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author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 03:19:09 +0200 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-08-22 03:19:09 +0200 |
commit | d9a185f8b49678775ef56ecbdbc7b76970302897 (patch) | |
tree | 7ace1b26133e5d796af09e5d71d6531bcb69865c /fs/file_table.c | |
parent | Merge tag 'xfs-4.19-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux (diff) | |
parent | ovl: Enable metadata only feature (diff) | |
download | linux-d9a185f8b49678775ef56ecbdbc7b76970302897.tar.xz linux-d9a185f8b49678775ef56ecbdbc7b76970302897.zip |
Merge tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
"This contains two new features:
- Stack file operations: this allows removal of several hacks from
the VFS, proper interaction of read-only open files with copy-up,
possibility to implement fs modifying ioctls properly, and others.
- Metadata only copy-up: when file is on lower layer and only
metadata is modified (except size) then only copy up the metadata
and continue to use the data from the lower file"
* tag 'ovl-update-4.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (66 commits)
ovl: Enable metadata only feature
ovl: Do not do metacopy only for ioctl modifying file attr
ovl: Do not do metadata only copy-up for truncate operation
ovl: add helper to force data copy-up
ovl: Check redirect on index as well
ovl: Set redirect on upper inode when it is linked
ovl: Set redirect on metacopy files upon rename
ovl: Do not set dentry type ORIGIN for broken hardlinks
ovl: Add an inode flag OVL_CONST_INO
ovl: Treat metacopy dentries as type OVL_PATH_MERGE
ovl: Check redirects for metacopy files
ovl: Move some dir related ovl_lookup_single() code in else block
ovl: Do not expose metacopy only dentry from d_real()
ovl: Open file with data except for the case of fsync
ovl: Add helper ovl_inode_realdata()
ovl: Store lower data inode in ovl_inode
ovl: Fix ovl_getattr() to get number of blocks from lower
ovl: Add helper ovl_dentry_lowerdata() to get lower data dentry
ovl: Copy up meta inode data from lowest data inode
ovl: Modify ovl_lookup() and friends to lookup metacopy dentry
...
Diffstat (limited to 'fs/file_table.c')
-rw-r--r-- | fs/file_table.c | 69 |
1 files changed, 48 insertions, 21 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index d6eccd04d703..e49af4caf15d 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -52,7 +52,8 @@ static void file_free_rcu(struct rcu_head *head) static inline void file_free(struct file *f) { security_file_free(f); - percpu_counter_dec(&nr_files); + if (!(f->f_mode & FMODE_NOACCOUNT)) + percpu_counter_dec(&nr_files); call_rcu(&f->f_u.fu_rcuhead, file_free_rcu); } @@ -91,6 +92,34 @@ int proc_nr_files(struct ctl_table *table, int write, } #endif +static struct file *__alloc_file(int flags, const struct cred *cred) +{ + struct file *f; + int error; + + f = kmem_cache_zalloc(filp_cachep, GFP_KERNEL); + if (unlikely(!f)) + return ERR_PTR(-ENOMEM); + + f->f_cred = get_cred(cred); + error = security_file_alloc(f); + if (unlikely(error)) { + file_free_rcu(&f->f_u.fu_rcuhead); + return ERR_PTR(error); + } + + atomic_long_set(&f->f_count, 1); + rwlock_init(&f->f_owner.lock); + spin_lock_init(&f->f_lock); + mutex_init(&f->f_pos_lock); + eventpoll_init_file(f); + f->f_flags = flags; + f->f_mode = OPEN_FMODE(flags); + /* f->f_version: 0 */ + + return f; +} + /* Find an unused file structure and return a pointer to it. * Returns an error pointer if some error happend e.g. we over file * structures limit, run out of memory or operation is not permitted. @@ -105,7 +134,6 @@ struct file *alloc_empty_file(int flags, const struct cred *cred) { static long old_max; struct file *f; - int error; /* * Privileged users can go above max_files @@ -119,26 +147,10 @@ struct file *alloc_empty_file(int flags, const struct cred *cred) goto over; } - f = kmem_cache_zalloc(filp_cachep, GFP_KERNEL); - if (unlikely(!f)) - return ERR_PTR(-ENOMEM); - - f->f_cred = get_cred(cred); - error = security_file_alloc(f); - if (unlikely(error)) { - file_free_rcu(&f->f_u.fu_rcuhead); - return ERR_PTR(error); - } + f = __alloc_file(flags, cred); + if (!IS_ERR(f)) + percpu_counter_inc(&nr_files); - atomic_long_set(&f->f_count, 1); - rwlock_init(&f->f_owner.lock); - spin_lock_init(&f->f_lock); - mutex_init(&f->f_pos_lock); - eventpoll_init_file(f); - f->f_flags = flags; - f->f_mode = OPEN_FMODE(flags); - /* f->f_version: 0 */ - percpu_counter_inc(&nr_files); return f; over: @@ -150,6 +162,21 @@ over: return ERR_PTR(-ENFILE); } +/* + * Variant of alloc_empty_file() that doesn't check and modify nr_files. + * + * Should not be used unless there's a very good reason to do so. + */ +struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred) +{ + struct file *f = __alloc_file(flags, cred); + + if (!IS_ERR(f)) + f->f_mode |= FMODE_NOACCOUNT; + + return f; +} + /** * alloc_file - allocate and initialize a 'struct file' * |