- 17 Dec, 2018 40 commits
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Josef Bacik authored
With my delayed refs patches in place we started seeing a large amount of aborts in __btrfs_free_extent: BTRFS error (device sdb1): unable to find ref byte nr 91947008 parent 0 root 35964 owner 1 offset 0 Call Trace: ? btrfs_merge_delayed_refs+0xaf/0x340 __btrfs_run_delayed_refs+0x6ea/0xfc0 ? btrfs_set_path_blocking+0x31/0x60 btrfs_run_delayed_refs+0xeb/0x180 btrfs_commit_transaction+0x179/0x7f0 ? btrfs_check_space_for_delayed_refs+0x30/0x50 ? should_end_transaction.isra.19+0xe/0x40 btrfs_drop_snapshot+0x41c/0x7c0 btrfs_clean_one_deleted_snapshot+0xb5/0xd0 cleaner_kthread+0xf6/0x120 kthread+0xf8/0x130 ? btree_invalidatepage+0x90/0x90 ? kthread_bind+0x10/0x10 ret_from_fork+0x35/0x40 This was because btrfs_drop_snapshot depends on the root not being modified while it's dropping the snapshot. It will unlock the root node (and really every node) as it walks down the tree, only to re-lock it when it needs to do something. This is a problem because if we modify the tree we could cow a block in our path, which frees our reference to that block. Then once we get back to that shared block we'll free our reference to it again, and get ENOENT when trying to lookup our extent reference to that block in __btrfs_free_extent. This is ultimately happening because we have delayed items left to be processed for our deleted snapshot _after_ all of the inodes are closed for the snapshot. We only run the delayed inode item if we're deleting the inode, and even then we do not run the delayed insertions or delayed removals. These can be run at any point after our final inode does its last iput, which is what triggers the snapshot deletion. We can end up with the snapshot deletion happening and then have the delayed items run on that file system, resulting in the above problem. This problem has existed forever, however my patches made it much easier to hit as I wake up the cleaner much more often to deal with delayed iputs, which made us more likely to start the snapshot dropping work before the transaction commits, which is when the delayed items would generally be run. Before, generally speaking, we would run the delayed items, commit the transaction, and wakeup the cleaner thread to start deleting snapshots, which means we were less likely to hit this problem. You could still hit it if you had multiple snapshots to be deleted and ended up with lots of delayed items, but it was definitely harder. Fix for now by simply running all the delayed items before starting to drop the snapshot. We could make this smarter in the future by making the delayed items per-root, and then simply drop any delayed items for roots that we are going to delete. But for now just a quick and easy solution is the safest. CC: stable@vger.kernel.org # 4.4+ Reviewed-by:
Filipe Manana <fdmanana@suse.com> Signed-off-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
David Sterba <dsterba@suse.com>
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Josef Bacik authored
When debugging some weird extent reference bug I suspected that we were changing a snapshot while we were deleting it, which could explain my bug. This was indeed what was happening, and this patch helped me verify my theory. It is never correct to modify the snapshot once it's being deleted, so mark the root when we are deleting it and make sure we complain about it when it happens. Reviewed-by:
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Qu Wenruo authored
@blocksize variable in do_walk_down() is only used once, really no need to declare it. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by:
Qu Wenruo <wqu@suse.com> Signed-off-by:
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Filipe Manana authored
Since scrub workers only do memory allocation with GFP_KERNEL when they need to perform repair, we can move the recent setup of the nofs context up to scrub_handle_errored_block() instead of setting it up down the call chain at insert_full_stripe_lock() and scrub_add_page_to_wr_bio(), removing some duplicate code and comment. So the only paths for which a scrub worker can do memory allocations using GFP_KERNEL are the following: scrub_bio_end_io_worker() scrub_block_complete() scrub_handle_errored_block() lock_full_stripe() insert_full_stripe_lock() -> kmalloc with GFP_KERNEL scrub_bio_end_io_worker() scrub_block_complete() scrub_handle_errored_block() scrub_write_page_to_dev_replace() scrub_add_page_to_wr_bio() -> kzalloc with GFP_KERNEL Signed-off-by: -
David Sterba authored
The scrub context is allocated with GFP_KERNEL and called from btrfs_scrub_dev under the fs_info::device_list_mutex. This is not safe regarding reclaim that could try to flush filesystem data in order to get the memory. And the device_list_mutex is held during superblock commit, so this would cause a lockup. Move the alocation and initialization before any changes that require the mutex. Signed-off-by: -
David Sterba authored
We can pass fs_info directly as this is the only member of btrfs_device that's bing used inside scrub_setup_ctx. Reviewed-by:
