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path: root/fs/btrfs/ordered-data.c
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2019-04-29btrfs: track DIO bytes in flightJosef Bacik
When diagnosing a slowdown of generic/224 I noticed we were not doing anything when calling into shrink_delalloc(). This is because all writes in 224 are O_DIRECT, not delalloc, and thus our delalloc_bytes counter is 0, which short circuits most of the work inside of shrink_delalloc(). However O_DIRECT writes still consume metadata resources and generate ordered extents, which we can still wait on. Fix this by tracking outstanding DIO write bytes, and use this as well as the delalloc bytes counter to decide if we need to lookup and wait on any ordered extents. If we have more DIO writes than delalloc bytes we'll go ahead and wait on any ordered extents regardless of our flush state as flushing delalloc is likely to not gain us anything. Signed-off-by: Josef Bacik <josef@toxicpanda.com> [ use dio instead of odirect in identifiers ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29btrfs: Remove redundant inode argument from btrfs_add_ordered_sumNikolay Borisov
Ordered csums are keyed off of a btrfs_ordered_extent, which already has a reference to the inode. This implies that an explicit inode argument is redundant. So remove it. Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de> Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-25btrfs: Switch memory allocations in async csum calculation path to kvmallocNikolay Borisov
Recent multi-page biovec rework allowed creation of bios that can span large regions - up to 128 megabytes in the case of btrfs. OTOH btrfs' submission path currently allocates a contiguous array to store the checksums for every bio submitted. This means we can request up to (128mb / BTRFS_SECTOR_SIZE) * 4 bytes + 32bytes of memory from kmalloc. On busy systems with possibly fragmented memory said kmalloc can fail which will trigger BUG_ON due to improper error handling IO submission context in btrfs. Until error handling is improved or bios in btrfs limited to a more manageable size (e.g. 1m) let's use kvmalloc to fallback to vmalloc for such large allocations. There is no hard requirement that the memory allocated for checksums during IO submission has to be contiguous, but this is a simple fix that does not require several non-contiguous allocations. For small writes this is unlikely to have any visible effect since kmalloc will still satisfy allocation requests as usual. For larger requests the code will just fallback to vmalloc. We've performed evaluation on several workload types and there was no significant difference kmalloc vs kvmalloc. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17Btrfs: remove no longer used stuff for tracking pending ordered extentsFilipe Manana
Tracking pending ordered extents per transaction was introduced in commit 50d9aa99bd35 ("Btrfs: make sure logged extents complete in the current transaction V3") and later updated in commit 161c3549b45a ("Btrfs: change how we wait for pending ordered extents"). However now that on fsync we always wait for ordered extents to complete before logging, done in commit 5636cf7d6dc8 ("btrfs: remove the logged extents infrastructure"), we no longer need the stuff to track for pending ordered extents, which was not completely removed in the mentioned commit. So remove the remaining of the pending ordered extents infrastructure. Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: prune unused includesDavid Sterba
Remove includes if none of the interfaces and exports is used in the given source file. Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: remove remaing full_sync logic from btrfs_sync_fileDavid Sterba
The logic to check if the inode is already in the log can now be simplified since we always wait for the ordered extents to complete before deciding whether the inode needs to be logged. The big comment about it can go away too. CC: Filipe Manana <fdmanana@suse.com> Suggested-by: Filipe Manana <fdmanana@suse.com> [ code and changelog copied from mail discussion ] Signed-off-by: David Sterba <dsterba@suse.com>
2018-08-06btrfs: remove the logged extents infrastructureJosef Bacik
This is no longer used anywhere, remove all of it. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-05-28btrfs: replace waitqueue_actvie with cond_wake_upDavid Sterba
Use the wrappers and reduce the amount of low-level details about the waitqueue management. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-04-12btrfs: replace GPL boilerplate by SPDX -- sourcesDavid Sterba
Remove GPL boilerplate text (long, short, one-line) and keep the rest, ie. personal, company or original source copyright statements. Add the SPDX header. Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-31btrfs: qgroup: Use separate meta reservation type for delallocQu Wenruo
Before this patch, btrfs qgroup is mixing per-transcation meta rsv with preallocated meta rsv, making it quite easy to underflow qgroup meta reservation. Since we have the new qgroup meta rsv types, apply it to delalloc reservation. Now for delalloc, most of its reserved space will use META_PREALLOC qgroup rsv type. And for callers reducing outstanding extent like btrfs_finish_ordered_io(), they will convert corresponding META_PREALLOC reservation to META_PERTRANS. This is mainly due to the fact that current qgroup numbers will only be updated in btrfs_commit_transaction(), that's to say if we don't keep such placeholder reservation, we can exceed qgroup limitation. And for callers freeing outstanding extent in error handler, we will just free META_PREALLOC bytes. This behavior makes callers of btrfs_qgroup_release_meta() or btrfs_qgroup_convert_meta() to be aware of which type they are. So in this patch, btrfs_delalloc_release_metadata() and its callers get an extra parameter to info qgroup to do correct meta convert/release. The good news is, even we use the wrong type (convert or free), it won't cause obvious bug, as prealloc type is always in good shape, and the type only affects how per-trans meta is increased or not. So the worst case will be at most metadata limitation can be sometimes exceeded (no convert at all) or metadata limitation is reached too soon (no free at all). Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2018-03-26btrfs: add more __cold annotationsDavid Sterba
