diff options
Diffstat (limited to 'Documentation/filesystems/Locking')
| -rw-r--r-- | Documentation/filesystems/Locking | 16 |
1 files changed, 9 insertions, 7 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 0dd2cc8eb..421b17318 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -66,6 +66,7 @@ getattr: (see below) revalidate: no (see below) Additionally, ->rmdir() has i_zombie on victim and so does ->rename() in case when target exists and is a directory. + ->rename() on directories has (per-superblock) ->s_vfs_rename_sem. ->revalidate(), it may be called both with and without the i_sem on dentry->d_inode. VFS never calls it with i_zombie on dentry->d_inode, but watch for other methods directly calling this one... @@ -226,7 +227,7 @@ ioctl: yes (see below) mmap: no open: maybe (see below) flush: yes -release: yes +release: no fsync: yes (see below) fasync: yes (see below) lock: yes @@ -238,12 +239,13 @@ The only exception is ->open() in the instances of file_operations that never end up in ->i_fop/->proc_fops, i.e. ones that belong to character devices (chrdev_open() takes lock before replacing ->f_op and calling the secondary method. As soon as we fix the handling of module reference counters all -instances of ->open() will be called without the BKL. At the same point -->release() will lose BKL. Currently ext2_release() is *the* source of -contention on fs-intensive loads and dropping BKL on ->release() will get -rid of that (we will still need some locking for cases when we close a file -that had been opened r/w, but that can be done using the internal locking with -smaller critical areas). sock_close() is also going to win from that change. +instances of ->open() will be called without the BKL. + +Note: ext2_release() was *the* source of contention on fs-intensive +loads and dropping BKL on ->release() helps to get rid of that (we still +grab BKL for cases when we close a file that had been opened r/w, but that +can and should be done using the internal locking with smaller critical areas). +Current worst offender is ext2_get_block()... ->fasync() is a mess. This area needs a big cleanup and that will probably affect locking. |