linux-stable.git/fs, branch v5.7.5 Linux kernel stable tree f2fs: fix checkpoint=disable:%u%% 2020-06-22T07:33:12+00:00 Jaegeuk Kim jaegeuk@kernel.org 2020-05-16T00:20:50+00:00 98a27816066d658712ecca3c82c2d921f5492c77 commit 1ae18f71cb522684bac1718f5c188fb5e30eb23d upstream. When parsing the mount option, we don't have sbi->user_block_count. Should do it after getting it. Cc: <stable@vger.kernel.org> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1ae18f71cb522684bac1718f5c188fb5e30eb23d upstream.

When parsing the mount option, we don't have sbi->user_block_count.
Should do it after getting it.

Cc: <stable@vger.kernel.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
f2fs: don't leak filename in f2fs_try_convert_inline_dir() 2020-06-22T07:33:11+00:00 Eric Biggers ebiggers@google.com 2020-05-07T07:59:02+00:00 77fb2cd99caec5885382753876448bec416aefb2 commit ff5f85c8d62a487bde415ef4c9e2d0be718021df upstream. We need to call fscrypt_free_filename() to free the memory allocated by fscrypt_setup_filename(). Fixes: b06af2aff28b ("f2fs: convert inline_dir early before starting rename") Cc: <stable@vger.kernel.org> # v5.6+ Signed-off-by: Eric Biggers <ebiggers@google.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit ff5f85c8d62a487bde415ef4c9e2d0be718021df upstream.

We need to call fscrypt_free_filename() to free the memory allocated by
fscrypt_setup_filename().

Fixes: b06af2aff28b ("f2fs: convert inline_dir early before starting rename")
Cc: <stable@vger.kernel.org> # v5.6+
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
jbd2: avoid leaking transaction credits when unreserving handle 2020-06-22T07:33:06+00:00 Jan Kara jack@suse.cz 2020-05-20T13:31:19+00:00 fe75b26dd966c803f88c21773f6384091f928a20 commit 14ff6286309e2853aed50083c9a83328423fdd8c upstream. When reserved transaction handle is unused, we subtract its reserved credits in __jbd2_journal_unreserve_handle() called from jbd2_journal_stop(). However this function forgets to remove reserved credits from transaction->t_outstanding_credits and thus the transaction space that was reserved remains effectively leaked. The leaked transaction space can be quite significant in some cases and leads to unnecessarily small transactions and thus reducing throughput of the journalling machinery. E.g. fsmark workload creating lots of 4k files was observed to have about 20% lower throughput due to this when ext4 is mounted with dioread_nolock mount option. Subtract reserved credits from t_outstanding_credits as well. CC: stable@vger.kernel.org Fixes: 8f7d89f36829 ("jbd2: transaction reservation support") Reviewed-by: Andreas Dilger <adilger@dilger.ca> Signed-off-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/20200520133119.1383-3-jack@suse.cz Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 14ff6286309e2853aed50083c9a83328423fdd8c upstream.

When reserved transaction handle is unused, we subtract its reserved
credits in __jbd2_journal_unreserve_handle() called from
jbd2_journal_stop(). However this function forgets to remove reserved
credits from transaction->t_outstanding_credits and thus the transaction
space that was reserved remains effectively leaked. The leaked
transaction space can be quite significant in some cases and leads to
unnecessarily small transactions and thus reducing throughput of the
journalling machinery. E.g. fsmark workload creating lots of 4k files
was observed to have about 20% lower throughput due to this when ext4 is
mounted with dioread_nolock mount option.

Subtract reserved credits from t_outstanding_credits as well.