The __cold functions are placed to a special section, as they're expected to be called rarely. This could help i-cache prefetches or help compiler to decide which branches are more/less likely to be taken without any other annotations needed. Though we can't add more __exit annotations, it's still possible to add __cold (that's also added with __exit). That way the following function categories are tagged: - printf wrappers, error messages - exit helpers Signed-off-by: David Sterba <dsterba@suse.com>
2017-11-01Btrfs: rework outstanding_extentsJosef Bacik
Right now we do a lot of weird hoops around outstanding_extents in order to keep the extent count consistent. This is because we logically transfer the outstanding_extent count from the initial reservation through the set_delalloc_bits. This makes it pretty difficult to get a handle on how and when we need to mess with outstanding_extents. Fix this by revamping the rules of how we deal with outstanding_extents. Now instead everybody that is holding on to a delalloc extent is required to increase the outstanding extents count for itself. This means we'll have something like this btrfs_delalloc_reserve_metadata - outstanding_extents = 1 btrfs_set_extent_delalloc - outstanding_extents = 2 btrfs_release_delalloc_extents - outstanding_extents = 1 for an initial file write. Now take the append write where we extend an existing delalloc range but still under the maximum extent size btrfs_delalloc_reserve_metadata - outstanding_extents = 2 btrfs_set_extent_delalloc btrfs_set_bit_hook - outstanding_extents = 3 btrfs_merge_extent_hook - outstanding_extents = 2 btrfs_delalloc_release_extents - outstanding_extnets = 1 In order to make the ordered extent transition we of course must now make ordered extents carry their own outstanding_extent reservation, so for cow_file_range we end up with btrfs_add_ordered_extent - outstanding_extents = 2 clear_extent_bit - outstanding_extents = 1 btrfs_remove_ordered_extent - outstanding_extents = 0 This makes all manipulations of outstanding_extents much more explicit. Every successful call to btrfs_delalloc_reserve_metadata _must_ now be combined with btrfs_release_delalloc_extents, even in the error case, as that is the only function that actually modifies the outstanding_extents counter. The drawback to this is now we are much more likely to have transient cases where outstanding_extents is much larger than it actually should be. This could happen before as we manipulated the delalloc bits, but now it happens basically at every write. This may put more pressure on the ENOSPC flushing code, but I think making this code simpler is worth the cost. I have another change coming to mitigate this side-effect somewhat. I also added trace points for the counter manipulation. These were used by a bpf script I wrote to help track down leak issues. Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29btrfs: fix integer overflow in calc_reclaim_items_nrChris Mason
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with v4.12-rc6. This was because commit 70e7af244 made it possible for calc_reclaim_items_nr() to return a negative number. It's not really a bug in that commit, it just didn't go far enough down the stack to find all the possible 64->32 bit overflows. This switches calc_reclaim_items_nr() to return a u64 and changes everyone that uses the results of that math to u64 as well. Reported-by: Dave Jones <davej@codemonkey.org.uk> Fixes: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow") Signed-off-by: Chris Mason <clm@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_ordered_extent.refs from atomic_t to refcount_tElena Reshetova
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18btrfs: convert btrfs_transaction.use_count from atomic_t to refcount_tElena Reshetova
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28btrfs: Make btrfs_lookup_ordered_range take btrfs_inodeNikolay Borisov
Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14Btrfs: clean up btrfs_ordered_update_i_sizeLiu Bo
Since we have a good helper entry_end, use it for ordered extent. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> [ whitespace reformatting ] Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14Btrfs: fix btrfs_ordered_update_i_size to update disk_i_size properlyLiu Bo
btrfs_ordered_update_i_size can be called by truncate and endio, but only endio takes ordered_extent which contains the completed IO. while truncating down a file, if there are some in-flight IOs, btrfs_ordered_update_i_size in endio will set disk_i_size to @orig_offset that is zero. If truncating-down fails somehow, we try to recover in memory isize with this zero'd disk_i_size. Fix it by only updating disk_i_size with @orig_offset when btrfs_ordered_update_i_size is not called from endio while truncating down and waiting for in-flight IOs completing their work before recover in-memory size. Besides fixing the above issue, add an assertion for last_size to double check we truncate down to the desired size. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-14btrfs: Make btrfs_get_logged_extents take btrfs_inodeNikolay Borisov
Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: root->fs_info cleanup, add fs_info convenience variablesJeff Mahoney
In routines where someptr->fs_info is referenced multiple times, we introduce a convenience variable. This makes the code considerably more readable. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-12-06btrfs: pull node/sector/stripe sizes out of root and into fs_infoJeff Mahoney
We track the node sizes per-root, but they never vary from the values in the superblock. This patch messes with the 80-column style a bit, but subsequent patches to factor out root->fs_info into a convenience variable fix it up again. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-09-26btrfs: unsplit printed stringsJeff Mahoney
CodingStyle chapter 2: "[...] never break user-visible strings such as printk messages, because that breaks the ability to grep for them." This patch unsplits user-visible strings. Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-07-26btrfs: Fix slab accounting flagsNikolay Borisov
BTRFS is using a variety of slab caches to satisfy internal needs. Those slab caches are always allocated with the SLAB_RECLAIM_ACCOUNT, meaning allocations from the caches are going to be accounted as SReclaimable. At the same time btrfs is not registering any shrinkers whatsoever, thus preventing memory from the slabs to be shrunk. This means those caches are not in fact reclaimable. To fix this remove the SLAB_RECLAIM_ACCOUNT on all caches apart from the inode cache, since this one is being freed by the generic VFS super_block shrinker. Also set the transaction related caches as SLAB_TEMPORARY, to better document the lifetime of the objects (it just translates to SLAB_RECLAIM_ACCOUNT). Signed-off-by: Nikolay Borisov <n.borisov.lkml@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-06-23btrfs: fix disk_i_size update bug when fallocate() failsWang Xiaoguang
When doing truncate operation, btrfs_setsize() will first call truncate_setsize() to set new inode->i_size, but if later btrfs_truncate() fails, btrfs_setsize() will call "i_size_write(inode, BTRFS_I(inode)->disk_i_size)" to reset the inmemory inode size, now bug occurs. It's because for truncate case btrfs_ordered_update_i_size() directly uses inode->i_size to update BTRFS_I(inode)->disk_i_size, indeed we should use the "offset" argument to update disk_i_size. Here is the call graph: ==>btrfs_truncate() ====>btrfs_truncate_inode_items() ======>btrfs_ordered_update_i_size(inode, last_size, NULL); Here btrfs_ordered_update_i_size()'s offset argument is last_size. And below test case can reveal this bug: dd if=/dev/zero of=fs.img bs=$((1024*1024)) count=100 dev=$(losetup --show -f fs.img) mkdir -p /mnt/mntpoint mkfs.btrfs -f $dev mount $dev /mnt/mntpoint cd /mnt/mntpoint echo "workdir is: /mnt/mntpoint" blocksize=$((128 * 1024)) dd if=/dev/zero of=testfile bs=$blocksize count=1 sync count=$((17*1024*1024*1024/blocksize)) echo "file size is:" $((count*blocksize)) for ((i = 1; i <= $count; i++)); do i=$((i + 1)) dst_offset=$((blocksize * i)) xfs_io -f -c "reflink testfile 0 $dst_offset $blocksize"\ testfile > /dev/null done sync truncate --size 0 testfile ls -l testfile du -sh testfile exit In this case, truncate operation will fail for enospc reason and "du -sh testfile" returns value greater than 0, but testfile's size is 0, we need to reflect correct inode->i_size. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-05-30Btrfs: fix race setting block group readonly during device replaceFilipe Manana
When we do a device replace, for each device extent we find from the source device, we set the corresponding block group to readonly mode to prevent writes into it from happening while we are copying the device extent from the source to the target device. However just before we set the block group to readonly mode some concurrent task might have already allocated an extent from it or decided it could perform a nocow write into one of its extents, which can make the device replace process to miss copying an extent since it uses the extent tree's commit root to search for extents and only once it finishes searching for all extents belonging to the block group it does set the left cursor to the logical end address of the block group - this is a problem if the respective ordered extents finish while we are searching for extents using the extent tree's commit root and no transaction commit happens while we are iterating the tree, since it's the delayed references created by the ordered extents (when they complete) that insert the extent items into the extent tree (using the non-commit root of course). Example: CPU 1 CPU 2 btrfs_dev_replace_start() btrfs_scrub_dev() scrub_enumerate_chunks() --> finds device extent belonging to block group X <transaction N starts> starts buffered write against some inode writepages is run against that inode forcing dellaloc to run btrfs_writepages() extent_writepages() extent_write_cache_pages() __extent_writepage() writepage_delalloc() run_delalloc_range() cow_file_range() btrfs_reserve_extent() --> allocates an extent from block group X (which is not yet in RO mode) btrfs_add_ordered_extent() --> creates ordered extent Y flush_epd_write_bio() --> bio against the extent from block group X is submitted btrfs_inc_block_group_ro(bg X) --> sets block group X to readonly scrub_chunk(bg X) scrub_stripe(device extent from srcdev) --> keeps searching for extent items belonging to the block group using the extent tree's commit root --> it never blocks due to fs_info->scrub_pause_req as no one tries to commit transaction N --> copies all extents found from the source device into the target device --> finishes search loop bio completes ordered extent Y completes and creates delayed data reference which will add an extent item to the extent tree when run (typically at transaction commit time) --> so the task doing the scrub/device replace at CPU 1 misses this and does not copy this extent into the new/target device btrfs_dec_block_group_ro(bg X) --> turns block group X back to RW mode dev_replace->cursor_left is set to the logical end offset of block group X So fix this by waiting for all cow and nocow writes after setting a block group to readonly mode. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com>
