diff options
| author | Jeff Layton <jlayton@redhat.com> | 2011-07-26 13:33:16 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2011-07-26 13:41:14 -0400 |
| commit | c46c887744b330795eba55fdb96343c36d481765 (patch) | |
| tree | 3e4608981b87d8b5d2b23827988312d7c35778b2 | |
| parent | 41c96486f238e6a545f52215f95fe69748abf603 (diff) | |
| download | op-kernel-dev-c46c887744b330795eba55fdb96343c36d481765.zip op-kernel-dev-c46c887744b330795eba55fdb96343c36d481765.tar.gz | |
vfs: document locking requirements for d_move, __d_move and d_materialise_unique
Adding a comment to d_materialise_unique per Al's request...
d_move and __d_move have some pretty substantial locking requirements,
but they are not clearly documented. Add some comments spelling them
out. Also, document the requirement for the i_mutex of the parent in
d_materialise_unique.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/dcache.c | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index be18598..b05aac3 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2138,8 +2138,9 @@ static void dentry_unlock_parents_for_move(struct dentry *dentry, * @target: new dentry * * Update the dcache to reflect the move of a file name. Negative - * dcache entries should not be moved in this way. Caller hold - * rename_lock. + * dcache entries should not be moved in this way. Caller must hold + * rename_lock, the i_mutex of the source and target directories, + * and the sb->s_vfs_rename_mutex if they differ. See lock_rename(). */ static void __d_move(struct dentry * dentry, struct dentry * target) { @@ -2202,7 +2203,8 @@ static void __d_move(struct dentry * dentry, struct dentry * target) * @target: new dentry * * Update the dcache to reflect the move of a file name. Negative - * dcache entries should not be moved in this way. + * dcache entries should not be moved in this way. See the locking + * requirements for __d_move. */ void d_move(struct dentry *dentry, struct dentry *target) { @@ -2320,7 +2322,8 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) * @inode: inode to bind to the dentry, to which aliases may be attached * * Introduces an dentry into the tree, substituting an extant disconnected - * root directory alias in its place if there is one + * root directory alias in its place if there is one. Caller must hold the + * i_mutex of the parent directory. */ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) { |
