(正的)返回值.loff_t?參數是一

個"longoffset",?并且就算在32位平臺上也至少64?位寬.錯誤由一個負返回值指示.如果這個

函數指針是NULL, seek?調用會以潛在地無法預知的方式修改file?結構中的位置計數器.

3.ssize_t (*read) (struct file *, char __user *, size_t, loff_t*);

用來從設備中獲取數據.在這個位置的一個空指針導致read?系統調用以-EINVAL("Invalid

argument")?失敗.一個非負返回值代表了成功讀取的字節數(返回值是一個"signed size"?類型,

常常是目標平臺本地的整數類型).

4.ssize_t (*aio_read)(struct kiocb *, char __user *, size_t,loff_t);

初始化一個異步讀--?可能在函數返回前不結束的讀操作.如果這個方法是NULL,?所有的操

作會由read?代替進行(同步地).

5.ssize_t (*write) (struct file *, const char __user *, size_t,loff_t *);

發送數據給設備.如果NULL, -EINVAL?返回給調用write?系統調用的程序.如果非負,返回值

代表成功寫的字節數.

6.ssize_t (*aio_write)(struct kiocb *, const char __user *,size_t, loff_t *);

初始化設備上的一個異步寫.

7.int (*readdir) (struct file *, void *, filldir_t);

對于設備文件這個成員應當為NULL;?它用來讀取目錄,并且僅對文件系統有用.

8.unsigned int (*poll) (struct file *, struct poll_table_struct*);

poll?方法是3?個系統調用的后端:poll, epoll,?和select,?都用作查詢對一個或多個文件描述符的

讀或寫是否會阻塞.poll?方法應當返回一個位掩碼指示是否非阻塞的讀或寫是可能的,并且,

可能地,提供給內核信息用來使調用進程睡眠直到I/O?變為可能.如果一個驅動的poll?方法

為NULL,?設備假定為不阻塞地可讀可寫.

9.int (*ioctl) (struct inode *, struct file *, unsigned int,unsigned long);

ioctl?系統調用提供了發出設備特定命令的方法(例如格式化軟盤的一個磁道,這不是讀也不

是寫).另外,幾個ioctl?命令被內核識別而不必引用fops?表.如果設備不提供ioctl?方法,對于

任何未事先定義的請求(-ENOTTY,"設備無這樣的ioctl"),?系統調用返回一個錯誤.

10.int (*mmap) (struct file *, struct vm_area_struct *);

mmap?用來請求將設備內存映射到進程的地址空間.如果這個方法是NULL, mmap?系統調用

返回-ENODEV.

11.int (*open) (struct inode *, struct file *);

盡管這常常是對設備文件進行的第一個操作,不要求驅動聲明一個對應的方法.如果這個項

是NULL,?設備打開一直成功,但是你的驅動不會得到通知.

12.int (*flush) (struct file *);

flush?操作在進程關閉它的設備文件描述符的拷貝時調用;它應當執行(并且等待)設備的任何

未完成的操作.這個必須不要和用戶查詢請求的fsync?操作混淆了.當前,flush?在很少驅動中

使用;SCSI?磁帶驅動使用它,例如,為確保所有寫的數據在設備關閉前寫到磁帶上.如果flush

為NULL,?內核簡單地忽略用戶應用程序的請求.

13.int (*release) (struct inode *, struct file *);

在文件結構被釋放時引用這個操作.如同open, release?可以為NULL.

14.int (*fsync) (struct file *, struct dentry *, int);

這個方法是fsync?系統調用的后端,用戶調用來刷新任何掛著的數據.如果這個指針是

NULL,?系統調用返回-EINVAL.

15.int (*aio_fsync)(struct kiocb *, int);

這是fsync?方法的異步版本.

16.int (*fasync) (int, struct file *, int);

這個操作用來通知設備它的FASYNC?標志的改變.異步通知是一個高級的主題,在第6?章中

描述.這個成員可以是NULL如果驅動不支持異步通知.

17.int (*lock) (struct file *, int, struct file_lock *);

lock?方法用來實現文件加鎖;加鎖對常規文件是必不可少的特性,但是設備驅動幾乎從不實

現它.

18.ssize_t (*readv) (struct file *, const struct iovec *, unsignedlong, loff_t *);

19.ssize_t (*writev) (struct file *, const struct iovec *,unsigned long, loff_t *);

這些方法實現發散/匯聚讀和寫操作.應用程序偶爾需要做一個包含多個內存區的單個讀或

寫操作;這些系統調用允許它們這樣做而不必對數據進行額外拷貝.如果這些函數指針為

NULL, read?和write?方法被調用(可能多于一次).

20.ssize_t (*sendfile)(struct file *, loff_t *, size_t,read_actor_t, void *);

這個方法實現sendfile?系統調用的讀,使用最少的拷貝從一個文件描述符搬移數據到另一個.

例如,它被一個需要發送文件內容到一個網絡連接的web?服務器使用.設備驅動常常使

sendfile?為NULL.

21.ssize_t (*sendpage) (struct file *, struct page *, int, size_t,loff_t *, int);

sendpage?是sendfile?的另一半;它由內核調用來發送數據,一次一頁,到對應的文件.設備驅動

實際上不實現sendpage.

22.unsigned long (*get_unmapped_area)(struct file *, unsignedlong, unsigned long, unsigned long, unsigned long);

這個方法的目的是在進程的地址空間找一個合適的位置來映射在底層設備上的內存段中.

這個任務通常由內存管理代碼進行;這個方法存在為了使驅動能強制特殊設備可能有的任

何的對齊請求.大部分驅動可以置這個方法為NULL.

23.int (*check_flags)(int)

這個方法允許模塊檢查傳遞給fnctl(F_SETFL...)?調用的標志.

24.int (*dir_notify)(struct file *, unsigned long);

