- 23 Mar, 2020 40 commits
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Naohiro Aota authored
This commit introduces extent allocation policy for btrfs. This policy controls how btrfs allocate an extents from block groups. There is no functional change introduced with this commit. 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:
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Naohiro Aota authored
Currently, we ignore a device whose available space is less than "BTRFS_STRIPE_LEN * dev_stripes". This is a lower limit for current allocation policy (to maximize the number of stripes). This commit parameterizes dev_extent_min, so that other policies can set their own lower limitat to ignore a device with insufficient space. Reviewed-by:
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Naohiro Aota authored
Factor out create_chunk() from __btrfs_alloc_chunk(). This function finally creates a chunk. There is no functional changes. Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
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Naohiro Aota authored
Factor out decide_stripe_size() from __btrfs_alloc_chunk(). This function calculates the actual stripe size to allocate. decide_stripe_size() handles the common case to round down the 'ndevs' to 'devs_increment' and check the upper and lower limitation of 'ndevs'. decide_stripe_size_regular() decides the size of a stripe and the size of a chunk. The policy is to maximize the number of stripes. This commit has no functional changes. Reviewed-by:
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Naohiro Aota authored
Factor out gather_device_info() from __btrfs_alloc_chunk(). This function iterates over devices list and gather information about devices. This commit also introduces "max_avail" and "dev_extent_min" to fold the same calculation to one variable. This commit has no functional changes. Reviewed-by:
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Naohiro Aota authored
Factor out init_alloc_chunk_ctl() from __btrfs_alloc_chunk(). This function initialises parameters of "struct alloc_chunk_ctl" for allocation. init_alloc_chunk_ctl() handles a common part of the initialisation to load the RAID parameters from btrfs_raid_array. init_alloc_chunk_ctl_policy_regular() decides some parameters for its allocation. The last "else" case in the original code is moved to __btrfs_alloc_chunk() to handle the error case in the common code. Replace the BUG_ON with ASSERT() and error return at the same time. Reviewed-by:
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Naohiro Aota authored
Introduce "struct alloc_chunk_ctl" to wrap needed parameters for the chunk allocation. This will be used to split __btrfs_alloc_chunk() into smaller functions. This commit folds a number of local variables in __btrfs_alloc_chunk() into one "struct alloc_chunk_ctl ctl". There is no functional change. Reviewed-by:
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Naohiro Aota authored
Factor out two functions from find_free_dev_extent_start(). dev_extent_search_start() decides the starting position of the search. dev_extent_hole_check() checks if a hole found is suitable for device extent allocation. These functions also have the switch-cases to change the allocation behavior depending on the policy. Reviewed-by:
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Naohiro Aota authored
Introduce chunk allocation policy for btrfs. This policy controls how chunks and device extents are allocated from devices. Reviewed-by:
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Naohiro Aota authored
Do not BUG_ON() when an invalid profile is passed to __btrfs_alloc_chunk(). Instead return -EINVAL with ASSERT() to catch a bug in the development stage. Suggested-by:
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Naohiro Aota authored
While the "full_search" variable defined in find_free_extent() is bool, but the full_search argument of find_free_extent_update_loop() is defined as int. Let's trivially fix the argument type. Reviewed-by:
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Qu Wenruo authored
After the previous patch, qgroup_rescan_running is protected by btrfs_fs_info::qgroup_rescan_lock, thus no need for the extra spinlock. Suggested-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
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Qu Wenruo authored
[BUG] There are some reports about btrfs wait forever to unmount itself, with the following call trace: INFO: task umount:4631 blocked for more than 491 seconds. Tainted: G X 5.3.8-2-default #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. umount D 0 4631 3337 0x00000000 Call Trace: ([<00000000174adf7a>] __schedule+0x342/0x748) [<00000000174ae3ca>] schedule+0x4a/0xd8 [<00000000174b1f08>] schedule_timeout+0x218/0x420 [<00000000174af10c>] wait_for_common+0x104/0x1d8 [<000003ff804d6994>] btrfs_qgroup_wait_for_completion+0x84/0xb0 [btrfs] [<000003ff8044a616>] close_ctree+0x4e/0x380 [btrfs] [<0000000016fa3136>] generic_shutdown_super+0x8e/0x158 [<0000000016fa34d6>] kill_anon_super+0x26/0x40 [<000003ff8041ba88>] btrfs_kill_super+0x28/0xc8 [btrfs] [<0000000016fa39f8>] deactivate_locked_super+0x68/0x98 [<0000000016fcb198>] cleanup_mnt+0xc0/0x140 [<0000000016d6a846>] task_work_run+0xc6/0x110 [<0000000016d04f76>] do_notify_resume+0xae/0xb8 [<00000000174b30ae>] system_call+0xe2/0x2c8 [CAUSE] The problem happens when we have called qgroup_rescan_init(), but not queued the worker. It can be caused mostly by error handling. Qgroup ioctl thread | Unmount thread ----------------------------------------+----------------------------------- | btrfs_qgroup_rescan() | |- qgroup_rescan_init() | | |- qgroup_rescan_running = true; | | | |- trans = btrfs_join_transaction() | | Some error happened | | | |- btrfs_qgroup_rescan() returns error | But qgroup_rescan_running == true; | | close_ctree() | |- btrfs_qgroup_wait_for_completion() | |- running == true; | |- wait_for_completion(); btrfs_qgroup_rescan_worker is never queued, thus no one is going to wake up close_ctree() and we get a deadlock. All involved qgroup_rescan_init() callers are: - btrfs_qgroup_rescan() The example above. It's possible to trigger the deadlock when error happened. - btrfs_quota_enable() Not possible. Just after qgroup_rescan_init() we queue the work. - btrfs_read_qgroup_config() It's possible to trigger the deadlock. It only init the work, the work queueing happens in btrfs_qgroup_rescan_resume(). Thus if error happened in between, deadlock is possible. We shouldn't set fs_info->qgroup_rescan_running just in qgroup_rescan_init(), as at that stage we haven't yet queued qgroup rescan worker to run. [FIX] Set qgroup_rescan_running before queueing the work, so that we ensure the rescan work is queued when we wait for it. Fixes: 8d9eddad ("Btrfs: fix qgroup rescan worker initialization") Signed-off-by:Jeff Mahoney <jeffm@suse.com> [ Change subject and cause analyse, use a smaller fix ] Signed-off-by:
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Andy Shevchenko authored
uuid_le_gen() is no used anymore, remove it for good. Reviewed-by:
Christoph Hellwig <hch@lst.de> Signed-off-by:
Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by:
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Andy Shevchenko authored
There are new types and helpers that are supposed to be used in new code. As a preparation to get rid of legacy types and API functions do the conversion here. Reviewed-by:
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Andy Shevchenko authored
In some cases we would like to generate a GUID and export it. Though it would require either casting to internal kernel types or an intermediate buffer. Instead we may achieve this by supplying a pointer to raw buffer and make a complimentary API to existing one for UUIDs. Reviewed-by:
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Andy Shevchenko authored
Sometimes we may need to import UUID from or export to the raw buffer, which is provided outside of kernel and can't be declared as UUID type. With current API this operation will require an explicit casting to one of UUID types and length, that is always a constant derived as sizeof the certain UUID type. Provide a helpful set of inline helpers to minimize developer's effort in the cases when raw buffers are involved. Suggested-by:
David Sterba <dsterba@suse.cz> Acked-by:
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Qu Wenruo authored
[BUG] There is a fuzzed image which could cause KASAN report at unmount time. BUG: KASAN: use-after-free in btrfs_queue_work+0x2c1/0x390 Read of size 8 at addr ffff888067cf6848 by task umount/1922 CPU: 0 PID: 1922 Comm: umount Tainted: G W 5.0.21 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 Call Trace: dump_stack+0x5b/0x8b print_address_description+0x70/0x280 kasan_report+0x13a/0x19b btrfs_queue_work+0x2c1/0x390 btrfs_wq_submit_bio+0x1cd/0x240 btree_submit_bio_hook+0x18c/0x2a0 submit_one_bio+0x1be/0x320 flush_write_bio.isra.41+0x2c/0x70 btree_write_cache_pages+0x3bb/0x7f0 do_writepages+0x5c/0x130 __writeback_single_inode+0xa3/0x9a0 writeback_single_inode+0x23d/0x390 write_inode_now+0x1b5/0x280 iput+0x2ef/0x600 close_ctree+0x341/0x750 generic_shutdown_super+0x126/0x370 kill_anon_super+0x31/0x50 btrfs_kill_super+0x36/0x2b0 deactivate_locked_super+0x80/0xc0 deactivate_super+0x13c/0x150 cleanup_mnt+0x9a/0x130 task_work_run+0x11a/0x1b0 exit_to_usermode_loop+0x107/0x130 do_syscall_64+0x1e5/0x280 entry_SYSCALL_64_after_hwframe+0x44/0xa9 [CAUSE] The fuzzed image has a completely screwd up extent tree: leaf 29421568 gen 8 total ptrs 6 free space 3587 owner EXTENT_TREE refs 2 lock (w:0 r:0 bw:0 br:0 sw:0 sr:0) lock_owner 0 current 5938 item 0 key (12587008 168 4096) itemoff 3942 itemsize 53 extent refs 1 gen 9 flags 1 ref#0: extent data backref root 5 objectid 259 offset 0 count 1 item 1 key (12591104 168 8192) itemoff 3889 itemsize 53 extent refs 1 gen 9 flags 1 ref#0: extent data backref root 5 objectid 271 offset 0 count 1 item 2 key (12599296 168 4096) itemoff 3836 itemsize 53 extent refs 1 gen 9 flags 1 ref#0: extent data backref root 5 objectid 259 offset 4096 count 1 item 3 key (29360128 169 0) itemoff 3803 itemsize 33 extent refs 1 gen 9 flags 2 ref#0: tree block backref root 5 item 4 key (29368320 169 1) itemoff 3770 itemsize 33 extent refs 1 gen 9 flags 2 ref#0: tree block backref root 5 item 5 key (29372416 169 0) itemoff 3737 itemsize 33 extent refs 1 gen 9 flags 2 ref#0: tree block backref root 5 Note that leaf 29421568 doesn't have its backref in the extent tree. Thus extent allocator can re-allocate leaf 29421568 for other trees. In short, the bug is caused by: - Existing tree block gets allocated to log tree This got its generation bumped. - Log tree balance cleaned dirty bit of offending tree block It will not be written back to disk, thus no WRITTEN flag. - Original owner of the tree block gets COWed Since the tree block has higher transid, no WRITTEN flag, it's reused, and not traced by transaction::dirty_pages. - Transaction aborted Tree blocks get cleaned according to transaction::dirty_pages. But the offending tree block is not recorded at all. - Filesystem unmount All pages are assumed to be are clean, destroying all workqueue, then call iput(btree_inode). But offending tree block is still dirty, which triggers writeback, and causes use-after-free bug. The detailed sequence looks like this: - Initial status eb: 29421568, header=WRITTEN bflags_dirty=0, page_dirty=0, gen=8, not traced by any dirty extent_iot_tree. - New tree block is allocated Since there is no backref for 29421568, it's re-allocated as new tree block. Keep in mind that tree block 29421568 is still referred by extent tree. - Tree block 29421568 is filled for log tree eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9 << (gen bumped) traced by btrfs_root::dirty_log_pages - Some log tree operations Since the fs is using node size 4096, the log tree can easily go a level higher. - Log tree needs balance Tree block 29421568 gets all its content pushed to right, thus now it is empty, and we don't need it. btrfs_clean_tree_block() from __push_leaf_right() get called. eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9 traced by btrfs_root::dirty_log_pages - Log tree write back btree_write_cache_pages() goes through dirty pages ranges, but since page of tree block 29421568 gets cleaned already, it's not written back to disk. Thus it doesn't have WRITTEN bit set. But ranges in dirty_log_pages are cleared. eb: 29421568, header=0 bflags_dirty=0, page_dirty=0, gen=9 not traced by any dirty extent_iot_tree. - Extent tree update when committing transaction Since tree block 29421568 has transid equal to running trans, and has no WRITTEN bit, should_cow_block() will use it directly without adding it to btrfs_transaction::dirty_pages. eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9 not traced by any dirty extent_iot_tree. At this stage, we're doomed. We have a dirty eb not tracked by any extent io tree. - Transaction gets aborted due to corrupted extent tree Btrfs cleans up dirty pages according to transaction::dirty_pages and btrfs_root::dirty_log_pages. But since tree block 29421568 is not tracked by neither of them, it's still dirty. eb: 29421568, header=0 bflags_dirty=1, page_dirty=1, gen=9 not traced by any dirty extent_iot_tree. - Filesystem unmount Since all cleanup is assumed to be done, all workqueus are destroyed. Then iput(btree_inode) is called, expecting no dirty pages. But tree 29421568 is still dirty, thus triggering writeback. Since all workqueues are already freed, we cause use-after-free. This shows us that, log tree blocks + bad extent tree can cause wild dirty pages. [FIX] To fix the problem, don't submit any btree write bio if the filesytem has any error. This is the last safe net, just in case other cleanup haven't caught catch it. Link: https://github.com/bobfuzzer/CVE/tree/master/CVE-2019-19377 CC: stable@vger.kernel.org # 5.4+ Reviewed-by: -
Marcos Paulo de Souza authored
There is no point to inform the user about size change if there's none. Update the message to conform to a commonly used format where the path and devid are printed and also print old and new sizes. Reviewed-by:
Marcos Paulo de Souza <marcos@mpdesouza.com> Reviewed-by:
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Anand Jain authored
In btrfs_update_global_block_rsv the lines: num_bytes = block_rsv->size - block_rsv->reserved; block_rsv->reserved += num_bytes; imply: block_rsv->reserved = block_rsv->size; Assign block_rsv->size to block_rsv->reserved directly and reorder lines so they match the other branch. Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
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David Sterba authored
The tree_log_mutex and reloc_mutex locks are properly nested so we can simplify error handling and add labels for them. This reduces line count of the function. Reviewed-by:
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David Sterba authored
All we need to read is checksum size from fs_info superblock, and fs_info is provided by extent buffer so we can get rid of the wild pointer indirections from page/inode/root. Reviewed-by:
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David Sterba authored
The message seems to be for debugging and has little value for users. Reviewed-by:
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David Sterba authored
We don't use the u_XX types anywhere, though they're defined. Reviewed-by:
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David Sterba authored
Remove trivial comprator and open coded swap of two values. Reviewed-by:
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David Sterba authored
An unrecognized option is a failure that should get user/administrator attention, the info level is often below what gets logged, so make it error. Reviewed-by:
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David Sterba authored
All callers pass extent buffer start and length so the extent buffer itself should work fine. Reviewed-by:
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David Sterba authored
The helper btrfs_header_chunk_tree_uuid follows naming convention of other struct accessors but does something compeletly different. As the offsetof calculation is clear in the context of extent buffer operations we can remove it. Reviewed-by:
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David Sterba authored
The helper btrfs_header_fsid follows naming convention of other struct accessors but does something compeletly different. As the offsetof calculation is clear in the context of extent buffer operations we can remove it. Reviewed-by:
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David Sterba authored
There's a simple forwarded call based on the operation that would better fit the caller btrfs_map_block that's until now a trivial wrapper. Reviewed-by:
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David Sterba authored
The struct_size macro does the same calculation and is safe regarding overflows. Though we're not expecting them to happen, use the helper for clarity. Reviewed-by:
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Nikolay Borisov authored
This patch removes all haphazard code implementing nocow writers exclusion from pending snapshot creation and switches to using the drew lock to ensure this invariant still holds. 'Readers' are snapshot creators from create_snapshot and 'writers' are nocow writers from buffered write path or btrfs_setsize. This locking scheme allows for multiple snapshots to happen while any nocow writers are blocked, since writes to page cache in the nocow path will make snapshots inconsistent. So for performance reasons we'd like to have the ability to run multiple concurrent snapshots and also favors readers in this case. And in case there aren't pending snapshots (which will be the majority of the cases) we rely on the percpu's writers counter to avoid cacheline contention. The main gain from using the drew lock is it's now a lot easier to reason about the guarantees of the locking scheme and whether there is some silent breakage lurking. Signed-off-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
