diff options
Diffstat (limited to 'Documentation/filesystems/vfs.txt')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 24 |
1 files changed, 22 insertions, 2 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index e3869098163..bc4b06b3160 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -900,6 +900,7 @@ defined: struct dentry_operations { int (*d_revalidate)(struct dentry *, unsigned int); + int (*d_weak_revalidate)(struct dentry *, unsigned int); int (*d_hash)(const struct dentry *, const struct inode *, struct qstr *); int (*d_compare)(const struct dentry *, const struct inode *, @@ -915,8 +916,13 @@ struct dentry_operations { d_revalidate: called when the VFS needs to revalidate a dentry. This is called whenever a name look-up finds a dentry in the - dcache. Most filesystems leave this as NULL, because all their - dentries in the dcache are valid + dcache. Most local filesystems leave this as NULL, because all their + dentries in the dcache are valid. Network filesystems are different + since things can change on the server without the client necessarily + being aware of it. + + This function should return a positive value if the dentry is still + valid, and zero or a negative error code if it isn't. d_revalidate may be called in rcu-walk mode (flags & LOOKUP_RCU). If in rcu-walk mode, the filesystem must revalidate the dentry without @@ -927,6 +933,20 @@ struct dentry_operations { If a situation is encountered that rcu-walk cannot handle, return -ECHILD and it will be called again in ref-walk mode. + d_weak_revalidate: called when the VFS needs to revalidate a "jumped" dentry. + This is called when a path-walk ends at dentry that was not acquired by + doing a lookup in the parent directory. This includes "/", "." and "..", + as well as procfs-style symlinks and mountpoint traversal. + + In this case, we are less concerned with whether the dentry is still + fully correct, but rather that the inode is still valid. As with + d_revalidate, most local filesystems will set this to NULL since their + dcache entries are always valid. + + This function has the same return code semantics as d_revalidate. + + d_weak_revalidate is only called after leaving rcu-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. |