這個方法在應用程序使用fcntl?來請求目錄改變通知時調用.只對文件系統有用;驅動不需要

/include/linux/fs.h +1791 file_operation 頭文件內容

/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _LINUX_FS_H #define _LINUX_FS_H#include <linux/linkage.h> #include <linux/wait_bit.h> #include <linux/kdev_t.h> #include <linux/dcache.h> #include <linux/path.h> #include <linux/stat.h> #include <linux/cache.h> #include <linux/list.h> #include <linux/list_lru.h> #include <linux/llist.h> #include <linux/radix-tree.h> #include <linux/xarray.h> #include <linux/rbtree.h> #include <linux/init.h> #include <linux/pid.h> #include <linux/bug.h> #include <linux/mutex.h> #include <linux/rwsem.h> #include <linux/mm_types.h> #include <linux/capability.h> #include <linux/semaphore.h> #include <linux/fcntl.h> #include <linux/fiemap.h> #include <linux/rculist_bl.h> #include <linux/atomic.h> #include <linux/shrinker.h> #include <linux/migrate_mode.h> #include <linux/uidgid.h> #include <linux/lockdep.h> #include <linux/percpu-rwsem.h> #include <linux/workqueue.h> #include <linux/delayed_call.h> #include <linux/uuid.h> #include <linux/errseq.h> #include <linux/ioprio.h> #include <linux/fs_types.h> #include <linux/build_bug.h> #include <linux/stddef.h>#include <asm/byteorder.h> #include <uapi/linux/fs.h>struct backing_dev_info; struct bdi_writeback; struct bio; struct export_operations; struct hd_geometry; struct iovec; struct kiocb; struct kobject; struct pipe_inode_info; struct poll_table_struct; struct kstatfs; struct vm_area_struct; struct vfsmount; struct cred; struct swap_info_struct; struct seq_file; struct workqueue_struct; struct iov_iter; struct fscrypt_info; struct fscrypt_operations; struct fs_context; struct fs_parameter_description;extern void __init inode_init(void); extern void __init inode_init_early(void); extern void __init files_init(void); extern void __init files_maxfiles_init(void);extern struct files_stat_struct files_stat; extern unsigned long get_max_files(void); extern unsigned int sysctl_nr_open; extern struct inodes_stat_t inodes_stat; extern int leases_enable, lease_break_time; extern int sysctl_protected_symlinks; extern int sysctl_protected_hardlinks; extern int sysctl_protected_fifos; extern int sysctl_protected_regular;typedef __kernel_rwf_t rwf_t;struct buffer_head; typedef int (get_block_t)(struct inode *inode, sector_t iblock,struct buffer_head *bh_result, int create); typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset,ssize_t bytes, void *private);#define MAY_EXEC 0x00000001 #define MAY_WRITE 0x00000002 #define MAY_READ 0x00000004 #define MAY_APPEND 0x00000008 #define MAY_ACCESS 0x00000010 #define MAY_OPEN 0x00000020 #define MAY_CHDIR 0x00000040 /* called from RCU mode, don't block */ #define MAY_NOT_BLOCK 0x00000080/** flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must correspond* to O_WRONLY and O_RDWR via the strange trick in do_dentry_open()*//* file is open for reading */ #define FMODE_READ ((__force fmode_t)0x1) /* file is open for writing */ #define FMODE_WRITE ((__force fmode_t)0x2) /* file is seekable */ #define FMODE_LSEEK ((__force fmode_t)0x4) /* file can be accessed using pread */ #define FMODE_PREAD ((__force fmode_t)0x8) /* file can be accessed using pwrite */ #define FMODE_PWRITE ((__force fmode_t)0x10) /* File is opened for execution with sys_execve / sys_uselib */ #define FMODE_EXEC ((__force fmode_t)0x20) /* File is opened with O_NDELAY (only set for block devices) */ #define FMODE_NDELAY ((__force fmode_t)0x40) /* File is opened with O_EXCL (only set for block devices) */ #define FMODE_EXCL ((__force fmode_t)0x80) /* File is opened using open(.., 3, ..) and is writeable only for ioctls(specialy hack for floppy.c) */ #define FMODE_WRITE_IOCTL ((__force fmode_t)0x100) /* 32bit hashes as llseek() offset (for directories) */ #define FMODE_32BITHASH ((__force fmode_t)0x200) /* 64bit hashes as llseek() offset (for directories) */ #define FMODE_64BITHASH ((__force fmode_t)0x400)/** Don't update ctime and mtime.** Currently a special hack for the XFS open_by_handle ioctl, but we'll* hopefully graduate it to a proper O_CMTIME flag supported by open(2) soon.*/ #define FMODE_NOCMTIME ((__force fmode_t)0x800)/* Expect random access pattern */ #define FMODE_RANDOM ((__force fmode_t)0x1000)/* File is huge (eg. /dev/kmem): treat loff_t as unsigned */ #define FMODE_UNSIGNED_OFFSET ((__force fmode_t)0x2000)/* File is opened with O_PATH; almost nothing can be done with it */ #define FMODE_PATH ((__force fmode_t)0x4000)/* File needs atomic accesses to f_pos */ #define FMODE_ATOMIC_POS ((__force fmode_t)0x8000) /* Write access to underlying fs */ #define FMODE_WRITER ((__force fmode_t)0x10000) /* Has read method(s) */ #define FMODE_CAN_READ ((__force fmode_t)0x20000) /* Has write method(s) */ #define FMODE_CAN_WRITE ((__force fmode_t)0x40000)#define FMODE_OPENED ((__force fmode_t)0x80000) #define FMODE_CREATED ((__force fmode_t)0x100000)/* File is stream-like */ #define FMODE_STREAM ((__force fmode_t)0x200000)/* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x4000000)/* File is capable of returning -EAGAIN if I/O will block */ #define FMODE_NOWAIT ((__force fmode_t)0x8000000)/* File represents mount that needs unmounting */ #define FMODE_NEED_UNMOUNT ((__force fmode_t)0x10000000)/* File does not contribute to nr_files count */ #define FMODE_NOACCOUNT ((__force fmode_t)0x20000000)/** Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector* that indicates that they should check the contents of the iovec are* valid, but not check the memory that the iovec elements* points too.*/ #define CHECK_IOVEC_ONLY -1/** Attribute flags. These should be or-ed together to figure out what* has been changed!*/ #define ATTR_MODE (1 << 0) #define ATTR_UID (1 << 1) #define ATTR_GID (1 << 2) #define ATTR_SIZE (1 << 3) #define ATTR_ATIME (1 << 4) #define ATTR_MTIME (1 << 5) #define ATTR_CTIME (1 << 6) #define ATTR_ATIME_SET (1 << 7) #define ATTR_MTIME_SET (1 << 8) #define ATTR_FORCE (1 << 9) /* Not a change, but a change it */ #define ATTR_KILL_SUID (1 << 11) #define ATTR_KILL_SGID (1 << 12) #define ATTR_FILE (1 << 13) #define ATTR_KILL_PRIV (1 << 14) #define ATTR_OPEN (1 << 15) /* Truncating from open(O_TRUNC) */ #define ATTR_TIMES_SET (1 << 16) #define ATTR_TOUCH (1 << 17)/** Whiteout is represented by a char device. The following constants define the* mode and device number to use.*/ #define WHITEOUT_MODE 0 #define WHITEOUT_DEV 0/** This is the Inode Attributes structure, used for notify_change(). It* uses the above definitions as flags, to know which values have changed.* Also, in this manner, a Filesystem can look at only the values it cares* about. Basically, these are the attributes that the VFS layer can* request to change from the FS layer.** Derek Atkins <warlord@MIT.EDU> 94-10-20*/ struct iattr {unsigned int ia_valid;umode_t ia_mode;kuid_t ia_uid;kgid_t ia_gid;loff_t ia_size;struct timespec64 ia_atime;struct timespec64 ia_mtime;struct timespec64 ia_ctime;/** Not an attribute, but an auxiliary info for filesystems wanting to* implement an ftruncate() like method. NOTE: filesystem should* check for (ia_valid & ATTR_FILE), and not for (ia_file != NULL).*/struct file *ia_file; };/** Includes for diskquotas.*/ #include <linux/quota.h>/** Maximum number of layers of fs stack. Needs to be limited to* prevent kernel stack overflow*/ #define FILESYSTEM_MAX_STACK_DEPTH 2/** * enum positive_aop_returns - aop return codes with specific semantics** @AOP_WRITEPAGE_ACTIVATE: Informs the caller that page writeback has* completed, that the page is still locked, and* should be considered active. The VM uses this hint* to return the page to the active list -- it won't* be a candidate for writeback again in the near* future. Other callers must be careful to unlock* the page if they get this return. Returned by* writepage(); ** @AOP_TRUNCATED_PAGE: The AOP method that was handed a locked page has* unlocked it and the page might have been truncated.* The caller should back up to acquiring a new page and* trying again. The aop will be taking reasonable* precautions not to livelock. If the caller held a page* reference, it should drop it before retrying. Returned* by readpage().** address_space_operation functions return these large constants to indicate* special semantics to the caller. These are much larger than the bytes in a* page to allow for functions that return the number of bytes operated on in a* given page.*/enum positive_aop_returns {AOP_WRITEPAGE_ACTIVATE = 0x80000,AOP_TRUNCATED_PAGE = 0x80001, };#define AOP_FLAG_CONT_EXPAND 0x0001 /* called from cont_expand */ #define AOP_FLAG_NOFS 0x0002 /* used by filesystem to direct* helper code (eg buffer layer)* to clear GFP_FS from alloc *//** oh the beauties of C type declarations.*/ struct page; struct address_space; struct writeback_control;/** Write life time hint values.* Stored in struct inode as u8.*/ enum rw_hint {WRITE_LIFE_NOT_SET = 0,WRITE_LIFE_NONE = RWH_WRITE_LIFE_NONE,WRITE_LIFE_SHORT = RWH_WRITE_LIFE_SHORT,WRITE_LIFE_MEDIUM = RWH_WRITE_LIFE_MEDIUM,WRITE_LIFE_LONG = RWH_WRITE_LIFE_LONG,WRITE_LIFE_EXTREME = RWH_WRITE_LIFE_EXTREME, };#define IOCB_EVENTFD (1 << 0) #define IOCB_APPEND (1 << 1) #define IOCB_DIRECT (1 << 2) #define IOCB_HIPRI (1 << 3) #define IOCB_DSYNC (1 << 4) #define IOCB_SYNC (1 << 5) #define IOCB_WRITE (1 << 6) #define IOCB_NOWAIT (1 << 7)struct kiocb {struct file *ki_filp;/* The 'ki_filp' pointer is shared in a union for aio */randomized_struct_fields_startloff_t ki_pos;void (*ki_complete)(struct kiocb *iocb, long ret, long ret2);void *private;int ki_flags;u16 ki_hint;u16 ki_ioprio; /* See linux/ioprio.h */unsigned int ki_cookie; /* for ->iopoll */randomized_struct_fields_end };static inline bool is_sync_kiocb(struct kiocb *kiocb) {return kiocb->ki_complete == NULL; }/** "descriptor" for what we're up to with a read.* This allows us to use the same read code yet* have multiple different users of the data that* we read from a file.** The simplest case just copies the data to user* mode.*/ typedef struct {size_t written;size_t count;union {char __user *buf;void *data;} arg;int error; } read_descriptor_t;typedef int (*read_actor_t)(read_descriptor_t *, struct page *,unsigned long, unsigned long);struct address_space_operations {int (*writepage)(struct page *page, struct writeback_control *wbc);int (*readpage)(struct file *, struct page *);/* Write back some dirty pages from this mapping. */int (*writepages)(struct address_space *, struct writeback_control *);/* Set a page dirty. Return true if this dirtied it */int (*set_page_dirty)(struct page *page);/** Reads in the requested pages. Unlike ->readpage(), this is* PURELY used for read-ahead!.*/int (*readpages)(struct file *filp, struct address_space *mapping,struct list_head *pages, unsigned nr_pages);int (*write_begin)(struct file *, struct address_space *mapping,loff_t pos, unsigned len, unsigned flags,struct page **pagep, void **fsdata);int (*write_end)(struct file *, struct address_space *mapping,loff_t pos, unsigned len, unsigned copied,struct page *page, void *fsdata);/* Unfortunately this kludge is needed for FIBMAP. Don't use it */sector_t (*bmap)(struct address_space *, sector_t);void (*invalidatepage) (struct page *, unsigned int, unsigned int);int (*releasepage) (struct page *, gfp_t);void (*freepage)(struct page *);ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter);/** migrate the contents of a page to the specified target. If* migrate_mode is MIGRATE_ASYNC, it must not block.*/int (*migratepage) (struct address_space *,struct page *, struct page *, enum migrate_mode);bool (*isolate_page)(struct page *, isolate_mode_t);void (*putback_page)(struct page *);int (*launder_page) (struct page *);int (*is_partially_uptodate) (struct page *, unsigned long,unsigned long);void (*is_dirty_writeback) (struct page *, bool *, bool *);int (*error_remove_page)(struct address_space *, struct page *);/* swapfile support */int (*swap_activate)(struct swap_info_struct *sis, struct file *file,sector_t *span);void (*swap_deactivate)(struct file *file); };extern const struct address_space_operations empty_aops;/** pagecache_write_begin/pagecache_write_end must be used by general code* to write into the pagecache.*/ int pagecache_write_begin(struct file *, struct address_space *mapping,loff_t pos, unsigned len, unsigned flags,struct page **pagep, void **fsdata);int pagecache_write_end(struct file *, struct address_space *mapping,loff_t pos, unsigned len, unsigned copied,struct page *page, void *fsdata);/*** struct address_space - Contents of a cacheable, mappable object.* @host: Owner, either the inode or the block_device.* @i_pages: Cached pages.* @gfp_mask: Memory allocation flags to use for allocating pages.* @i_mmap_writable: Number of VM_SHARED mappings.* @i_mmap: Tree of private and shared mappings.* @i_mmap_rwsem: Protects @i_mmap and @i_mmap_writable.* @nrpages: Number of page entries, protected by the i_pages lock.* @nrexceptional: Shadow or DAX entries, protected by the i_pages lock.* @writeback_index: Writeback starts here.* @a_ops: Methods.* @flags: Error bits and flags (AS_*).* @wb_err: The most recent error which has occurred.* @private_lock: For use by the owner of the address_space.* @private_list: For use by the owner of the address_space.* @private_data: For use by the owner of the address_space.*/ struct address_space {struct inode *host;struct xarray i_pages;gfp_t gfp_mask;atomic_t i_mmap_writable;struct rb_root_cached i_mmap;struct rw_semaphore i_mmap_rwsem;unsigned long nrpages;unsigned long nrexceptional;pgoff_t writeback_index;const struct address_space_operations *a_ops;unsigned long flags;errseq_t wb_err;spinlock_t private_lock;struct list_head private_list;void *private_data; } __attribute__((aligned(sizeof(long)))) __randomize_layout;/** On most architectures that alignment is already the case; but* must be enforced here for CRIS, to let the least significant bit* of struct page's "mapping" pointer be used for PAGE_MAPPING_ANON.*/ struct request_queue;struct block_device {dev_t bd_dev; /* not a kdev_t - it's a search key */int bd_openers;struct inode * bd_inode; /* will die */struct super_block * bd_super;struct mutex bd_mutex; /* open/close mutex */void * bd_claiming;void * bd_holder;int bd_holders;bool bd_write_holder; #ifdef CONFIG_SYSFSstruct list_head bd_holder_disks; #endifstruct block_device * bd_contains;unsigned bd_block_size;u8 bd_partno;struct hd_struct * bd_part;/* number of times partitions within this device have been opened. */unsigned bd_part_count;int bd_invalidated;struct gendisk * bd_disk;struct request_queue * bd_queue;struct backing_dev_info *bd_bdi;struct list_head bd_list;/** Private data. You must have bd_claim'ed the block_device* to use this. NOTE: bd_claim allows an owner to claim* the same device multiple times, the owner must take special* care to not mess up bd_private for that case.*/unsigned long bd_private;/* The counter of freeze processes */int bd_fsfreeze_count;/* Mutex for freeze */struct mutex bd_fsfreeze_mutex; } __randomize_layout;/* XArray tags, for tagging dirty and writeback pages in the pagecache. */ #define PAGECACHE_TAG_DIRTY XA_MARK_0 #define PAGECACHE_TAG_WRITEBACK XA_MARK_1 #define PAGECACHE_TAG_TOWRITE XA_MARK_2/** Returns true if any of the pages in the mapping are marked with the tag.*/ static inline bool mapping_tagged(struct address_space *mapping, xa_mark_t tag) {return xa_marked(&mapping->i_pages, tag); }static inline void i_mmap_lock_write(struct address_space *mapping) {down_write(&mapping->i_mmap_rwsem); }static inline void i_mmap_unlock_write(struct address_space *mapping) {up_write(&mapping->i_mmap_rwsem); }static inline void i_mmap_lock_read(struct address_space *mapping) {down_read(&mapping->i_mmap_rwsem); }static inline void i_mmap_unlock_read(struct address_space *mapping) {up_read(&mapping->i_mmap_rwsem); }/** Might pages of this file be mapped into userspace?