CC: stable@vger.kernel.org
Fixes: 8f7d89f36829 ("jbd2: transaction reservation support")
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200520133119.1383-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: fix race between ext4_sync_parent() and rename() 2020-06-22T07:32:58+00:00 Eric Biggers ebiggers@google.com 2020-05-06T18:31:40+00:00 3f214faa09d65eb30cc8ef5d4d65c51f462e869e commit 08adf452e628b0e2ce9a01048cfbec52353703d7 upstream. 'igrab(d_inode(dentry->d_parent))' without holding dentry->d_lock is broken because without d_lock, d_parent can be concurrently changed due to a rename(). Then if the old directory is immediately deleted, old d_parent->inode can be NULL. That causes a NULL dereference in igrab(). To fix this, use dget_parent() to safely grab a reference to the parent dentry, which pins the inode. This also eliminates the need to use d_find_any_alias() other than for the initial inode, as we no longer throw away the dentry at each step. This is an extremely hard race to hit, but it is possible. Adding a udelay() in between the reads of ->d_parent and its ->d_inode makes it reproducible on a no-journal filesystem using the following program: #include <fcntl.h> #include <unistd.h> int main() { if (fork()) { for (;;) { mkdir("dir1", 0700); int fd = open("dir1/file", O_RDWR|O_CREAT|O_SYNC); write(fd, "X", 1); close(fd); } } else { mkdir("dir2", 0700); for (;;) { rename("dir1/file", "dir2/file"); rmdir("dir1"); } } } Fixes: d59729f4e794 ("ext4: fix races in ext4_sync_parent()") Cc: stable@vger.kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com> Link: https://lore.kernel.org/r/20200506183140.541194-1-ebiggers@kernel.org Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 08adf452e628b0e2ce9a01048cfbec52353703d7 upstream.

'igrab(d_inode(dentry->d_parent))' without holding dentry->d_lock is
broken because without d_lock, d_parent can be concurrently changed due
to a rename().  Then if the old directory is immediately deleted, old
d_parent->inode can be NULL.  That causes a NULL dereference in igrab().

To fix this, use dget_parent() to safely grab a reference to the parent
dentry, which pins the inode.  This also eliminates the need to use
d_find_any_alias() other than for the initial inode, as we no longer
throw away the dentry at each step.

This is an extremely hard race to hit, but it is possible.  Adding a
udelay() in between the reads of ->d_parent and its ->d_inode makes it
reproducible on a no-journal filesystem using the following program:

    #include <fcntl.h>
    #include <unistd.h>

    int main()
    {
        if (fork()) {
            for (;;) {
                mkdir("dir1", 0700);
                int fd = open("dir1/file", O_RDWR|O_CREAT|O_SYNC);
                write(fd, "X", 1);
                close(fd);
            }
        } else {
            mkdir("dir2", 0700);
            for (;;) {
                rename("dir1/file", "dir2/file");
                rmdir("dir1");
            }
        }
    }

Fixes: d59729f4e794 ("ext4: fix races in ext4_sync_parent()")
Cc: stable@vger.kernel.org
Signed-off-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20200506183140.541194-1-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: fix error pointer dereference 2020-06-22T07:32:58+00:00 Jeffle Xu jefflexu@linux.alibaba.com 2020-04-23T07:46:44+00:00 53e67b64ba22a26f624dd92487806e42fd20621f commit 8418897f1bf87da0cb6936489d57a4320c32c0af upstream. Don't pass error pointers to brelse(). commit 7159a986b420 ("ext4: fix some error pointer dereferences") has fixed some cases, fix the remaining one case. Once ext4_xattr_block_find()->ext4_sb_bread() failed, error pointer is stored in @bs->bh, which will be passed to brelse() in the cleanup routine of ext4_xattr_set_handle(). This will then cause a NULL panic crash in __brelse(). BUG: unable to handle kernel NULL pointer dereference at 000000000000005b RIP: 0010:__brelse+0x1b/0x50 Call Trace: ext4_xattr_set_handle+0x163/0x5d0 ext4_xattr_set+0x95/0x110 __vfs_setxattr+0x6b/0x80 __vfs_setxattr_noperm+0x68/0x1b0 vfs_setxattr+0xa0/0xb0 setxattr+0x12c/0x1a0 path_setxattr+0x8d/0xc0 __x64_sys_setxattr+0x27/0x30 do_syscall_64+0x60/0x250 entry_SYSCALL_64_after_hwframe+0x49/0xbe In this case, @bs->bh stores '-EIO' actually. Fixes: fb265c9cb49e ("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases") Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: stable@kernel.org # 2.6.19 Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Jan Kara <jack@suse.cz> Link: https://lore.kernel.org/r/1587628004-95123-1-git-send-email-jefflexu@linux.alibaba.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 8418897f1bf87da0cb6936489d57a4320c32c0af upstream.