2016-05-13Btrfs: don't wait for unrelated IO to finish before relocationFilipe Manana
Before the relocation process of a block group starts, it sets the block group to readonly mode, then flushes all delalloc writes and then finally it waits for all ordered extents to complete. This last step includes waiting for ordered extents destinated at extents allocated in other block groups, making us waste unecessary time. So improve this by waiting only for ordered extents that fall into the block group's range. Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2016-03-14btrfs: Fix misspellings in comments.Adam Buchbinder
Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-03-11btrfs: move btrfs_compression_type to compression.hAnand Jain
So that its better organized. Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2016-02-18btrfs: drop null testing before destroy functionsKinglong Mee
Cleanup. kmem_cache_destroy has support NULL argument checking, so drop the double null testing before calling it. Signed-off-by: Kinglong Mee <kinglongmee@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>
2015-10-21Btrfs: change how we wait for pending ordered extentsJosef Bacik
We have a mechanism to make sure we don't lose updates for ordered extents that were logged in the transaction that is currently running. We add the ordered extent to a transaction list and then the transaction waits on all the ordered extents in that list. However are substantially large file systems this list can be extremely large, and can give us soft lockups, since the ordered extents don't remove themselves from the list when they do complete. To fix this we simply add a counter to the transaction that is incremented any time we have a logged extent that needs to be completed in the current transaction. Then when the ordered extent finally completes it decrements the per transaction counter and wakes up the transaction if we are the last ones. This will eliminate the softlockup. Thanks, Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-10-10btrfs: add comments to barriers before waitqueue_activeDavid Sterba
Reduce number of undocumented barriers out there. Signed-off-by: David Sterba <dsterba@suse.com>
2015-07-01Btrfs: fix memory corruption on failure to submit bio for direct IOFilipe Manana
If we fail to submit a bio for a direct IO request, we were grabbing the corresponding ordered extent and decrementing its reference count twice, once for our lookup reference and once for the ordered tree reference. This was a problem because it caused the ordered extent to be freed without removing it from the ordered tree and any lists it might be attached to, leaving dangling pointers to the ordered extent around. Example trace with CONFIG_DEBUG_PAGEALLOC=y: [161779.858707] BUG: unable to handle kernel paging request at 0000000087654330 [161779.859983] IP: [<ffffffff8124ca68>] rb_prev+0x22/0x3b [161779.860636] PGD 34d818067 PUD 0 [161779.860636] Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC (...) [161779.860636] Call Trace: [161779.860636] [<ffffffffa06b36a6>] __tree_search+0xd9/0xf9 [btrfs] [161779.860636] [<ffffffffa06b3708>] tree_search+0x42/0x63 [btrfs] [161779.860636] [<ffffffffa06b4868>] ? btrfs_lookup_ordered_range+0x2d/0xa5 [btrfs] [161779.860636] [<ffffffffa06b4873>] btrfs_lookup_ordered_range+0x38/0xa5 [btrfs] [161779.860636] [<ffffffffa06aab8e>] btrfs_get_blocks_direct+0x11b/0x615 [btrfs] [161779.860636] [<ffffffff8119727f>] do_blockdev_direct_IO+0x5ff/0xb43 [161779.860636] [<ffffffffa06aaa73>] ? btrfs_page_exists_in_range+0x1ad/0x1ad [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffffa06a10ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [161779.860636] [<ffffffffa06a2c9a>] ? btrfs_get_extent_fiemap+0x1bc/0x1bc [btrfs] [161779.860636] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [161779.860636] [<ffffffffa06affaa>] ? btrfs_file_write_iter+0x15f/0x3e0 [btrfs] [161779.860636] [<ffffffffa06b004c>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] (...) We were also not freeing the btrfs_dio_private we allocated previously, which kmemleak reported with the following trace in its sysfs file: unreferenced object 0xffff8803f553bf80 (size 96): comm "xfs_io", pid 4501, jiffies 4295039588 (age 173.936s) hex dump (first 32 bytes): 88 6c 9b f5 02 88 ff ff 00 00 00 00 00 00 00 00 .l.............. 00 00 00 00 00 00 00 00 00 00 c4 00 00 00 00 00 ................ backtrace: [<ffffffff81161ffe>] create_object+0x172/0x29a [<ffffffff8145870f>] kmemleak_alloc+0x25/0x41 [<ffffffff81154e64>] kmemleak_alloc_recursive.constprop.40+0x16/0x18 [<ffffffff811579ed>] kmem_cache_alloc_trace+0xfb/0x148 [<ffffffffa03d8cff>] btrfs_submit_direct+0x65/0x16a [btrfs] [<ffffffff811968dc>] dio_bio_submit+0x62/0x8f [<ffffffff811975fe>] do_blockdev_direct_IO+0x97e/0xb43 [<ffffffff811977f5>] __blockdev_direct_IO+0x32/0x34 [<ffffffffa03d70ae>] btrfs_direct_IO+0x198/0x21f [btrfs] [<ffffffff81112ca1>] generic_file_direct_write+0xb3/0x128 [<ffffffffa03e604d>] btrfs_file_write_iter+0x201/0x3e0 [btrfs] [<ffffffff8116586a>] __vfs_write+0x7c/0xa5 [<ffffffff81165da9>] vfs_write+0xa0/0xe4 [<ffffffff81166675>] SyS_pwrite64+0x64/0x82 [<ffffffff81464fd7>] system_call_fastpath+0x12/0x6f [<ffffffffffffffff>] 0xffffffffffffffff For read requests we weren't doing any cleanup either (none of the work done by btrfs_endio_direct_read()), so a failure submitting a bio for a read request would leave a range in the inode's io_tree locked forever, blocking any future operations (both reads and writes) against that range. So fix this by making sure we do the same cleanup that we do for the case where the bio submission succeeds. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: don't attach unnecessary extents to transaction on fsyncFilipe Manana
