linux/fs/gfs2
Andreas Gruenbacher 20f829999c gfs2: Rework read and page fault locking
So far, gfs2 has taken the inode glocks inside the ->readpage and
->readahead address space operations.  Since commit d4388340ae ("fs:
convert mpage_readpages to mpage_readahead"), gfs2_readahead is passed
the pages to read ahead locked.  With that, the current holder of the
inode glock may be trying to lock one of those pages while
gfs2_readahead is trying to take the inode glock, resulting in a
deadlock.

Fix that by moving the lock taking to the higher-level ->read_iter file
and ->fault vm operations.  This also gets rid of an ugly lock inversion
workaround in gfs2_readpage.

The cache consistency model of filesystems like gfs2 is such that if
data is found in the page cache, the data is up to date and can be used
without taking any filesystem locks.  If a page is not cached,
filesystem locks must be taken before populating the page cache.

To avoid taking the inode glock when the data is already cached,
gfs2_file_read_iter first tries to read the data with the IOCB_NOIO flag
set.  If that fails, the inode glock is taken and the operation is
retried with the IOCB_NOIO flag cleared.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-07-07 23:40:12 +02:00
..
Kconfig treewide: Add SPDX license identifier - Makefile/Kconfig 2019-05-21 10:50:46 +02:00
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
acl.c gfs2: Change inode qa_data to allow multiple users 2020-03-27 14:08:04 -05:00
acl.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
aops.c gfs2: Rework read and page fault locking 2020-07-07 23:40:12 +02:00
aops.h gfs2: mark stuffed_readpage static 2019-07-03 14:45:18 +02:00
bmap.c gfs2: Another gfs2_walk_metadata fix 2020-05-08 15:15:12 +02:00
bmap.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
dentry.c gfs2: untangle the logic in gfs2_drevalidate 2019-09-03 09:42:41 +02:00
dir.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
dir.h gfs2: Delete an unnecessary check before brelse() 2019-09-04 20:22:17 +02:00
export.c gfs2: Minor gfs2_lookup_by_inum cleanup 2020-06-05 20:19:21 +02:00
file.c gfs2: Rework read and page fault locking 2020-07-07 23:40:12 +02:00
gfs2.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
glock.c gfs2: Don't sleep during glock hash walk 2020-06-30 13:04:45 +02:00
glock.h Merge branch 'gfs2-iopen' into for-next 2020-06-05 21:25:36 +02:00
glops.c gfs2: freeze should work on read-only mounts 2020-07-03 12:05:35 +02:00
glops.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
incore.h gfs2: eliminate GIF_ORDERED in favor of list_empty 2020-07-03 12:05:34 +02:00
inode.c gfs2: Don't return NULL from gfs2_inode_lookup 2020-06-30 13:04:45 +02:00
inode.h gfs2: Minor gfs2_lookup_by_inum cleanup 2020-06-05 20:19:21 +02:00
lock_dlm.c gfs2: Force withdraw to replay journals and wait for it to finish 2020-02-27 07:53:12 -06:00
log.c gfs2: eliminate GIF_ORDERED in favor of list_empty 2020-07-03 12:05:34 +02:00
log.h gfs2: eliminate GIF_ORDERED in favor of list_empty 2020-07-03 12:05:34 +02:00
lops.c gfs2: Even more gfs2_find_jhead fixes 2020-05-29 17:00:24 +02:00
lops.h gfs2: Remove active journal side effect from gfs2_write_log_header 2019-11-12 15:17:53 +01:00
main.c gfs2: eliminate GIF_ORDERED in favor of list_empty 2020-07-03 12:05:34 +02:00
meta_io.c gfs2: fix withdraw sequence deadlock 2020-05-06 21:25:26 +02:00
meta_io.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
ops_fstype.c gfs2: The freeze glock should never be frozen 2020-07-03 12:05:35 +02:00
quota.c mm: remove the pgprot argument to __vmalloc 2020-06-02 10:59:11 -07:00
quota.h gfs2: move privileged user check to gfs2_quota_lock_check 2020-05-08 18:47:58 +02:00
recovery.c gfs2: When freezing gfs2, use GL_EXACT and not GL_NOCACHE 2020-07-03 12:05:35 +02:00
recovery.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
rgrp.c gfs2: Turn gl_delete into a delayed work 2020-06-05 20:19:21 +02:00
rgrp.h gfs2: Split gfs2_rsqa_delete into gfs2_rs_delete and gfs2_qa_put 2020-03-27 14:08:04 -05:00
super.c gfs2: The freeze glock should never be frozen 2020-07-03 12:05:35 +02:00
super.h gfs2: Force withdraw to replay journals and wait for it to finish 2020-02-27 07:53:12 -06:00
sys.c gfs2: Force withdraw to replay journals and wait for it to finish 2020-02-27 07:53:12 -06:00
sys.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00
trace_gfs2.h gfs2: eliminate rs_inum and reduce the size of gfs2 inodes 2018-06-21 07:39:31 -05:00
trans.c gfs2: new slab for transactions 2020-06-05 21:24:25 +02:00
trans.h gfs2: new slab for transactions 2020-06-05 21:24:25 +02:00
util.c gfs2: new slab for transactions 2020-06-05 21:24:25 +02:00
util.h gfs2: new slab for transactions 2020-06-05 21:24:25 +02:00
xattr.c gfs2: Change inode qa_data to allow multiple users 2020-03-27 14:08:04 -05:00
xattr.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 398 2019-06-05 17:37:12 +02:00