Don't pass error pointers to brelse().

commit 7159a986b420 ("ext4: fix some error pointer dereferences") has fixed
some cases, fix the remaining one case.

Once ext4_xattr_block_find()->ext4_sb_bread() failed, error pointer is
stored in @bs->bh, which will be passed to brelse() in the cleanup
routine of ext4_xattr_set_handle(). This will then cause a NULL panic
crash in __brelse().

BUG: unable to handle kernel NULL pointer dereference at 000000000000005b
RIP: 0010:__brelse+0x1b/0x50
Call Trace:
 ext4_xattr_set_handle+0x163/0x5d0
 ext4_xattr_set+0x95/0x110
 __vfs_setxattr+0x6b/0x80
 __vfs_setxattr_noperm+0x68/0x1b0
 vfs_setxattr+0xa0/0xb0
 setxattr+0x12c/0x1a0
 path_setxattr+0x8d/0xc0
 __x64_sys_setxattr+0x27/0x30
 do_syscall_64+0x60/0x250
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

In this case, @bs->bh stores '-EIO' actually.

Fixes: fb265c9cb49e ("ext4: add ext4_sb_bread() to disambiguate ENOMEM cases")
Signed-off-by: Jeffle Xu <jefflexu@linux.alibaba.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: stable@kernel.org # 2.6.19
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/1587628004-95123-1-git-send-email-jefflexu@linux.alibaba.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: fix buffer_head refcnt leak when ext4_iget() fails 2020-06-22T07:32:58+00:00 Xiyu Yang xiyuyang19@fudan.edu.cn 2020-04-23T05:09:27+00:00 e83c4df0ddaa06fb42384053956f46501816777d commit 3bbd0ef26098d241dc59ee77ba14b7dab0df0786 upstream. ext4_orphan_get() invokes ext4_read_inode_bitmap(), which returns a reference of the specified buffer_head object to "bitmap_bh" with increased refcnt. When ext4_orphan_get() returns, local variable "bitmap_bh" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of ext4_orphan_get(). When ext4_iget() fails, the function forgets to decrease the refcnt increased by ext4_read_inode_bitmap(), causing a refcnt leak. Fix this issue by calling brelse() when ext4_iget() fails. Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Cc: stable@kernel.org Link: https://lore.kernel.org/r/1587618568-13418-1-git-send-email-xiyuyang19@fudan.edu.cn Signed-off-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 3bbd0ef26098d241dc59ee77ba14b7dab0df0786 upstream.

ext4_orphan_get() invokes ext4_read_inode_bitmap(), which returns a
reference of the specified buffer_head object to "bitmap_bh" with
increased refcnt.

When ext4_orphan_get() returns, local variable "bitmap_bh" becomes
invalid, so the refcount should be decreased to keep refcount balanced.

The reference counting issue happens in one exception handling path of
ext4_orphan_get(). When ext4_iget() fails, the function forgets to
decrease the refcnt increased by ext4_read_inode_bitmap(), causing a
refcnt leak.

Fix this issue by calling brelse() when ext4_iget() fails.

Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn>
Signed-off-by: Xin Tan <tanxin.ctf@gmail.com>
Cc: stable@kernel.org
Link: https://lore.kernel.org/r/1587618568-13418-1-git-send-email-xiyuyang19@fudan.edu.cn
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ext4: fix EXT_MAX_EXTENT/INDEX to check for zeroed eh_max 2020-06-22T07:32:58+00:00 Harshad Shirwadkar harshadshirwadkar@gmail.com 2020-04-21T02:39:59+00:00 b1e1a430cf7c44181004c41389a464fca776da64 commit c36a71b4e35ab35340facdd6964a00956b9fef0a upstream. If eh->eh_max is 0, EXT_MAX_EXTENT/INDEX would evaluate to unsigned (-1) resulting in illegal memory accesses. Although there is no consistent repro, we see that generic/019 sometimes crashes because of this bug. Ran gce-xfstests smoke and verified that there were no regressions. Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com> Link: https://lore.kernel.org/r/20200421023959.20879-2-harshadshirwadkar@gmail.com Signed-off-by: Theodore Ts'o <tytso@mit.edu> Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit c36a71b4e35ab35340facdd6964a00956b9fef0a upstream.

If eh->eh_max is 0, EXT_MAX_EXTENT/INDEX would evaluate to unsigned
(-1) resulting in illegal memory accesses. Although there is no
consistent repro, we see that generic/019 sometimes crashes because of
this bug.

Ran gce-xfstests smoke and verified that there were no regressions.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20200421023959.20879-2-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
btrfs: fix space_info bytes_may_use underflow during space cache writeout 2020-06-22T07:32:56+00:00 Filipe Manana fdmanana@suse.com 2020-05-27T10:16:19+00:00 75cd096eca2dee1174e06f626b102eaf5a16558b commit 2166e5edce9ac1edf3b113d6091ef72fcac2d6c4 upstream. We always preallocate a data extent for writing a free space cache, which causes writeback to always try the nocow path first, since the free space inode has the prealloc bit set in its flags. However if the block group that contains the data extent for the space cache has been turned to RO mode due to a running scrub or balance for example, we have to fallback to the cow path. In that case once a new data extent is allocated we end up calling btrfs_add_reserved_bytes(), which decrements the counter named bytes_may_use from the data space_info object with the expection that this counter was previously incremented with the same amount (the size of the data extent). However when we started writeout of the space cache at cache_save_setup(), we incremented the value of the bytes_may_use counter through a call to btrfs_check_data_free_space() and then decremented it through a call to btrfs_prealloc_file_range_trans() immediately after. So when starting the writeback if we fallback to cow mode we have to increment the counter bytes_may_use of the data space_info again to compensate for the extent allocation done by the cow path. When this issue happens we are incorrectly decrementing the bytes_may_use counter and when its current value is smaller then the amount we try to subtract we end up with the following warning: ------------[ cut here ]------------ WARNING: CPU: 3 PID: 657 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs] Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...) CPU: 3 PID: 657 Comm: kworker/u8:7 Tainted: G W 5.6.0-rc7-btrfs-next-58 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Workqueue: writeback wb_workfn (flush-btrfs-1591) RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs] Code: ff ff 48 (...) RSP: 0000:ffffa41608f13660 EFLAGS: 00010287 RAX: 0000000000001000 RBX: ffff9615b93ae400 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9615b96ab410 RBP: fffffffffffee000 R08: 0000000000000001 R09: 0000000000000000 R10: ffff961585e62a40 R11: 0000000000000000 R12: ffff9615b96ab400 R13: ffff9615a1a2a000 R14: 0000000000012000 R15: ffff9615b93ae400 FS: 0000000000000000(0000) GS:ffff9615bb200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055cbbc2ae178 CR3: 0000000115794006 CR4: 00000000003606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_free_extent+0x4a0/0x16c0 [btrfs] btrfs_reserve_extent+0x91/0x180 [btrfs] cow_file_range+0x12d/0x490 [btrfs] btrfs_run_delalloc_range+0x9f/0x6d0 [btrfs] ? find_lock_delalloc_range+0x221/0x250 [btrfs] writepage_delalloc+0xe8/0x150 [btrfs] __extent_writepage+0xe8/0x4c0 [btrfs] extent_write_cache_pages+0x237/0x530 [btrfs] extent_writepages+0x44/0xa0 [btrfs] do_writepages+0x23/0x80 __writeback_single_inode+0x59/0x700 writeback_sb_inodes+0x267/0x5f0 __writeback_inodes_wb+0x87/0xe0 wb_writeback+0x382/0x590 ? wb_workfn+0x4a2/0x6c0 wb_workfn+0x4a2/0x6c0 process_one_work+0x26d/0x6a0 worker_thread+0x4f/0x3e0 ? process_one_work+0x6a0/0x6a0 kthread+0x103/0x140 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x3a/0x50 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020 softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace bd7c03622e0b0a52 ]--- ------------[ cut here ]------------ So fix this by incrementing the bytes_may_use counter of the data space_info when we fallback to the cow path. If the cow path is successful the counter is decremented after extent allocation (by btrfs_add_reserved_bytes()), if it fails it ends up being decremented as well when clearing the delalloc range (extent_clear_unlock_delalloc()). This could be triggered sporadically by the test case btrfs/061 from fstests. Fixes: 82d5902d9c681b ("Btrfs: Support reading/writing on disk free ino cache") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 2166e5edce9ac1edf3b113d6091ef72fcac2d6c4 upstream.