*/ static inline int mapping_mapped(struct address_space *mapping) {return !RB_EMPTY_ROOT(&mapping->i_mmap.rb_root); }/** Might pages of this file have been modified in userspace?* Note that i_mmap_writable counts all VM_SHARED vmas: do_mmap_pgoff* marks vma as VM_SHARED if it is shared, and the file was opened for* writing i.e. vma may be mprotected writable even if now readonly.** If i_mmap_writable is negative, no new writable mappings are allowed. You* can only deny writable mappings, if none exists right now.*/ static inline int mapping_writably_mapped(struct address_space *mapping) {return atomic_read(&mapping->i_mmap_writable) > 0; }static inline int mapping_map_writable(struct address_space *mapping) {return atomic_inc_unless_negative(&mapping->i_mmap_writable) ?0 : -EPERM; }static inline void mapping_unmap_writable(struct address_space *mapping) {atomic_dec(&mapping->i_mmap_writable); }static inline int mapping_deny_writable(struct address_space *mapping) {return atomic_dec_unless_positive(&mapping->i_mmap_writable) ?0 : -EBUSY; }static inline void mapping_allow_writable(struct address_space *mapping) {atomic_inc(&mapping->i_mmap_writable); }/** Use sequence counter to get consistent i_size on 32-bit processors.*/ #if BITS_PER_LONG==32 && defined(CONFIG_SMP) #include <linux/seqlock.h> #define __NEED_I_SIZE_ORDERED #define i_size_ordered_init(inode) seqcount_init(&inode->i_size_seqcount) #else #define i_size_ordered_init(inode) do { } while (0) #endifstruct posix_acl; #define ACL_NOT_CACHED ((void *)(-1)) #define ACL_DONT_CACHE ((void *)(-3))static inline struct posix_acl * uncached_acl_sentinel(struct task_struct *task) {return (void *)task + 1; }static inline bool is_uncached_acl(struct posix_acl *acl) {return (long)acl & 1; }#define IOP_FASTPERM 0x0001 #define IOP_LOOKUP 0x0002 #define IOP_NOFOLLOW 0x0004 #define IOP_XATTR 0x0008 #define IOP_DEFAULT_READLINK 0x0010struct fsnotify_mark_connector;/** Keep mostly read-only and often accessed (especially for* the RCU path lookup and 'stat' data) fields at the beginning* of the 'struct inode'*/ struct inode {umode_t i_mode;unsigned short i_opflags;kuid_t i_uid;kgid_t i_gid;unsigned int i_flags;#ifdef CONFIG_FS_POSIX_ACLstruct posix_acl *i_acl;struct posix_acl *i_default_acl; #endifconst struct inode_operations *i_op;struct super_block *i_sb;struct address_space *i_mapping;#ifdef CONFIG_SECURITYvoid *i_security; #endif/* Stat data, not accessed from path walking */unsigned long i_ino;/** Filesystems may only read i_nlink directly. They shall use the* following functions for modification:** (set|clear|inc|drop)_nlink* inode_(inc|dec)_link_count*/union {const unsigned int i_nlink;unsigned int __i_nlink;};dev_t i_rdev;loff_t i_size;struct timespec64 i_atime;struct timespec64 i_mtime;struct timespec64 i_ctime;spinlock_t i_lock; /* i_blocks, i_bytes, maybe i_size */unsigned short i_bytes;u8 i_blkbits;u8 i_write_hint;blkcnt_t i_blocks;#ifdef __NEED_I_SIZE_ORDEREDseqcount_t i_size_seqcount; #endif/* Misc */unsigned long i_state;struct rw_semaphore i_rwsem;unsigned long dirtied_when; /* jiffies of first dirtying */unsigned long dirtied_time_when;struct hlist_node i_hash;struct list_head i_io_list; /* backing dev IO list */ #ifdef CONFIG_CGROUP_WRITEBACKstruct bdi_writeback *i_wb; /* the associated cgroup wb *//* foreign inode detection, see wbc_detach_inode() */int i_wb_frn_winner;u16 i_wb_frn_avg_time;u16 i_wb_frn_history; #endifstruct list_head i_lru; /* inode LRU list */struct list_head i_sb_list;struct list_head i_wb_list; /* backing dev writeback list */union {struct hlist_head i_dentry;struct rcu_head i_rcu;};atomic64_t i_version;atomic_t i_count;atomic_t i_dio_count;atomic_t i_writecount; #ifdef CONFIG_IMAatomic_t i_readcount; /* struct files open RO */ #endifunion {const struct file_operations *i_fop; /* former ->i_op->default_file_ops */void (*free_inode)(struct inode *);};struct file_lock_context *i_flctx;struct address_space i_data;struct list_head i_devices;union {struct pipe_inode_info *i_pipe;struct block_device *i_bdev;struct cdev *i_cdev;char *i_link;unsigned i_dir_seq;};__u32 i_generation;#ifdef CONFIG_FSNOTIFY__u32 i_fsnotify_mask; /* all events this inode cares about */struct fsnotify_mark_connector __rcu *i_fsnotify_marks; #endif#ifdef CONFIG_FS_ENCRYPTIONstruct fscrypt_info *i_crypt_info; #endifvoid *i_private; /* fs or device private pointer */ } __randomize_layout;static inline unsigned int i_blocksize(const struct inode *node) {return (1 << node->i_blkbits); }static inline int inode_unhashed(struct inode *inode) {return hlist_unhashed(&inode->i_hash); }/** __mark_inode_dirty expects inodes to be hashed. Since we don't* want special inodes in the fileset inode space, we make them* appear hashed, but do not put on any lists. hlist_del()* will work fine and require no locking.*/ static inline void inode_fake_hash(struct inode *inode) {hlist_add_fake(&inode->i_hash); }/** inode->i_mutex nesting subclasses for the lock validator:** 0: the object of the current VFS operation* 1: parent* 2: child/target* 3: xattr* 4: second non-directory* 5: second parent (when locking independent directories in rename)** I_MUTEX_NONDIR2 is for certain operations (such as rename) which lock two* non-directories at once.** The locking order between these classes is* parent[2] -> child -> grandchild -> normal -> xattr -> second non-directory*/ enum inode_i_mutex_lock_class {I_MUTEX_NORMAL,I_MUTEX_PARENT,I_MUTEX_CHILD,I_MUTEX_XATTR,I_MUTEX_NONDIR2,I_MUTEX_PARENT2, };static inline void inode_lock(struct inode *inode) {down_write(&inode->i_rwsem); }static inline void inode_unlock(struct inode *inode) {up_write(&inode->i_rwsem); }static inline void inode_lock_shared(struct inode *inode) {down_read(&inode->i_rwsem); }static inline void inode_unlock_shared(struct inode *inode) {up_read(&inode->i_rwsem); }static inline int inode_trylock(struct inode *inode) {return down_write_trylock(&inode->i_rwsem); }static inline int inode_trylock_shared(struct inode *inode) {return down_read_trylock(&inode->i_rwsem); }static inline int inode_is_locked(struct inode *inode) {return rwsem_is_locked(&inode->i_rwsem); }static inline void inode_lock_nested(struct inode *inode, unsigned subclass) {down_write_nested(&inode->i_rwsem, subclass); }static inline void inode_lock_shared_nested(struct inode *inode, unsigned subclass) {down_read_nested(&inode->i_rwsem, subclass); }void lock_two_nondirectories(struct inode *, struct inode*); void unlock_two_nondirectories(struct inode *, struct inode*);/** NOTE: in a 32bit arch with a preemptable kernel and* an UP compile the i_size_read/write must be atomic* with respect to the local cpu (unlike with preempt disabled),* but they don't need to be atomic with respect to other cpus like in* true SMP (so they need either to either locally disable irq around* the read or for example on x86 they can be still implemented as a* cmpxchg8b without the need of the lock prefix). For SMP compiles* and 64bit archs it makes no difference if preempt is enabled or not.*/ static inline loff_t i_size_read(const struct inode *inode) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP)loff_t i_size;unsigned int seq;do {seq = read_seqcount_begin(&inode->i_size_seqcount);i_size = inode->i_size;} while (read_seqcount_retry(&inode->i_size_seqcount, seq));return i_size; #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)loff_t i_size;preempt_disable();i_size = inode->i_size;preempt_enable();return i_size; #elsereturn inode->i_size; #endif }/** NOTE: unlike i_size_read(), i_size_write() does need locking around it* (normally i_mutex), otherwise on 32bit/SMP an update of i_size_seqcount* can be lost, resulting in subsequent i_size_read() calls spinning forever.*/ static inline void i_size_write(struct inode *inode, loff_t i_size) { #if BITS_PER_LONG==32 && defined(CONFIG_SMP)preempt_disable();write_seqcount_begin(&inode->i_size_seqcount);inode->i_size = i_size;write_seqcount_end(&inode->i_size_seqcount);preempt_enable(); #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)preempt_disable();inode->i_size = i_size;preempt_enable(); #elseinode->i_size = i_size; #endif }static inline unsigned iminor(const struct inode *inode) {return MINOR(inode->i_rdev); }static inline unsigned imajor(const struct inode *inode) {return MAJOR(inode->i_rdev); }extern struct block_device *I_BDEV(struct inode *inode);struct fown_struct {rwlock_t lock; /* protects pid, uid, euid fields */struct pid *pid; /* pid or -pgrp where SIGIO should be sent */enum pid_type pid_type; /* Kind of process group SIGIO should be sent to */kuid_t uid, euid; /* uid/euid of process setting the owner */int signum; /* posix.1b rt signal to be delivered on IO */ };/** Track a single file's readahead state*/ struct file_ra_state {pgoff_t start; /* where readahead started */unsigned int size; /* # of readahead pages */unsigned int async_size; /* do asynchronous readahead whenthere are only # of pages ahead */unsigned int ra_pages; /* Maximum readahead window */unsigned int mmap_miss; /* Cache miss stat for mmap accesses */loff_t prev_pos; /* Cache last read() position */ };/** Check if @index falls in the readahead windows.*/ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) {return (index >= ra->start &&index < ra->start + ra->size); }struct file {union {struct llist_node fu_llist;struct rcu_head fu_rcuhead;} f_u;struct path f_path;struct inode *f_inode; /* cached value */const struct file_operations *f_op;/** Protects f_ep_links, f_flags.* Must not be taken from IRQ context.*/spinlock_t f_lock;enum rw_hint f_write_hint;atomic_long_t f_count;unsigned int f_flags;fmode_t f_mode;struct mutex f_pos_lock;loff_t f_pos;struct fown_struct f_owner;const struct cred *f_cred;struct file_ra_state f_ra;u64 f_version; #ifdef CONFIG_SECURITYvoid *f_security; #endif/* needed for tty driver, and maybe others */void *private_data;#ifdef CONFIG_EPOLL/* Used by fs/eventpoll.c to link all the hooks to this file */struct list_head f_ep_links;struct list_head f_tfile_llink; #endif /* #ifdef CONFIG_EPOLL */struct address_space *f_mapping;errseq_t f_wb_err; } __randomize_layout__attribute__((aligned(4))); /* lest something weird decides that 2 is OK */struct file_handle {__u32 handle_bytes;int handle_type;/* file identifier */unsigned char f_handle[0]; };static inline struct file *get_file(struct file *f) {atomic_long_inc(&f->f_count);return f; } #define get_file_rcu_many(x, cnt) \atomic_long_add_unless(&(x)->f_count, (cnt), 0) #define get_file_rcu(x) get_file_rcu_many((x), 1) #define file_count(x) atomic_long_read(&(x)->f_count)#define MAX_NON_LFS ((1UL<<31) - 1)/* Page cache limit. The filesystems should put that into their s_maxbytes limits, otherwise bad things can happen in VM. */ #if BITS_PER_LONG==32 #define MAX_LFS_FILESIZE ((loff_t)ULONG_MAX << PAGE_SHIFT) #elif BITS_PER_LONG==64 #define MAX_LFS_FILESIZE ((loff_t)LLONG_MAX) #endif#define FL_POSIX 1 #define FL_FLOCK 2 #define FL_DELEG 4 /* NFSv4 delegation */ #define FL_ACCESS 8 /* not trying to lock, just looking */ #define FL_EXISTS 16 /* when unlocking, test for existence */ #define FL_LEASE 32 /* lease held on this file */ #define FL_CLOSE 64 /* unlock on close */ #define FL_SLEEP 128 /* A blocking lock */ #define FL_DOWNGRADE_PENDING 256 /* Lease is being downgraded */ #define FL_UNLOCK_PENDING 512 /* Lease is being broken */ #define FL_OFDLCK 1024 /* lock is "owned" by struct file */ #define FL_LAYOUT 2048 /* outstanding pNFS layout */#define FL_CLOSE_POSIX (FL_POSIX | FL_CLOSE)/** Special return value from posix_lock_file() and vfs_lock_file() for* asynchronous locking.*/ #define FILE_LOCK_DEFERRED 1/* legacy typedef, should eventually be removed */ typedef void *fl_owner_t;struct file_lock;struct file_lock_operations {void (*fl_copy_lock)(struct file_lock *, struct file_lock *);void (*fl_release_private)(struct file_lock *); };struct lock_manager_operations {int (*lm_compare_owner)(struct file_lock *, struct file_lock *);unsigned long (*lm_owner_key)(struct file_lock *);fl_owner_t (*lm_get_owner)(fl_owner_t);void (*lm_put_owner)(fl_owner_t);void (*lm_notify)(struct file_lock *); /* unblock callback */int (*lm_grant)(struct file_lock *, int);bool (*lm_break)(struct file_lock *);int (*lm_change)(struct file_lock *, int, struct list_head *);void (*lm_setup)(struct file_lock *, void **); };struct lock_manager {struct list_head list;/** NFSv4 and up also want opens blocked during the grace period;* NLM doesn't care:*/bool block_opens; };struct net; void locks_start_grace(struct net *, struct lock_manager *); void locks_end_grace(struct lock_manager *); bool locks_in_grace(struct net *); bool opens_in_grace(struct net *);/* that will die - we need it for nfs_lock_info */ #include <linux/nfs_fs_i.h>/** struct file_lock represents a generic "file lock". It's used to represent* POSIX byte range locks, BSD (flock) locks, and leases. It's important to* note that the same struct is used to represent both a request for a lock and* the lock itself, but the same object is never used for both.** FIXME: should we create a separate "struct lock_request" to help distinguish* these two uses?** The varous i_flctx lists are ordered by:** 1) lock owner* 2) lock range start* 3) lock range end** Obviously, the last two criteria only matter for POSIX locks.