We don't need to attach ordered extents that have completed to the current transaction. Doing so only makes us hold memory for longer than necessary and delaying the iput of the inode until the transaction is committed (for each created ordered extent we do an igrab and then schedule an asynchronous iput when the ordered extent's reference count drops to 0), preventing the inode from being evictable until the transaction commits. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-10Btrfs: avoid syncing log in the fast fsync path when not necessaryFilipe Manana
Commit 3a8b36f37806 ("Btrfs: fix data loss in the fast fsync path") added a performance regression for that causes an unnecessary sync of the log trees (fs/subvol and root log trees) when 2 consecutive fsyncs are done against a file, without no writes or any metadata updates to the inode in between them and if a transaction is committed before the second fsync is called. Huang Ying reported this to lkml (https://lkml.org/lkml/2015/3/18/99) after a test sysbench test that measured a -62% decrease of file io requests per second for that tests' workload. The test is: echo performance > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu1/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu2/cpufreq/scaling_governor echo performance > /sys/devices/system/cpu/cpu3/cpufreq/scaling_governor mkfs -t btrfs /dev/sda2 mount -t btrfs /dev/sda2 /fs/sda2 cd /fs/sda2 for ((i = 0; i < 1024; i++)); do fallocate -l 67108864 testfile.$i; done sysbench --test=fileio --max-requests=0 --num-threads=4 --max-time=600 \ --file-test-mode=rndwr --file-total-size=68719476736 --file-io-mode=sync \ --file-num=1024 run A test on kvm guest, running a debug kernel gave me the following results: Without 3a8b36f378060d: 16.01 reqs/sec With 3a8b36f378060d: 3.39 reqs/sec With 3a8b36f378060d and this patch: 16.04 reqs/sec Reported-by: Huang Ying <ying.huang@intel.com> Tested-by: Huang, Ying <ying.huang@intel.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-06-03Btrfs: remove csum_bytes_leftLiu Bo
After commit 8407f553268a ("Btrfs: fix data corruption after fast fsync and writeback error"), during wait_ordered_extents(), we wait for ordered extent setting BTRFS_ORDERED_IO_DONE or BTRFS_ORDERED_IOERR, at which point we've already got checksum information, so we don't need to check (csum_bytes_left == 0) in the whole logging path. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-05-11Btrfs: fix panic when starting bg cache writeout after IO errorFilipe Manana
When waiting for the writeback of block group cache we returned immediately if there was an error during writeback without waiting for the ordered extent to complete. This left a short time window where if some other task attempts to start the writeout for the same block group cache it can attempt to add a new ordered extent, starting at the same offset (0) before the previous one is removed from the ordered tree, causing an ordered tree panic (calls BUG()). This normally doesn't happen in other write paths, such as buffered writes or direct IO writes for regular files, since before marking page ranges dirty we lock the ranges and wait for any ordered extents within the range to complete first. Fix this by making btrfs_wait_ordered_range() not return immediately if it gets an error from the writeback, waiting for all ordered extents to complete first. This issue happened often when running the fstest btrfs/088 and it's easy to trigger it by running in a loop until the panic happens: for ((i = 1; i <= 10000; i++)) do ./check btrfs/088 ; done [17156.862573] BTRFS critical (device sdc): panic in ordered_data_tree_panic:70: Inconsistency in ordered tree at offset 0 (errno=-17 Object already exists) [17156.864052] ------------[ cut here ]------------ [17156.864052] kernel BUG at fs/btrfs/ordered-data.c:70! (...) [17156.864052] Call Trace: [17156.864052] [<ffffffffa03876e3>] btrfs_add_ordered_extent+0x12/0x14 [btrfs] [17156.864052] [<ffffffffa03787e2>] run_delalloc_nocow+0x5bf/0x747 [btrfs] [17156.864052] [<ffffffffa03789ff>] run_delalloc_range+0x95/0x353 [btrfs] [17156.864052] [<ffffffffa038b7fe>] writepage_delalloc.isra.16+0xb9/0x13f [btrfs] [17156.864052] [<ffffffffa038d75b>] __extent_writepage+0x129/0x1f7 [btrfs] [17156.864052] [<ffffffffa038da5a>] extent_write_cache_pages.isra.15.constprop.28+0x231/0x2f4 [btrfs] [17156.864052] [<ffffffff810ad2af>] ? __module_text_address+0x12/0x59 [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa038df76>] extent_writepages+0x4b/0x5c [btrfs] [17156.864052] [<ffffffff81144431>] ? kmem_cache_free+0x9b/0xce [17156.864052] [<ffffffffa0376a46>] ? btrfs_submit_direct+0x3fc/0x3fc [btrfs] [17156.864052] [<ffffffffa0389cd6>] ? free_extent_state+0x8c/0xc1 [btrfs] [17156.864052] [<ffffffffa0374871>] btrfs_writepages+0x28/0x2a [btrfs] [17156.864052] [<ffffffff8110c4c8>] do_writepages+0x23/0x2c [17156.864052] [<ffffffff81102f36>] __filemap_fdatawrite_range+0x5a/0x61 [17156.864052] [<ffffffff81102f6e>] filemap_fdatawrite_range+0x13/0x15 [17156.864052] [<ffffffffa0383ef7>] btrfs_fdatawrite_range+0x21/0x48 [btrfs] [17156.864052] [<ffffffffa03ab89e>] __btrfs_write_out_cache.isra.14+0x2d9/0x3a7 [btrfs] [17156.864052] [<ffffffffa03ac1ab>] ? btrfs_write_out_cache+0x41/0xdc [btrfs] [17156.864052] [<ffffffffa03ac1fd>] btrfs_write_out_cache+0x93/0xdc [btrfs] [17156.864052] [<ffffffffa0363847>] ? btrfs_start_dirty_block_groups+0x13a/0x2b2 [btrfs] [17156.864052] [<ffffffffa03638e6>] btrfs_start_dirty_block_groups+0x1d9/0x2b2 [btrfs] [17156.864052] [<ffffffff8107d33d>] ? trace_hardirqs_on+0xd/0xf [17156.864052] [<ffffffffa037209e>] btrfs_commit_transaction+0x130/0x9c9 [btrfs] [17156.864052] [<ffffffffa034c748>] btrfs_sync_fs+0xe1/0x12d [btrfs] Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2015-03-02Btrfs: fix fsync race leading to ordered extent memory leaksFilipe Manana
