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authorChristoph Hellwig <hch@lst.de>2009-06-19 20:22:37 +0200
committerAl Viro <viro@zeniv.linux.org.uk>2009-06-24 08:15:25 -0400
commit7e325d3a6b117c7288bfc0755410e9d9d2b71326 (patch)
tree37a59f2c771c31559118987d2ee91e870274ec8b /Documentation
parentf6cc746bbb3b8a8ceb8514a7906ba582607a8cf7 (diff)
downloadop-kernel-dev-7e325d3a6b117c7288bfc0755410e9d9d2b71326.zip
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update Documentation/filesystems/Locking
The rules for locking in many superblock operations has changed significantly, so update the documentation for it. Also correct some older updates and ommissions. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/filesystems/Locking43
1 files changed, 22 insertions, 21 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 229d7b7..18b9d0c 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -109,27 +109,28 @@ prototypes:
locking rules:
All may block.
- BKL s_lock s_umount
-alloc_inode: no no no
-destroy_inode: no
-dirty_inode: no (must not sleep)
-write_inode: no
-drop_inode: no !!!inode_lock!!!
-delete_inode: no
-put_super: yes yes no
-write_super: no yes read
-sync_fs: no no read
-freeze_fs: ?
-unfreeze_fs: ?
-statfs: no no no
-remount_fs: yes yes maybe (see below)
-clear_inode: no
-umount_begin: yes no no
-show_options: no (vfsmount->sem)
-quota_read: no no no (see below)
-quota_write: no no no (see below)
-
-->remount_fs() will have the s_umount lock if it's already mounted.
+ None have BKL
+ s_umount
+alloc_inode:
+destroy_inode:
+dirty_inode: (must not sleep)
+write_inode:
+drop_inode: !!!inode_lock!!!
+delete_inode:
+put_super: write
+write_super: read
+sync_fs: read
+freeze_fs: read
+unfreeze_fs: read
+statfs: no
+remount_fs: maybe (see below)
+clear_inode:
+umount_begin: no
+show_options: no (namespace_sem)
+quota_read: no (see below)
+quota_write: no (see below)
+
+->remount_fs() will have the s_umount exclusive lock if it's already mounted.
When called from get_sb_single, it does NOT have the s_umount lock.
->quota_read() and ->quota_write() functions are both guaranteed to
be the only ones operating on the quota file by the quota code (via
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