diff options
Diffstat (limited to 'include/linux/fs.h')
| -rw-r--r-- | include/linux/fs.h | 104 |
1 files changed, 68 insertions, 36 deletions
diff --git a/include/linux/fs.h b/include/linux/fs.h index 8045c7ef4000..ed5b32dc2625 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -164,6 +164,9 @@ typedef int (dio_iodone_t)(struct kiocb *iocb, loff_t offset, /* File supports non-exclusive O_DIRECT writes from multiple threads */ #define FMODE_DIO_PARALLEL_WRITE ((__force fmode_t)0x1000000) +/* File is embedded in backing_file object */ +#define FMODE_BACKING ((__force fmode_t)0x2000000) + /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x4000000) @@ -949,29 +952,35 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index) index < ra->start + ra->size); } +/* + * f_{lock,count,pos_lock} members can be highly contended and share + * the same cacheline. f_{lock,mode} are very frequently used together + * and so share the same cacheline as well. The read-mostly + * f_{path,inode,op} are kept on a separate cacheline. + */ struct file { union { struct llist_node f_llist; struct rcu_head f_rcuhead; unsigned int f_iocb_flags; }; - struct path f_path; - struct inode *f_inode; /* cached value */ - const struct file_operations *f_op; /* * Protects f_ep, f_flags. * Must not be taken from IRQ context. */ spinlock_t f_lock; - atomic_long_t f_count; - unsigned int f_flags; fmode_t f_mode; + atomic_long_t f_count; struct mutex f_pos_lock; loff_t f_pos; + unsigned int f_flags; struct fown_struct f_owner; const struct cred *f_cred; struct file_ra_state f_ra; + struct path f_path; + struct inode *f_inode; /* cached value */ + const struct file_operations *f_op; u64 f_version; #ifdef CONFIG_SECURITY @@ -1069,29 +1078,29 @@ 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_INLINECRYPT (1<<17) /* Use blk-crypto for encrypted files */ -#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 */ +#define SB_RDONLY BIT(0) /* Mount read-only */ +#define SB_NOSUID BIT(1) /* Ignore suid and sgid bits */ +#define SB_NODEV BIT(2) /* Disallow access to device special files */ +#define SB_NOEXEC BIT(3) /* Disallow program execution */ +#define SB_SYNCHRONOUS BIT(4) /* Writes are synced at once */ +#define SB_MANDLOCK BIT(6) /* Allow mandatory locks on an FS */ +#define SB_DIRSYNC BIT(7) /* Directory modifications are synchronous */ +#define SB_NOATIME BIT(10) /* Do not update access times. */ +#define SB_NODIRATIME BIT(11) /* Do not update directory access times */ +#define SB_SILENT BIT(15) +#define SB_POSIXACL BIT(16) /* VFS does not apply the umask */ +#define SB_INLINECRYPT BIT(17) /* Use blk-crypto for encrypted files */ +#define SB_KERNMOUNT BIT(22) /* this is a kern_mount call */ +#define SB_I_VERSION BIT(23) /* Update inode I_version field */ +#define SB_LAZYTIME BIT(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) +#define SB_SUBMOUNT BIT(26) +#define SB_FORCE BIT(27) +#define SB_NOSEC BIT(28) +#define SB_BORN BIT(29) +#define SB_ACTIVE BIT(30) +#define SB_NOUSER BIT(31) /* These flags relate to encoding and casefolding */ #define SB_ENC_STRICT_MODE_FL (1 << 0) @@ -1234,7 +1243,7 @@ struct super_block { */ atomic_long_t s_fsnotify_connectors; - /* Being remounted read-only */ + /* Read-only state of the superblock is being changed */ int s_readonly_remount; /* per-sb errseq_t for reporting writeback errors via syncfs */ @@ -1664,9 +1673,12 @@ static inline int vfs_whiteout(struct mnt_idmap *idmap, WHITEOUT_DEV); } -struct file *vfs_tmpfile_open(struct mnt_idmap *idmap, - const struct path *parentpath, - umode_t mode, int open_flag, const struct cred *cred); +struct file *kernel_tmpfile_open(struct mnt_idmap *idmap, + const struct path *parentpath, + umode_t mode, int open_flag, + const struct cred *cred); +struct file *kernel_file_open(const struct path *path, int flags, + struct inode *inode, const struct cred *cred); int vfs_mkobj(struct dentry *, umode_t, int (*f)(struct dentry *, umode_t, void *), @@ -2342,11 +2354,31 @@ static inline struct file *file_open_root_mnt(struct vfsmount *mnt, return file_open_root(&(struct path){.mnt = mnt, .dentry = mnt->mnt_root}, name, flags, mode); } -extern struct file * dentry_open(const struct path *, int, const struct cred *); -extern struct file *dentry_create(const struct path *path, int flags, - umode_t mode, const struct cred *cred); -extern struct file * open_with_fake_path(const struct path *, int, - struct inode*, const struct cred *); +struct file *dentry_open(const struct path *path, int flags, + const struct cred *creds); +struct file *dentry_create(const struct path *path, int flags, umode_t mode, + const struct cred *cred); +struct file *backing_file_open(const struct path *path, int flags, + const struct path *real_path, + const struct cred *cred); +struct path *backing_file_real_path(struct file *f); + +/* + * file_real_path - get the path corresponding to f_inode + * + * When opening a backing file for a stackable filesystem (e.g., + * overlayfs) f_path may be on the stackable filesystem and f_inode on + * the underlying filesystem. When the path associated with f_inode is + * needed, this helper should be used instead of accessing f_path + * directly. +*/ +static inline const struct path *file_real_path(struct file *f) +{ + if (unlikely(f->f_mode & FMODE_BACKING)) + return backing_file_real_path(f); + return &f->f_path; +} + static inline struct file *file_clone_open(struct file *file) { return dentry_open(&file->f_path, file->f_flags, file->f_cred); @@ -2662,7 +2694,7 @@ extern void evict_inodes(struct super_block *sb); void dump_mapping(const struct address_space *); /* - * Userspace may rely on the the inode number being non-zero. For example, glibc + * Userspace may rely on the inode number being non-zero. For example, glibc * simply ignores files with zero i_ino in unlink() and other places. * * As an additional complication, if userspace was compiled with |