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Josef Bacik authored
We have a bunch of magic to make sure we're throttling delayed refs when truncating a file. Now that we have a delayed refs rsv and a mechanism for refilling that reserve simply use that instead of all of this magic. Reviewed-by:
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Josef Bacik authored
Over the years we have built up a lot of infrastructure to keep delayed refs in check, mostly by running them at btrfs_end_transaction() time. We have a lot of different maths we do to figure out how much, if we should do it inline or async, etc. This existed because we had no feedback mechanism to force the flushing of delayed refs when they became a problem. However with the enospc flushing infrastructure in place for flushing delayed refs when they put too much pressure on the enospc system we have this problem solved. Rip out all of this code as it is no longer needed. Signed-off-by:
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Josef Bacik authored
Now with the delayed_refs_rsv we can now know exactly how much pending delayed refs space we need. This means we can drastically simplify btrfs_check_space_for_delayed_refs by simply checking how much space we have reserved for the global rsv (which acts as a spill over buffer) and the delayed refs rsv. If our total size is beyond that amount then we know it's time to commit the transaction and stop any more delayed refs from being generated. With the introduction of dealyed_refs_rsv infrastructure, namely btrfs_update_delayed_refs_rsv we now know exactly how much pending delayed refs space is required. Reviewed-by:
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Josef Bacik authored
A nice thing we gain with the delayed refs rsv is the ability to flush the delayed refs on demand to deal with enospc pressure. Add states to flush delayed refs on demand, and this will allow us to remove a lot of ad-hoc work around checking to see if we should commit the transaction to run our delayed refs. Signed-off-by:
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Josef Bacik authored
Any space used in the delayed_refs_rsv will be freed up by a transaction commit, so instead of just counting the pinned space we also need to account for any space in the delayed_refs_rsv when deciding if it will make a different to commit the transaction to satisfy our space reservation. If we have enough bytes to satisfy our reservation ticket then we are good to go, otherwise subtract out what space we would gain back by committing the transaction and compare that against the pinned space to make our decision. Reviewed-by:
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Josef Bacik authored
Traditionally we've had voodoo in btrfs to account for the space that delayed refs may take up by having a global_block_rsv. This works most of the time, except when it doesn't. We've had issues reported and seen in production where sometimes the global reserve is exhausted during transaction commit before we can run all of our delayed refs, resulting in an aborted transaction. Because of this voodoo we have equally dubious flushing semantics around throttling delayed refs which we often get wrong. So instead give them their own block_rsv. This way we can always know exactly how much outstanding space we need for delayed refs. This allows us to make sure we are constantly filling that reservation up with space, and allows us to put more precise pressure on the enospc system. Instead of doing math to see if its a good time to throttle, the normal enospc code will be invoked if we have a lot of delayed refs pending, and they will be run via the normal flushing mechanism. For now the delayed_refs_rsv will hold the reservations for the delayed refs, the block group updates, and deleting csums. We could have a separate rsv for the block group updates, but the csum deletion stuff is still handled via the delayed_refs so that will stay there. Historical background: The global reserve has grown to cover everything we don't reserve space explicitly for, and we've grown a lot of weird ad-hoc heuristics to know if we're running short on space and when it's time to force a commit. A failure rate of 20-40 file systems when we run hundreds of thousands of them isn't super high, but cleaning up this code will make things less ugly and more predictible. Thus the delayed refs rsv. We always know how many delayed refs we have outstanding, and although running them generates more we can use the global reserve for that spill over, which fits better into it's desired use than a full blown reservation. This first approach is to simply take how many times we're reserving space for and multiply that by 2 in order to save enough space for the delayed refs that could be generated. This is a niave approach and will probably evolve, but for now it works. Signed-off-by:
Josef Bacik <jbacik@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> # high-level review [ added background notes from the cover letter ] Signed-off-by:
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Josef Bacik authored
We use this number to figure out how many delayed refs to run, but __btrfs_run_delayed_refs really only checks every time we need a new delayed ref head, so we always run at least one ref head completely no matter what the number of items on it. Fix the accounting to only be adjusted when we add/remove a ref head. In addition to using this number to limit the number of delayed refs run, a future patch is also going to use it to calculate the amount of space required for delayed refs space reservation. Reviewed-by:
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Josef Bacik authored
The cleanup_extent_op function actually would run the extent_op if it needed running, which made the name sort of a misnomer. Change it to run_and_cleanup_extent_op, and move the actual cleanup work to cleanup_extent_op so it can be used by check_ref_cleanup() in order to unify the extent op handling. Reviewed-by:
Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by:
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Josef Bacik authored
We were missing some quota cleanups in check_ref_cleanup, so break the ref head accounting cleanup into a helper and call that from both check_ref_cleanup and cleanup_ref_head. This will hopefully ensure that we don't screw up accounting in the future for other things that we add. Reviewed-by:
Omar Sandoval <osandov@fb.com> Reviewed-by:
Liu Bo <bo.liu@linux.alibaba.com> Reviewed-by:
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Josef Bacik authored
We do this dance in cleanup_ref_head and check_ref_cleanup, unify it into a helper and cleanup the calling functions. Reviewed-by:
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Johannes Thumshirn authored
When using a 'var & (PAGE_SIZE - 1)' construct one is checking for a page alignment and thus should use the PAGE_ALIGNED() macro instead of open-coding it. Convert all open-coded occurrences of PAGE_ALIGNED(). Reviewed-by:
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Johannes Thumshirn authored
Constructs like 'var & (PAGE_SIZE - 1)' or 'var & ~PAGE_MASK' can denote an offset into a page. So replace them by the offset_in_page() macro instead of open-coding it if they're not used as an alignment check. Reviewed-by:
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David Sterba authored
The dev-replace locking functions are now trivial wrappers around rw semaphore that can be used directly everywhere. No functional change. Signed-off-by: -
David Sterba authored
After the rw semaphore has been added, the custom blocking using ::blocking_readers and ::read_lock_wq is redundant. The blocking logic in __btrfs_map_block is replaced by extending the time the semaphore is held, that has the same blocking effect on writes as the previous custom scheme that waited until ::blocking_readers was zero. Signed-off-by: -
David Sterba authored
This is the first part of removing the custom locking and waiting scheme used for device replace. It was probably copied from extent buffer locking, but there's nothing that would require more than is provided by the common locking primitives. The rw spinlock protects waiting tasks counter in case of incompatible locks and the waitqueue. Same as rw semaphore. This patch only switches the locking primitive, for better bisectability. There should be no functional change other than the overhead of the locking and potential sleeping instead of spinning when the lock is contended. Signed-off-by: -
David Sterba authored
The device-replace read lock is going to use rw semaphore in followup commits. The semaphore might sleep which is not possible in the radix tree preload section. The lock nesting is now: * device replace * radix tree preload * readahead spinlock Signed-off-by: -
Nikolay Borisov authored
Running btrfs/124 in a loop hung up on me sporadically with the following call trace: btrfs D 0 5760 5324 0x00000000 Call Trace: ? __schedule+0x243/0x800 schedule+0x33/0x90 btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs] ? wait_woken+0xa0/0xa0 btrfs_wait_ordered_range+0xbb/0x100 [btrfs] btrfs_relocate_block_group+0x1ff/0x230 [btrfs] btrfs_relocate_chunk+0x49/0x100 [btrfs] btrfs_balance+0xbeb/0x1740 [btrfs] btrfs_ioctl_balance+0x2ee/0x380 [btrfs] btrfs_ioctl+0x1691/0x3110 [btrfs] ? lockdep_hardirqs_on+0xed/0x180 ? __handle_mm_fault+0x8e7/0xfb0 ? _raw_spin_unlock+0x24/0x30 ? __handle_mm_fault+0x8e7/0xfb0 ? do_vfs_ioctl+0xa5/0x6e0 ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs] do_vfs_ioctl+0xa5/0x6e0 ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe ksys_ioctl+0x3a/0x70 __x64_sys_ioctl+0x16/0x20 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x49/0xbe This happens because during page writeback it's valid for writepage_delalloc to instantiate a delalloc range which doesn't belong to the page currently being written back. The reason this case is valid is due to find_lock_delalloc_range returning any available range after the passed delalloc_start and ignoring whether the page under writeback is within that range. In turn ordered extents (OE) are always created for the returned range from find_lock_delalloc_range. If, however, a failure occurs while OE are being created then the clean up code in btrfs_cleanup_ordered_extents will be called. Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider the case of such 'foreign' range being processed and instead it always assumes that the range OE are created for belongs to the page. This leads to the first page of such foregin range to not be cleaned up since it's deliberately missed and skipped by the current cleaning up code. Fix this by correctly checking whether the current page belongs to the range being instantiated and if so adjsut the range parameters passed for cleaning up. If it doesn't, then just clean the whole OE range directly. Fixes: 52427260 ("btrfs: Handle delalloc error correctly to avoid ordered extent hang") CC: stable@vger.kernel.org # 4.14+ Reviewed-by:
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Lu Fengqi authored
The @found is always false when it comes to the if branch. Besides, the bool type is more suitable for @found. Change the return value of the function and its caller to bool as well. Reviewed-by:
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Lu Fengqi authored
The test case btrfs/001 with inode_cache mount option will encounter the following warning: WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs] CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G W O 4.20.0-rc4-custom+ #30 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs] Call Trace: ? free_extent_buffer+0x46/0x90 [btrfs] run_delalloc_nocow+0x455/0x900 [btrfs] btrfs_run_delalloc_range+0x1a7/0x360 [btrfs] writepage_delalloc+0xf9/0x150 [btrfs] __extent_writepage+0x125/0x3e0 [btrfs] extent_write_cache_pages+0x1b6/0x3e0 [btrfs] ? __wake_up_common_lock+0x63/0xc0 extent_writepages+0x50/0x80 [btrfs] do_writepages+0x41/0xd0 ? __filemap_fdatawrite_range+0x9e/0xf0 __filemap_fdatawrite_range+0xbe/0xf0 btrfs_fdatawrite_range+0x1b/0x50 [btrfs] __btrfs_write_out_cache+0x42c/0x480 [btrfs] btrfs_write_out_ino_cache+0x84/0xd0 [btrfs] btrfs_save_ino_cache+0x551/0x660 [btrfs] commit_fs_roots+0xc5/0x190 [btrfs] btrfs_commit_transaction+0x2bf/0x8d0 [btrfs] btrfs_mksubvol+0x48d/0x4d0 [btrfs] btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs] btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs] btrfs_ioctl+0x123f/0x3030 [btrfs] The file extent generation of the free space inode is equal to the last snapshot of the file root, so the inode will be passed to cow_file_rage. But the inode was created and its extents were preallocated in btrfs_save_ino_cache, there are no cow copies on disk. The preallocated extent is not yet in the extent tree, and btrfs_cross_ref_exist will ignore the -ENOENT returned by check_committed_ref, so we can directly write the inode to the disk. Fixes: 78d4295b ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path") CC: stable@vger.kernel.org # 4.18+ Reviewed-by:
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Filipe Manana authored
The log tree has a long standing problem that when a file is fsync'ed we only check for new ancestors, created in the current transaction, by following only the hard link for which the fsync was issued. We follow the ancestors using the VFS' dget_parent() API. This means that if we create a new link for a file in a directory that is new (or in an any other new ancestor directory) and then fsync the file using an old hard link, we end up not logging the new ancestor, and on log replay that new hard link and ancestor do not exist. In some cases, involving renames, the file will not exist at all. Example: mkfs.btrfs -f /dev/sdb mount /dev/sdb /mnt mkdir /mnt/A touch /mnt/foo ln /mnt/foo /mnt/A/bar xfs_io -c fsync /mnt/foo <power failure> In this example after log replay only the hard link named 'foo' exists and directory A does not exist, which is unexpected. In other major linux filesystems, such as ext4, xfs and f2fs for example, both hard links exist and so does directory A after mounting again the filesystem. Checking if any new ancestors are new and need to be logged was added in 2009 by commit 12fcfd22 ("Btrfs: tree logging unlink/rename fixes"), however only for the ancestors of the hard link (dentry) for which the fsync was issued, instead of checking for all ancestors for all of the inode's hard links. So fix this by tracking the id of the last transaction where a hard link was created for an inode and then on fsync fallback to a full transaction commit when an inode has more than one hard link and at least one new hard link was created in the current transaction. This is the simplest solution since this is not a common use case (adding frequently hard links for which there's an ancestor created in the current transaction and then fsync the file). In case it ever becomes a common use case, a solution that consists of iterating the fs/subvol btree for each hard link and check if any ancestor is new, could be implemented. This solves many unexpected scenarios reported by Jayashree Mohan and Vijay Chidambaram, and for which there is a new test case for fstests under review. Fixes: 12fcfd22 ("Btrfs: tree logging unlink/rename fixes") CC: stable@vger.kernel.org # 4.4+ Reported-by:
