53b74fa990
984250 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Naohiro Aota
|
53b74fa990 |
btrfs: zoned: move superblock logging zone location
Moves the location of the superblock logging zones. The new locations of the logging zones are now determined based on fixed block addresses instead of on fixed zone numbers. The old placement method based on fixed zone numbers causes problems when one needs to inspect a file system image without access to the drive zone information. In such case, the super block locations cannot be reliably determined as the zone size is unknown. By locating the superblock logging zones using fixed addresses, we can scan a dumped file system image without the zone information since a super block copy will always be present at or after the fixed known locations. Introduce the following three pairs of zones containing fixed offset locations, regardless of the device zone size. - primary superblock: offset 0B (and the following zone) - first copy: offset 512G (and the following zone) - Second copy: offset 4T (4096G, and the following zone) If a logging zone is outside of the disk capacity, we do not record the superblock copy. The first copy position is much larger than for a non-zoned filesystem, which is at 64M. This is to avoid overlapping with the log zones for the primary superblock. This higher location is arbitrary but allows supporting devices with very large zone sizes, plus some space around in between. Such large zone size is unrealistic and very unlikely to ever be seen in real devices. Currently, SMR disks have a zone size of 256MB, and we are expecting ZNS drives to be in the 1-4GB range, so this limit gives us room to breathe. For now, we only allow zone sizes up to 8GB. The maximum zone size that would still fit in the space is 256G. The fixed location addresses are somewhat arbitrary, with the intent of maintaining superblock reliability for smaller and larger devices, with the preference for the latter. For this reason, there are two superblocks under the first 1T. This should cover use cases for physical devices and for emulated/device-mapper devices. The superblock logging zones are reserved for superblock logging and never used for data or metadata blocks. Note that we only reserve the two zones per primary/copy actually used for superblock logging. We do not reserve the ranges of zones possibly containing superblocks with the largest supported zone size (0-16GB, 512G-528GB, 4096G-4112G). The zones containing the fixed location offsets used to store superblocks on a non-zoned volume are also reserved to avoid confusion. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Omar Sandoval
|
c1d6abdac4 |
btrfs: fix check_data_csum() error message for direct I/O
Commit 1dae796aabf6 ("btrfs: inode: sink parameter start and len to
check_data_csum()") replaced the start parameter to check_data_csum()
with page_offset(), but page_offset() is not meaningful for direct I/O
pages. Bring back the start parameter.
Fixes:
|
||
Filipe Manana
|
0bb7883009 |
btrfs: fix sleep while in non-sleep context during qgroup removal
While removing a qgroup's sysfs entry we end up taking the kernfs_mutex,
through kobject_del(), while holding the fs_info->qgroup_lock spinlock,
producing the following trace:
[821.843637] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:281
[821.843641] in_atomic(): 1, irqs_disabled(): 0, non_block: 0, pid: 28214, name: podman
[821.843644] CPU: 3 PID: 28214 Comm: podman Tainted: G W 5.11.6 #15
[821.843646] Hardware name: Dell Inc. PowerEdge R330/084XW4, BIOS 2.11.0 12/08/2020
[821.843647] Call Trace:
[821.843650] dump_stack+0xa1/0xfb
[821.843656] ___might_sleep+0x144/0x160
[821.843659] mutex_lock+0x17/0x40
[821.843662] kernfs_remove_by_name_ns+0x1f/0x80
[821.843666] sysfs_remove_group+0x7d/0xe0
[821.843668] sysfs_remove_groups+0x28/0x40
[821.843670] kobject_del+0x2a/0x80
[821.843672] btrfs_sysfs_del_one_qgroup+0x2b/0x40 [btrfs]
[821.843685] __del_qgroup_rb+0x12/0x150 [btrfs]
[821.843696] btrfs_remove_qgroup+0x288/0x2a0 [btrfs]
[821.843707] btrfs_ioctl+0x3129/0x36a0 [btrfs]
[821.843717] ? __mod_lruvec_page_state+0x5e/0xb0
[821.843719] ? page_add_new_anon_rmap+0xbc/0x150
[821.843723] ? kfree+0x1b4/0x300
[821.843725] ? mntput_no_expire+0x55/0x330
[821.843728] __x64_sys_ioctl+0x5a/0xa0
[821.843731] do_syscall_64+0x33/0x70
[821.843733] entry_SYSCALL_64_after_hwframe+0x44/0xa9
[821.843736] RIP: 0033:0x4cd3fb
[821.843741] RSP: 002b:000000c000906b20 EFLAGS: 00000206 ORIG_RAX: 0000000000000010
[821.843744] RAX: ffffffffffffffda RBX: 000000c000050000 RCX: 00000000004cd3fb
[821.843745] RDX: 000000c000906b98 RSI: 000000004010942a RDI: 000000000000000f
[821.843747] RBP: 000000c000907cd0 R08: 000000c000622901 R09: 0000000000000000
[821.843748] R10: 000000c000d992c0 R11: 0000000000000206 R12: 000000000000012d
[821.843749] R13: 000000000000012c R14: 0000000000000200 R15: 0000000000000049
Fix this by removing the qgroup sysfs entry while not holding the spinlock,
since the spinlock is only meant for protection of the qgroup rbtree.
Reported-by: Stuart Shelton <srcshelton@gmail.com>
Link: https://lore.kernel.org/linux-btrfs/7A5485BB-0628-419D-A4D3-27B1AF47E25A@gmail.com/
Fixes:
|
||
|
Filipe Manana
|
8d488a8c7b |
btrfs: fix subvolume/snapshot deletion not triggered on mount
During the mount procedure we are calling btrfs_orphan_cleanup() against
the root tree, which will find all orphans items in this tree. When an
orphan item corresponds to a deleted subvolume/snapshot (instead of an
inode space cache), it must not delete the orphan item, because that will
cause btrfs_find_orphan_roots() to not find the orphan item and therefore
not add the corresponding subvolume root to the list of dead roots, which
results in the subvolume's tree never being deleted by the cleanup thread.
The same applies to the remount from RO to RW path.
Fix this by making btrfs_find_orphan_roots() run before calling
btrfs_orphan_cleanup() against the root tree.
A test case for fstests will follow soon.
Reported-by: Robbie Ko <robbieko@synology.com>
Link: https://lore.kernel.org/linux-btrfs/b19f4310-35e0-606e-1eea-2dd84d28c5da@synology.com/
Fixes:
|
||
David Sterba
|
ebd99a6b34 |
btrfs: fix build when using M=fs/btrfs
There are people building the module with M= that's supposed to be used
for external modules. This got broken in
|
||
Josef Bacik
|
3cb894972f |
btrfs: do not initialize dev replace for bad dev root
While helping Neal fix his broken file system I added a debug patch to catch if we were calling btrfs_search_slot with a NULL root, and this stack trace popped: we tried to search with a NULL root CPU: 0 PID: 1760 Comm: mount Not tainted 5.11.0-155.nealbtrfstest.1.fc34.x86_64 #1 Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 07/22/2020 Call Trace: dump_stack+0x6b/0x83 btrfs_search_slot.cold+0x11/0x1b ? btrfs_init_dev_replace+0x36/0x450 btrfs_init_dev_replace+0x71/0x450 open_ctree+0x1054/0x1610 btrfs_mount_root.cold+0x13/0xfa legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x131/0x3d0 ? legacy_get_tree+0x27/0x40 ? btrfs_show_options+0x640/0x640 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x441/0xa80 __x64_sys_mount+0xf4/0x130 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f644730352e Fix this by not starting the device replace stuff if we do not have a NULL dev root. Reported-by: Neal Gompa <ngompa13@gmail.com> CC: stable@vger.kernel.org # 5.11+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
820a49dafc |
btrfs: initialize device::fs_info always
Neal reported a panic trying to use -o rescue=all BUG: kernel NULL pointer dereference, address: 0000000000000030 PGD 0 P4D 0 Oops: 0000 [#1] SMP NOPTI CPU: 0 PID: 696 Comm: mount Tainted: G W 5.12.0-rc2+ #296 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:btrfs_device_init_dev_stats+0x1d/0x200 RSP: 0018:ffffafaec1483bb8 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffff9a5715bcb298 RCX: 0000000000000070 RDX: ffff9a5703248000 RSI: ffff9a57052ea150 RDI: ffff9a5715bca400 RBP: ffff9a57052ea150 R08: 0000000000000070 R09: ffff9a57052ea150 R10: 000130faf0741c10 R11: 0000000000000000 R12: ffff9a5703700000 R13: 0000000000000000 R14: ffff9a5715bcb278 R15: ffff9a57052ea150 FS: 00007f600d122c40(0000) GS:ffff9a577bc00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000112a46005 CR4: 0000000000370ef0 Call Trace: ? btrfs_init_dev_stats+0x1f/0xf0 ? kmem_cache_alloc+0xef/0x1f0 btrfs_init_dev_stats+0x5f/0xf0 open_ctree+0x10cb/0x1720 btrfs_mount_root.cold+0x12/0xea legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x10d/0x380 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x433/0xa00 __x64_sys_mount+0xe3/0x120 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xae This happens because when we call btrfs_init_dev_stats we do device->fs_info->dev_root. However device->fs_info isn't initialized because we were only calling btrfs_init_devices_late() if we properly read the device root. However we don't actually need the device root to init the devices, this function simply assigns the devices their ->fs_info pointer properly, so this needs to be done unconditionally always so that we can properly dereference device->fs_info in rescue cases. Reported-by: Neal Gompa <ngompa13@gmail.com> CC: stable@vger.kernel.org # 5.11+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Josef Bacik
|
82d62d06db |
btrfs: do not initialize dev stats if we have no dev_root
Neal reported a panic trying to use -o rescue=all BUG: kernel NULL pointer dereference, address: 0000000000000030 PGD 0 P4D 0 Oops: 0000 [#1] SMP PTI CPU: 0 PID: 4095 Comm: mount Not tainted 5.11.0-0.rc7.149.fc34.x86_64 #1 RIP: 0010:btrfs_device_init_dev_stats+0x4c/0x1f0 RSP: 0018:ffffa60285fbfb68 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88b88f806498 RCX: ffff88b82e7a2a10 RDX: ffffa60285fbfb97 RSI: ffff88b82e7a2a10 RDI: 0000000000000000 RBP: ffff88b88f806b3c R08: 0000000000000000 R09: 0000000000000000 R10: ffff88b82e7a2a10 R11: 0000000000000000 R12: ffff88b88f806a00 R13: ffff88b88f806478 R14: ffff88b88f806a00 R15: ffff88b82e7a2a10 FS: 00007f698be1ec40(0000) GS:ffff88b937e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000030 CR3: 0000000092c9c006 CR4: 00000000003706f0 Call Trace: ? btrfs_init_dev_stats+0x1f/0xf0 btrfs_init_dev_stats+0x62/0xf0 open_ctree+0x1019/0x15ff btrfs_mount_root.cold+0x13/0xfa legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 vfs_kern_mount.part.0+0x71/0xb0 btrfs_mount+0x131/0x3d0 ? legacy_get_tree+0x27/0x40 ? btrfs_show_options+0x640/0x640 legacy_get_tree+0x27/0x40 vfs_get_tree+0x25/0xb0 path_mount+0x441/0xa80 __x64_sys_mount+0xf4/0x130 do_syscall_64+0x33/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f698c04e52e This happens because we unconditionally attempt to initialize device stats on mount, but we may not have been able to read the device root. Fix this by skipping initializing the device stats if we do not have a device root. Reported-by: Neal Gompa <ngompa13@gmail.com> CC: stable@vger.kernel.org # 5.11+ Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Johannes Thumshirn
|
f3da882eae |
btrfs: zoned: remove outdated WARN_ON in direct IO
In btrfs_submit_direct() there's a WAN_ON_ONCE() that will trigger if we're submitting a DIO write on a zoned filesystem but are not using REQ_OP_ZONE_APPEND to submit the IO to the block device. This is a left over from a previous version where btrfs_dio_iomap_begin() didn't use btrfs_use_zone_append() to check for sequential write only zones. It is an oversight from the development phase. In v11 (I think) I've added |
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|
Filipe Manana
|
485df75554 |
btrfs: always pin deleted leaves when there are active tree mod log users
When freeing a tree block we may end up adding its extent back to the free space cache/tree, as long as there are no more references for it, it was created in the current transaction and writeback for it never happened. This is generally fine, however when we have tree mod log operations it can result in inconsistent versions of a btree after unwinding extent buffers with the recorded tree mod log operations. This is because: * We only log operations for nodes (adding and removing key/pointers), for leaves we don't do anything; * This means that we can log a MOD_LOG_KEY_REMOVE_WHILE_FREEING operation for a node that points to a leaf that was deleted; * Before we apply the logged operation to unwind a node, we can have that leaf's extent allocated again, either as a node or as a leaf, and possibly for another btree. This is possible if the leaf was created in the current transaction and writeback for it never started, in which case btrfs_free_tree_block() returns its extent back to the free space cache/tree; * Then, before applying the tree mod log operation, some task allocates the metadata extent just freed before, and uses it either as a leaf or as a node for some btree (can be the same or another one, it does not matter); * After applying the MOD_LOG_KEY_REMOVE_WHILE_FREEING operation we now get the target node with an item pointing to the metadata extent that now has content different from what it had before the leaf was deleted. It might now belong to a different btree and be a node and not a leaf anymore. As a consequence, the results of searches after the unwinding can be unpredictable and produce unexpected results. So make sure we pin extent buffers corresponding to leaves when there are tree mod log users. CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
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Filipe Manana
|
dbcc7d57bf |
btrfs: fix race when cloning extent buffer during rewind of an old root
While resolving backreferences, as part of a logical ino ioctl call or
fiemap, we can end up hitting a BUG_ON() when replaying tree mod log
operations of a root, triggering a stack trace like the following:
------------[ cut here ]------------
kernel BUG at fs/btrfs/ctree.c:1210!
invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 1 PID: 19054 Comm: crawl_335 Tainted: G W 5.11.0-2d11c0084b02-misc-next+ #89
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
RIP: 0010:__tree_mod_log_rewind+0x3b1/0x3c0
Code: 05 48 8d 74 10 (...)
RSP: 0018:ffffc90001eb70b8 EFLAGS: 00010297
RAX: 0000000000000000 RBX: ffff88812344e400 RCX: ffffffffb28933b6
RDX: 0000000000000007 RSI: dffffc0000000000 RDI: ffff88812344e42c
RBP: ffffc90001eb7108 R08: 1ffff11020b60a20 R09: ffffed1020b60a20
R10: ffff888105b050f9 R11: ffffed1020b60a1f R12: 00000000000000ee
R13: ffff8880195520c0 R14: ffff8881bc958500 R15: ffff88812344e42c
FS: 00007fd1955e8700(0000) GS:ffff8881f5600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007efdb7928718 CR3: 000000010103a006 CR4: 0000000000170ee0
Call Trace:
btrfs_search_old_slot+0x265/0x10d0
? lock_acquired+0xbb/0x600
? btrfs_search_slot+0x1090/0x1090
? free_extent_buffer.part.61+0xd7/0x140
? free_extent_buffer+0x13/0x20
resolve_indirect_refs+0x3e9/0xfc0
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? add_prelim_ref.part.11+0x150/0x150
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x600
? __kasan_check_write+0x14/0x20
? do_raw_spin_unlock+0xa8/0x140
? rb_insert_color+0x30/0x360
? prelim_ref_insert+0x12d/0x430
find_parent_nodes+0x5c3/0x1830
? resolve_indirect_refs+0xfc0/0xfc0
? lock_release+0xc8/0x620
? fs_reclaim_acquire+0x67/0xf0
? lock_acquire+0xc7/0x510
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x160/0x210
? lock_release+0xc8/0x620
? fs_reclaim_acquire+0x67/0xf0
? lock_acquire+0xc7/0x510
? poison_range+0x38/0x40
? unpoison_range+0x14/0x40
? trace_hardirqs_on+0x55/0x120
btrfs_find_all_roots_safe+0x142/0x1e0
? find_parent_nodes+0x1830/0x1830
? btrfs_inode_flags_to_xflags+0x50/0x50
iterate_extent_inodes+0x20e/0x580
? tree_backref_for_extent+0x230/0x230
? lock_downgrade+0x3d0/0x3d0
? read_extent_buffer+0xdd/0x110
? lock_downgrade+0x3d0/0x3d0
? __kasan_check_read+0x11/0x20
? lock_acquired+0xbb/0x600
? __kasan_check_write+0x14/0x20
? _raw_spin_unlock+0x22/0x30
? __kasan_check_write+0x14/0x20
iterate_inodes_from_logical+0x129/0x170
? iterate_inodes_from_logical+0x129/0x170
? btrfs_inode_flags_to_xflags+0x50/0x50
? iterate_extent_inodes+0x580/0x580
? __vmalloc_node+0x92/0xb0
? init_data_container+0x34/0xb0
? init_data_container+0x34/0xb0
? kvmalloc_node+0x60/0x80
btrfs_ioctl_logical_to_ino+0x158/0x230
btrfs_ioctl+0x205e/0x4040
? __might_sleep+0x71/0xe0
? btrfs_ioctl_get_supported_features+0x30/0x30
? getrusage+0x4b6/0x9c0
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x620
? __might_fault+0x64/0xd0
? lock_acquire+0xc7/0x510
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x210/0x210
? lockdep_hardirqs_on_prepare+0x210/0x210
? __kasan_check_read+0x11/0x20
? do_vfs_ioctl+0xfc/0x9d0
? ioctl_file_clone+0xe0/0xe0
? lock_downgrade+0x3d0/0x3d0
? lockdep_hardirqs_on_prepare+0x210/0x210
? __kasan_check_read+0x11/0x20
? lock_release+0xc8/0x620
? __task_pid_nr_ns+0xd3/0x250
? lock_acquire+0xc7/0x510
? __fget_files+0x160/0x230
? __fget_light+0xf2/0x110
__x64_sys_ioctl+0xc3/0x100
do_syscall_64+0x37/0x80
entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x7fd1976e2427
Code: 00 00 90 48 8b 05 (...)
RSP: 002b:00007fd1955e5cf8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fd1955e5f40 RCX: 00007fd1976e2427
RDX: 00007fd1955e5f48 RSI: 00000000c038943b RDI: 0000000000000004
RBP: 0000000001000000 R08: 0000000000000000 R09: 00007fd1955e6120
R10: 0000557835366b00 R11: 0000000000000246 R12: 0000000000000004
R13: 00007fd1955e5f48 R14: 00007fd1955e5f40 R15: 00007fd1955e5ef8
Modules linked in:
---[ end trace ec8931a1c36e57be ]---
(gdb) l *(__tree_mod_log_rewind+0x3b1)
0xffffffff81893521 is in __tree_mod_log_rewind (fs/btrfs/ctree.c:1210).
1205 * the modification. as we're going backwards, we do the
1206 * opposite of each operation here.
1207 */
1208 switch (tm->op) {
1209 case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
1210 BUG_ON(tm->slot < n);
1211 fallthrough;
1212 case MOD_LOG_KEY_REMOVE_WHILE_MOVING:
1213 case MOD_LOG_KEY_REMOVE:
1214 btrfs_set_node_key(eb, &tm->key, tm->slot);
Here's what happens to hit that BUG_ON():
1) We have one tree mod log user (through fiemap or the logical ino ioctl),
with a sequence number of 1, so we have fs_info->tree_mod_seq == 1;
2) Another task is at ctree.c:balance_level() and we have eb X currently as
the root of the tree, and we promote its single child, eb Y, as the new
root.
Then, at ctree.c:balance_level(), we call:
tree_mod_log_insert_root(eb X, eb Y, 1);
3) At tree_mod_log_insert_root() we create tree mod log elements for each
slot of eb X, of operation type MOD_LOG_KEY_REMOVE_WHILE_FREEING each
with a ->logical pointing to ebX->start. These are placed in an array
named tm_list.
Lets assume there are N elements (N pointers in eb X);
4) Then, still at tree_mod_log_insert_root(), we create a tree mod log
element of operation type MOD_LOG_ROOT_REPLACE, ->logical set to
ebY->start, ->old_root.logical set to ebX->start, ->old_root.level set
to the level of eb X and ->generation set to the generation of eb X;
5) Then tree_mod_log_insert_root() calls tree_mod_log_free_eb() with
tm_list as argument. After that, tree_mod_log_free_eb() calls
__tree_mod_log_insert() for each member of tm_list in reverse order,
from highest slot in eb X, slot N - 1, to slot 0 of eb X;
6) __tree_mod_log_insert() sets the sequence number of each given tree mod
log operation - it increments fs_info->tree_mod_seq and sets
fs_info->tree_mod_seq as the sequence number of the given tree mod log
operation.
This means that for the tm_list created at tree_mod_log_insert_root(),
the element corresponding to slot 0 of eb X has the highest sequence
number (1 + N), and the element corresponding to the last slot has the
lowest sequence number (2);
7) Then, after inserting tm_list's elements into the tree mod log rbtree,
the MOD_LOG_ROOT_REPLACE element is inserted, which gets the highest
sequence number, which is N + 2;
8) Back to ctree.c:balance_level(), we free eb X by calling
btrfs_free_tree_block() on it. Because eb X was created in the current
transaction, has no other references and writeback did not happen for
it, we add it back to the free space cache/tree;
9) Later some other task T allocates the metadata extent from eb X, since
it is marked as free space in the space cache/tree, and uses it as a
node for some other btree;
10) The tree mod log user task calls btrfs_search_old_slot(), which calls
get_old_root(), and finally that calls __tree_mod_log_oldest_root()
with time_seq == 1 and eb_root == eb Y;
11) First iteration of the while loop finds the tree mod log element with
sequence number N + 2, for the logical address of eb Y and of type
MOD_LOG_ROOT_REPLACE;
12) Because the operation type is MOD_LOG_ROOT_REPLACE, we don't break out
of the loop, and set root_logical to point to tm->old_root.logical
which corresponds to the logical address of eb X;
13) On the next iteration of the while loop, the call to
tree_mod_log_search_oldest() returns the smallest tree mod log element
for the logical address of eb X, which has a sequence number of 2, an
operation type of MOD_LOG_KEY_REMOVE_WHILE_FREEING and corresponds to
the old slot N - 1 of eb X (eb X had N items in it before being freed);
14) We then break out of the while loop and return the tree mod log operation
of type MOD_LOG_ROOT_REPLACE (eb Y), and not the one for slot N - 1 of
eb X, to get_old_root();
15) At get_old_root(), we process the MOD_LOG_ROOT_REPLACE operation
and set "logical" to the logical address of eb X, which was the old
root. We then call tree_mod_log_search() passing it the logical
address of eb X and time_seq == 1;
16) Then before calling tree_mod_log_search(), task T adds a key to eb X,
which results in adding a tree mod log operation of type
MOD_LOG_KEY_ADD to the tree mod log - this is done at
ctree.c:insert_ptr() - but after adding the tree mod log operation
and before updating the number of items in eb X from 0 to 1...
17) The task at get_old_root() calls tree_mod_log_search() and gets the
tree mod log operation of type MOD_LOG_KEY_ADD just added by task T.
Then it enters the following if branch:
if (old_root && tm && tm->op != MOD_LOG_KEY_REMOVE_WHILE_FREEING) {
(...)
} (...)
Calls read_tree_block() for eb X, which gets a reference on eb X but
does not lock it - task T has it locked.
Then it clones eb X while it has nritems set to 0 in its header, before
task T sets nritems to 1 in eb X's header. From hereupon we use the
clone of eb X which no other task has access to;
18) Then we call __tree_mod_log_rewind(), passing it the MOD_LOG_KEY_ADD
mod log operation we just got from tree_mod_log_search() in the
previous step and the cloned version of eb X;
19) At __tree_mod_log_rewind(), we set the local variable "n" to the number
of items set in eb X's clone, which is 0. Then we enter the while loop,
and in its first iteration we process the MOD_LOG_KEY_ADD operation,
which just decrements "n" from 0 to (u32)-1, since "n" is declared with
a type of u32. At the end of this iteration we call rb_next() to find the
next tree mod log operation for eb X, that gives us the mod log operation
of type MOD_LOG_KEY_REMOVE_WHILE_FREEING, for slot 0, with a sequence
number of N + 1 (steps 3 to 6);
20) Then we go back to the top of the while loop and trigger the following
BUG_ON():
(...)
switch (tm->op) {
case MOD_LOG_KEY_REMOVE_WHILE_FREEING:
BUG_ON(tm->slot < n);
fallthrough;
(...)
Because "n" has a value of (u32)-1 (4294967295) and tm->slot is 0.
Fix this by taking a read lock on the extent buffer before cloning it at
ctree.c:get_old_root(). This should be done regardless of the extent
buffer having been freed and reused, as a concurrent task might be
modifying it (while holding a write lock on it).
Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Link: https://lore.kernel.org/linux-btrfs/20210227155037.GN28049@hungrycats.org/
Fixes:
|
||
|
David Sterba
|
34e49994d0 |
btrfs: fix slab cache flags for free space tree bitmap
The free space tree bitmap slab cache is created with SLAB_RED_ZONE but
that's a debugging flag and not always enabled. Also the other slabs are
created with at least SLAB_MEM_SPREAD that we want as well to average
the memory placement cost.
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Fixes:
|
||
Qu Wenruo
|
60484cd9d5 |
btrfs: subpage: make readahead work properly
In readahead infrastructure, we are using a lot of hard coded PAGE_SHIFT while we're not doing anything specific to PAGE_SIZE. One of the most affected part is the radix tree operation of btrfs_fs_info::reada_tree. If using PAGE_SHIFT, subpage metadata readahead is broken and does no help reading metadata ahead. Fix the problem by using btrfs_fs_info::sectorsize_bits so that readahead could work for subpage. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Qu Wenruo
|
d9bb77d51e |
btrfs: subpage: fix wild pointer access during metadata read failure
[BUG] When running fstests for btrfs subpage read-write test, it has a very high chance to crash at generic/475 with the following stack: BTRFS warning (device dm-8): direct IO failed ino 510 rw 1,34817 sector 0xcdf0 len 94208 err no 10 Unable to handle kernel paging request at virtual address ffff80001157e7c0 CPU: 2 PID: 687125 Comm: kworker/u12:4 Tainted: G WC 5.12.0-rc2-custom+ #5 Hardware name: Khadas VIM3 (DT) Workqueue: btrfs-endio-meta btrfs_work_helper [btrfs] pc : queued_spin_lock_slowpath+0x1a0/0x390 lr : do_raw_spin_lock+0xc4/0x11c Call trace: queued_spin_lock_slowpath+0x1a0/0x390 _raw_spin_lock+0x68/0x84 btree_readahead_hook+0x38/0xc0 [btrfs] end_bio_extent_readpage+0x504/0x5f4 [btrfs] bio_endio+0x170/0x1a4 end_workqueue_fn+0x3c/0x60 [btrfs] btrfs_work_helper+0x1b0/0x1b4 [btrfs] process_one_work+0x22c/0x430 worker_thread+0x70/0x3a0 kthread+0x13c/0x140 ret_from_fork+0x10/0x30 Code: 910020e0 8b0200c2 f861d884 aa0203e1 (f8246827) [CAUSE] In end_bio_extent_readpage(), if we hit an error during read, we will handle the error differently for data and metadata. For data we queue a repair, while for metadata, we record the error and let the caller choose what to do. But the code is still using page->private to grab extent buffer, which no longer points to extent buffer for subpage metadata pages. Thus this wild pointer access leads to above crash. [FIX] Introduce a helper, find_extent_buffer_readpage(), to grab extent buffer. The difference against find_extent_buffer_nospinlock() is: - Also handles regular sectorsize == PAGE_SIZE case - No extent buffer refs increase/decrease As extent buffer under IO must have non-zero refs, so this is safe Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Filipe Manana
|
e3d3b41576 |
btrfs: zoned: fix linked list corruption after log root tree allocation failure
When using a zoned filesystem, while syncing the log, if we fail to
allocate the root node for the log root tree, we are not removing the
log context we allocated on stack from the list of log contexts of the
log root tree. This means after the return from btrfs_sync_log() we get
a corrupted linked list.
Fix this by allocating the node before adding our stack allocated context
to the list of log contexts of the log root tree.
Fixes:
|
||
|
Qu Wenruo
|
a3ee79bd8f |
btrfs: fix qgroup data rsv leak caused by falloc failure
[BUG]
When running fsstress with only falloc workload, and a very low qgroup
limit set, we can get qgroup data rsv leak at unmount time.
BTRFS warning (device dm-0): qgroup 0/5 has unreleased space, type 0 rsv 20480
BTRFS error (device dm-0): qgroup reserved space leaked
The minimal reproducer looks like:
#!/bin/bash
dev=/dev/test/test
mnt="/mnt/btrfs"
fsstress=~/xfstests-dev/ltp/fsstress
runtime=8
workload()
{
umount $dev &> /dev/null
umount $mnt &> /dev/null
mkfs.btrfs -f $dev > /dev/null
mount $dev $mnt
btrfs quota en $mnt
btrfs quota rescan -w $mnt
btrfs qgroup limit 16m 0/5 $mnt
$fsstress -w -z -f creat=10 -f fallocate=10 -p 2 -n 100 \
-d $mnt -v > /tmp/fsstress
umount $mnt
if dmesg | grep leak ; then
echo "!!! FAILED !!!"
exit 1
fi
}
for (( i=0; i < $runtime; i++)); do
echo "=== $i/$runtime==="
workload
done
Normally it would fail before round 4.
[CAUSE]
In function insert_prealloc_file_extent(), we first call
btrfs_qgroup_release_data() to know how many bytes are reserved for
qgroup data rsv.
Then use that @qgroup_released number to continue our work.
But after we call btrfs_qgroup_release_data(), we should either queue
@qgroup_released to delayed ref or free them manually in error path.
Unfortunately, we lack the error handling to free the released bytes,
leaking qgroup data rsv.
All the error handling function outside won't help at all, as we have
released the range, meaning in inode io tree, the EXTENT_QGROUP_RESERVED
bit is already cleared, thus all btrfs_qgroup_free_data() call won't
free any data rsv.
[FIX]
Add free_qgroup tag to manually free the released qgroup data rsv.
Reported-by: Nikolay Borisov <nborisov@suse.com>
Reported-by: David Sterba <dsterba@suse.cz>
Fixes:
|
||
|
Qu Wenruo
|
fbf48bb0b1 |
btrfs: track qgroup released data in own variable in insert_prealloc_file_extent
There is a piece of weird code in insert_prealloc_file_extent(), which
looks like:
ret = btrfs_qgroup_release_data(inode, file_offset, len);
if (ret < 0)
return ERR_PTR(ret);
if (trans) {
ret = insert_reserved_file_extent(trans, inode,
file_offset, &stack_fi,
true, ret);
...
}
extent_info.is_new_extent = true;
extent_info.qgroup_reserved = ret;
...
Note how the variable @ret is abused here, and if anyone is adding code
just after btrfs_qgroup_release_data() call, it's super easy to
overwrite the @ret and cause tons of qgroup related bugs.
Fix such abuse by introducing new variable @qgroup_released, so that we
won't reuse the existing variable @ret.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Qu Wenruo
|
d2dcc8ed8e |
btrfs: fix wrong offset to zero out range beyond i_size
[BUG] The test generic/091 fails , with the following output: fsx -N 10000 -o 128000 -l 500000 -r PSIZE -t BSIZE -w BSIZE -Z -W mapped writes DISABLED Seed set to 1 main: filesystem does not support fallocate mode FALLOC_FL_COLLAPSE_RANGE, disabling! main: filesystem does not support fallocate mode FALLOC_FL_INSERT_RANGE, disabling! skipping zero size read truncating to largest ever: 0xe400 copying to largest ever: 0x1f400 cloning to largest ever: 0x70000 cloning to largest ever: 0x77000 fallocating to largest ever: 0x7a120 Mapped Read: non-zero data past EOF (0x3a7ff) page offset 0x800 is 0xf2e1 <<< ... [CAUSE] In commit |
||
|
Naohiro Aota
|
badae9c869 |
btrfs: zoned: do not account freed region of read-only block group as zone_unusable
We migrate zone unusable bytes to read-only bytes when a block group is
set to read-only, and account all the free region as bytes_readonly.
Thus, we should not increase block_group->zone_unusable when the block
group is read-only.
Fixes:
|
||
|
Naohiro Aota
|
d734492a14 |
btrfs: zoned: use sector_t for zone sectors
We need to use sector_t for zone_sectors, or it would set the zone size
to zero when the size >= 4GB (= 2^24 sectors) by shifting the
zone_sectors value by SECTOR_SHIFT. We're assuming zones sizes up to
8GiB.
Fixes:
|
||
|
Qu Wenruo
|
c28ea613fa |
btrfs: subpage: fix the false data csum mismatch error
[BUG]
When running fstresss, we can hit strange data csum mismatch where the
on-disk data is in fact correct (passes scrub).
With some extra debug info added, we have the following traces:
0482us: btrfs_do_readpage: root=5 ino=284 offset=393216, submit force=0 pgoff=0 iosize=8192
0494us: btrfs_do_readpage: root=5 ino=284 offset=401408, submit force=0 pgoff=8192 iosize=4096
0498us: btrfs_submit_data_bio: root=5 ino=284 bio first bvec=393216 len=8192
0591us: btrfs_do_readpage: root=5 ino=284 offset=405504, submit force=0 pgoff=12288 iosize=36864
0594us: btrfs_submit_data_bio: root=5 ino=284 bio first bvec=401408 len=4096
0863us: btrfs_submit_data_bio: root=5 ino=284 bio first bvec=405504 len=36864
0933us: btrfs_verify_data_csum: root=5 ino=284 offset=393216 len=8192
0967us: btrfs_do_readpage: root=5 ino=284 offset=442368, skip beyond isize pgoff=49152 iosize=16384
1047us: btrfs_verify_data_csum: root=5 ino=284 offset=401408 len=4096
1163us: btrfs_verify_data_csum: root=5 ino=284 offset=405504 len=36864
1290us: check_data_csum: !!! root=5 ino=284 offset=438272 pg_off=45056 !!!
7387us: end_bio_extent_readpage: root=5 ino=284 before pending_read_bios=0
[CAUSE]
Normally we expect all submitted bio reads to only touch the range we
specified, and under subpage context, it means we should only touch the
range specified in each bvec.
But in data read path, inside end_bio_extent_readpage(), we have page
zeroing which only takes regular page size into consideration.
This means for subpage if we have an inode whose content looks like below:
0 16K 32K 48K 64K
|///////| |///////| |
|//| = data needs to be read from disk
| | = hole
And i_size is 64K initially.
Then the following race can happen:
T1 | T2
--------------------------------+--------------------------------
btrfs_do_readpage() |
|- isize = 64K; |
| At this time, the isize is |
| 64K |
| |
|- submit_extent_page() |
| submit previous assembled bio|
| assemble bio for [0, 16K) |
| |
|- submit_extent_page() |
submit read bio for [0, 16K) |
assemble read bio for |
[32K, 48K) |
|
| btrfs_setsize()
| |- i_size_write(, 16K);
| Now i_size is only 16K
end_io() for [0K, 16K) |
|- end_bio_extent_readpage() |
|- btrfs_verify_data_csum() |
| No csum error |
|- i_size = 16K; |
|- zero_user_segment(16K, |
PAGE_SIZE); |
!!! We zeroed range |
!!! [32K, 48K) |
| end_io for [32K, 48K)
| |- end_bio_extent_readpage()
| |- btrfs_verify_data_csum()
| ! CSUM MISMATCH !
| ! As the range is zeroed now !
[FIX]
To fix the problem, make end_bio_extent_readpage() to only zero the
range of bvec.
The bug only affects subpage read-write support, as for full read-only
mount we can't change i_size thus won't hit the race condition.
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Filipe Manana
|
fd57a98d6f |
btrfs: fix warning when creating a directory with smack enabled
When we have smack enabled, during the creation of a directory smack may attempt to add a "smack transmute" xattr on the inode, which results in the following warning and trace: WARNING: CPU: 3 PID: 2548 at fs/btrfs/transaction.c:537 start_transaction+0x489/0x4f0 Modules linked in: nft_objref nf_conntrack_netbios_ns (...) CPU: 3 PID: 2548 Comm: mkdir Not tainted 5.9.0-rc2smack+ #81 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 RIP: 0010:start_transaction+0x489/0x4f0 Code: e9 be fc ff ff (...) RSP: 0018:ffffc90001887d10 EFLAGS: 00010202 RAX: ffff88816f1e0000 RBX: 0000000000000201 RCX: 0000000000000003 RDX: 0000000000000201 RSI: 0000000000000002 RDI: ffff888177849000 RBP: ffff888177849000 R08: 0000000000000001 R09: 0000000000000004 R10: ffffffff825e8f7a R11: 0000000000000003 R12: ffffffffffffffe2 R13: 0000000000000000 R14: ffff88803d884270 R15: ffff8881680d8000 FS: 00007f67317b8440(0000) GS:ffff88817bcc0000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f67247a22a8 CR3: 000000004bfbc002 CR4: 0000000000370ee0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: ? slab_free_freelist_hook+0xea/0x1b0 ? trace_hardirqs_on+0x1c/0xe0 btrfs_setxattr_trans+0x3c/0xf0 __vfs_setxattr+0x63/0x80 smack_d_instantiate+0x2d3/0x360 security_d_instantiate+0x29/0x40 d_instantiate_new+0x38/0x90 btrfs_mkdir+0x1cf/0x1e0 vfs_mkdir+0x14f/0x200 do_mkdirat+0x6d/0x110 do_syscall_64+0x2d/0x40 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7f673196ae6b Code: 8b 05 11 (...) RSP: 002b:00007ffc3c679b18 EFLAGS: 00000246 ORIG_RAX: 0000000000000053 RAX: ffffffffffffffda RBX: 00000000000001ff RCX: 00007f673196ae6b RDX: 0000000000000000 RSI: 00000000000001ff RDI: 00007ffc3c67a30d RBP: 00007ffc3c67a30d R08: 00000000000001ff R09: 0000000000000000 R10: 000055d3e39fe930 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc3c679cd8 R14: 00007ffc3c67a30d R15: 00007ffc3c679ce0 irq event stamp: 11029 hardirqs last enabled at (11037): [<ffffffff81153fe6>] console_unlock+0x486/0x670 hardirqs last disabled at (11044): [<ffffffff81153c01>] console_unlock+0xa1/0x670 softirqs last enabled at (8864): [<ffffffff81e0102f>] asm_call_on_stack+0xf/0x20 softirqs last disabled at (8851): [<ffffffff81e0102f>] asm_call_on_stack+0xf/0x20 This happens because at btrfs_mkdir() we call d_instantiate_new() while holding a transaction handle, which results in the following call chain: btrfs_mkdir() trans = btrfs_start_transaction(root, 5); d_instantiate_new() smack_d_instantiate() __vfs_setxattr() btrfs_setxattr_trans() btrfs_start_transaction() start_transaction() WARN_ON() --> a tansaction start has TRANS_EXTWRITERS set in its type h->orig_rsv = h->block_rsv h->block_rsv = NULL btrfs_end_transaction(trans) Besides the warning triggered at start_transaction, we set the handle's block_rsv to NULL which may cause some surprises later on. So fix this by making btrfs_setxattr_trans() not start a transaction when we already have a handle on one, stored in current->journal_info, and use that handle. We are good to use the handle because at btrfs_mkdir() we did reserve space for the xattr and the inode item. Reported-by: Casey Schaufler <casey@schaufler-ca.com> CC: stable@vger.kernel.org # 5.4+ Acked-by: Casey Schaufler <casey@schaufler-ca.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Link: https://lore.kernel.org/linux-btrfs/434d856f-bd7b-4889-a6ec-e81aaebfa735@schaufler-ca.com/ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Nikolay Borisov
|
4d14c5cde5 |
btrfs: don't flush from btrfs_delayed_inode_reserve_metadata
Calling btrfs_qgroup_reserve_meta_prealloc from btrfs_delayed_inode_reserve_metadata can result in flushing delalloc while holding a transaction and delayed node locks. This is deadlock prone. In the past multiple commits: * |
||
|
Nikolay Borisov
|
80e9baed72 |
btrfs: export and rename qgroup_reserve_meta
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Nikolay Borisov
|
0f9c03d824 |
btrfs: free correct amount of space in btrfs_delayed_inode_reserve_metadata
Following commit |
||
