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| author | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 09:49:28 +0300 |
|---|---|---|
| committer | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 09:50:20 +0300 |
| commit | b1e6a015a580ad145689ad1d6b4aa0e03e6c868b (patch) | |
| tree | 57a10ef164e4d2f798d9b832dbeaf973aca2ab83 /Documentation/filesystems | |
| parent | 621e155a3591962420eacdd39f6f0aa29ceb221e (diff) | |
| download | linux-b1e6a015a580ad145689ad1d6b4aa0e03e6c868b.tar.xz | |
fs: change d_hash for rcu-walk
Change d_hash so it may be called from lock-free RCU lookups. See similar
patch for d_compare for details.
For in-tree filesystems, this is just a mechanical change.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 5 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 8 |
3 files changed, 16 insertions, 4 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 9a76f8d8bf95..a15ee207b449 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -10,7 +10,8 @@ be able to use diff(1). --------------------------- dentry_operations -------------------------- prototypes: int (*d_revalidate)(struct dentry *, int); - int (*d_hash) (struct dentry *, struct qstr *); + int (*d_hash)(const struct dentry *, const struct inode *, + struct qstr *); int (*d_compare)(const struct dentry *, const struct inode *, const struct dentry *, const struct inode *, unsigned int, const char *, const struct qstr *); @@ -22,7 +23,7 @@ prototypes: locking rules: dcache_lock rename_lock ->d_lock may block d_revalidate: no no no yes -d_hash no no no yes +d_hash no no no no d_compare: no yes no no d_delete: yes no yes no d_release: no no no yes diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index d44511e20828..9fd31940a8ef 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -333,3 +333,10 @@ unreferenced dentries, and is now only called when the dentry refcount goes to .d_compare() calling convention and locking rules are significantly changed. Read updated documentation in Documentation/filesystems/vfs.txt (and look at examples of other filesystems) for guidance. + +--- +[mandatory] + + .d_hash() calling convention and locking rules are significantly +changed. Read updated documentation in Documentation/filesystems/vfs.txt (and +look at examples of other filesystems) for guidance. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 250681b8c7cc..69b10ff5ec81 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -847,7 +847,8 @@ defined: struct dentry_operations { int (*d_revalidate)(struct dentry *, struct nameidata *); - int (*d_hash)(struct dentry *, struct qstr *); + int (*d_hash)(const struct dentry *, const struct inode *, + struct qstr *); int (*d_compare)(const struct dentry *, const struct inode *, const struct dentry *, const struct inode *, unsigned int, const char *, const struct qstr *); @@ -864,7 +865,10 @@ struct dentry_operations { d_hash: called when the VFS adds a dentry to the hash table. The first dentry passed to d_hash is the parent directory that the name is - to be hashed into. + to be hashed into. The inode is the dentry's inode. + + Same locking and synchronisation rules as d_compare regarding + what is safe to dereference etc. d_compare: called to compare a dentry name with a given name. The first dentry is the parent of the dentry to be compared, the second is |