We always preallocate a data extent for writing a free space cache, which
causes writeback to always try the nocow path first, since the free space
inode has the prealloc bit set in its flags.

However if the block group that contains the data extent for the space
cache has been turned to RO mode due to a running scrub or balance for
example, we have to fallback to the cow path. In that case once a new data
extent is allocated we end up calling btrfs_add_reserved_bytes(), which
decrements the counter named bytes_may_use from the data space_info object
with the expection that this counter was previously incremented with the
same amount (the size of the data extent).

However when we started writeout of the space cache at cache_save_setup(),
we incremented the value of the bytes_may_use counter through a call to
btrfs_check_data_free_space() and then decremented it through a call to
btrfs_prealloc_file_range_trans() immediately after. So when starting the
writeback if we fallback to cow mode we have to increment the counter
bytes_may_use of the data space_info again to compensate for the extent
allocation done by the cow path.

When this issue happens we are incorrectly decrementing the bytes_may_use
counter and when its current value is smaller then the amount we try to
subtract we end up with the following warning:

 ------------[ cut here ]------------
 WARNING: CPU: 3 PID: 657 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
 Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
 CPU: 3 PID: 657 Comm: kworker/u8:7 Tainted: G        W         5.6.0-rc7-btrfs-next-58 #5
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
 Workqueue: writeback wb_workfn (flush-btrfs-1591)
 RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
 Code: ff ff 48 (...)
 RSP: 0000:ffffa41608f13660 EFLAGS: 00010287
 RAX: 0000000000001000 RBX: ffff9615b93ae400 RCX: 0000000000000000
 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9615b96ab410
 RBP: fffffffffffee000 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff961585e62a40 R11: 0000000000000000 R12: ffff9615b96ab400
 R13: ffff9615a1a2a000 R14: 0000000000012000 R15: ffff9615b93ae400
 FS:  0000000000000000(0000) GS:ffff9615bb200000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 000055cbbc2ae178 CR3: 0000000115794006 CR4: 00000000003606e0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  find_free_extent+0x4a0/0x16c0 [btrfs]
  btrfs_reserve_extent+0x91/0x180 [btrfs]
  cow_file_range+0x12d/0x490 [btrfs]
  btrfs_run_delalloc_range+0x9f/0x6d0 [btrfs]
  ? find_lock_delalloc_range+0x221/0x250 [btrfs]
  writepage_delalloc+0xe8/0x150 [btrfs]
  __extent_writepage+0xe8/0x4c0 [btrfs]
  extent_write_cache_pages+0x237/0x530 [btrfs]
  extent_writepages+0x44/0xa0 [btrfs]
  do_writepages+0x23/0x80
  __writeback_single_inode+0x59/0x700
  writeback_sb_inodes+0x267/0x5f0
  __writeback_inodes_wb+0x87/0xe0
  wb_writeback+0x382/0x590
  ? wb_workfn+0x4a2/0x6c0
  wb_workfn+0x4a2/0x6c0
  process_one_work+0x26d/0x6a0
  worker_thread+0x4f/0x3e0
  ? process_one_work+0x6a0/0x6a0
  kthread+0x103/0x140
  ? kthread_create_worker_on_cpu+0x70/0x70
  ret_from_fork+0x3a/0x50
 irq event stamp: 0
 hardirqs last  enabled at (0): [<0000000000000000>] 0x0
 hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
 softirqs last  enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
 softirqs last disabled at (0): [<0000000000000000>] 0x0
 ---[ end trace bd7c03622e0b0a52 ]---
 ------------[ cut here ]------------

