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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 12:59:05 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-07-28 12:59:05 -0700 |
commit | 6784725ab0b9473ce44bfad91a256bd72b5cddc1 (patch) | |
tree | f31e2bfc4795c2ee490b0eb9fb752be58060568f /Documentation/filesystems/Locking | |
parent | 554828ee0db41618d101d9549db8808af9fd9d65 (diff) | |
parent | 47be61845c775643f1aa4d2a54343549f943c94c (diff) | |
download | linux-stable-6784725ab0b9473ce44bfad91a256bd72b5cddc1.tar.gz linux-stable-6784725ab0b9473ce44bfad91a256bd72b5cddc1.tar.bz2 linux-stable-6784725ab0b9473ce44bfad91a256bd72b5cddc1.zip |
Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs updates from Al Viro:
"Assorted cleanups and fixes.
Probably the most interesting part long-term is ->d_init() - that will
have a bunch of followups in (at least) ceph and lustre, but we'll
need to sort the barrier-related rules before it can get used for
really non-trivial stuff.
Another fun thing is the merge of ->d_iput() callers (dentry_iput()
and dentry_unlink_inode()) and a bunch of ->d_compare() ones (all
except the one in __d_lookup_lru())"
* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
fs/dcache.c: avoid soft-lockup in dput()
vfs: new d_init method
vfs: Update lookup_dcache() comment
bdev: get rid of ->bd_inodes
Remove last traces of ->sync_page
new helper: d_same_name()
dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()
vfs: clean up documentation
vfs: document ->d_real()
vfs: merge .d_select_inode() into .d_real()
unify dentry_iput() and dentry_unlink_inode()
binfmt_misc: ->s_root is not going anywhere
drop redundant ->owner initializations
ufs: get rid of redundant checks
orangefs: constify inode_operations
missed comment updates from ->direct_IO() prototype change
file_inode(f)->i_mapping is f->f_mapping
trim fsnotify hooks a bit
9p: new helper - v9fs_parent_fid()
debugfs: ->d_parent is never NULL or negative
...
Diffstat (limited to 'Documentation/filesystems/Locking')
-rw-r--r-- | Documentation/filesystems/Locking | 18 |
1 files changed, 7 insertions, 11 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 5a7386e38e2d..ef46d3ac5774 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -15,11 +15,14 @@ prototypes: int (*d_compare)(const struct dentry *, const struct dentry *, unsigned int, const char *, const struct qstr *); int (*d_delete)(struct dentry *); + int (*d_init)(struct dentry *); void (*d_release)(struct dentry *); void (*d_iput)(struct dentry *, struct inode *); char *(*d_dname)((struct dentry *dentry, char *buffer, int buflen); struct vfsmount *(*d_automount)(struct path *path); int (*d_manage)(struct dentry *, bool); + struct dentry *(*d_real)(struct dentry *, const struct inode *, + unsigned int); locking rules: rename_lock ->d_lock may block rcu-walk @@ -28,12 +31,14 @@ d_weak_revalidate:no no yes no d_hash no no no maybe d_compare: yes no no maybe d_delete: no yes no no +d_init: no no yes no d_release: no no yes no d_prune: no yes no no d_iput: no no yes no d_dname: no no no no d_automount: no no yes no d_manage: no no yes (ref-walk) maybe +d_real no no yes no --------------------------- inode_operations --------------------------- prototypes: @@ -66,7 +71,6 @@ prototypes: struct file *, unsigned open_flag, umode_t create_mode, int *opened); int (*tmpfile) (struct inode *, struct dentry *, umode_t); - int (*dentry_open)(struct dentry *, struct file *, const struct cred *); locking rules: all may block @@ -95,7 +99,6 @@ fiemap: no update_time: no atomic_open: yes tmpfile: no -dentry_open: no Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_mutex on victim. @@ -179,7 +182,6 @@ unlocks and drops the reference. prototypes: int (*writepage)(struct page *page, struct writeback_control *wbc); int (*readpage)(struct file *, struct page *); - int (*sync_page)(struct page *); int (*writepages)(struct address_space *, struct writeback_control *); int (*set_page_dirty)(struct page *page); int (*readpages)(struct file *filp, struct address_space *mapping, @@ -210,7 +212,6 @@ locking rules: PageLocked(page) i_mutex writepage: yes, unlocks (see below) readpage: yes, unlocks -sync_page: maybe writepages: set_page_dirty no readpages: @@ -230,8 +231,8 @@ error_remove_page: yes swap_activate: no swap_deactivate: no - ->write_begin(), ->write_end(), ->sync_page() and ->readpage() -may be called from the request handler (/dev/loop). + ->write_begin(), ->write_end() and ->readpage() may be called from +the request handler (/dev/loop). ->readpage() unlocks the page, either synchronously or via I/O completion. @@ -287,11 +288,6 @@ will leave the page itself marked clean but it will be tagged as dirty in the radix tree. This incoherency can lead to all sorts of hard-to-debug problems in the filesystem like having dirty inodes at umount and losing written data. - ->sync_page() locking rules are not well-defined - usually it is called -with lock on page, but that is not guaranteed. Considering the currently -existing instances of this method ->sync_page() itself doesn't look -well-defined... - ->writepages() is used for periodic writeback and for syscall-initiated sync operations. The address_space should start I/O against at least *nr_to_write pages. *nr_to_write must be decremented for each page which is |