We can have multiple fsync operations against the same file during the same transaction and they can collect the same ordered extents while they don't complete (still accessible from the inode's ordered tree). If this happens, those ordered extents will never get their reference counts decremented to 0, leading to memory leaks and inode leaks (an iput for an ordered extent's inode is scheduled only when the ordered extent's refcount drops to 0). The following sequence diagram explains this race: CPU 1 CPU 2 btrfs_sync_file() btrfs_sync_file() mutex_lock(inode->i_mutex) btrfs_log_inode() btrfs_get_logged_extents() --> collects ordered extent X --> increments ordered extent X's refcount btrfs_submit_logged_extents() mutex_unlock(inode->i_mutex) mutex_lock(inode->i_mutex) btrfs_sync_log() btrfs_wait_logged_extents() --> list_del_init(&ordered->log_list) btrfs_log_inode() btrfs_get_logged_extents() --> Adds ordered extent X to logged_list because at this point: list_empty(&ordered->log_list) && test_bit(BTRFS_ORDERED_LOGGED, &ordered->flags) == 0 --> Increments ordered extent X's refcount --> check if ordered extent's io is finished or not, start it if necessary and wait for it to finish --> sets bit BTRFS_ORDERED_LOGGED on ordered extent X's flags and adds it to trans->ordered btrfs_sync_log() finishes btrfs_submit_logged_extents() btrfs_log_inode() finishes mutex_unlock(inode->i_mutex) btrfs_sync_file() finishes btrfs_sync_log() btrfs_wait_logged_extents() --> Sees ordered extent X has the bit BTRFS_ORDERED_LOGGED set in its flags --> X's refcount is untouched btrfs_sync_log() finishes btrfs_sync_file() finishes btrfs_commit_transaction() --> called by transaction kthread for e.g. btrfs_wait_pending_ordered() --> waits for ordered extent X to complete --> decrements ordered extent X's refcount by 1 only, corresponding to the increment done by the fsync task ran by CPU 1 In the scenario of the above diagram, after the transaction commit, the ordered extent will remain with a refcount of 1 forever, leaking the ordered extent structure and preventing the i_count of its inode from ever decreasing to 0, since the delayed iput is scheduled only when the ordered extent's refcount drops to 0, preventing the inode from ever being evicted by the VFS. Fix this by using the flag BTRFS_ORDERED_LOGGED differently. Use it to mean that an ordered extent is already being processed by an fsync call, which will attach it to the current transaction, preventing it from being collected by subsequent fsync operations against the same inode. This race was introduced with the following change (added in 3.19 and backported to stable 3.18 and 3.17): Btrfs: make sure logged extents complete in the current transaction V3 commit 50d9aa99bd35c77200e0e3dd7a72274f8304701f I ran into this issue while running xfstests/generic/113 in a loop, which failed about 1 out of 10 runs with the following warning in dmesg: [ 2612.440038] WARNING: CPU: 4 PID: 22057 at fs/btrfs/disk-io.c:3558 free_fs_root+0x36/0x133 [btrfs]() [ 2612.442810] Modules linked in: btrfs crc32c_generic xor raid6_pq nfsd auth_rpcgss oid_registry nfs_acl nfs lockd grace fscache sunrpc loop processor parport_pc parport psmouse therma l_sys i2c_piix4 serio_raw pcspkr evdev microcode button i2c_core ext4 crc16 jbd2 mbcache sd_mod sg sr_mod cdrom virtio_scsi ata_generic virtio_pci ata_piix virtio_ring libata virtio flo ppy e1000 scsi_mod [last unloaded: btrfs] [ 2612.452711] CPU: 4 PID: 22057 Comm: umount Tainted: G W 3.19.0-rc5-btrfs-next-4+ #1 [ 2612.454921] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.7.5-0-ge51488c-20140602_164612-nilsson.home.kraxel.org 04/01/2014 [ 2612.457709] 0000000000000009 ffff8801342c3c78 ffffffff8142425e ffff88023ec8f2d8 [ 2612.459829] 0000000000000000 ffff8801342c3cb8 ffffffff81045308 ffff880046460000 [ 2612.461564] ffffffffa036da56 ffff88003d07b000 ffff880046460000 ffff880046460068 [ 2612.463163] Call Trace: [ 2612.463719] [<ffffffff8142425e>] dump_stack+0x4c/0x65 [ 2612.464789] [<ffffffff81045308>] warn_slowpath_common+0xa1/0xbb [ 2612.466026] [<ffffffffa036da56>] ? free_fs_root+0x36/0x133 [btrfs] [ 2612.467247] [<ffffffff810453c5>] warn_slowpath_null+0x1a/0x1c [ 2612.468416] [<ffffffffa036da56>] free_fs_root+0x36/0x133 [btrfs] [ 2612.469625] [<ffffffffa036f2a7>] btrfs_drop_and_free_fs_root+0x93/0x9b [btrfs] [ 2612.471251] [<ffffffffa036f353>] btrfs_free_fs_roots+0xa4/0xd6 [btrfs] [ 2612.472536] [<ffffffff8142612e>] ? wait_for_completion+0x24/0x26 [ 2612.473742] [<ffffffffa0370bbc>] close_ctree+0x1f3/0x33c [btrfs] [ 2612.475477] [<ffffffff81059d1d>] ? destroy_workqueue+0x148/0x1ba [ 2612.476695] [<ffffffffa034e3da>] btrfs_put_super+0x19/0x1b [btrfs] [ 2612.477911] [<ffffffff81153e53>] generic_shutdown_super+0x73/0xef [ 2612.479106] [<ffffffff811540e2>] kill_anon_super+0x13/0x1e [ 2612.480226] [<ffffffffa034e1e3>] btrfs_kill_super+0x17/0x23 [btrfs] [ 2612.481471] [<ffffffff81154307>] deactivate_locked_super+0x3b/0x50 [ 2612.482686] [<ffffffff811547a7>] deactivate_super+0x3f/0x43 [ 2612.483791] [<ffffffff8116b3ed>] cleanup_mnt+0x59/0x78 [ 2612.484842] [<ffffffff8116b44c>] __cleanup_mnt+0x12/0x14 [ 2612.485900] [<ffffffff8105d019>] task_work_run+0x8f/0xbc [ 2612.486960] [<ffffffff810028d8>] do_notify_resume+0x5a/0x6b [ 2612.488083] [<ffffffff81236e5b>] ? trace_hardirqs_on_thunk+0x3a/0x3f [ 2612.489333] [<ffffffff8142a17f>] int_signal+0x12/0x17 [ 2612.490353] ---[ end trace 54a960a6bdcb8d93 ]--- [ 2612.557253] VFS: Busy inodes after unmount of sdb. Self-destruct in 5 seconds. Have a nice day... Kmemleak confirmed the ordered extent leak (and btrfs inode specific structures such as delayed nodes): $ cat /sys/kernel/debug/kmemleak unreferenced object 0xffff880154290db0 (size 576): comm "btrfsck", pid 21980, jiffies 4295542503 (age 1273.412s) hex dump (first 32 bytes): 01 40 00 00 01 00 00 00 b0 1d f1 4e 01 88 ff ff .