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Nikolay Borisov authored
A (D)ouble (R)eader (W)riter (E)xclustion lock is a locking primitive that allows to have multiple readers or multiple writers but not multiple readers and writers holding it concurrently. The code is factored out from the existing open-coded locking scheme used to exclude pending snapshots from nocow writers and vice-versa. Current implementation actually favors Readers (that is snapshot creaters) to writers (nocow writers of the filesystem). The API provides lock/unlock/trylock for reads and writes. Formal specification for TLA+ provided by Valentin Schneider is at https://lore.kernel.org/linux-btrfs/2dcaf81c-f0d3-409e-cb29-733d8b3b4cc9@arm.com/Signed-off-by:
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Johannes Thumshirn authored
The error cleanup gotos in __btrfs_write_out_cache() needlessly jump back making the code less readable then needed. Flatten them out so no back-jump is necessary and the read flow is uninterrupted. Reviewed-by:
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Johannes Thumshirn authored
free-space-cache.c has it's own set of DEBUG ifdefs which need to be turned on instead of the global CONFIG_BTRFS_DEBUG to print debug messages about failed block-group writes. Switch this over to CONFIG_BTRFS_DEBUG so we always see these messages when running a debug kernel. Reviewed-by:
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Johannes Thumshirn authored
Make the uptodate argument of io_ctl_add_pages() boolean. Reviewed-by:
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Johannes Thumshirn authored
io_ctl_prepare_pages() gets a 'struct btrfs_io_ctl' as well as a 'struct inode', but btrfs_io_ctl::inode points to the same struct inode as this is assgined in io_ctl_init(). Use the inode form io_ctl to reduce the arguments of io_ctl_prepare_pages. Reviewed-by:
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Marcos Paulo de Souza authored
This ioctl will be responsible for deleting a subvolume using its id. This can be used when a system has a file system mounted from a subvolume, rather than the root file system, like below: / @subvol1/ @subvol2/ @subvol_default/ If only @subvol_default is mounted, we have no path to reach @subvol1 and @subvol2, thus no way to delete them. Current subvolume delete ioctl takes a file handle point as argument, and if @subvol_default is mounted, we can't reach @subvol1 and @subvol2 from the same mount point. This patch introduces a new ioctl BTRFS_IOC_SNAP_DESTROY_V2 that takes the extended structure with flags to allow to delete subvolume using subvolid. Now, we can use this new ioctl specifying the subvolume id and refer to the same mount point. It doesn't matter which subvolume was mounted, since we can reach to the desired one using the subvolume id, and then delete it. The full path to the subvolume id is resolved internally and access is verified as if the subvolume was accessed by path. The volume args v2 structure is extended to use the existing union for subvolume id specification, that's valid in case the BTRFS_SUBVOL_SPEC_BY_ID is set. Signed-off-by:
Marcos Paulo de Souza <mpdesouza@suse.com> Reviewed-by:
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Marcos Paulo de Souza authored
The functions will be used outside of export.c and super.c to allow resolving subvolume name from a given id, eg. for subvolume deletion by id ioctl. Signed-off-by:
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David Sterba authored
When the device remove v2 ioctl was added, the full support mask was added to sanity check the flags. However this would allow to let the subvolume related flags to be accepted. This is not supposed to happen. Use the correct support mask, which means that now any of BTRFS_SUBVOL_CREATE_ASYNC, BTRFS_SUBVOL_RDONLY or BTRFS_SUBVOL_QGROUP_INHERIT will be rejected as ENOTSUPP. Though this is a user-visible change, specifying subvolume flags for device deletion does not make sense and there are hopefully no applications doing that. Reviewed-by:
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