So fix this by incrementing the bytes_may_use counter of the data
space_info when we fallback to the cow path. If the cow path is successful
the counter is decremented after extent allocation (by
btrfs_add_reserved_bytes()), if it fails it ends up being decremented as
well when clearing the delalloc range (extent_clear_unlock_delalloc()).

This could be triggered sporadically by the test case btrfs/061 from
fstests.

Fixes: 82d5902d9c681b ("Btrfs: Support reading/writing on disk free ino cache")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
btrfs: fix space_info bytes_may_use underflow after nocow buffered write 2020-06-22T07:32:56+00:00 Filipe Manana fdmanana@suse.com 2020-05-27T10:16:07+00:00 6a3e4702368d652201befdfdea4b817ed790faae commit 467dc47ea99c56e966e99d09dae54869850abeeb upstream. When doing a buffered write we always try to reserve data space for it, even when the file has the NOCOW bit set or the write falls into a file range covered by a prealloc extent. This is done both because it is expensive to check if we can do a nocow write (checking if an extent is shared through reflinks or if there's a hole in the range for example), and because when writeback starts we might actually need to fallback to COW mode (for example the block group containing the target extents was turned into RO mode due to a scrub or balance). When we are unable to reserve data space we check if we can do a nocow write, and if we can, we proceed with dirtying the pages and setting up the range for delalloc. In this case the bytes_may_use counter of the data space_info object is not incremented, unlike in the case where we are able to reserve data space (done through btrfs_check_data_free_space() which calls btrfs_alloc_data_chunk_ondemand()). Later when running delalloc we attempt to start writeback in nocow mode but we might revert back to cow mode, for example because in the meanwhile a block group was turned into RO mode by a scrub or relocation. The cow path after successfully allocating an extent ends up calling btrfs_add_reserved_bytes(), which expects the bytes_may_use counter of the data space_info object to have been incremented before - but we did not do it when the buffered write started, since there was not enough available data space. So btrfs_add_reserved_bytes() ends up decrementing the bytes_may_use counter anyway, and when the counter's current value is smaller then the size of the allocated extent we get a stack trace like the following: ------------[ cut here ]------------ WARNING: CPU: 0 PID: 20138 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs] Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...) CPU: 0 PID: 20138 Comm: kworker/u8:15 Not tainted 5.6.0-rc7-btrfs-next-58 #5 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Workqueue: writeback wb_workfn (flush-btrfs-1754) RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs] Code: ff ff 48 (...) RSP: 0018:ffffbda18a4b3568 EFLAGS: 00010287 RAX: 0000000000000000 RBX: ffff9ca076f5d800 RCX: 0000000000000000 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9ca068470410 RBP: fffffffffffff000 R08: 0000000000000001 R09: 0000000000000000 R10: ffff9ca079d58040 R11: 0000000000000000 R12: ffff9ca068470400 R13: ffff9ca0408b2000 R14: 0000000000001000 R15: ffff9ca076f5d800 FS: 0000000000000000(0000) GS:ffff9ca07a600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005605dbfe7048 CR3: 0000000138570006 CR4: 00000000003606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: find_free_extent+0x4a0/0x16c0 [btrfs] btrfs_reserve_extent+0x91/0x180 [btrfs] cow_file_range+0x12d/0x490 [btrfs] run_delalloc_nocow+0x341/0xa40 [btrfs] btrfs_run_delalloc_range+0x1ea/0x6d0 [btrfs] ? find_lock_delalloc_range+0x221/0x250 [btrfs] writepage_delalloc+0xe8/0x150 [btrfs] __extent_writepage+0xe8/0x4c0 [btrfs] extent_write_cache_pages+0x237/0x530 [btrfs] ? btrfs_wq_submit_bio+0x9f/0xc0 [btrfs] extent_writepages+0x44/0xa0 [btrfs] do_writepages+0x23/0x80 __writeback_single_inode+0x59/0x700 writeback_sb_inodes+0x267/0x5f0 __writeback_inodes_wb+0x87/0xe0 wb_writeback+0x382/0x590 ? wb_workfn+0x4a2/0x6c0 wb_workfn+0x4a2/0x6c0 process_one_work+0x26d/0x6a0 worker_thread+0x4f/0x3e0 ? process_one_work+0x6a0/0x6a0 kthread+0x103/0x140 ? kthread_create_worker_on_cpu+0x70/0x70 ret_from_fork+0x3a/0x50 irq event stamp: 0 hardirqs last enabled at (0): [<0000000000000000>] 0x0 hardirqs last disabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020 softirqs last enabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020 softirqs last disabled at (0): [<0000000000000000>] 0x0 ---[ end trace f9f6ef8ec4cd8ec9 ]--- So to fix this, when falling back into cow mode check if space was not reserved, by testing for the bit EXTENT_NORESERVE in the respective file range, and if not, increment the bytes_may_use counter for the data space_info object. Also clear the EXTENT_NORESERVE bit from the range, so that if the cow path fails it decrements the bytes_may_use counter when clearing the delalloc range (through the btrfs_clear_delalloc_extent() callback). Fixes: 7ee9e4405f264e ("Btrfs: check if we can nocow if we don't have data space") CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 467dc47ea99c56e966e99d09dae54869850abeeb upstream.