@.........N.... 00 00 00 00 00 00 00 00 c8 0d 29 54 01 88 ff ff ..........)T.... backtrace: [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83 [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190 [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs] [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs] [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs] [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs] [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff88014ef11db0 (size 576): comm "rm", pid 22009, jiffies 4295542593 (age 1273.052s) hex dump (first 32 bytes): 02 00 00 00 01 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 c8 1d f1 4e 01 88 ff ff ...........N.... backtrace: [<ffffffff8141d74d>] kmemleak_update_trace+0x4c/0x6a [<ffffffff8122f2c0>] radix_tree_node_alloc+0x6d/0x83 [<ffffffff8122fb26>] __radix_tree_create+0x109/0x190 [<ffffffff8122fbdd>] radix_tree_insert+0x30/0xac [<ffffffffa03b9bde>] btrfs_get_or_create_delayed_node+0x130/0x187 [btrfs] [<ffffffffa03bb82d>] btrfs_delayed_delete_inode_ref+0x32/0xac [btrfs] [<ffffffffa0379dae>] __btrfs_unlink_inode+0xee/0x288 [btrfs] [<ffffffffa037c715>] btrfs_unlink_inode+0x1e/0x40 [btrfs] [<ffffffffa037c797>] btrfs_unlink+0x60/0x9b [btrfs] [<ffffffff8115d7f0>] vfs_unlink+0x9c/0xed [<ffffffff8115f5de>] do_unlinkat+0x12c/0x1fa [<ffffffff811601a7>] SyS_unlinkat+0x29/0x2b [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 [<ffffffffffffffff>] 0xffffffffffffffff unreferenced object 0xffff8800336feda8 (size 584): comm "aio-stress", pid 22031, jiffies 4295543006 (age 1271.400s) hex dump (first 32 bytes): 00 40 3e 00 00 00 00 00 00 00 8f 42 00 00 00 00 .@>........B.... 00 00 01 00 00 00 00 00 00 00 01 00 00 00 00 00 ................ backtrace: [<ffffffff8114eb34>] create_object+0x172/0x29a [<ffffffff8141d790>] kmemleak_alloc+0x25/0x41 [<ffffffff81141ae6>] kmemleak_alloc_recursive.constprop.52+0x16/0x18 [<ffffffff81145288>] kmem_cache_alloc+0xf7/0x198 [<ffffffffa0389243>] __btrfs_add_ordered_extent+0x43/0x309 [btrfs] [<ffffffffa038968b>] btrfs_add_ordered_extent_dio+0x12/0x14 [btrfs] [<ffffffffa03810e2>] btrfs_get_blocks_direct+0x3ef/0x571 [btrfs] [<ffffffff81181349>] do_blockdev_direct_IO+0x62a/0xb47 [<ffffffff8118189a>] __blockdev_direct_IO+0x34/0x36 [<ffffffffa03776e5>] btrfs_direct_IO+0x16a/0x1e8 [btrfs] [<ffffffff81100373>] generic_file_direct_write+0xb8/0x12d [<ffffffffa038615c>] btrfs_file_write_iter+0x24b/0x42f [btrfs] [<ffffffff8118bb0d>] aio_run_iocb+0x2b7/0x32e [<ffffffff8118c99a>] do_io_submit+0x26e/0x2ff [<ffffffff8118ca3b>] SyS_io_submit+0x10/0x12 [<ffffffff81429e92>] system_call_fastpath+0x12/0x17 CC: <stable@vger.kernel.org> # 3.19, 3.18 and 3.17 Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-21Btrfs: collect only the necessary ordered extents on ranged fsyncFilipe Manana
Instead of collecting all ordered extents from the inode's ordered tree and then wait for all of them to complete, just collect the ones that overlap the fsync range. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-21Btrfs: make sure logged extents complete in the current transaction V3Josef Bacik
Liu Bo pointed out that my previous fix would lose the generation update in the scenario I described. It is actually much worse than that, we could lose the entire extent if we lose power right after the transaction commits. Consider the following write extent 0-4k log extent in log tree commit transaction < power fail happens here ordered extent completes We would lose the 0-4k extent because it hasn't updated the actual fs tree, and the transaction commit will reset the log so it isn't replayed. If we lose power before the transaction commit we are save, otherwise we are not. Fix this by keeping track of all extents we logged in this transaction. Then when we go to commit the transaction make sure we wait for all of those ordered extents to complete before proceeding. This will make sure that if we lose power after the transaction commit we still have our data. This also fixes the problem of the improperly updated extent generation. Thanks, cc: stable@vger.kernel.org Signed-off-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-11-20Btrfs: add helper btrfs_fdatawrite_rangeFilipe Manana
To avoid duplicating this double filemap_fdatawrite_range() call for inodes with async extents (compressed writes) so often. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-24Btrfs: fix task hang under heavy compressed writeLiu Bo
