kernel/git/stable/linux.git/fs/gfs2, branch linux-5.9.y

gfs2: Don't freeze the file system during unmount

2020-12-11T12:22:12+00:00

commit f39e7d3aae2934b1cfdd209b54c508e2552e9531 upstream. GFS2's freeze/thaw mechanism uses a special freeze glock to control its operation. It does this with a sync glock operation (glops.c) called freeze_go_sync. When the freeze glock is demoted (glock's do_xmote) the glops function causes the file system to be frozen. This is intended. However, GFS2's mount and unmount processes also hold the freeze glock to prevent other processes, perhaps on different cluster nodes, from mounting the frozen file system in read-write mode. Before this patch, there was no check in freeze_go_sync for whether a freeze in intended or whether the glock demote was caused by a normal unmount. So it was trying to freeze the file system it's trying to unmount, which ends up in a deadlock. This patch adds an additional check to freeze_go_sync so that demotes of the freeze glock are ignored if they come from the unmount process. Fixes: 20b329129009 ("gfs2: Fix regression in freeze_go_sync") Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Fix deadlock dumping resource group glocks

2020-12-11T12:22:12+00:00

commit 16e6281b6b22b0178eab95c6a82502d7b10f67b8 upstream. Commit 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") introduced additional locking in gfs2_rgrp_go_dump, which is also used for dumping resource group glocks via debugfs. However, on that code path, the glock spin lock is already taken in dump_glock, and taking it again in gfs2_glock2rgrp leads to deadlock. This can be reproduced with: $ mkfs.gfs2 -O -p lock_nolock /dev/FOO $ mount /dev/FOO /mnt/foo $ touch /mnt/foo/bar $ cat /sys/kernel/debug/gfs2/FOO/glocks Fix that by not taking the glock spin lock inside the go_dump callback. Fixes: 0e539ca1bbbe ("gfs2: Fix NULL pointer dereference in gfs2_rgrp_dump") Signed-off-by: Alexander Aring Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: check for empty rgrp tree in gfs2_ri_update

2020-12-11T12:22:11+00:00

commit 778721510e84209f78e31e2ccb296ae36d623f5e upstream. If gfs2 tries to mount a (corrupt) file system that has no resource groups it still tries to set preferences on the first one, which causes a kernel null pointer dereference. This patch adds a check to function gfs2_ri_update so this condition is detected and reported back as an error. Reported-by: syzbot+e3f23ce40269a4c9053a@syzkaller.appspotmail.com Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Fix deadlock between gfs2_{create_inode,inode_lookup} and delete_work_func

2020-12-11T12:22:07+00:00

commit dd0ecf544125639e54056d851e4887dbb94b6d2f upstream. In gfs2_create_inode and gfs2_inode_lookup, make sure to cancel any pending delete work before taking the inode glock. Otherwise, gfs2_cancel_delete_work may block waiting for delete_work_func to complete, and delete_work_func may block trying to acquire the inode glock in gfs2_inode_lookup. Reported-by: Alexander Aring Fixes: a0e3cc65fa29 ("gfs2: Turn gl_delete into a delayed work") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Upgrade shared glocks for atime updates

2020-12-11T12:22:07+00:00

commit 82e938bd5382b322ce81e6cb8fd030987f2da022 upstream. Commit 20f829999c38 ("gfs2: Rework read and page fault locking") lifted the glock lock taking from the low-level ->readpage and ->readahead address space operations to the higher-level ->read_iter file and ->fault vm operations. The glocks are still taken in LM_ST_SHARED mode only. On filesystems mounted without the noatime option, ->read_iter sometimes needs to update the atime as well, though. Right now, this leads to a failed locking mode assertion in gfs2_dirty_inode. Fix that by introducing a new update_time inode operation. There, if the glock is held non-exclusively, upgrade it to an exclusive lock. Reported-by: Alexander Aring Fixes: 20f829999c38 ("gfs2: Rework read and page fault locking") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Fix regression in freeze_go_sync