When doing a buffered write we always try to reserve data space for it,
even when the file has the NOCOW bit set or the write falls into a file
range covered by a prealloc extent. This is done both because it is
expensive to check if we can do a nocow write (checking if an extent is
shared through reflinks or if there's a hole in the range for example),
and because when writeback starts we might actually need to fallback to
COW mode (for example the block group containing the target extents was
turned into RO mode due to a scrub or balance).

When we are unable to reserve data space we check if we can do a nocow
write, and if we can, we proceed with dirtying the pages and setting up
the range for delalloc. In this case the bytes_may_use counter of the
data space_info object is not incremented, unlike in the case where we
are able to reserve data space (done through btrfs_check_data_free_space()
which calls btrfs_alloc_data_chunk_ondemand()).

Later when running delalloc we attempt to start writeback in nocow mode
but we might revert back to cow mode, for example because in the meanwhile
a block group was turned into RO mode by a scrub or relocation. The cow
path after successfully allocating an extent ends up calling
btrfs_add_reserved_bytes(), which expects the bytes_may_use counter of
the data space_info object to have been incremented before - but we did
not do it when the buffered write started, since there was not enough
available data space. So btrfs_add_reserved_bytes() ends up decrementing
the bytes_may_use counter anyway, and when the counter's current value
is smaller then the size of the allocated extent we get a stack trace
like the following:

 ------------[ cut here ]------------
 WARNING: CPU: 0 PID: 20138 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
 Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
 CPU: 0 PID: 20138 Comm: kworker/u8:15 Not tainted 5.6.0-rc7-btrfs-next-58 #5
 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
 Workqueue: writeback wb_workfn (flush-btrfs-1754)
 RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
 Code: ff ff 48 (...)
 RSP: 0018:ffffbda18a4b3568 EFLAGS: 00010287
 RAX: 0000000000000000 RBX: ffff9ca076f5d800 RCX: 0000000000000000
 RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9ca068470410
 RBP: fffffffffffff000 R08: 0000000000000001 R09: 0000000000000000
 R10: ffff9ca079d58040 R11: 0000000000000000 R12: ffff9ca068470400
 R13: ffff9ca0408b2000 R14: 0000000000001000 R15: ffff9ca076f5d800
 FS:  0000000000000000(0000) GS:ffff9ca07a600000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00005605dbfe7048 CR3: 0000000138570006 CR4: 00000000003606f0
 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 Call Trace:
  find_free_extent+0x4a0/0x16c0 [btrfs]
  btrfs_reserve_extent+0x91/0x180 [btrfs]
  cow_file_range+0x12d/0x490 [btrfs]
  run_delalloc_nocow+0x341/0xa40 [btrfs]
  btrfs_run_delalloc_range+0x1ea/0x6d0 [btrfs]
  ? find_lock_delalloc_range+0x221/0x250 [btrfs]
  writepage_delalloc+0xe8/0x150 [btrfs]
  __extent_writepage+0xe8/0x4c0 [btrfs]
  extent_write_cache_pages+0x237/0x530 [btrfs]
  ? btrfs_wq_submit_bio+0x9f/0xc0 [btrfs]
  extent_writepages+0x44/0xa0 [btrfs]
  do_writepages+0x23/0x80
  __writeback_single_inode+0x59/0x700
  writeback_sb_inodes+0x267/0x5f0
  __writeback_inodes_wb+0x87/0xe0
  wb_writeback+0x382/0x590
  ? wb_workfn+0x4a2/0x6c0
  wb_workfn+0x4a2/0x6c0
  process_one_work+0x26d/0x6a0
  worker_thread+0x4f/0x3e0
  ? process_one_work+0x6a0/0x6a0
  kthread+0x103/0x140
  ? kthread_create_worker_on_cpu+0x70/0x70
  ret_from_fork+0x3a/0x50
 irq event stamp: 0
 hardirqs last  enabled at (0): [<0000000000000000>] 0x0
 hardirqs last disabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
 softirqs last  enabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
 softirqs last disabled at (0): [<0000000000000000>] 0x0
 ---[ end trace f9f6ef8ec4cd8ec9 ]---

So to fix this, when falling back into cow mode check if space was not
reserved, by testing for the bit EXTENT_NORESERVE in the respective file
range, and if not, increment the bytes_may_use counter for the data
space_info object. Also clear the EXTENT_NORESERVE bit from the range, so
that if the cow path fails it decrements the bytes_may_use counter when
clearing the delalloc range (through the btrfs_clear_delalloc_extent()
callback).

Fixes: 7ee9e4405f264e ("Btrfs: check if we can nocow if we don't have data space")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
btrfs: fix wrong file range cleanup after an error filling dealloc range 2020-06-22T07:32:55+00:00 Filipe Manana fdmanana@suse.com 2020-05-27T10:15:53+00:00 788093fa4e1b8f55c107c6ff00f05787ee75edd4 commit e2c8e92d1140754073ad3799eb6620c76bab2078 upstream. If an error happens while running dellaloc in COW mode for a range, we can end up calling extent_clear_unlock_delalloc() for a range that goes beyond our range's end offset by 1 byte, which affects 1 extra page. This results in clearing bits and doing page operations (such as a page unlock) outside our target range. Fix that by calling extent_clear_unlock_delalloc() with an inclusive end offset, instead of an exclusive end offset, at cow_file_range(). Fixes: a315e68f6e8b30 ("Btrfs: fix invalid attempt to free reserved space on failure to cow range") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e2c8e92d1140754073ad3799eb6620c76bab2078 upstream.

If an error happens while running dellaloc in COW mode for a range, we can
end up calling extent_clear_unlock_delalloc() for a range that goes beyond
our range's end offset by 1 byte, which affects 1 extra page. This results
in clearing bits and doing page operations (such as a page unlock) outside
our target range.

Fix that by calling extent_clear_unlock_delalloc() with an inclusive end
offset, instead of an exclusive end offset, at cow_file_range().

Fixes: a315e68f6e8b30 ("Btrfs: fix invalid attempt to free reserved space on failure to cow range")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>