kernel.git/fs/gfs2, branch linux-4.4.y

gfs2: Don't call dlm after protocol is unmounted

2021-09-22T09:41:26Z

[ Upstream commit d1340f80f0b8066321b499a376780da00560e857 ] In the gfs2 withdraw sequence, the dlm protocol is unmounted with a call to lm_unmount. After a withdraw, users are allowed to unmount the withdrawn file system. But at that point we may still have glocks left over that we need to free via unmount's call to gfs2_gl_hash_clear. These glocks may have never been completed because of whatever problem caused the withdraw (IO errors or whatever). Before this patch, function gdlm_put_lock would still try to call into dlm to unlock these leftover glocks, which resulted in dlm returning -EINVAL because the lock space was abandoned. These glocks were never freed because there was no mechanism after that to free them. This patch adds a check to gdlm_put_lock to see if the locking protocol was inactive (DFL_UNMOUNT flag) and if so, free the glock and not make the invalid call into dlm. I could have combined this "if" with the one that follows, related to leftover glock LVBs, but I felt the code was more readable with its own if clause. Signed-off-by: Bob Peterson Signed-off-by: Sasha Levin

gfs2: Fix use-after-free in gfs2_glock_shrink_scan

2021-06-30T12:49:30Z

[ Upstream commit 1ab19c5de4c537ec0d9b21020395a5b5a6c059b2 ] The GLF_LRU flag is checked under lru_lock in gfs2_glock_remove_from_lru() to remove the glock from the lru list in __gfs2_glock_put(). On the shrink scan path, the same flag is cleared under lru_lock but because of cond_resched_lock(&lru_lock) in gfs2_dispose_glock_lru(), progress on the put side can be made without deleting the glock from the lru list. Keep GLF_LRU across the race window opened by cond_resched_lock(&lru_lock) to ensure correct behavior on both sides - clear GLF_LRU after list_del under lru_lock. Reported-by: syzbot Signed-off-by: Hillf Danton Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: Don't skip dlm unlock if glock has an lvb

2021-03-03T15:44:23Z

commit 78178ca844f0eb88f21f31c7fde969384be4c901 upstream. Patch fb6791d100d1 was designed to allow gfs2 to unmount quicker by skipping the step where it tells dlm to unlock glocks in EX with lvbs. This was done because when gfs2 unmounts a file system, it destroys the dlm lockspace shortly after it destroys the glocks so it doesn't need to unlock them all: the unlock is implied when the lockspace is destroyed by dlm. However, that patch introduced a use-after-free in dlm: as part of its normal dlm_recoverd process, it can call ls_recovery to recover dead locks. In so doing, it can call recover_rsbs which calls recover_lvb for any mastered rsbs. Func recover_lvb runs through the list of lkbs queued to the given rsb (if the glock is cached but unlocked, it will still be queued to the lkb, but in NL--Unlocked--mode) and if it has an lvb, copies it to the rsb, thus trying to preserve the lkb. However, when gfs2 skips the dlm unlock step, it frees the glock and its lvb, which means dlm's function recover_lvb references the now freed lvb pointer, copying the freed lvb memory to the rsb. This patch changes the check in gdlm_put_lock so that it calls dlm_unlock for all glocks that contain an lvb pointer. Fixes: fb6791d100d1 ("GFS2: skip dlm_unlock calls in unmount") Cc: stable@vger.kernel.org # v3.8+ Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Greg Kroah-Hartman

gfs2: check for empty rgrp tree in gfs2_ri_update

2020-12-11T12:36:46Z

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

2020-11-18T17:24:59Z

[ 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: Free rd_bits later in gfs2_clear_rgrpd to fix use-after-free

2020-11-18T17:24:59Z

[ Upstream commit d0f17d3883f1e3f085d38572c2ea8edbd5150172 ] Function gfs2_clear_rgrpd calls kfree(rgd->rd_bits) before calling return_all_reservations, but return_all_reservations still dereferences rgd->rd_bits in __rs_deltree. Fix that by moving the call to kfree below the call to return_all_reservations. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: Wake up when sd_glock_disposal becomes zero

2020-11-18T17:24:57Z

[ Upstream commit da7d554f7c62d0c17c1ac3cc2586473c2d99f0bd ] Commit fc0e38dae645 ("GFS2: Fix glock deallocation race") fixed a sd_glock_disposal accounting bug by adding a missing atomic_dec statement, but it failed to wake up sd_glock_wait when that decrement causes sd_glock_disposal to reach zero. As a consequence, gfs2_gl_hash_clear can now run into a 10-minute timeout instead of being woken up. Add the missing wakeup. Fixes: fc0e38dae645 ("GFS2: Fix glock deallocation race") Cc: stable@vger.kernel.org # v2.6.39+ Signed-off-by: Alexander Aring Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: add validation checks for size of superblock

2020-11-10T09:22:14Z

[ Upstream commit 0ddc5154b24c96f20e94d653b0a814438de6032b ] In gfs2_check_sb(), no validation checks are performed with regards to the size of the superblock. syzkaller detected a slab-out-of-bounds bug that was primarily caused because the block size for a superblock was set to zero. A valid size for a superblock is a power of 2 between 512 and PAGE_SIZE. Performing validation checks and ensuring that the size of the superblock is valid fixes this bug. Reported-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com Tested-by: syzbot+af90d47a37376844e731@syzkaller.appspotmail.com Suggested-by: Andrew Price Signed-off-by: Anant Thazhemadam [Minor code reordering.] Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

gfs2: Allow lock_nolock mount to specify jid=X

2020-06-30T00:07:53Z

[ Upstream commit ea22eee4e6027d8927099de344f7fff43c507ef9 ] Before this patch, a simple typo accidentally added \n to the jid= string for lock_nolock mounts. This made it impossible to mount a gfs2 file system with a journal other than journal0. Thus: mount -tgfs2 -o hostdata="jid=1" Resulted in: mount: wrong fs type, bad option, bad superblock on In most cases this is not a problem. However, for debugging and testing purposes we sometimes want to test the integrity of other journals. This patch removes the unnecessary \n and thus allows lock_nolock users to specify an alternate journal. Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher Signed-off-by: Sasha Levin

Revert "gfs2: Don't demote a glock until its revokes are written"

2020-05-27T14:40:33Z

[ Upstream commit b14c94908b1b884276a6608dea3d0b1b510338b7 ] This reverts commit df5db5f9ee112e76b5202fbc331f990a0fc316d6. This patch fixes a regression: patch df5db5f9ee112 allowed function run_queue() to bypass its call to do_xmote() if revokes were queued for the glock. That's wrong because its call to do_xmote() is what is responsible for calling the go_sync() glops functions to sync both the ail list and any revokes queued for it. By bypassing the call, gfs2 could get into a stand-off where the glock could not be demoted until its revokes are written back, but the revokes would not be written back because do_xmote() was never called. It "sort of" works, however, because there are other mechanisms like the log flush daemon (logd) that can sync the ail items and revokes, if it deems it necessary. The problem is: without file system pressure, it might never deem it necessary. Signed-off-by: Bob Peterson Signed-off-by: Sasha Levin