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| author | Russell King <rmk@dyn-67.arm.linux.org.uk> | 2008-10-09 21:31:58 +0100 |
|---|---|---|
| committer | Russell King <rmk+kernel@arm.linux.org.uk> | 2008-10-09 21:31:58 +0100 |
| commit | 9e165acf1b9e37af7c0fa39399b43d0bd8600039 (patch) | |
| tree | 7ffdb0ad4c35ac9c19c4096b4f22ccc9b1eeefad /Documentation/filesystems/Locking | |
| parent | 6a4690c22f5da1eb1c898b61b6a80da52fbd976f (diff) | |
| parent | 791ccf2e4deeea8426b389fd0f5bb0e9167bb75d (diff) | |
Merge branch 'at91' into devel
Diffstat (limited to 'Documentation/filesystems/Locking')
| -rw-r--r-- | Documentation/filesystems/Locking | 15 |
1 files changed, 4 insertions, 11 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 680fb566b92..8362860e21a 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -144,8 +144,8 @@ prototypes: void (*kill_sb) (struct super_block *); locking rules: may block BKL -get_sb yes yes -kill_sb yes yes +get_sb yes no +kill_sb yes no ->get_sb() returns error or 0 with locked superblock attached to the vfsmount (exclusive on ->s_umount). @@ -409,12 +409,12 @@ ioctl: yes (see below) unlocked_ioctl: no (see below) compat_ioctl: no mmap: no -open: maybe (see below) +open: no flush: no release: no fsync: no (see below) aio_fsync: no -fasync: yes (see below) +fasync: no lock: yes readv: no writev: no @@ -431,13 +431,6 @@ For many filesystems, it is probably safe to acquire the inode semaphore. Note some filesystems (i.e. remote ones) provide no protection for i_size so you will need to use the BKL. -->open() locking is in-transit: big lock partially moved into the methods. -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. - 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 |