From 7e325d3a6b117c7288bfc0755410e9d9d2b71326 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Fri, 19 Jun 2009 20:22:37 +0200 Subject: 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 Signed-off-by: Al Viro --- Documentation/filesystems/Locking | 43 ++++++++++++++++++++------------------- 1 file changed, 22 insertions(+), 21 deletions(-) (limited to 'Documentation') diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 229d7b7c50a3..18b9d0ca0630 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 -- cgit v1.2.3-58-ga151