2020-11-24T12:39:12+00:00

commit 20b329129009caf1c646152abe09b697227e1c37 upstream. Patch 541656d3a513 ("gfs2: freeze should work on read-only mounts") changed the check for glock state in function freeze_go_sync() from "gl->gl_state == LM_ST_SHARED" to "gl->gl_req == LM_ST_EXCLUSIVE". That's wrong and it regressed gfs2's freeze/thaw mechanism because it caused only the freezing node (which requests the glock in EX) to queue freeze work. All nodes go through this go_sync code path during the freeze to drop their SHared hold on the freeze glock, allowing the freezing node to acquire it in EXclusive mode. But all the nodes must freeze access to the file system locally, so they ALL must queue freeze work. The freeze_work calls freeze_func, which makes a request to reacquire the freeze glock in SH, effectively blocking until the thaw from the EX holder. Once thawed, the freezing node drops its EX hold on the freeze glock, then the (blocked) freeze_func reacquires the freeze glock in SH again (on all nodes, including the freezer) so all nodes go back to a thawed state. This patch changes the check back to gl_state == LM_ST_SHARED like it was prior to 541656d3a513. Fixes: 541656d3a513 ("gfs2: freeze should work on read-only mounts") Cc: stable@vger.kernel.org # v5.8+ Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: Fix case in which ail writes are done to jdata holes

2020-11-24T12:38:54+00:00

[ Upstream commit 4e79e3f08e576acd51dffb4520037188703238b3 ] Patch b2a846dbef4e ("gfs2: Ignore journal log writes for jdata holes") tried (unsuccessfully) to fix a case in which writes were done to jdata blocks, the blocks are sent to the ail list, then a punch_hole or truncate operation caused the blocks to be freed. In other words, the ail items are for jdata holes. Before b2a846dbef4e, the jdata hole caused function gfs2_block_map to return -EIO, which was eventually interpreted as an IO error to the journal, and then withdraw. This patch changes function gfs2_get_block_noalloc, which is only used for jdata writes, so it returns -ENODATA rather than -EIO, and when -ENODATA is returned to gfs2_ail1_start_one, the error is ignored. We can safely ignore it because gfs2_ail1_start_one is only called when the jdata pages have already been written and truncated, so the ail1 content no longer applies. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: fix possible reference leak in gfs2_check_blk_type

2020-11-24T12:38:53+00:00

[ Upstream commit bc923818b190c8b63c91a47702969c8053574f5b ] In the fail path of gfs2_check_blk_type, forgetting to call gfs2_glock_dq_uninit will result in rgd_gh reference leak. Signed-off-by: Zhang Qilong Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: check for live vs. read-only file system in gfs2_fitrim

2020-11-18T18:22:10+00:00

[ Upstream commit c5c68724696e7d2f8db58a5fce3673208d35c485 ] Before this patch, gfs2_fitrim was not properly checking for a "live" file system. If the file system had something to trim and the file system was read-only (or spectator) it would start the trim, but when it starts the transaction, gfs2_trans_begin returns -EROFS (read-only file system) and it errors out. However, if the file system was already trimmed so there's no work to do, it never called gfs2_trans_begin. That code is bypassed so it never returns the error. Instead, it returns a good return code with 0 work. All this makes for inconsistent behavior: The same fstrim command can return -EROFS in one case and 0 in another. This tripped up xfstests generic/537 which reports the error as: +fstrim with unrecovered metadata just ate your filesystem This patch adds a check for a "live" (iow, active journal, iow, RW) file system, and if not, returns the error properly. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: Add missing truncate_inode_pages_final for sd_aspace

2020-11-18T18:22:10+00:00

[ Upstream commit a9dd945ccef07a904e412f208f8de708a3d7159e ] Gfs2 creates an address space for its rgrps called sd_aspace, but it never called truncate_inode_pages_final on it. This confused vfs greatly which tried to reference the address space after gfs2 had freed the superblock that contained it. This patch adds a call to truncate_inode_pages_final for sd_aspace, thus avoiding the use-after-free. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin