diff options
| author | Jeff Layton <jlayton@redhat.com> | 2009-09-21 06:47:50 -0400 |
|---|---|---|
| committer | Steve French <sfrench@us.ibm.com> | 2009-09-24 18:33:18 +0000 |
| commit | 3bc303c254335dbd7c7012cc1760b12f1d5514d3 (patch) | |
| tree | 7da17fbfd697216d9ed0ccd64ea9c03aaf3d52c1 /fs/cifs/Kconfig | |
| parent | 48541bd3dd4739b4d574b44ea47660c88d833677 (diff) | |
| download | lwn-3bc303c254335dbd7c7012cc1760b12f1d5514d3.tar.gz lwn-3bc303c254335dbd7c7012cc1760b12f1d5514d3.zip | |
cifs: convert oplock breaks to use slow_work facility (try #4)
This is the fourth respin of the patch to convert oplock breaks to
use the slow_work facility.
A customer of ours was testing a backport of one of the earlier
patchsets, and hit a "Busy inodes after umount..." problem. An oplock
break job had raced with a umount, and the superblock got torn down and
its memory reused. When the oplock break job tried to dereference the
inode->i_sb, the kernel oopsed.
This patchset has the oplock break job hold an inode and vfsmount
reference until the oplock break completes. With this, there should be
no need to take a tcon reference (the vfsmount implicitly holds one
already).
Currently, when an oplock break comes in there's a chance that the
oplock break job won't occur if the allocation of the oplock_q_entry
fails. There are also some rather nasty races in the allocation and
handling these structs.
Rather than allocating oplock queue entries when an oplock break comes
in, add a few extra fields to the cifsFileInfo struct. Get rid of the
dedicated cifs_oplock_thread as well and queue the oplock break job to
the slow_work thread pool.
This approach also has the advantage that the oplock break jobs can
potentially run in parallel rather than be serialized like they are
today.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
Diffstat (limited to 'fs/cifs/Kconfig')
| -rw-r--r-- | fs/cifs/Kconfig | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig index 6994a0f54f02..80f352596807 100644 --- a/fs/cifs/Kconfig +++ b/fs/cifs/Kconfig @@ -2,6 +2,7 @@ config CIFS tristate "CIFS support (advanced network filesystem, SMBFS successor)" depends on INET select NLS + select SLOW_WORK help This is the client VFS module for the Common Internet File System (CIFS) protocol which is the successor to the Server Message Block |