Boris Burkov
|
c55a4319c4 |
btrfs: fix spurious free_space_tree remount warning
The intended logic of the check is to catch cases where the desired free_space_tree setting doesn't match the mounted setting, and the remount is anything but ro->rw. However, it makes the mistake of checking equality on a masked integer (btrfs_test_opt) against a boolean (btrfs_fs_compat_ro). If you run the reproducer: $ mount -o space_cache=v2 dev mnt $ mount -o remount,ro mnt you would expect no warning, because the remount is not attempting to change the free space tree setting, but we do see the warning. To fix this, add explicit bool type casts to the condition. I tested a variety of transitions: sudo mount -o space_cache=v2 /dev/vg0/lv0 mnt/lol (fst enabled) mount -o remount,ro mnt/lol (no warning, no fst change) sudo mount -o remount,rw,space_cache=v1,clear_cache (no warning, ro->rw) sudo mount -o remount,rw,space_cache=v2 mnt (warning, rw->rw with change) sudo mount -o remount,ro mnt (no warning, no fst change) sudo mount -o remount,rw,space_cache=v2 mnt (no warning, no fst change) Reported-by: Chris Murphy <lists@colorremedies.com> CC: stable@vger.kernel.org # 5.11 Signed-off-by: Boris Burkov <boris@bur.io> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Dan Carpenter
|
5011c5a663 |
btrfs: validate qgroup inherit for SNAP_CREATE_V2 ioctl
The problem is we're copying "inherit" from user space but we don't
necessarily know that we're copying enough data for a 64 byte
struct. Then the next problem is that 'inherit' has a variable size
array at the end, and we have to verify that array is the size we
expected.
Fixes:
|
||
|
Nikolay Borisov
|
4f6a49de64 |
btrfs: unlock extents in btrfs_zero_range in case of quota reservation errors
If btrfs_qgroup_reserve_data returns an error (i.e quota limit reached)
the handling logic directly goes to the 'out' label without first
unlocking the extent range between lockstart, lockend. This results in
deadlocks as other processes try to lock the same extent.
Fixes:
|
||
Randy Dunlap
|
aedb9d9089 |
btrfs: ref-verify: use 'inline void' keyword ordering
Fix build warnings of function signature when CONFIG_STACKTRACE is not enabled by reordering the 'inline' and 'void' keywords. ../fs/btrfs/ref-verify.c:221:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] static void inline __save_stack_trace(struct ref_action *ra) ../fs/btrfs/ref-verify.c:225:1: warning: ‘inline’ is not at beginning of declaration [-Wold-style-declaration] static void inline __print_stack_trace(struct btrfs_fs_info *fs_info, Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Johannes Thumshirn
|
6e37d24599 |
btrfs: zoned: fix deadlock on log sync
Lockdep with fstests test case btrfs/041 detected a unsafe locking
scenario when we allocate the log node on a zoned filesystem.
btrfs/041
============================================
WARNING: possible recursive locking detected
5.11.0-rc7+ #939 Not tainted
--------------------------------------------
xfs_io/698 is trying to acquire lock:
ffff88810cd673a0 (&root->log_mutex){+.+.}-{3:3}, at: btrfs_sync_log+0x3d1/0xee0 [btrfs]
but task is already holding lock:
ffff88810b0fc3a0 (&root->log_mutex){+.+.}-{3:3}, at: btrfs_sync_log+0x313/0xee0 [btrfs]
other info that might help us debug this:
Possible unsafe locking scenario:
CPU0
----
lock(&root->log_mutex);
lock(&root->log_mutex);
*** DEADLOCK ***
May be due to missing lock nesting notation
2 locks held by xfs_io/698:
#0: ffff88810cd66620 (sb_internal){.+.+}-{0:0}, at: btrfs_sync_file+0x2c3/0x570 [btrfs]
#1: ffff88810b0fc3a0 (&root->log_mutex){+.+.}-{3:3}, at: btrfs_sync_log+0x313/0xee0 [btrfs]
stack backtrace:
CPU: 0 PID: 698 Comm: xfs_io Not tainted 5.11.0-rc7+ #939
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.13.0-0-gf21b5a4-rebuilt.opensuse.org 04/01/2014
Call Trace:
dump_stack+0x77/0x97
__lock_acquire.cold+0xb9/0x32a
lock_acquire+0xb5/0x400
? btrfs_sync_log+0x3d1/0xee0 [btrfs]
__mutex_lock+0x7b/0x8d0
? btrfs_sync_log+0x3d1/0xee0 [btrfs]
? btrfs_sync_log+0x3d1/0xee0 [btrfs]
? find_first_extent_bit+0x9f/0x100 [btrfs]
? __mutex_unlock_slowpath+0x35/0x270
btrfs_sync_log+0x3d1/0xee0 [btrfs]
btrfs_sync_file+0x3a8/0x570 [btrfs]
__x64_sys_fsync+0x34/0x60
do_syscall_64+0x33/0x40
entry_SYSCALL_64_after_hwframe+0x44/0xa9
This happens, because we are taking the ->log_mutex albeit it has already
been locked.
Also while at it, fix the bogus unlock of the tree_log_mutex in the error
handling.
Fixes:
|
||
|
Josef Bacik
|
95c85fba1f |
btrfs: avoid double put of block group when emptying cluster
It's wrong calling btrfs_put_block_group in
__btrfs_return_cluster_to_free_space if the block group passed is
different than the block group the cluster represents. As this means the
cluster doesn't have a reference to the passed block group. This results
in double put and a use-after-free bug.
Fix this by simply bailing if the block group we passed in does not
match the block group on the cluster.
Fixes:
|
||
|
Filipe Manana
|
3660d0bcdb |
btrfs: fix stale data exposure after cloning a hole with NO_HOLES enabled
When using the NO_HOLES feature, if we clone a file range that spans only
a hole into a range that is at or beyond the current i_size of the
destination file, we end up not setting the full sync runtime flag on the
inode. As a result, if we then fsync the destination file and have a power
failure, after log replay we can end up exposing stale data instead of
having a hole for that range.
The conditions for this to happen are the following:
1) We have a file with a size of, for example, 1280K;
2) There is a written (non-prealloc) extent for the file range from 1024K
to 1280K with a length of 256K;
3) This particular file extent layout is durably persisted, so that the
existing superblock persisted on disk points to a subvolume root where
the file has that exact file extent layout and state;
4) The file is truncated to a smaller size, to an offset lower than the
start offset of its last extent, for example to 800K. The truncate sets
the full sync runtime flag on the inode;
6) Fsync the file to log it and clear the full sync runtime flag;
7) Clone a region that covers only a hole (implicit hole due to NO_HOLES)
into the file with a destination offset that starts at or beyond the
256K file extent item we had - for example to offset 1024K;
8) Since the clone operation does not find extents in the source range,
we end up in the if branch at the bottom of btrfs_clone() where we
punch a hole for the file range starting at offset 1024K by calling
btrfs_replace_file_extents(). There we end up not setting the full
sync flag on the inode, because we don't know we are being called in
a clone context (and not fallocate's punch hole operation), and
neither do we create an extent map to represent a hole because the
requested range is beyond eof;
9) A further fsync to the file will be a fast fsync, since the clone
operation did not set the full sync flag, and therefore it relies on
modified extent maps to correctly log the file layout. But since
it does not find any extent map marking the range from 1024K (the
previous eof) to the new eof, it does not log a file extent item
for that range representing the hole;
10) After a power failure no hole for the range starting at 1024K is
punched and we end up exposing stale data from the old 256K extent.