*/ struct file_lock {struct file_lock *fl_blocker; /* The lock, that is blocking us */struct list_head fl_list; /* link into file_lock_context */struct hlist_node fl_link; /* node in global lists */struct list_head fl_blocked_requests; /* list of requests with* ->fl_blocker pointing here*/struct list_head fl_blocked_member; /* node in* ->fl_blocker->fl_blocked_requests*/fl_owner_t fl_owner;unsigned int fl_flags;unsigned char fl_type;unsigned int fl_pid;int fl_link_cpu; /* what cpu's list is this on? */wait_queue_head_t fl_wait;struct file *fl_file;loff_t fl_start;loff_t fl_end;struct fasync_struct * fl_fasync; /* for lease break notifications *//* for lease breaks: */unsigned long fl_break_time;unsigned long fl_downgrade_time;const struct file_lock_operations *fl_ops; /* Callbacks for filesystems */const struct lock_manager_operations *fl_lmops; /* Callbacks for lockmanagers */union {struct nfs_lock_info nfs_fl;struct nfs4_lock_info nfs4_fl;struct {struct list_head link; /* link in AFS vnode's pending_locks list */int state; /* state of grant or error if -ve */unsigned int debug_id;} afs;} fl_u; } __randomize_layout;struct file_lock_context {spinlock_t flc_lock;struct list_head flc_flock;struct list_head flc_posix;struct list_head flc_lease; };/* The following constant reflects the upper bound of the file/locking space */ #ifndef OFFSET_MAX #define INT_LIMIT(x) (~((x)1 << (sizeof(x)*8 - 1))) #define OFFSET_MAX INT_LIMIT(loff_t) #define OFFT_OFFSET_MAX INT_LIMIT(off_t) #endifextern void send_sigio(struct fown_struct *fown, int fd, int band);#define locks_inode(f) file_inode(f)#ifdef CONFIG_FILE_LOCKING extern int fcntl_getlk(struct file *, unsigned int, struct flock *); extern int fcntl_setlk(unsigned int, struct file *, unsigned int,struct flock *);#if BITS_PER_LONG == 32 extern int fcntl_getlk64(struct file *, unsigned int, struct flock64 *); extern int fcntl_setlk64(unsigned int, struct file *, unsigned int,struct flock64 *); #endifextern int fcntl_setlease(unsigned int fd, struct file *filp, long arg); extern int fcntl_getlease(struct file *filp);/* fs/locks.c */ void locks_free_lock_context(struct inode *inode); void locks_free_lock(struct file_lock *fl); extern void locks_init_lock(struct file_lock *); extern struct file_lock * locks_alloc_lock(void); extern void locks_copy_lock(struct file_lock *, struct file_lock *); extern void locks_copy_conflock(struct file_lock *, struct file_lock *); extern void locks_remove_posix(struct file *, fl_owner_t); extern void locks_remove_file(struct file *); extern void locks_release_private(struct file_lock *); extern void posix_test_lock(struct file *, struct file_lock *); extern int posix_lock_file(struct file *, struct file_lock *, struct file_lock *); extern int locks_delete_block(struct file_lock *); extern int vfs_test_lock(struct file *, struct file_lock *); extern int vfs_lock_file(struct file *, unsigned int, struct file_lock *, struct file_lock *); extern int vfs_cancel_lock(struct file *filp, struct file_lock *fl); extern int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl); extern int __break_lease(struct inode *inode, unsigned int flags, unsigned int type); extern void lease_get_mtime(struct inode *, struct timespec64 *time); extern int generic_setlease(struct file *, long, struct file_lock **, void **priv); extern int vfs_setlease(struct file *, long, struct file_lock **, void **); extern int lease_modify(struct file_lock *, int, struct list_head *); struct files_struct; extern void show_fd_locks(struct seq_file *f,struct file *filp, struct files_struct *files); #else /* !CONFIG_FILE_LOCKING */ static inline int fcntl_getlk(struct file *file, unsigned int cmd,struct flock __user *user) {return -EINVAL; }static inline int fcntl_setlk(unsigned int fd, struct file *file,unsigned int cmd, struct flock __user *user) {return -EACCES; }#if BITS_PER_LONG == 32 static inline int fcntl_getlk64(struct file *file, unsigned int cmd,struct flock64 __user *user) {return -EINVAL; }static inline int fcntl_setlk64(unsigned int fd, struct file *file,unsigned int cmd, struct flock64 __user *user) {return -EACCES; } #endif static inline int fcntl_setlease(unsigned int fd, struct file *filp, long arg) {return -EINVAL; }static inline int fcntl_getlease(struct file *filp) {return F_UNLCK; }static inline void locks_free_lock_context(struct inode *inode) { }static inline void locks_init_lock(struct file_lock *fl) {return; }static inline void locks_copy_conflock(struct file_lock *new, struct file_lock *fl) {return; }static inline void locks_copy_lock(struct file_lock *new, struct file_lock *fl) {return; }static inline void locks_remove_posix(struct file *filp, fl_owner_t owner) {return; }static inline void locks_remove_file(struct file *filp) {return; }static inline void posix_test_lock(struct file *filp, struct file_lock *fl) {return; }static inline int posix_lock_file(struct file *filp, struct file_lock *fl,struct file_lock *conflock) {return -ENOLCK; }static inline int locks_delete_block(struct file_lock *waiter) {return -ENOENT; }static inline int vfs_test_lock(struct file *filp, struct file_lock *fl) {return 0; }static inline int vfs_lock_file(struct file *filp, unsigned int cmd,struct file_lock *fl, struct file_lock *conf) {return -ENOLCK; }static inline int vfs_cancel_lock(struct file *filp, struct file_lock *fl) {return 0; }static inline int locks_lock_inode_wait(struct inode *inode, struct file_lock *fl) {return -ENOLCK; }static inline int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) {return 0; }static inline void lease_get_mtime(struct inode *inode,struct timespec64 *time) {return; }static inline int generic_setlease(struct file *filp, long arg,struct file_lock **flp, void **priv) {return -EINVAL; }static inline int vfs_setlease(struct file *filp, long arg,struct file_lock **lease, void **priv) {return -EINVAL; }static inline int lease_modify(struct file_lock *fl, int arg,struct list_head *dispose) {return -EINVAL; }struct files_struct; static inline void show_fd_locks(struct seq_file *f,struct file *filp, struct files_struct *files) {} #endif /* !CONFIG_FILE_LOCKING */static inline struct inode *file_inode(const struct file *f) {return f->f_inode; }static inline struct dentry *file_dentry(const struct file *file) {return d_real(file->f_path.dentry, file_inode(file)); }static inline int locks_lock_file_wait(struct file *filp, struct file_lock *fl) {return locks_lock_inode_wait(locks_inode(filp), fl); }struct fasync_struct {rwlock_t fa_lock;int magic;int fa_fd;struct fasync_struct *fa_next; /* singly linked list */struct file *fa_file;struct rcu_head fa_rcu; };#define FASYNC_MAGIC 0x4601/* SMP safe fasync helpers: */ extern int fasync_helper(int, struct file *, int, struct fasync_struct **); extern struct fasync_struct *fasync_insert_entry(int, struct file *, struct fasync_struct **, struct fasync_struct *); extern int fasync_remove_entry(struct file *, struct fasync_struct **); extern struct fasync_struct *fasync_alloc(void); extern void fasync_free(struct fasync_struct *);/* can be called from interrupts */ extern void kill_fasync(struct fasync_struct **, int, int);extern void __f_setown(struct file *filp, struct pid *, enum pid_type, int force); extern int f_setown(struct file *filp, unsigned long arg, int force); extern void f_delown(struct file *filp); extern pid_t f_getown(struct file *filp); extern int send_sigurg(struct fown_struct *fown);/** sb->s_flags. Note that these mirror the equivalent MS_* flags where* represented in both.*/ #define SB_RDONLY 1 /* Mount read-only */ #define SB_NOSUID 2 /* Ignore suid and sgid bits */ #define SB_NODEV 4 /* Disallow access to device special files */ #define SB_NOEXEC 8 /* Disallow program execution */ #define SB_SYNCHRONOUS 16 /* Writes are synced at once */ #define SB_MANDLOCK 64 /* Allow mandatory locks on an FS */ #define SB_DIRSYNC 128 /* Directory modifications are synchronous */ #define SB_NOATIME 1024 /* Do not update access times. */ #define SB_NODIRATIME 2048 /* Do not update directory access times */ #define SB_SILENT 32768 #define SB_POSIXACL (1<<16) /* VFS does not apply the umask */ #define SB_KERNMOUNT (1<<22) /* this is a kern_mount call */ #define SB_I_VERSION (1<<23) /* Update inode I_version field */ #define SB_LAZYTIME (1<<25) /* Update the on-disk [acm]times lazily *//* These sb flags are internal to the kernel */ #define SB_SUBMOUNT (1<<26) #define SB_FORCE (1<<27) #define SB_NOSEC (1<<28) #define SB_BORN (1<<29) #define SB_ACTIVE (1<<30) #define SB_NOUSER (1<<31)/** Umount options*/#define MNT_FORCE 0x00000001 /* Attempt to forcibily umount */ #define MNT_DETACH 0x00000002 /* Just detach from the tree */ #define MNT_EXPIRE 0x00000004 /* Mark for expiry */ #define UMOUNT_NOFOLLOW 0x00000008 /* Don't follow symlink on umount */ #define UMOUNT_UNUSED 0x80000000 /* Flag guaranteed to be unused *//* sb->s_iflags */ #define SB_I_CGROUPWB 0x00000001 /* cgroup-aware writeback enabled */ #define SB_I_NOEXEC 0x00000002 /* Ignore executables on this fs */ #define SB_I_NODEV 0x00000004 /* Ignore devices on this fs */ #define SB_I_MULTIROOT 0x00000008 /* Multiple roots to the dentry tree *//* sb->s_iflags to limit user namespace mounts */ #define SB_I_USERNS_VISIBLE 0x00000010 /* fstype already mounted */ #define SB_I_IMA_UNVERIFIABLE_SIGNATURE 0x00000020 #define SB_I_UNTRUSTED_MOUNTER 0x00000040/* Possible states of 'frozen' field */ enum {SB_UNFROZEN = 0, /* FS is unfrozen */SB_FREEZE_WRITE = 1, /* Writes, dir ops, ioctls frozen */SB_FREEZE_PAGEFAULT = 2, /* Page faults stopped as well */SB_FREEZE_FS = 3, /* For internal FS use (e.g. to stop* internal threads if needed) */SB_FREEZE_COMPLETE = 4, /* ->freeze_fs finished successfully */ };#define SB_FREEZE_LEVELS (SB_FREEZE_COMPLETE - 1)struct sb_writers {int frozen; /* Is sb frozen? */wait_queue_head_t wait_unfrozen; /* for get_super_thawed() */struct percpu_rw_semaphore rw_sem[SB_FREEZE_LEVELS]; };struct super_block {struct list_head s_list; /* Keep this first */dev_t s_dev; /* search index; _not_ kdev_t */unsigned char s_blocksize_bits;unsigned long s_blocksize;loff_t s_maxbytes; /* Max file size */struct file_system_type *s_type;const struct super_operations *s_op;const struct dquot_operations *dq_op;const struct quotactl_ops *s_qcop;const struct export_operations *s_export_op;unsigned long s_flags;unsigned long s_iflags; /* internal SB_I_* flags */unsigned long s_magic;struct dentry *s_root;struct rw_semaphore s_umount;int s_count;atomic_t s_active; #ifdef CONFIG_SECURITYvoid *s_security; #endifconst struct xattr_handler **s_xattr; #ifdef CONFIG_FS_ENCRYPTIONconst struct fscrypt_operations *s_cop; #endifstruct hlist_bl_head s_roots; /* alternate root dentries for NFS */struct list_head s_mounts; /* list of mounts; _not_ for fs use */struct block_device *s_bdev;struct backing_dev_info *s_bdi;struct mtd_info *s_mtd;struct hlist_node s_instances;unsigned int s_quota_types; /* Bitmask of supported quota types */struct quota_info s_dquot; /* Diskquota specific options */struct sb_writers s_writers;/** Keep s_fs_info, s_time_gran, s_fsnotify_mask, and* s_fsnotify_marks together for cache efficiency. They are frequently* accessed and rarely modified.*/void *s_fs_info; /* Filesystem private info *//* Granularity of c/m/atime in ns (cannot be worse than a second) */u32 s_time_gran; #ifdef CONFIG_FSNOTIFY__u32 s_fsnotify_mask;struct fsnotify_mark_connector __rcu *s_fsnotify_marks; #endifchar s_id[32]; /* Informational name */uuid_t s_uuid; /* UUID */unsigned int s_max_links;fmode_t s_mode;/** The next field is for VFS *only*. No filesystems have any business* even looking at it. You had been warned.*/struct mutex s_vfs_rename_mutex; /* Kludge *//** Filesystem subtype. If non-empty the filesystem type field* in /proc/mounts will be "type.subtype"*/const char *s_subtype;const struct dentry_operations *s_d_op; /* default d_op for dentries *//** Saved pool identifier for cleancache (-1 means none)*/int cleancache_poolid;struct shrinker s_shrink; /* per-sb shrinker handle *//* Number of inodes with nlink == 0 but still referenced */atomic_long_t s_remove_count;/* Pending fsnotify inode refs */atomic_long_t s_fsnotify_inode_refs;/* Being remounted read-only */int s_readonly_remount;/* AIO completions deferred from interrupt context */struct workqueue_struct *s_dio_done_wq;struct hlist_head s_pins;/** Owning user namespace and default context in which to* interpret filesystem uids, gids, quotas, device nodes,* xattrs and security labels.*/struct user_namespace *s_user_ns;/** The list_lru structure is essentially just a pointer to a table* of per-node lru lists, each of which has its own spinlock.* There is no need to put them into separate cachelines.*/struct list_lru s_dentry_lru;struct list_lru s_inode_lru;struct rcu_head rcu;struct work_struct destroy_work;struct mutex s_sync_lock; /* sync serialisation lock *//** Indicates how deep in a filesystem stack this SB is*/int s_stack_depth;/* s_inode_list_lock protects s_inodes */spinlock_t s_inode_list_lock ____cacheline_aligned_in_smp;struct list_head s_inodes; /* all inodes */spinlock_t s_inode_wblist_lock;struct list_head s_inodes_wb; /* writeback inodes */ } __randomize_layout;/* Helper functions so that in most cases filesystems will* not need to deal directly with kuid_t and kgid_t and can* instead deal with the raw numeric values that are stored* in the filesystem.*/ static inline uid_t i_uid_read(const struct inode *inode) {return from_kuid(inode->i_sb->s_user_ns, inode->i_uid); }static inline gid_t i_gid_read(const struct inode *inode) {return from_kgid(inode->i_sb->s_user_ns, inode->i_gid); }static inline void i_uid_write(struct inode *inode, uid_t uid) {inode->i_uid = make_kuid(inode->i_sb->s_user_ns, uid); }static inline void i_gid_write(struct inode *inode, gid_t gid) {inode->i_gid = make_kgid(inode->i_sb->s_user_ns, gid); }extern struct timespec64 timespec64_trunc(struct timespec64 t, unsigned gran); extern struct timespec64 current_time(struct inode *inode);/** Snapshotting support.*/void __sb_end_write(struct super_block *sb, int level); int __sb_start_write(struct super_block *sb, int level, bool wait);#define __sb_writers_acquired(sb, lev) \percpu_rwsem_acquire(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_) #define __sb_writers_release(sb, lev) \percpu_rwsem_release(&(sb)->s_writers.rw_sem[(lev)-1], 1, _THIS_IP_)/*** sb_end_write - drop write access to a superblock* @sb: the super we wrote to** Decrement number of writers to the filesystem. Wake up possible waiters* wanting to freeze the filesystem.*/ static inline void sb_end_write(struct super_block *sb) {__sb_end_write(sb, SB_FREEZE_WRITE); }/*** sb_end_pagefault - drop write access to a superblock from a page fault* @sb: the super we wrote to** Decrement number of processes handling write page fault to the filesystem.* Wake up possible waiters wanting to freeze the filesystem.*/ static inline void sb_end_pagefault(struct super_block *sb) {__sb_end_write(sb, SB_FREEZE_PAGEFAULT); }/*** sb_end_intwrite - drop write access to a superblock for internal fs purposes* @sb: the super we wrote to** Decrement fs-internal number of writers to the filesystem. Wake up possible* waiters wanting to freeze the filesystem.*/ static inline void sb_end_intwrite(struct super_block *sb) {__sb_end_write(sb, SB_FREEZE_FS); }/*** sb_start_write - get write access to a superblock* @sb: the super we write to** When a process wants to write data or metadata to a file system (i.e. dirty* a page or an inode), it should embed the operation in a sb_start_write() -* sb_end_write() pair to get exclusion against file system freezing. This* function increments number of writers preventing freezing. If the file* system is already frozen, the function waits until the file system is* thawed.** Since freeze protection behaves as a lock, users have to preserve* ordering of freeze protection and other filesystem locks. Generally,* freeze protection should be the outermost lock. In particular, we have:** sb_start_write* -> i_mutex (write path, truncate, directory ops, ...)* -> s_umount (freeze_super, thaw_super)*/ static inline void sb_start_write(struct super_block *sb) {__sb_start_write(sb, SB_FREEZE_WRITE, true); }static inline int sb_start_write_trylock(struct super_block *sb) {return __sb_start_write(sb, SB_FREEZE_WRITE, false); }/*** sb_start_pagefault - get write access to a superblock from a page fault* @sb: the super we write to** When a process starts handling write page fault, it should embed the* operation into sb_start_pagefault() - sb_end_pagefault() pair to get* exclusion against file system freezing. This is needed since the page fault* is going to dirty a page. This function increments number of running page* faults preventing freezing. If the file system is already frozen, the* function waits until the file system is thawed.** Since page fault freeze protection behaves as a lock, users have to preserve* ordering of freeze protection and other filesystem locks. It is advised to* put sb_start_pagefault() close to mmap_sem in lock ordering. Page fault* handling code implies lock dependency:** mmap_sem* -> sb_start_pagefault*/ static inline void sb_start_pagefault(struct super_block *sb) {__sb_start_write(sb, SB_FREEZE_PAGEFAULT, true); }/** sb_start_intwrite - get write access to a superblock for internal fs purposes* @sb: the super we write to** This is the third level of protection against filesystem freezing. It is* free for use by a filesystem. The only requirement is that it must rank* below sb_start_pagefault.** For example filesystem can call sb_start_intwrite() when starting a* transaction which somewhat eases handling of freezing for internal sources* of filesystem changes (internal fs threads, discarding preallocation on file* close, etc.).*/ static inline void sb_start_intwrite(struct super_block *sb) {__sb_start_write(sb, SB_FREEZE_FS, true); }static inline int sb_start_intwrite_trylock(struct super_block *sb) {return __sb_start_write(sb, SB_FREEZE_FS, false); }extern bool inode_owner_or_capable(const struct inode *inode);/** VFS helper functions..