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Diffstat (limited to 'Documentation/filesystems/vfs.txt')
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index d56151fe77d..fd24f34f120 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -229,6 +229,8 @@ struct super_operations { ssize_t (*quota_read)(struct super_block *, int, char *, size_t, loff_t); ssize_t (*quota_write)(struct super_block *, int, const char *, size_t, loff_t); + int (*nr_cached_objects)(struct super_block *); + void (*free_cached_objects)(struct super_block *, int); }; All methods are called without any locks being held, unless otherwise @@ -301,6 +303,20 @@ or bottom half). quota_write: called by the VFS to write to filesystem quota file. + nr_cached_objects: called by the sb cache shrinking function for the + filesystem to return the number of freeable cached objects it contains. + Optional. + + free_cache_objects: called by the sb cache shrinking function for the + filesystem to scan the number of objects indicated to try to free them. + Optional, but any filesystem implementing this method needs to also + implement ->nr_cached_objects for it to be called correctly. + + We can't do anything with any errors that the filesystem might + encountered, hence the void return type. This will never be called if + the VM is trying to reclaim under GFP_NOFS conditions, hence this + method does not need to handle that situation itself. + Whoever sets up the inode is responsible for filling in the "i_op" field. This is a pointer to a "struct inode_operations" which describes the methods that can be performed on individual inodes. |