Turning this into exact steps:
$ mkfs.btrfs -f -O no-holes /dev/sdi
$ mount /dev/sdi /mnt
# Create our test file with 3 extents of 256K and a 256K hole at offset
# 256K. The file has a size of 1280K.
$ xfs_io -f -s \
-c "pwrite -S 0xab -b 256K 0 256K" \
-c "pwrite -S 0xcd -b 256K 512K 256K" \
-c "pwrite -S 0xef -b 256K 768K 256K" \
-c "pwrite -S 0x73 -b 256K 1024K 256K" \
/mnt/sdi/foobar
# Make sure it's durably persisted. We want the last committed super
# block to point to this particular file extent layout.
sync
# Now truncate our file to a smaller size, falling within a position of
# the second extent. This sets the full sync runtime flag on the inode.
# Then fsync the file to log it and clear the full sync flag from the
# inode. The third extent is no longer part of the file and therefore
# it is not logged.
$ xfs_io -c "truncate 800K" -c "fsync" /mnt/foobar
# Now do a clone operation that only clones the hole and sets back the
# file size to match the size it had before the truncate operation
# (1280K).
$ xfs_io \
-c "reflink /mnt/foobar 256K 1024K 256K" \
-c "fsync" \
/mnt/foobar
# File data before power failure:
$ od -A d -t x1 /mnt/foobar
|
||
|
Josef Bacik
|
1119a72e22 |
btrfs: tree-checker: do not error out if extent ref hash doesn't match
The tree checker checks the extent ref hash at read and write time to
make sure we do not corrupt the file system. Generally extent
references go inline, but if we have enough of them we need to make an
item, which looks like
key.objectid = <bytenr>
key.type = <BTRFS_EXTENT_DATA_REF_KEY|BTRFS_TREE_BLOCK_REF_KEY>
key.offset = hash(tree, owner, offset)
However if key.offset collide with an unrelated extent reference we'll
simply key.offset++ until we get something that doesn't collide.
Obviously this doesn't match at tree checker time, and thus we error
while writing out the transaction. This is relatively easy to
reproduce, simply do something like the following
xfs_io -f -c "pwrite 0 1M" file
offset=2
for i in {0..10000}
do
xfs_io -c "reflink file 0 ${offset}M 1M" file
offset=$(( offset + 2 ))
done
xfs_io -c "reflink file 0 17999258914816 1M" file
xfs_io -c "reflink file 0 35998517829632 1M" file
xfs_io -c "reflink file 0 53752752058368 1M" file
btrfs filesystem sync
And the sync will error out because we'll abort the transaction. The
magic values above are used because they generate hash collisions with
the first file in the main subvol.
The fix for this is to remove the hash value check from tree checker, as
we have no idea which offset ours should belong to.
Reported-by: Tuomas Lähdekorpi <tuomas.lahdekorpi@gmail.com>
Fixes:
|
||
|
Filipe Manana
|
dd0734f2a8 |
btrfs: fix race between swap file activation and snapshot creation
When creating a snapshot we check if the current number of swap files, in
the root, is non-zero, and if it is, we error out and warn that we can not
create the snapshot because there are active swap files.
However this is racy because when a task started activation of a swap
file, another task might have started already snapshot creation and might
have seen the counter for the number of swap files as zero. This means
that after the swap file is activated we may end up with a snapshot of the
same root successfully created, and therefore when the first write to the
swap file happens it has to fall back into COW mode, which should never
happen for active swap files.
Basically what can happen is:
1) Task A starts snapshot creation and enters ioctl.c:create_snapshot().
There it sees that root->nr_swapfiles has a value of 0 so it continues;
2) Task B enters btrfs_swap_activate(). It is not aware that another task
started snapshot creation but it did not finish yet. It increments
root->nr_swapfiles from 0 to 1;
3) Task B checks that the file meets all requirements to be an active
swap file - it has NOCOW set, there are no snapshots for the inode's
root at the moment, no file holes, no reflinked extents, etc;
4) Task B returns success and now the file is an active swap file;
5) Task A commits the transaction to create the snapshot and finishes.
The swap file's extents are now shared between the original root and
the snapshot;
6) A write into an extent of the swap file is attempted - there is a
snapshot of the file's root, so we fall back to COW mode and therefore
the physical location of the extent changes on disk.
So fix this by taking the snapshot lock during swap file activation before
locking the extent range, as that is the order in which we lock these
during buffered writes.
Fixes:
|
||
|
Filipe Manana
|
195a49eaf6 |
btrfs: fix race between writes to swap files and scrub
When we active a swap file, at btrfs_swap_activate(), we acquire the
exclusive operation lock to prevent the physical location of the swap
file extents to be changed by operations such as balance and device
replace/resize/remove. We also call there can_nocow_extent() which,
among other things, checks if the block group of a swap file extent is
currently RO, and if it is we can not use the extent, since a write
into it would result in COWing the extent.
However we have no protection against a scrub operation running after we
activate the swap file, which can result in the swap file extents to be
COWed while the scrub is running and operating on the respective block
group, because scrub turns a block group into RO before it processes it
and then back again to RW mode after processing it. That means an attempt
to write into a swap file extent while scrub is processing the respective
block group, will result in COWing the extent, changing its physical
location on disk.
Fix this by making sure that block groups that have extents that are used
by active swap files can not be turned into RO mode, therefore making it
not possible for a scrub to turn them into RO mode. When a scrub finds a
block group that can not be turned to RO due to the existence of extents
used by swap files, it proceeds to the next block group and logs a warning
message that mentions the block group was skipped due to active swap
files - this is the same approach we currently use for balance.
Fixes:
|
||
|
Filipe Manana
|
20903032cd |
btrfs: avoid checking for RO block group twice during nocow writeback
During the nocow writeback path, we currently iterate the rbtree of block groups twice: once for checking if the target block group is RO with the call to btrfs_extent_readonly()), and once again for getting a nocow reference on the block group with a call to btrfs_inc_nocow_writers(). Since btrfs_inc_nocow_writers() already returns false when the target block group is RO, remove the call to btrfs_extent_readonly(). Not only we avoid searching the blocks group rbtree twice, it also helps reduce contention on the lock that protects it (specially since it is a spin lock and not a read-write lock). That may make a noticeable difference on very large filesystems, with thousands of allocated block groups. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Nikolay Borisov
|
3c17916510 |
btrfs: fix race between extent freeing/allocation when using bitmaps
During allocation the allocator will try to allocate an extent using
cluster policy. Once the current cluster is exhausted it will remove the
entry under btrfs_free_cluster::lock and subsequently acquire
btrfs_free_space_ctl::tree_lock to dispose of the already-deleted entry
and adjust btrfs_free_space_ctl::total_bitmap. This poses a problem
because there exists a race condition between removing the entry under
one lock and doing the necessary accounting holding a different lock
since extent freeing only uses the 2nd lock. This can result in the
following situation:
T1: T2:
btrfs_alloc_from_cluster insert_into_bitmap <holds tree_lock>
if (entry->bytes == 0) if (block_group && !list_empty(&block_group->cluster_list)) {
rb_erase(entry)
spin_unlock(&cluster->lock);
(total_bitmaps is still 4) spin_lock(&cluster->lock);
<doesn't find entry in cluster->root>
spin_lock(&ctl->tree_lock); <goes to new_bitmap label, adds
<blocked since T2 holds tree_lock> <a new entry and calls add_new_bitmap>
recalculate_thresholds <crashes,
due to total_bitmaps
becoming 5 and triggering
an ASSERT>
To fix this ensure that once depleted, the cluster entry is deleted when
both cluster lock and tree locks are held in the allocator (T1), this
ensures that even if there is a race with a concurrent
insert_into_bitmap call it will correctly find the entry in the cluster
and add the new space to it.