*/ extern int vfs_create(struct inode *, struct dentry *, umode_t, bool); extern int vfs_mkdir(struct inode *, struct dentry *, umode_t); extern int vfs_mknod(struct inode *, struct dentry *, umode_t, dev_t); extern int vfs_symlink(struct inode *, struct dentry *, const char *); extern int vfs_link(struct dentry *, struct inode *, struct dentry *, struct inode **); extern int vfs_rmdir(struct inode *, struct dentry *); extern int vfs_unlink(struct inode *, struct dentry *, struct inode **); extern int vfs_rename(struct inode *, struct dentry *, struct inode *, struct dentry *, struct inode **, unsigned int); extern int vfs_whiteout(struct inode *, struct dentry *);extern struct dentry *vfs_tmpfile(struct dentry *dentry, umode_t mode,int open_flag);int vfs_mkobj(struct dentry *, umode_t,int (*f)(struct dentry *, umode_t, void *),void *);extern long vfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);/** VFS file helper functions.*/ extern void inode_init_owner(struct inode *inode, const struct inode *dir,umode_t mode); extern bool may_open_dev(const struct path *path); /** VFS FS_IOC_FIEMAP helper definitions.*/ struct fiemap_extent_info {unsigned int fi_flags; /* Flags as passed from user */unsigned int fi_extents_mapped; /* Number of mapped extents */unsigned int fi_extents_max; /* Size of fiemap_extent array */struct fiemap_extent __user *fi_extents_start; /* Start offiemap_extent array */ }; int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,u64 phys, u64 len, u32 flags); int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);/** This is the "filldir" function type, used by readdir() to let* the kernel specify what kind of dirent layout it wants to have.* This allows the kernel to read directories into kernel space or* to have different dirent layouts depending on the binary type.*/ struct dir_context; typedef int (*filldir_t)(struct dir_context *, const char *, int, loff_t, u64,unsigned);struct dir_context {filldir_t actor;loff_t pos; };struct block_device_operations;/* These macros are for out of kernel modules to test that* the kernel supports the unlocked_ioctl and compat_ioctl* fields in struct file_operations. */ #define HAVE_COMPAT_IOCTL 1 #define HAVE_UNLOCKED_IOCTL 1/** These flags let !MMU mmap() govern direct device mapping vs immediate* copying more easily for MAP_PRIVATE, especially for ROM filesystems.** NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE)* NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED)* NOMMU_MAP_READ: Can be mapped for reading* NOMMU_MAP_WRITE: Can be mapped for writing* NOMMU_MAP_EXEC: Can be mapped for execution*/ #define NOMMU_MAP_COPY 0x00000001 #define NOMMU_MAP_DIRECT 0x00000008 #define NOMMU_MAP_READ VM_MAYREAD #define NOMMU_MAP_WRITE VM_MAYWRITE #define NOMMU_MAP_EXEC VM_MAYEXEC#define NOMMU_VMFLAGS \(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)/** These flags control the behavior of the remap_file_range function pointer.* If it is called with len == 0 that means "remap to end of source file".* See Documentation/filesystems/vfs.txt for more details about this call.** REMAP_FILE_DEDUP: only remap if contents identical (i.e. deduplicate)* REMAP_FILE_CAN_SHORTEN: caller can handle a shortened request*/ #define REMAP_FILE_DEDUP (1 << 0) #define REMAP_FILE_CAN_SHORTEN (1 << 1)/** These flags signal that the caller is ok with altering various aspects of* the behavior of the remap operation. The changes must be made by the* implementation; the vfs remap helper functions can take advantage of them.* Flags in this category exist to preserve the quirky behavior of the hoisted* btrfs clone/dedupe ioctls.*/ #define REMAP_FILE_ADVISORY (REMAP_FILE_CAN_SHORTEN)struct iov_iter;struct file_operations {struct module *owner;loff_t (*llseek) (struct file *, loff_t, int);ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);int (*iopoll)(struct kiocb *kiocb, bool spin);int (*iterate) (struct file *, struct dir_context *);int (*iterate_shared) (struct file *, struct dir_context *);__poll_t (*poll) (struct file *, struct poll_table_struct *);long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);long (*compat_ioctl) (struct file *, unsigned int, unsigned long);int (*mmap) (struct file *, struct vm_area_struct *);unsigned long mmap_supported_flags;int (*open) (struct inode *, struct file *);int (*flush) (struct file *, fl_owner_t id);int (*release) (struct inode *, struct file *);int (*fsync) (struct file *, loff_t, loff_t, int datasync);int (*fasync) (int, struct file *, int);int (*lock) (struct file *, int, struct file_lock *);ssize_t (*sendpage) (struct file *, struct page *, int, size_t, loff_t *, int);unsigned long (*get_unmapped_area)(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);int (*check_flags)(int);int (*flock) (struct file *, int, struct file_lock *);ssize_t (*splice_write)(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int);ssize_t (*splice_read)(struct file *, loff_t *, struct pipe_inode_info *, size_t, unsigned int);int (*setlease)(struct file *, long, struct file_lock **, void **);long (*fallocate)(struct file *file, int mode, loff_t offset,loff_t len);void (*show_fdinfo)(struct seq_file *m, struct file *f); #ifndef CONFIG_MMUunsigned (*mmap_capabilities)(struct file *); #endifssize_t (*copy_file_range)(struct file *, loff_t, struct file *,loff_t, size_t, unsigned int);loff_t (*remap_file_range)(struct file *file_in, loff_t pos_in,struct file *file_out, loff_t pos_out,loff_t len, unsigned int remap_flags);int (*fadvise)(struct file *, loff_t, loff_t, int); } __randomize_layout;struct inode_operations {struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);const char * (*get_link) (struct dentry *, struct inode *, struct delayed_call *);int (*permission) (struct inode *, int);struct posix_acl * (*get_acl)(struct inode *, int);int (*readlink) (struct dentry *, char __user *,int);int (*create) (struct inode *,struct dentry *, umode_t, bool);int (*link) (struct dentry *,struct inode *,struct dentry *);int (*unlink) (struct inode *,struct dentry *);int (*symlink) (struct inode *,struct dentry *,const char *);int (*mkdir) (struct inode *,struct dentry *,umode_t);int (*rmdir) (struct inode *,struct dentry *);int (*mknod) (struct inode *,struct dentry *,umode_t,dev_t);int (*rename) (struct inode *, struct dentry *,struct inode *, struct dentry *, unsigned int);int (*setattr) (struct dentry *, struct iattr *);int (*getattr) (const struct path *, struct kstat *, u32, unsigned int);ssize_t (*listxattr) (struct dentry *, char *, size_t);int (*fiemap)(struct inode *, struct fiemap_extent_info *, u64 start,u64 len);int (*update_time)(struct inode *, struct timespec64 *, int);int (*atomic_open)(struct inode *, struct dentry *,struct file *, unsigned open_flag,umode_t create_mode);int (*tmpfile) (struct inode *, struct dentry *, umode_t);int (*set_acl)(struct inode *, struct posix_acl *, int); } ____cacheline_aligned;static inline ssize_t call_read_iter(struct file *file, struct kiocb *kio,struct iov_iter *iter) {return file->f_op->read_iter(kio, iter); }static inline ssize_t call_write_iter(struct file *file, struct kiocb *kio,struct iov_iter *iter) {return file->f_op->write_iter(kio, iter); }static inline int call_mmap(struct file *file, struct vm_area_struct *vma) {return file->f_op->mmap(file, vma); }ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector,unsigned long nr_segs, unsigned long fast_segs,struct iovec *fast_pointer,struct iovec **ret_pointer);extern ssize_t __vfs_read(struct file *, char __user *, size_t, loff_t *); extern ssize_t vfs_read(struct file *, char __user *, size_t, loff_t *); extern ssize_t vfs_write(struct file *, const char __user *, size_t, loff_t *); extern ssize_t vfs_readv(struct file *, const struct iovec __user *,unsigned long, loff_t *, rwf_t); extern ssize_t vfs_copy_file_range(struct file *, loff_t , struct file *,loff_t, size_t, unsigned int); extern int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in,struct file *file_out, loff_t pos_out,loff_t *count,unsigned int remap_flags); extern loff_t do_clone_file_range(struct file *file_in, loff_t pos_in,struct file *file_out, loff_t pos_out,loff_t len, unsigned int remap_flags); extern loff_t vfs_clone_file_range(struct file *file_in, loff_t pos_in,struct file *file_out, loff_t pos_out,loff_t len, unsigned int remap_flags); extern int vfs_dedupe_file_range(struct file *file,struct file_dedupe_range *same); extern loff_t vfs_dedupe_file_range_one(struct file *src_file, loff_t src_pos,struct file *dst_file, loff_t dst_pos,loff_t len, unsigned int remap_flags);struct super_operations {struct inode *(*alloc_inode)(struct super_block *sb);void (*destroy_inode)(struct inode *);void (*free_inode)(struct inode *);void (*dirty_inode) (struct inode *, int flags);int (*write_inode) (struct inode *, struct writeback_control *wbc);int (*drop_inode) (struct inode *);void (*evict_inode) (struct inode *);void (*put_super) (struct super_block *);int (*sync_fs)(struct super_block *sb, int wait);int (*freeze_super) (struct super_block *);int (*freeze_fs) (struct super_block *);int (*thaw_super) (struct super_block *);int (*unfreeze_fs) (struct super_block *);int (*statfs) (struct dentry *, struct kstatfs *);int (*remount_fs) (struct super_block *, int *, char *);void (*umount_begin) (struct super_block *);int (*show_options)(struct seq_file *, struct dentry *);int (*show_devname)(struct seq_file *, struct dentry *);int (*show_path)(struct seq_file *, struct dentry *);int (*show_stats)(struct seq_file *, struct dentry *); #ifdef CONFIG_QUOTAssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t);ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t);struct dquot **(*get_dquots)(struct inode *); #endifint (*bdev_try_to_free_page)(struct super_block*, struct page*, gfp_t);long (*nr_cached_objects)(struct super_block *,struct shrink_control *);long (*free_cached_objects)(struct super_block *,struct shrink_control *); };/** Inode flags - they have no relation to superblock flags now*/ #define S_SYNC 1 /* Writes are synced at once */ #define S_NOATIME 2 /* Do not update access times */ #define S_APPEND 4 /* Append-only file */ #define S_IMMUTABLE 8 /* Immutable file */ #define S_DEAD 16 /* removed, but still open directory */ #define S_NOQUOTA 32 /* Inode is not counted to quota */ #define S_DIRSYNC 64 /* Directory modifications are synchronous */ #define S_NOCMTIME 128 /* Do not update file c/mtime */ #define S_SWAPFILE 256 /* Do not truncate: swapon got its bmaps */ #define S_PRIVATE 512 /* Inode is fs-internal */ #define S_IMA 1024 /* Inode has an associated IMA struct */ #define S_AUTOMOUNT 2048 /* Automount/referral quasi-directory */ #define S_NOSEC 4096 /* no suid or xattr security attributes */ #ifdef CONFIG_FS_DAX #define S_DAX 8192 /* Direct Access, avoiding the page cache */ #else #define S_DAX 0 /* Make all the DAX code disappear */ #endif #define S_ENCRYPTED 16384 /* Encrypted file (using fs/crypto/) */ #define S_CASEFOLD 32768 /* Casefolded file *//** Note that nosuid etc flags are inode-specific: setting some file-system* flags just means all the inodes inherit those flags by default. It might be* possible to override it selectively if you really wanted to with some* ioctl() that is not currently implemented.** Exception: SB_RDONLY is always applied to the entire file system.** Unfortunately, it is possible to change a filesystems flags with it mounted* with files in use. This means that all of the inodes will not have their* i_flags updated. Hence, i_flags no longer inherit the superblock mount* flags, so these have to be checked separately. -- rmk@arm.uk.linux.org*/ #define __IS_FLG(inode, flg) ((inode)->i_sb->s_flags & (flg))static inline bool sb_rdonly(const struct super_block *sb) { return sb->s_flags & SB_RDONLY; } #define IS_RDONLY(inode) sb_rdonly((inode)->i_sb) #define IS_SYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS) || \((inode)->i_flags & S_SYNC)) #define IS_DIRSYNC(inode) (__IS_FLG(inode, SB_SYNCHRONOUS|SB_DIRSYNC) || \((inode)->i_flags & (S_SYNC|S_DIRSYNC))) #define IS_MANDLOCK(inode) __IS_FLG(inode, SB_MANDLOCK) #define IS_NOATIME(inode) __IS_FLG(inode, SB_RDONLY|SB_NOATIME) #define IS_I_VERSION(inode) __IS_FLG(inode, SB_I_VERSION)#define IS_NOQUOTA(inode) ((inode)->i_flags & S_NOQUOTA) #define IS_APPEND(inode) ((inode)->i_flags & S_APPEND) #define IS_IMMUTABLE(inode) ((inode)->i_flags & S_IMMUTABLE) #define IS_POSIXACL(inode) __IS_FLG(inode, SB_POSIXACL)#define IS_DEADDIR(inode) ((inode)->i_flags & S_DEAD) #define IS_NOCMTIME(inode) ((inode)->i_flags & S_NOCMTIME) #define IS_SWAPFILE(inode) ((inode)->i_flags & S_SWAPFILE) #define IS_PRIVATE(inode) ((inode)->i_flags & S_PRIVATE) #define IS_IMA(inode) ((inode)->i_flags & S_IMA) #define IS_AUTOMOUNT(inode) ((inode)->i_flags & S_AUTOMOUNT) #define IS_NOSEC(inode) ((inode)->i_flags & S_NOSEC) #define IS_DAX(inode) ((inode)->i_flags & S_DAX) #define IS_ENCRYPTED(inode) ((inode)->i_flags & S_ENCRYPTED) #define IS_CASEFOLDED(inode) ((inode)->i_flags & S_CASEFOLD)#define IS_WHITEOUT(inode) (S_ISCHR(inode->i_mode) && \(inode)->i_rdev == WHITEOUT_DEV)static inline bool HAS_UNMAPPED_ID(struct inode *inode) {return !uid_valid(inode->i_uid) || !gid_valid(inode->i_gid); }static inline enum rw_hint file_write_hint(struct file *file) {if (file->f_write_hint != WRITE_LIFE_NOT_SET)return file->f_write_hint;return file_inode(file)->i_write_hint; }static inline int iocb_flags(struct file *file);static inline u16 ki_hint_validate(enum rw_hint hint) {typeof(((struct kiocb *)0)->ki_hint) max_hint = -1;if (hint <= max_hint)return hint;return 0; }static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp) {*kiocb = (struct kiocb) {.ki_filp = filp,.ki_flags = iocb_flags(filp),.ki_hint = ki_hint_validate(file_write_hint(filp)),.ki_ioprio = get_current_ioprio(),}; }/** Inode state bits. Protected by inode->i_lock** Three bits determine the dirty state of the inode, I_DIRTY_SYNC,* I_DIRTY_DATASYNC and I_DIRTY_PAGES.** Four bits define the lifetime of an inode. Initially, inodes are I_NEW,* until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at* various stages of removing an inode.** Two bits are used for locking and completion notification, I_NEW and I_SYNC.** I_DIRTY_SYNC Inode is dirty, but doesn't have to be written on* fdatasync(). i_atime is the usual cause.* I_DIRTY_DATASYNC Data-related inode changes pending. We keep track of* these changes separately from I_DIRTY_SYNC so that we* don't have to write inode on fdatasync() when only* mtime has changed in it.* I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean.* I_NEW Serves as both a mutex and completion notification.* New inodes set I_NEW. If two processes both create* the same inode, one of them will release its inode and* wait for I_NEW to be released before returning.* Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can* also cause waiting on I_NEW, without I_NEW actually* being set. find_inode() uses this to prevent returning* nearly-dead inodes.* I_WILL_FREE Must be set when calling write_inode_now() if i_count* is zero. I_FREEING must be set when I_WILL_FREE is* cleared.* I_FREEING Set when inode is about to be freed but still has dirty* pages or buffers attached or the inode itself is still* dirty.* I_CLEAR Added by clear_inode(). In this state the inode is* clean and can be destroyed. Inode keeps I_FREEING.** Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are* prohibited for many purposes. iget() must wait for* the inode to be completely released, then create it* anew. Other functions will just ignore such inodes,* if appropriate. I_NEW is used for waiting.** I_SYNC Writeback of inode is running. The bit is set during* data writeback, and cleared with a wakeup on the bit* address once it is done. The bit is also used to pin* the inode in memory for flusher thread.