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| author | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 07:49:57 +0100 |
|---|---|---|
| committer | Nick Piggin <npiggin@kernel.dk> | 2011-01-07 07:50:29 +0100 |
| commit | 34286d6662308d82aed891852d04c7c3a2649b16 (patch) | |
| tree | c4b7311404d302e7cb94df7a4690298e1059910a /Documentation/filesystems/vfs.txt | |
| parent | fs: cache optimise dentry and inode for rcu-walk (diff) | |
| download | linux-34286d6662308d82aed891852d04c7c3a2649b16.tar.xz linux-34286d6662308d82aed891852d04c7c3a2649b16.zip | |
fs: rcu-walk aware d_revalidate method
Require filesystems be aware of .d_revalidate being called in rcu-walk
mode (nd->flags & LOOKUP_RCU). For now do a simple push down, returning
-ECHILD from all implementations.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Diffstat (limited to 'Documentation/filesystems/vfs.txt')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index 69b10ff5ec81..c936b4912383 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -863,6 +863,15 @@ struct dentry_operations { dcache. Most filesystems leave this as NULL, because all their dentries in the dcache are valid + d_revalidate may be called in rcu-walk mode (nd->flags & LOOKUP_RCU). + If in rcu-walk mode, the filesystem must revalidate the dentry without + blocking or storing to the dentry, d_parent and d_inode should not be + used without care (because they can go NULL), instead nd->inode should + be used. + + If a situation is encountered that rcu-walk cannot handle, return + -ECHILD and it will be called again in ref-walk mode. + 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. The inode is the dentry's inode. |