CC: <stable@vger.kernel.org> # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Qu Wenruo
|
04d4ba4c90 |
btrfs: make check_compressed_csum() to be subpage compatible
Currently check_compressed_csum() completely relies on sectorsize == PAGE_SIZE to do checksum verification for compressed extents. To make it subpage compatible, this patch will: - Do extra calculation for the csum range Since we have multiple sectors inside a page, we need to only hash the range we want, not the full page anymore. - Do sector-by-sector hash inside the page With this patch and previous conversion on btrfs_submit_compressed_read(), now we can read subpage compressed extents properly, and do proper csum verification. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Qu Wenruo
|
be6a13613f |
btrfs: make btrfs_submit_compressed_read() subpage compatible
For compressed read, we always submit page read using page size. This doesn't work well with subpage, as for subpage one page can contain several sectors. Such submission will read range out of what we want, and cause problems. Thankfully to make it subpage compatible, we only need to change how the last page of the compressed extent is read. Instead of always adding a full page to the compressed read bio, if we're at the last page, calculate the size using compressed length, so that we only add part of the range into the compressed read bio. Since we are here, also change the PAGE_SIZE used in lookup_extent_mapping() to sectorsize. This modification won't cause any functional change, as lookup_extent_mapping() can handle the case where the search range is larger than found extent range. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
Ira Weiny
|
d70cef0d46 |
btrfs: fix raid6 qstripe kmap
When a qstripe is required an extra page is allocated and mapped. There were 3 problems: 1) There is no corresponding call of kunmap() for the qstripe page. 2) There is no reason to map the qstripe page more than once if the number of bits set in rbio->dbitmap is greater than one. 3) There is no reason to map the parity page and unmap it each time through the loop. The page memory can continue to be reused with a single mapping on each iteration by raid6_call.gen_syndrome() without remapping. So map the page for the duration of the loop. Similarly, improve the algorithm by mapping the parity page just 1 time. Fixes: |
||
|
Naohiro Aota
|
9d294a685f |
btrfs: zoned: enable to mount ZONED incompat flag
This final patch adds the ZONED incompat flag to the supported flags and enables to mount ZONED flagged file system. Reviewed-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
b528f46713 |
btrfs: zoned: deal with holes writing out tree-log pages
Since the zoned filesystem requires sequential write out of metadata, we cannot proceed with a hole in tree-log pages. When such a hole exists, btree_write_cache_pages() will return -EAGAIN. This happens when someone, e.g., a concurrent transaction commit, writes a dirty extent in this tree-log commit. If we are not going to wait for the extents, we can hope the concurrent writing fills the hole for us. So, we can ignore the error in this case and hope the next write will succeed. If we want to wait for them and got the error, we cannot wait for them because it will cause a deadlock. So, let's bail out to a full commit in this case. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
3ddebf27fc |
btrfs: zoned: reorder log node allocation on zoned filesystem
This is the 3/3 patch to enable tree-log on zoned filesystems. The allocation order of nodes of "fs_info->log_root_tree" and nodes of "root->log_root" is not the same as the writing order of them. So, the writing causes unaligned write errors. Reorder the allocation of them by delaying allocation of the root node of "fs_info->log_root_tree," so that the node buffers can go out sequentially to devices. Cc: Filipe Manana <fdmanana@gmail.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
fa1a0f42a0 |
btrfs: zoned: serialize log transaction on zoned filesystems
This is the 2/3 patch to enable tree-log on zoned filesystems. Since we can start more than one log transactions per subvolume simultaneously, nodes from multiple transactions can be allocated interleaved. Such mixed allocation results in non-sequential writes at the time of a log transaction commit. The nodes of the global log root tree (fs_info->log_root_tree), also have the same problem with mixed allocation. Serializes log transactions by waiting for a committing transaction when someone tries to start a new transaction, to avoid the mixed allocation problem. We must also wait for running log transactions from another subvolume, but there is no easy way to detect which subvolume root is running a log transaction. So, this patch forbids starting a new log transaction when other subvolumes already allocated the global log root tree. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
40ab3be102 |
btrfs: zoned: extend zoned allocator to use dedicated tree-log block group
This is the 1/3 patch to enable tree log on zoned filesystems. The tree-log feature does not work on a zoned filesystem as is. Blocks for a tree-log tree are allocated mixed with other metadata blocks and btrfs writes and syncs the tree-log blocks to devices at the time of fsync(), which has a different timing than a global transaction commit. As a result, both writing tree-log blocks and writing other metadata blocks become non-sequential writes that zoned filesystems must avoid. Introduce a dedicated block group for tree-log blocks, so that tree-log blocks and other metadata blocks can be separate write streams. As a result, each write stream can now be written to devices separately. "fs_info->treelog_bg" tracks the dedicated block group and assigns "treelog_bg" on-demand on tree-log block allocation time. This commit extends the zoned block allocator to use the block group. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
6ab6ebb760 |
btrfs: split alloc_log_tree()
This is a preparation patch for the next patch. Split alloc_log_tree() into two parts. The first one allocating the tree structure, remains in alloc_log_tree() and the second part allocating the tree node, which is moved into btrfs_alloc_log_tree_node(). Also export the latter part is to be used in the next patch. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
f7ef5287a6 |
btrfs: zoned: relocate block group to repair IO failure in zoned filesystems
When a bad checksum is found and if the filesystem has a mirror of the
damaged data, we read the correct data from the mirror and writes it to
damaged blocks. This however, violates the sequential write constraints
of a zoned block device.
We can consider three methods to repair an IO failure in zoned filesystems:
(1) Reset and rewrite the damaged zone
(2) Allocate new device extent and replace the damaged device extent to
the new extent
(3) Relocate the corresponding block group
Method (1) is most similar to a behavior done with regular devices.
However, it also wipes non-damaged data in the same device extent, and
so it unnecessary degrades non-damaged data.
Method (2) is much like device replacing but done in the same device. It
is safe because it keeps the device extent until the replacing finish.
However, extending device replacing is non-trivial. It assumes
"src_dev->physical == dst_dev->physical". Also, the extent mapping
replacing function should be extended to support replacing device extent
position in one device.
Method (3) invokes relocation of the damaged block group and is
straightforward to implement. It relocates all the mirrored device
extents, so it potentially is a more costly operation than method (1) or
(2). But it relocates only used extents which reduce the total IO size.
Let's apply method (3) for now. In the future, we can extend device-replace
and apply method (2).
For protecting a block group gets relocated multiple time with multiple
IO errors, this commit introduces "relocating_repair" bit to show it's
now relocating to repair IO failures. Also it uses a new kthread
"btrfs-relocating-repair", not to block IO path with relocating process.
This commit also supports repairing in the scrub process.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
|
||
|
Naohiro Aota
|
32430c6148 |
btrfs: zoned: enable relocation on a zoned filesystem
Currently fallocate() is disabled on a zoned filesystem. Since current relocation process relies on preallocation to move file data extents, it must be handled differently. On a zoned filesystem, we just truncate the inode to the size that we wanted to pre-allocate. Then, we flush dirty pages on the file before finishing the relocation process. run_delalloc_zoned() will handle all the allocations and submit IOs to the underlying layers. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
7db1c5d14d |
btrfs: zoned: support dev-replace in zoned filesystems
This is 4/4 patch to implement device-replace on zoned filesystems. Even after the copying is done, the write pointers of the source device and the destination device may not be synchronized. For example, when the last allocated extent is freed before device-replace process, the extent is not copied, leaving a hole there. Synchronize the write pointers by writing zeroes to the destination device. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com> |
||
|
Naohiro Aota
|
de17addce7 |
btrfs: zoned: implement copying for zoned device-replace
This is 3/4 patch to implement device-replace on zoned filesystems.
This commit implements copying. To do this, it tracks the write pointer
during the device replace process. As device-replace's copy process is
smart enough to only copy used extents on the source device, we have to
fill the gap to honor the sequential write requirement in the target
device.
The device-replace process on zoned filesystems must copy or clone all
the extents in the source device exactly once. So, we need to ensure
allocations started just before the dev-replace process to have their
corresponding extent information in the B-trees.
finish_extent_writes_for_zoned() implements that functionality, which
basically is the removed code in the commit
|