** I_REFERENCED Marks the inode as recently references on the LRU list.** I_DIO_WAKEUP Never set. Only used as a key for wait_on_bit().** I_WB_SWITCH Cgroup bdi_writeback switching in progress. Used to* synchronize competing switching instances and to tell* wb stat updates to grab the i_pages lock. See* inode_switch_wbs_work_fn() for details.** I_OVL_INUSE Used by overlayfs to get exclusive ownership on upper* and work dirs among overlayfs mounts.** I_CREATING New object's inode in the middle of setting up.** Q: What is the difference between I_WILL_FREE and I_FREEING?*/ #define I_DIRTY_SYNC (1 << 0) #define I_DIRTY_DATASYNC (1 << 1) #define I_DIRTY_PAGES (1 << 2) #define __I_NEW 3 #define I_NEW (1 << __I_NEW) #define I_WILL_FREE (1 << 4) #define I_FREEING (1 << 5) #define I_CLEAR (1 << 6) #define __I_SYNC 7 #define I_SYNC (1 << __I_SYNC) #define I_REFERENCED (1 << 8) #define __I_DIO_WAKEUP 9 #define I_DIO_WAKEUP (1 << __I_DIO_WAKEUP) #define I_LINKABLE (1 << 10) #define I_DIRTY_TIME (1 << 11) #define __I_DIRTY_TIME_EXPIRED 12 #define I_DIRTY_TIME_EXPIRED (1 << __I_DIRTY_TIME_EXPIRED) #define I_WB_SWITCH (1 << 13) #define I_OVL_INUSE (1 << 14) #define I_CREATING (1 << 15)#define I_DIRTY_INODE (I_DIRTY_SYNC | I_DIRTY_DATASYNC) #define I_DIRTY (I_DIRTY_INODE | I_DIRTY_PAGES) #define I_DIRTY_ALL (I_DIRTY | I_DIRTY_TIME)extern void __mark_inode_dirty(struct inode *, int); static inline void mark_inode_dirty(struct inode *inode) {__mark_inode_dirty(inode, I_DIRTY); }static inline void mark_inode_dirty_sync(struct inode *inode) {__mark_inode_dirty(inode, I_DIRTY_SYNC); }extern void inc_nlink(struct inode *inode); extern void drop_nlink(struct inode *inode); extern void clear_nlink(struct inode *inode); extern void set_nlink(struct inode *inode, unsigned int nlink);static inline void inode_inc_link_count(struct inode *inode) {inc_nlink(inode);mark_inode_dirty(inode); }static inline void inode_dec_link_count(struct inode *inode) {drop_nlink(inode);mark_inode_dirty(inode); }enum file_time_flags {S_ATIME = 1,S_MTIME = 2,S_CTIME = 4,S_VERSION = 8, };extern bool atime_needs_update(const struct path *, struct inode *); extern void touch_atime(const struct path *); static inline void file_accessed(struct file *file) {if (!(file->f_flags & O_NOATIME))touch_atime(&file->f_path); }int sync_inode(struct inode *inode, struct writeback_control *wbc); int sync_inode_metadata(struct inode *inode, int wait);struct file_system_type {const char *name;int fs_flags; #define FS_REQUIRES_DEV 1 #define FS_BINARY_MOUNTDATA 2 #define FS_HAS_SUBTYPE 4 #define FS_USERNS_MOUNT 8 /* Can be mounted by userns root */ #define FS_RENAME_DOES_D_MOVE 32768 /* FS will handle d_move() during rename() internally. */int (*init_fs_context)(struct fs_context *);const struct fs_parameter_description *parameters;struct dentry *(*mount) (struct file_system_type *, int,const char *, void *);void (*kill_sb) (struct super_block *);struct module *owner;struct file_system_type * next;struct hlist_head fs_supers;struct lock_class_key s_lock_key;struct lock_class_key s_umount_key;struct lock_class_key s_vfs_rename_key;struct lock_class_key s_writers_key[SB_FREEZE_LEVELS];struct lock_class_key i_lock_key;struct lock_class_key i_mutex_key;struct lock_class_key i_mutex_dir_key; };#define MODULE_ALIAS_FS(NAME) MODULE_ALIAS("fs-" NAME)extern struct dentry *mount_ns(struct file_system_type *fs_type,int flags, void *data, void *ns, struct user_namespace *user_ns,int (*fill_super)(struct super_block *, void *, int)); #ifdef CONFIG_BLOCK extern struct dentry *mount_bdev(struct file_system_type *fs_type,int flags, const char *dev_name, void *data,int (*fill_super)(struct super_block *, void *, int)); #else static inline struct dentry *mount_bdev(struct file_system_type *fs_type,int flags, const char *dev_name, void *data,int (*fill_super)(struct super_block *, void *, int)) {return ERR_PTR(-ENODEV); } #endif extern struct dentry *mount_single(struct file_system_type *fs_type,int flags, void *data,int (*fill_super)(struct super_block *, void *, int)); extern struct dentry *mount_nodev(struct file_system_type *fs_type,int flags, void *data,int (*fill_super)(struct super_block *, void *, int)); extern struct dentry *mount_subtree(struct vfsmount *mnt, const char *path); void generic_shutdown_super(struct super_block *sb); #ifdef CONFIG_BLOCK void kill_block_super(struct super_block *sb); #else static inline void kill_block_super(struct super_block *sb) {BUG(); } #endif void kill_anon_super(struct super_block *sb); void kill_litter_super(struct super_block *sb); void deactivate_super(struct super_block *sb); void deactivate_locked_super(struct super_block *sb); int set_anon_super(struct super_block *s, void *data); int set_anon_super_fc(struct super_block *s, struct fs_context *fc); int get_anon_bdev(dev_t *); void free_anon_bdev(dev_t); struct super_block *sget_fc(struct fs_context *fc,int (*test)(struct super_block *, struct fs_context *),int (*set)(struct super_block *, struct fs_context *)); struct super_block *sget_userns(struct file_system_type *type,int (*test)(struct super_block *,void *),int (*set)(struct super_block *,void *),int flags, struct user_namespace *user_ns,void *data); struct super_block *sget(struct file_system_type *type,int (*test)(struct super_block *,void *),int (*set)(struct super_block *,void *),int flags, void *data); extern struct dentry *mount_pseudo_xattr(struct file_system_type *, char *,const struct super_operations *ops,const struct xattr_handler **xattr,const struct dentry_operations *dops,unsigned long);static inline struct dentry * mount_pseudo(struct file_system_type *fs_type, char *name,const struct super_operations *ops,const struct dentry_operations *dops, unsigned long magic) {return mount_pseudo_xattr(fs_type, name, ops, NULL, dops, magic); }/* Alas, no aliases. Too much hassle with bringing module.h everywhere */ #define fops_get(fops) \(((fops) && try_module_get((fops)->owner) ? (fops) : NULL)) #define fops_put(fops) \do { if (fops) module_put((fops)->owner); } while(0) /** This one is to be used *ONLY* from ->open() instances.* fops must be non-NULL, pinned down *and* module dependencies* should be sufficient to pin the caller down as well.*/ #define replace_fops(f, fops) \do { \struct file *__file = (f); \fops_put(__file->f_op); \BUG_ON(!(__file->f_op = (fops))); \} while(0)extern int register_filesystem(struct file_system_type *); extern int unregister_filesystem(struct file_system_type *); extern struct vfsmount *kern_mount(struct file_system_type *); extern void kern_unmount(struct vfsmount *mnt); extern int may_umount_tree(struct vfsmount *); extern int may_umount(struct vfsmount *); extern long do_mount(const char *, const char __user *,const char *, unsigned long, void *); extern struct vfsmount *collect_mounts(const struct path *); extern void drop_collected_mounts(struct vfsmount *); extern int iterate_mounts(int (*)(struct vfsmount *, void *), void *,struct vfsmount *); extern int vfs_statfs(const struct path *, struct kstatfs *); extern int user_statfs(const char __user *, struct kstatfs *); extern int fd_statfs(int, struct kstatfs *); extern int freeze_super(struct super_block *super); extern int thaw_super(struct super_block *super); extern bool our_mnt(struct vfsmount *mnt); extern __printf(2, 3) int super_setup_bdi_name(struct super_block *sb, char *fmt, ...); extern int super_setup_bdi(struct super_block *sb);extern int current_umask(void);extern void ihold(struct inode * inode); extern void iput(struct inode *); extern int generic_update_time(struct inode *, struct timespec64 *, int);/* /sys/fs */ extern struct kobject *fs_kobj;#define MAX_RW_COUNT (INT_MAX & PAGE_MASK)#ifdef CONFIG_MANDATORY_FILE_LOCKING extern int locks_mandatory_locked(struct file *); extern int locks_mandatory_area(struct inode *, struct file *, loff_t, loff_t, unsigned char);/** Candidates for mandatory locking have the setgid bit set* but no group execute bit - an otherwise meaningless combination.*/static inline int __mandatory_lock(struct inode *ino) {return (ino->i_mode & (S_ISGID | S_IXGRP)) == S_ISGID; }/** ... and these candidates should be on SB_MANDLOCK mounted fs,* otherwise these will be advisory locks*/static inline int mandatory_lock(struct inode *ino) {return IS_MANDLOCK(ino) && __mandatory_lock(ino); }static inline int locks_verify_locked(struct file *file) {if (mandatory_lock(locks_inode(file)))return locks_mandatory_locked(file);return 0; }static inline int locks_verify_truncate(struct inode *inode,struct file *f,loff_t size) {if (!inode->i_flctx || !mandatory_lock(inode))return 0;if (size < inode->i_size) {return locks_mandatory_area(inode, f, size, inode->i_size - 1,F_WRLCK);} else {return locks_mandatory_area(inode, f, inode->i_size, size - 1,F_WRLCK);} }#else /* !CONFIG_MANDATORY_FILE_LOCKING */static inline int locks_mandatory_locked(struct file *file) {return 0; }static inline int locks_mandatory_area(struct inode *inode, struct file *filp,loff_t start, loff_t end, unsigned char type) {return 0; }static inline int __mandatory_lock(struct inode *inode) {return 0; }static inline int mandatory_lock(struct inode *inode) {return 0; }static inline int locks_verify_locked(struct file *file) {return 0; }static inline int locks_verify_truncate(struct inode *inode, struct file *filp,size_t size) {return 0; }#endif /* CONFIG_MANDATORY_FILE_LOCKING */#ifdef CONFIG_FILE_LOCKING static inline int break_lease(struct inode *inode, unsigned int mode) {/** Since this check is lockless, we must ensure that any refcounts* taken are done before checking i_flctx->flc_lease. Otherwise, we* could end up racing with tasks trying to set a new lease on this* file.*/smp_mb();if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))return __break_lease(inode, mode, FL_LEASE);return 0; }static inline int break_deleg(struct inode *inode, unsigned int mode) {/** Since this check is lockless, we must ensure that any refcounts* taken are done before checking i_flctx->flc_lease. Otherwise, we* could end up racing with tasks trying to set a new lease on this* file.*/smp_mb();if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))return __break_lease(inode, mode, FL_DELEG);return 0; }static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode) {int ret;ret = break_deleg(inode, O_WRONLY|O_NONBLOCK);if (ret == -EWOULDBLOCK && delegated_inode) {*delegated_inode = inode;ihold(inode);}return ret; }static inline int break_deleg_wait(struct inode **delegated_inode) {int ret;ret = break_deleg(*delegated_inode, O_WRONLY);iput(*delegated_inode);*delegated_inode = NULL;return ret; }static inline int break_layout(struct inode *inode, bool wait) {smp_mb();if (inode->i_flctx && !list_empty_careful(&inode->i_flctx->flc_lease))return __break_lease(inode,wait ? O_WRONLY : O_WRONLY | O_NONBLOCK,FL_LAYOUT);return 0; }#else /* !CONFIG_FILE_LOCKING */ static inline int break_lease(struct inode *inode, unsigned int mode) {return 0; }static inline int break_deleg(struct inode *inode, unsigned int mode) {return 0; }static inline int try_break_deleg(struct inode *inode, struct inode **delegated_inode) {return 0; }static inline int break_deleg_wait(struct inode **delegated_inode) {BUG();return 0; }static inline int break_layout(struct inode *inode, bool wait) {return 0; }#endif /* CONFIG_FILE_LOCKING *//* fs/open.c */ struct audit_names; struct filename {const char *name; /* pointer to actual string */const __user char *uptr; /* original userland pointer */int refcnt;struct audit_names *aname;const char iname[]; }; static_assert(offsetof(struct filename, iname) % sizeof(long) == 0);extern long vfs_truncate(const struct path *, loff_t); extern int do_truncate(struct dentry *, loff_t start, unsigned int time_attrs,struct file *filp); extern int vfs_fallocate(struct file *file, int mode, loff_t offset,loff_t len); extern long do_sys_open(int dfd, const char __user *filename, int flags,umode_t mode); extern struct file *file_open_name(struct filename *, int, umode_t); extern struct file *filp_open(const char *, int, umode_t); extern struct file *file_open_root(struct dentry *, struct vfsmount *,const char *, int, umode_t); extern struct file * dentry_open(const struct path *, int, const struct cred *); extern struct file * open_with_fake_path(const struct path *, int,struct inode*, const struct cred *); static inline struct file *file_clone_open(struct file *file) {return dentry_open(&file->f_path, file->f_flags, file->f_cred); } extern int filp_close(struct file *, fl_owner_t id);extern struct filename *getname_flags(const char __user *, int, int *); extern struct filename *getname(const char __user *); extern struct filename *getname_kernel(const char *); extern void putname(struct filename *name);extern int finish_open(struct file *file, struct dentry *dentry,int (*open)(struct inode *, struct file *)); extern int finish_no_open(struct file *file, struct dentry *dentry);/* fs/ioctl.c */extern int ioctl_preallocate(struct file *filp, void __user *argp);/* fs/dcache.c */ extern void __init vfs_caches_init_early(void); extern void __init vfs_caches_init(void);extern struct kmem_cache *names_cachep;#define __getname() kmem_cache_alloc(names_cachep, GFP_KERNEL) #define __putname(name) kmem_cache_free(names_cachep, (void *)(name))#ifdef CONFIG_BLOCK extern int register_blkdev(unsigned int, const char *); extern void unregister_blkdev(unsigned int, const char *); extern void bdev_unhash_inode(dev_t dev); extern struct block_device *bdget(dev_t); extern struct block_device *bdgrab(struct block_device *bdev); extern void bd_set_size(struct block_device *, loff_t size); extern void bd_forget(struct inode *inode); extern void bdput(struct block_device *); extern void invalidate_bdev(struct block_device *); extern void iterate_bdevs(void (*)(struct block_device *, void *), void *); extern int sync_blockdev(struct block_device *bdev); extern void kill_bdev(struct block_device *); extern struct super_block *freeze_bdev(struct block_device *); extern void emergency_thaw_all(void); extern void emergency_thaw_bdev(struct super_block *sb); extern int thaw_bdev(struct block_device *bdev, struct super_block *sb); extern int fsync_bdev(struct block_device *);extern struct super_block *blockdev_superblock;static inline bool sb_is_blkdev_sb(struct super_block *sb) {return sb == blockdev_superblock; } #else static inline void bd_forget(struct inode *inode) {} static inline int sync_blockdev(struct block_device *bdev) { return 0; } static inline void kill_bdev(struct block_device *bdev) {} static inline void invalidate_bdev(struct block_device *bdev) {}static inline struct super_block *freeze_bdev(struct block_device *sb) {return NULL; }static inline int thaw_bdev(struct block_device *bdev, struct super_block *sb) {return 0; }static inline int emergency_thaw_bdev(struct super_block *sb) {return 0; }static inline void iterate_bdevs(void (*f)(struct block_device *, void *), void *arg) { }static inline bool sb_is_blkdev_sb(struct super_block *sb) {return false; } #endif extern int sync_filesystem(struct super_block *); extern const struct file_operations def_blk_fops; extern const struct file_operations def_chr_fops; #ifdef CONFIG_BLOCK extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long); extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long); extern long compat_blkdev_ioctl(struct file *, unsigned, unsigned long); extern int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder); extern struct block_device *blkdev_get_by_path(const char *path, fmode_t mode,void *holder); extern struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode,void *holder); extern void blkdev_put(struct block_device *bdev, fmode_t mode); extern int __blkdev_reread_part(struct