Vijay Chidambaram <vvijay03@gmail.com> Reported-by:
Jayashree Mohan <jayashree2912@gmail.com> Signed-off-by:
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David Sterba authored
The first auto-assigned value to enum is 0, we can use that and not initialize all members where the auto-increment does the same. This is used for values that are not part of on-disk format. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: ordered extent flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent map flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: extent buffer flags; Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: root tree flags. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: internal filesystem states. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: block reserve types. Reviewed-by:
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David Sterba authored
We can use simple enum for values that are not part of on-disk format: global filesystem states. Reviewed-by:
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Nikolay Borisov authored
This function really checks whether adding more data to the bio will straddle a stripe/chunk. So first let's give it a more appropraite name - btrfs_bio_fits_in_stripe. Secondly, the offset parameter was never used to just remove it. Thirdly, pages are submitted to either btree or data inodes so it's guaranteed that tree->ops is set so replace the check with an ASSERT. Finally, document the parameters of the function. No functional changes. Signed-off-by:
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Lu Fengqi authored
When it was introduced in commit f094ac32 ("Btrfs: fix NULL pointer after aborting a transaction"), it was not used. Signed-off-by:
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Johannes Thumshirn authored
Document why map_private_extent_buffer() cannot return '1' (i.e. the map spans two pages) for the csum_tree_block() case. The current algorithm for detecting a page boundary crossing in map_private_extent_buffer() will return a '1' *IFF* the extent buffer's offset in the page + the offset passed in by csum_tree_block() and the minimal length passed in by csum_tree_block() - 1 are bigger than PAGE_SIZE. We always pass BTRFS_CSUM_SIZE (32) as offset and a minimal length of 32 and the current extent buffer allocator always guarantees page aligned extends, so the above condition can't be true. Reviewed-by:
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Johannes Thumshirn authored
In map_private_extent_buffer() the 'offset' variable is initialized to a page aligned version of the 'start' parameter. But later on it is overwritten with either the offset from the extent buffer's start or 0. So get rid of the initial initialization. Reviewed-by:
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Filipe Manana authored
When a transaction commit starts, it attempts to pause scrub and it blocks until the scrub is paused. So while the transaction is blocked waiting for scrub to pause, we can not do memory allocation with GFP_KERNEL from scrub, otherwise we risk getting into a deadlock with reclaim. Checking for scrub pause requests is done early at the beginning of the while loop of scrub_stripe() and later in the loop, scrub_extent() and scrub_raid56_parity() are called, which in turn call scrub_pages() and scrub_pages_for_parity() respectively. These last two functions do memory allocations using GFP_KERNEL. Same problem could happen while scrubbing the super blocks, since it calls scrub_pages(). We also can not have any of the worker tasks, created by the scrub task, doing GFP_KERNEL allocations, because before pausing, the scrub task waits for all the worker tasks to complete (also done at scrub_stripe()). So make sure GFP_NOFS is used for the memory allocations because at any time a scrub pause request can happen from another task that started to commit a transaction. Fixes: 58c4e173 ("btrfs: scrub: use GFP_KERNEL on the submission path") CC: stable@vger.kernel.org # 4.6+ Reviewed-by:
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Nikolay Borisov authored
For data inodes this hook does nothing but to return -EAGAIN which is used to signal to the endio routines that this bio belongs to a data inode. If this is the case the actual retrying is handled by bio_readpage_error. Alternatively, if this bio belongs to the btree inode then btree_io_failed_hook just does some cleanup and doesn't retry anything. This patch simplifies the code flow by eliminating readpage_io_failed_hook and instead open-coding btree_io_failed_hook in end_bio_extent_readpage. Also eliminate some needless checks since IO is always performed on either data inode or btree inode, both of which are guaranteed to have their extent_io_tree::ops set. Signed-off-by:
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