block_device *bdev); extern int blkdev_reread_part(struct block_device *bdev);#ifdef CONFIG_SYSFS extern int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk); extern void bd_unlink_disk_holder(struct block_device *bdev,struct gendisk *disk); #else static inline int bd_link_disk_holder(struct block_device *bdev,struct gendisk *disk) {return 0; } static inline void bd_unlink_disk_holder(struct block_device *bdev,struct gendisk *disk) { } #endif #endif/* fs/char_dev.c */ #define CHRDEV_MAJOR_MAX 512 /* Marks the bottom of the first segment of free char majors */ #define CHRDEV_MAJOR_DYN_END 234 /* Marks the top and bottom of the second segment of free char majors */ #define CHRDEV_MAJOR_DYN_EXT_START 511 #define CHRDEV_MAJOR_DYN_EXT_END 384extern int alloc_chrdev_region(dev_t *, unsigned, unsigned, const char *); extern int register_chrdev_region(dev_t, unsigned, const char *); extern int __register_chrdev(unsigned int major, unsigned int baseminor,unsigned int count, const char *name,const struct file_operations *fops); extern void __unregister_chrdev(unsigned int major, unsigned int baseminor,unsigned int count, const char *name); extern void unregister_chrdev_region(dev_t, unsigned); extern void chrdev_show(struct seq_file *,off_t);static inline int register_chrdev(unsigned int major, const char *name,const struct file_operations *fops) {return __register_chrdev(major, 0, 256, name, fops); }static inline void unregister_chrdev(unsigned int major, const char *name) {__unregister_chrdev(major, 0, 256, name); }/* fs/block_dev.c */ #define BDEVNAME_SIZE 32 /* Largest string for a blockdev identifier */ #define BDEVT_SIZE 10 /* Largest string for MAJ:MIN for blkdev */#ifdef CONFIG_BLOCK #define BLKDEV_MAJOR_MAX 512 extern const char *__bdevname(dev_t, char *buffer); extern const char *bdevname(struct block_device *bdev, char *buffer); extern struct block_device *lookup_bdev(const char *); extern void blkdev_show(struct seq_file *,off_t);#else #define BLKDEV_MAJOR_MAX 0 #endifextern void init_special_inode(struct inode *, umode_t, dev_t);/* Invalid inode operations -- fs/bad_inode.c */ extern void make_bad_inode(struct inode *); extern bool is_bad_inode(struct inode *);#ifdef CONFIG_BLOCK extern void check_disk_size_change(struct gendisk *disk,struct block_device *bdev, bool verbose); extern int revalidate_disk(struct gendisk *); extern int check_disk_change(struct block_device *); extern int __invalidate_device(struct block_device *, bool); extern int invalidate_partition(struct gendisk *, int); #endif unsigned long invalidate_mapping_pages(struct address_space *mapping,pgoff_t start, pgoff_t end);static inline void invalidate_remote_inode(struct inode *inode) {if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||S_ISLNK(inode->i_mode))invalidate_mapping_pages(inode->i_mapping, 0, -1); } extern int invalidate_inode_pages2(struct address_space *mapping); extern int invalidate_inode_pages2_range(struct address_space *mapping,pgoff_t start, pgoff_t end); extern int write_inode_now(struct inode *, int); extern int filemap_fdatawrite(struct address_space *); extern int filemap_flush(struct address_space *); extern int filemap_fdatawait_keep_errors(struct address_space *mapping); extern int filemap_fdatawait_range(struct address_space *, loff_t lstart,loff_t lend);static inline int filemap_fdatawait(struct address_space *mapping) {return filemap_fdatawait_range(mapping, 0, LLONG_MAX); }extern bool filemap_range_has_page(struct address_space *, loff_t lstart,loff_t lend); extern int filemap_write_and_wait(struct address_space *mapping); extern int filemap_write_and_wait_range(struct address_space *mapping,loff_t lstart, loff_t lend); extern int __filemap_fdatawrite_range(struct address_space *mapping,loff_t start, loff_t end, int sync_mode); extern int filemap_fdatawrite_range(struct address_space *mapping,loff_t start, loff_t end); extern int filemap_check_errors(struct address_space *mapping); extern void __filemap_set_wb_err(struct address_space *mapping, int err);extern int __must_check file_fdatawait_range(struct file *file, loff_t lstart,loff_t lend); extern int __must_check file_check_and_advance_wb_err(struct file *file); extern int __must_check file_write_and_wait_range(struct file *file,loff_t start, loff_t end);static inline int file_write_and_wait(struct file *file) {return file_write_and_wait_range(file, 0, LLONG_MAX); }/*** filemap_set_wb_err - set a writeback error on an address_space* @mapping: mapping in which to set writeback error* @err: error to be set in mapping** When writeback fails in some way, we must record that error so that* userspace can be informed when fsync and the like are called. We endeavor* to report errors on any file that was open at the time of the error. Some* internal callers also need to know when writeback errors have occurred.** When a writeback error occurs, most filesystems will want to call* filemap_set_wb_err to record the error in the mapping so that it will be* automatically reported whenever fsync is called on the file.*/ static inline void filemap_set_wb_err(struct address_space *mapping, int err) {/* Fastpath for common case of no error */if (unlikely(err))__filemap_set_wb_err(mapping, err); }/*** filemap_check_wb_error - has an error occurred since the mark was sampled?* @mapping: mapping to check for writeback errors* @since: previously-sampled errseq_t** Grab the errseq_t value from the mapping, and see if it has changed "since"* the given value was sampled.** If it has then report the latest error set, otherwise return 0.*/ static inline int filemap_check_wb_err(struct address_space *mapping,errseq_t since) {return errseq_check(&mapping->wb_err, since); }/*** filemap_sample_wb_err - sample the current errseq_t to test for later errors* @mapping: mapping to be sampled** Writeback errors are always reported relative to a particular sample point* in the past. This function provides those sample points.*/ static inline errseq_t filemap_sample_wb_err(struct address_space *mapping) {return errseq_sample(&mapping->wb_err); }extern int vfs_fsync_range(struct file *file, loff_t start, loff_t end,int datasync); extern int vfs_fsync(struct file *file, int datasync);extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,unsigned int flags);/** Sync the bytes written if this was a synchronous write. Expect ki_pos* to already be updated for the write, and will return either the amount* of bytes passed in, or an error if syncing the file failed.*/ static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count) {if (iocb->ki_flags & IOCB_DSYNC) {int ret = vfs_fsync_range(iocb->ki_filp,iocb->ki_pos - count, iocb->ki_pos - 1,(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);if (ret)return ret;}return count; }extern void emergency_sync(void); extern void emergency_remount(void); #ifdef CONFIG_BLOCK extern sector_t bmap(struct inode *, sector_t); #endif extern int notify_change(struct dentry *, struct iattr *, struct inode **); extern int inode_permission(struct inode *, int); extern int generic_permission(struct inode *, int); extern int __check_sticky(struct inode *dir, struct inode *inode);static inline bool execute_ok(struct inode *inode) {return (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode); }static inline void file_start_write(struct file *file) {if (!S_ISREG(file_inode(file)->i_mode))return;__sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true); }static inline bool file_start_write_trylock(struct file *file) {if (!S_ISREG(file_inode(file)->i_mode))return true;return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false); }static inline void file_end_write(struct file *file) {if (!S_ISREG(file_inode(file)->i_mode))return;__sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE); }/** get_write_access() gets write permission for a file.* put_write_access() releases this write permission.* This is used for regular files.* We cannot support write (and maybe mmap read-write shared) accesses and* MAP_DENYWRITE mmappings simultaneously. The i_writecount field of an inode* can have the following values:* 0: no writers, no VM_DENYWRITE mappings* < 0: (-i_writecount) vm_area_structs with VM_DENYWRITE set exist* > 0: (i_writecount) users are writing to the file.** Normally we operate on that counter with atomic_{inc,dec} and it's safe* except for the cases where we don't hold i_writecount yet. Then we need to* use {get,deny}_write_access() - these functions check the sign and refuse* to do the change if sign is wrong.*/ static inline int get_write_access(struct inode *inode) {return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY; } static inline int deny_write_access(struct file *file) {struct inode *inode = file_inode(file);return atomic_dec_unless_positive(&inode->i_writecount) ? 0 : -ETXTBSY; } static inline void put_write_access(struct inode * inode) {atomic_dec(&inode->i_writecount); } static inline void allow_write_access(struct file *file) {if (file)atomic_inc(&file_inode(file)->i_writecount); } static inline bool inode_is_open_for_write(const struct inode *inode) {return atomic_read(&inode->i_writecount) > 0; }#ifdef CONFIG_IMA static inline void i_readcount_dec(struct inode *inode) {BUG_ON(!atomic_read(&inode->i_readcount));atomic_dec(&inode->i_readcount); } static inline void i_readcount_inc(struct inode *inode) {atomic_inc(&inode->i_readcount); } #else static inline void i_readcount_dec(struct inode *inode) {return; } static inline void i_readcount_inc(struct inode *inode) {return; } #endif extern int do_pipe_flags(int *, int);#define __kernel_read_file_id(id) \id(UNKNOWN, unknown) \id(FIRMWARE, firmware) \id(FIRMWARE_PREALLOC_BUFFER, firmware) \id(MODULE, kernel-module) \id(KEXEC_IMAGE, kexec-image) \id(KEXEC_INITRAMFS, kexec-initramfs) \id(POLICY, security-policy) \id(X509_CERTIFICATE, x509-certificate) \id(MAX_ID, )#define __fid_enumify(ENUM, dummy) READING_ ## ENUM, #define __fid_stringify(dummy, str) #str,enum kernel_read_file_id {__kernel_read_file_id(__fid_enumify) };static const char * const kernel_read_file_str[] = {__kernel_read_file_id(__fid_stringify) };static inline const char *kernel_read_file_id_str(enum kernel_read_file_id id) {if ((unsigned)id >= READING_MAX_ID)return kernel_read_file_str[READING_UNKNOWN];return kernel_read_file_str[id]; }extern int kernel_read_file(struct file *, void **, loff_t *, loff_t,enum kernel_read_file_id); extern int kernel_read_file_from_path(const char *, void **, loff_t *, loff_t,enum kernel_read_file_id); extern int kernel_read_file_from_fd(int, void **, loff_t *, loff_t,enum kernel_read_file_id); extern ssize_t kernel_read(struct file *, void *, size_t, loff_t *); extern ssize_t kernel_write(struct file *, const void *, size_t, loff_t *); extern ssize_t __kernel_write(struct file *, const void *, size_t, loff_t *); extern struct file * open_exec(const char *);/* fs/dcache.c -- generic fs support functions */ extern bool is_subdir(struct dentry *, struct dentry *); extern bool path_is_under(const struct path *, const struct path *);extern char *file_path(struct file *, char *, int);#include <linux/err.h>/* needed for stackable file system support */ extern loff_t default_llseek(struct file *file, loff_t offset, int whence);extern loff_t vfs_llseek(struct file *file, loff_t offset, int whence);extern int inode_init_always(struct super_block *, struct inode *); extern void inode_init_once(struct inode *); extern void address_space_init_once(struct address_space *mapping); extern struct inode * igrab(struct inode *); extern ino_t iunique(struct super_block *, ino_t); extern int inode_needs_sync(struct inode *inode); extern int generic_delete_inode(struct inode *inode); static inline int generic_drop_inode(struct inode *inode) {return !inode->i_nlink || inode_unhashed(inode); }extern struct inode *ilookup5_nowait(struct super_block *sb,unsigned long hashval, int (*test)(struct inode *, void *),void *data); extern struct inode *ilookup5(struct super_block *sb, unsigned long hashval,int (*test)(struct inode *, void *), void *data); extern struct inode *ilookup(struct super_block *sb, unsigned long ino);extern struct inode *inode_insert5(struct inode *inode, unsigned long hashval,int (*test)(struct inode *, void *),int (*set)(struct inode *, void *),void *data); extern struct inode * iget5_locked(struct super_block *, unsigned long, int (*test)(struct inode *, void *), int (*set)(struct inode *, void *), void *); extern struct inode * iget_locked(struct super_block *, unsigned long); extern struct inode *find_inode_nowait(struct super_block *,unsigned long,int (*match)(struct inode *,unsigned long, void *),void *data); extern int insert_inode_locked4(struct inode *, unsigned long, int (*test)(struct inode *, void *), void *); extern int insert_inode_locked(struct inode *); #ifdef CONFIG_DEBUG_LOCK_ALLOC extern void lockdep_annotate_inode_mutex_key(struct inode *inode); #else static inline void lockdep_annotate_inode_mutex_key(struct inode *inode) { }; #endif extern void unlock_new_inode(struct inode *); extern void discard_new_inode(struct inode *); extern unsigned int get_next_ino(void); extern void evict_inodes(struct super_block *sb);extern void __iget(struct inode * inode); extern void iget_failed(struct inode *); extern void clear_inode(struct inode *); extern void __destroy_inode(struct inode *); extern struct inode *new_inode_pseudo(struct super_block *sb); extern struct inode *new_inode(struct super_block *sb); extern void free_inode_nonrcu(struct inode *inode); extern int should_remove_suid(struct dentry *); extern int file_remove_privs(struct file *);extern void __insert_inode_hash(struct inode *, unsigned long hashval); static inline void insert_inode_hash(struct inode *inode) {__insert_inode_hash(inode, inode->i_ino); }extern void __remove_inode_hash(struct inode *); static inline void remove_inode_hash(struct inode *inode) {if (!inode_unhashed(inode) && !hlist_fake(&inode->i_hash))__remove_inode_hash(inode); }extern void inode_sb_list_add(struct inode *inode);#ifdef CONFIG_BLOCK extern int bdev_read_only(struct block_device *); #endif extern int set_blocksize(struct block_device *, int); extern int sb_set_blocksize(struct super_block *, int); extern int sb_min_blocksize(struct super_block *, int);extern int generic_file_mmap(struct file *, struct vm_area_struct *); extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *); extern ssize_t generic_write_checks(struct kiocb *, struct iov_iter *); extern int generic_remap_checks(struct file *file_in, loff_t pos_in,struct file *file_out, loff_t pos_out,loff_t *count, unsigned int remap_flags); extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *); extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *); extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *); extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t);ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,rwf_t flags); ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,rwf_t flags);/* fs/block_dev.c */ extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to); extern ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from); extern int blkdev_fsync(struct file *filp, loff_t start, loff_t end,int datasync); extern void block_sync_page(struct page *page);/* fs/splice.c */ extern ssize_t generic_file_splice_read(struct file *, loff_t *,struct pipe_inode_info *, size_t, unsigned int); extern ssize_t iter_file_splice_write(struct pipe_inode_info *,struct file *, loff_t *, size_t, unsigned int); extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe,struct file *out, loff_t *, size_t len, unsigned int flags); extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out,loff_t *opos, size_t len, unsigned int flags);extern void file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); extern loff_t noop_llseek(struct file *file, loff_t offset, int whence); extern loff_t no_llseek(struct file *file, loff_t offset, int whence); extern loff_t vfs_setpos(struct file *file, loff_t offset, loff_t maxsize); extern loff_t generic_file_llseek(struct file *file, loff_t offset, int whence); extern loff_t generic_file_llseek_size(struct file *file, loff_t offset,int whence, loff_t maxsize, loff_t eof); extern loff_t fixed_size_llseek(struct file *file, loff_t offset,int whence, loff_t size); extern loff_t no_seek_end_llseek_size(struct file *, loff_t, int, loff_t); extern loff_t no_seek_end_llseek(struct file *, loff_t, int); extern int generic_file_open(struct inode * inode, struct file * filp); extern int nonseekable_open(struct inode * inode, struct file * filp); extern int stream_open(struct inode * inode, struct file * filp);#ifdef CONFIG_BLOCK typedef void (dio_submit_t)(struct bio *bio, struct inode *inode,loff_t file_offset);enum {/* need locking between buffered and direct access */DIO_LOCKING = 0x01,/* filesystem does not support filling holes */DIO_SKIP_HOLES = 0x02, };void dio_end_io(struct bio *bio); void dio_warn_stale_pagecache(struct file *filp);ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode,struct block_device *bdev, struct iov_iter *iter,get_block_t get_block,dio_iodone_t end_io, dio_submit_t submit_io,int flags);static inline ssize_t blockdev_direct_IO(struct kiocb *iocb,struct inode *inode,struct iov_iter *iter,get_block_t get_block) {return __blockdev_direct_IO(iocb, inode, inode->i_sb->s_bdev, iter,get_block, NULL, NULL, DIO_LOCKING | DIO_SKIP_HOLES); } #endifvoid inode_dio_wait(struct inode *inode);/** inode_dio_begin - signal start of a direct I/O requests* @inode: inode the direct I/O happens on** This is called once we've finished processing a direct I/O request,* and is used to wake up callers waiting for direct I/O to be quiesced.*/ static inline void inode_dio_begin(struct inode *inode) {atomic_inc(&inode->i_dio_count); }/** inode_dio_end - signal finish of a direct I/O requests* @inode: inode the direct I/O happens on** This is called once we've finished processing a direct I/O request,* and is used to wake up callers waiting for direct I/O to be quiesced.*/ static inline void inode_dio_end(struct inode *inode) {if (atomic_dec_and_test(&inode->i_dio_count))wake_up_bit(&inode->i_state, __I_DIO_WAKEUP); }extern void inode_set_flags(struct inode *inode, unsigned int flags,unsigned int mask);extern const struct file_operations generic_ro_fops;#define special_file(m) (S_ISCHR(m)||S_ISBLK(m)||S_ISFIFO(m)||S_ISSOCK(m))extern int readlink_copy(char __user *, int, const char *); extern int page_readlink(struct dentry *, char __user *, int); extern const char *page_get_link(struct dentry *, struct inode *,struct delayed_call *); extern void page_put_link(void *); extern int __page_symlink(struct inode *inode, const char *symname, int len,int nofs); extern int page_symlink(struct inode *inode, const char *symname, int len); extern const struct inode_operations page_symlink_inode_operations; extern void kfree_link(void *); extern void generic_fillattr(struct inode *, struct kstat *); extern int vfs_getattr_nosec(const struct path *, struct kstat *, u32, unsigned int); extern int vfs_getattr(const struct path *, struct kstat *, u32, unsigned int); void __inode_add_bytes(struct inode *inode, loff_t bytes); void inode_add_bytes(struct inode *inode, loff_t bytes); void __inode_sub_bytes(struct inode *inode, loff_t bytes); void inode_sub_bytes(struct inode *inode, loff_t bytes); static inline loff_t __inode_get_bytes(struct inode *inode) {return (((loff_t)inode->i_blocks) << 9) + inode->i_bytes; } loff_t inode_get_bytes(struct inode *inode); void inode_set_bytes(struct inode *inode, loff_t bytes); const char *simple_get_link(struct dentry *, struct inode *,struct delayed_call *); extern const struct inode_operations simple_symlink_inode_operations;extern int iterate_dir(struct file *, struct dir_context *);extern int vfs_statx(int, const char __user *, int, struct kstat *, u32); extern int vfs_statx_fd(unsigned int, struct kstat *, u32, unsigned int);static inline int vfs_stat(const char __user *filename, struct kstat *stat) {return vfs_statx(AT_FDCWD, filename, AT_NO_AUTOMOUNT,stat, STATX_BASIC_STATS); } static inline int vfs_lstat(const char __user *name, struct kstat *stat) {return vfs_statx(AT_FDCWD, name, AT_SYMLINK_NOFOLLOW | AT_NO_AUTOMOUNT,stat, STATX_BASIC_STATS); } static inline int vfs_fstatat(int dfd, const char __user *filename,struct kstat *stat, int flags) {return vfs_statx(dfd, filename, flags | AT_NO_AUTOMOUNT,stat, STATX_BASIC_STATS); } static inline int vfs_fstat(int fd, struct kstat *stat) {return vfs_statx_fd(fd, stat, STATX_BASIC_STATS, 0); }extern const char *vfs_get_link(struct dentry *, struct delayed_call *); extern int vfs_readlink(struct dentry *, char __user *, int);extern int __generic_block_fiemap(struct inode *inode,struct fiemap_extent_info *fieinfo,loff_t start, loff_t len,get_block_t *get_block); extern int generic_block_fiemap(struct inode *inode,struct fiemap_extent_info *fieinfo, u64 start,u64 len, get_block_t *get_block);extern struct file_system_type *get_filesystem(struct file_system_type *fs); extern void put_filesystem(struct file_system_type *fs); extern struct file_system_type *get_fs_type(const char *name); extern struct super_block *get_super(struct block_device *); extern struct super_block *get_super_thawed(struct block_device *); extern struct super_block *get_super_exclusive_thawed(struct block_device *bdev); extern struct super_block *get_active_super(struct block_device *bdev); extern void drop_super(struct super_block *sb); extern void drop_super_exclusive(struct super_block *sb); extern void iterate_supers(void (*)(struct super_block *, void *), void *); extern void iterate_supers_type(struct file_system_type *,void (*)(struct super_block *, void *), void *);extern int dcache_dir_open(struct inode *, struct file *); extern int dcache_dir_close(struct inode *, struct file *); extern loff_t dcache_dir_lseek(struct file *, loff_t, int); extern int dcache_readdir(struct file *, struct dir_context *); extern int simple_setattr(struct dentry *, struct iattr *); extern int simple_getattr(const struct path *, struct kstat *, u32, unsigned int); extern int simple_statfs(struct dentry *, struct kstatfs *); extern int simple_open(struct inode *inode, struct file *file); extern int simple_link(struct dentry *, struct inode *, struct dentry *); extern int simple_unlink(struct inode *, struct dentry *); extern int simple_rmdir(struct inode *, struct dentry *); extern int simple_rename(struct inode *, struct dentry *,struct inode *, struct dentry *, unsigned int); extern int noop_fsync(struct file *, loff_t, loff_t, int); extern int noop_set_page_dirty(struct page *page); extern void noop_invalidatepage(struct page *page, unsigned int offset,unsigned int length); extern ssize_t noop_direct_IO(struct kiocb *iocb, struct iov_iter *iter); extern int simple_empty(struct dentry *); extern int simple_readpage(struct file *file, struct page *page); extern int simple_write_begin(struct file *file, struct address_space *mapping,loff_t pos, unsigned len, unsigned flags,struct page **pagep, void **fsdata); extern int simple_write_end(struct file *file, struct address_space *mapping,loff_t pos, unsigned len, unsigned copied,struct page *page, void *fsdata); extern int always_delete_dentry(const struct dentry *); extern struct inode *alloc_anon_inode(struct super_block *); extern int simple_nosetlease(struct file *, long, struct file_lock **, void **); extern const struct dentry_operations simple_dentry_operations;extern struct dentry *simple_lookup(struct inode *, struct dentry *, unsigned int flags); extern ssize_t generic_read_dir(struct file *, char __user *, size_t, loff_t *); extern const struct file_operations simple_dir_operations; extern const struct inode_operations simple_dir_inode_operations; extern void make_empty_dir_inode(struct inode *inode); extern bool is_empty_dir_inode(struct inode *inode); struct tree_descr { const char *name; const struct file_operations *ops; int mode; }; struct dentry *d_alloc_name(struct dentry *, const char *); extern int simple_fill_super(struct super_block *, unsigned long,const struct tree_descr *); extern int simple_pin_fs(struct file_system_type *, struct vfsmount **mount, int *count); extern void simple_release_fs(struct vfsmount **mount, int *count);extern ssize_t simple_read_from_buffer(void __user *to, size_t count,loff_t *ppos, const void *from, size_t available); extern ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos,const void __user *from, size_t count);extern int __generic_file_fsync(struct file *, loff_t, loff_t, int); extern int generic_file_fsync(struct file *, loff_t, loff_t, int);extern int generic_check_addressable(unsigned, u64);#ifdef CONFIG_MIGRATION extern int buffer_migrate_page(struct address_space *,struct page *, struct page *,enum migrate_mode); extern int buffer_migrate_page_norefs(struct address_space *,struct page *, struct page *,enum migrate_mode); #else #define buffer_migrate_page NULL #define buffer_migrate_page_norefs NULL #endifextern int setattr_prepare(struct dentry *, struct iattr *); extern int inode_newsize_ok(const struct inode *, loff_t offset); extern void setattr_copy(struct inode *inode, const struct iattr *attr);extern int file_update_time(struct file *file);static inline bool io_is_direct(struct file *filp) {return (filp->f_flags & O_DIRECT) || IS_DAX(filp->f_mapping->host); }static inline bool vma_is_dax(struct vm_area_struct *vma) {return vma->vm_file && IS_DAX(vma->vm_file->f_mapping->host); }static inline bool vma_is_fsdax(struct vm_area_struct *vma) {struct inode *inode;if (!vma->vm_file)return false;if (!vma_is_dax(vma))return false;inode = file_inode(vma->vm_file);if (S_ISCHR(inode->i_mode))return false; /* device-dax */return true; }static inline int iocb_flags(struct file *file) {int res = 0;if (file->f_flags & O_APPEND)res |= IOCB_APPEND;if (io_is_direct(file))res |= IOCB_DIRECT;if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))res |= IOCB_DSYNC;if (file->f_flags & __O_SYNC)res |= IOCB_SYNC;return res; }static inline int kiocb_set_rw_flags(struct kiocb *ki, rwf_t flags) {if (unlikely(flags & ~RWF_SUPPORTED))return -EOPNOTSUPP;if (flags & RWF_NOWAIT) {if (!(ki->ki_filp->f_mode & FMODE_NOWAIT))return -EOPNOTSUPP;ki->ki_flags |= IOCB_NOWAIT;}if (flags & RWF_HIPRI)ki->ki_flags |= IOCB_HIPRI;if (flags & RWF_DSYNC)ki->ki_flags |= IOCB_DSYNC;if (flags & RWF_SYNC)ki->ki_flags |= (IOCB_DSYNC | IOCB_SYNC);if (flags & RWF_APPEND)ki->ki_flags |= IOCB_APPEND;return 0; }static inline ino_t parent_ino(struct dentry *dentry) {ino_t res;/** Don't strictly need d_lock here? If the parent ino could change* then surely we'd have a deeper race in the caller?*/spin_lock(&dentry->d_lock);res = dentry->d_parent->d_inode->i_ino;spin_unlock(&dentry->d_lock);return res; }/* Transaction based IO helpers *//** An argresp is stored in an allocated page and holds the* size of the argument or response, along with its content*/ struct simple_transaction_argresp {ssize_t size;char data[0]; };#define SIMPLE_TRANSACTION_LIMIT (PAGE_SIZE - sizeof(struct simple_transaction_argresp))char *simple_transaction_get(struct file *file, const char __user *buf,size_t size); ssize_t simple_transaction_read(struct file *file, char __user *buf,size_t size, loff_t *pos); int simple_transaction_release(struct inode *inode, struct file *file);void simple_transaction_set(struct file *file, size_t n);/** simple attribute files** These attributes behave similar to those in sysfs:** Writing to an attribute immediately sets a value, an open file can be* written to multiple times.** Reading from an attribute creates a buffer from the value that might get* read with multiple read calls. When the attribute has been read* completely, no further read calls are possible until the file is opened* again.** All attributes contain a text representation of a numeric value* that are accessed with the get() and set() functions.*/ #define DEFINE_SIMPLE_ATTRIBUTE(__fops, __get, __set, __fmt) \ static int __fops ## _open(struct inode *inode, struct file *file) \ { \__simple_attr_check_format(__fmt, 0ull); \return simple_attr_open(inode, file, __get, __set, __fmt); \ } \ static const struct file_operations __fops = { \.owner = THIS_MODULE, \.open = __fops ## _open, \.release = simple_attr_release, \.read = simple_attr_read, \.write = simple_attr_write, \.llseek = generic_file_llseek, \ }static inline __printf(1, 2) void __simple_attr_check_format(const char *fmt, ...) {/* don't do anything, just let the compiler check the arguments; */ }int simple_attr_open(struct inode *inode, struct file *file,int (*get)(void *, u64 *), int (*set)(void *, u64),const char *fmt); int simple_attr_release(struct inode *inode, struct file *file); ssize_t simple_attr_read(struct file *file, char __user *buf,size_t len, loff_t *ppos); ssize_t simple_attr_write(struct file *file, const char __user *buf,size_t len, loff_t *ppos);struct ctl_table; int proc_nr_files(struct ctl_table *table, int write,void __user *buffer, size_t *lenp, loff_t *ppos); int proc_nr_dentry(struct ctl_table *table, int write,void __user *buffer, size_t *lenp, loff_t *ppos); int proc_nr_inodes(struct ctl_table *table, int write,void __user *buffer, size_t *lenp, loff_t *ppos); int __init get_filesystem_list(char *buf);#define __FMODE_EXEC ((__force int) FMODE_EXEC) #define __FMODE_NONOTIFY ((__force int) FMODE_NONOTIFY)#define ACC_MODE(x) ("\004\002\006\006"[(x)&O_ACCMODE]) #define OPEN_FMODE(flag) ((__force fmode_t)(((flag + 1) & O_ACCMODE) | \(flag & __FMODE_NONOTIFY)))static inline bool is_sxid(umode_t mode) {return (mode & S_ISUID) || ((mode & S_ISGID) && (mode & S_IXGRP)); }static inline int check_sticky(struct inode *dir, struct inode *inode) {if (!(dir->i_mode & S_ISVTX))return 0;return __check_sticky(dir, inode); }static inline void inode_has_no_xattr(struct inode *inode) {if (!is_sxid(inode->i_mode) && (inode->i_sb->s_flags & SB_NOSEC))inode->i_flags |= S_NOSEC; }static inline bool is_root_inode(struct inode *inode) {return inode == inode->i_sb->s_root->d_inode; }static inline bool dir_emit(struct dir_context *ctx,const char *name, int namelen,u64 ino, unsigned type) {return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0; } static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) {return ctx->actor(ctx, ".", 1, ctx->pos,file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0; } static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) {return ctx->actor(ctx, "..", 2, ctx->pos,parent_ino(file->f_path.dentry), DT_DIR) == 0; } static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) {if (ctx->pos == 0) {if (!dir_emit_dot(file, ctx))return false;ctx->pos = 1;}if (ctx->pos == 1) {if (!dir_emit_dotdot(file, ctx))return false;ctx->pos = 2;}return true; } static inline bool dir_relax(struct inode *inode) {inode_unlock(inode);inode_lock(inode);return !IS_DEADDIR(inode); }static inline bool dir_relax_shared(struct inode *inode) {inode_unlock_shared(inode);inode_lock_shared(inode);return !IS_DEADDIR(inode); }extern bool path_noexec(const struct path *path); extern void inode_nohighmem(struct inode *inode);/* mm/fadvise.c */ extern int vfs_fadvise(struct file *file, loff_t offset, loff_t len,int advice);#if defined(CONFIG_IO_URING) extern struct sock *io_uring_get_socket(struct file *file); #else static inline struct sock *io_uring_get_socket(struct file *file) {return NULL; } #endif#endif /* _LINUX_FS_H */

總結

以上是生活随笔為你收集整理的file_operations结构体介绍的全部內容，希望文章能夠幫你解決所遇到的問題。

如果覺得生活随笔網站內容還不錯，歡迎將生活随笔推薦給好友。