This has been reported and discussed for a long time, and this hang occurs in both 3.15 and 3.16. Btrfs now migrates to use kernel workqueue, but it introduces this hang problem. Btrfs has a kind of work queued as an ordered way, which means that its ordered_func() must be processed in the way of FIFO, so it usually looks like -- normal_work_helper(arg) work = container_of(arg, struct btrfs_work, normal_work); work->func() <---- (we name it work X) for ordered_work in wq->ordered_list ordered_work->ordered_func() ordered_work->ordered_free() The hang is a rare case, first when we find free space, we get an uncached block group, then we go to read its free space cache inode for free space information, so it will file a readahead request btrfs_readpages() for page that is not in page cache __do_readpage() submit_extent_page() btrfs_submit_bio_hook() btrfs_bio_wq_end_io() submit_bio() end_workqueue_bio() <--(ret by the 1st endio) queue a work(named work Y) for the 2nd also the real endio() So the hang occurs when work Y's work_struct and work X's work_struct happens to share the same address. A bit more explanation, A,B,C -- struct btrfs_work arg -- struct work_struct kthread: worker_thread() pick up a work_struct from @worklist process_one_work(arg) worker->current_work = arg; <-- arg is A->normal_work worker->current_func(arg) normal_work_helper(arg) A = container_of(arg, struct btrfs_work, normal_work); A->func() A->ordered_func() A->ordered_free() <-- A gets freed B->ordered_func() submit_compressed_extents() find_free_extent() load_free_space_inode() ... <-- (the above readhead stack) end_workqueue_bio() btrfs_queue_work(work C) B->ordered_free() As if work A has a high priority in wq->ordered_list and there are more ordered works queued after it, such as B->ordered_func(), its memory could have been freed before normal_work_helper() returns, which means that kernel workqueue code worker_thread() still has worker->current_work pointer to be work A->normal_work's, ie. arg's address. Meanwhile, work C is allocated after work A is freed, work C->normal_work and work A->normal_work are likely to share the same address(I confirmed this with ftrace output, so I'm not just guessing, it's rare though). When another kthread picks up work C->normal_work to process, and finds our kthread is processing it(see find_worker_executing_work()), it'll think work C as a collision and skip then, which ends up nobody processing work C. So the situation is that our kthread is waiting forever on work C. Besides, there're other cases that can lead to deadlock, but the real problem is that all btrfs workqueue shares one work->func, -- normal_work_helper, so this makes each workqueue to have its own helper function, but only a wraper pf normal_work_helper. With this patch, I no long hit the above hang. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-08-15btrfs: disable strict file flushes for renames and truncatesChris Mason
Truncates and renames are often used to replace old versions of a file with new versions. Applications often expect this to be an atomic replacement, even if they haven't done anything to make sure the new version is fully on disk. Btrfs has strict flushing in place to make sure that renaming over an old file with a new file will fully flush out the new file before allowing the transaction commit with the rename to complete. This ordering means the commit code needs to be able to lock file pages, and there are a few paths in the filesystem where we will try to end a transaction with the page lock held. It's rare, but these things can deadlock. This patch removes the ordered flushes and switches to a best effort filemap_flush like ext4 uses. It's not perfect, but it should fix the deadlocks. Signed-off-by: Chris Mason <clm@fb.com>
2014-07-19Btrfs: fix abnormal long waiting in fsyncLiu Bo
xfstests generic/127 detected this problem. With commit 7fc34a62ca4434a79c68e23e70ed26111b7a4cf8, now fsync will only flush data within the passed range. This is the cause of the above problem, -- btrfs's fsync has a stage called 'sync log' which will wait for all the ordered extents it've recorded to finish. In xfstests/generic/127, with mixed operations such as truncate, fallocate, punch hole, and mapwrite, we get some pre-allocated extents, and mapwrite will mmap, and then msync. And I find that msync will wait for quite a long time (about 20s in my case), thanks to ftrace, it turns out that the previous fallocate calls 'btrfs_wait_ordered_range()' to flush dirty pages, but as the range of dirty pages may be larger than 'btrfs_wait_ordered_range()' wants, there can be some ordered extents created but not getting corresponding pages flushed, then they're left in memory until we fsync which runs into the stage 'sync log', and fsync will just wait for the system writeback thread to flush those pages and get ordered extents finished, so the latency is inevitable. This adds a flush similar to btrfs_start_ordered_extent() in btrfs_wait_logged_extents() to fix that. Reviewed-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-06-09btrfs: remove stale newlines from log messagesDavid Sterba
I've noticed an extra line after "use no compression", but search revealed much more in messages of more critical levels and rare errors. Signed-off-by: David Sterba <dsterba@suse.cz> Signed-off-by: Chris Mason <clm@fb.com>
2014-03-10Btrfs: split the global ordered extents mutexMiao Xie
When we create a snapshot, we just need wait the ordered extents in the source fs/file root, but because we use the global mutex to protect this ordered extents list of the source fs/file root to avoid accessing a empty list, if someone got the mutex to access the ordered extents list of the other fs/file root, we had to wait. This patch splits the above global mutex, now every fs/file root has its own mutex to protect its own list. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10Btrfs: wake up the tasks that wait for the io earlierMiao Xie
The tasks that wait for the IO_DONE flag just care about the io of the dirty pages, so it is better to wake up them immediately after all the pages are written, not the whole process of the io completes. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10Btrfs: fix early enospc due to the race of the two ordered extent waitMiao Xie
btrfs_wait_ordered_roots() moves all the list entries to a new list, and then deals with them one by one. But if the other task invokes this function at that time, it would get a empty list. It makes the enospc error happens more early. Fix it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10btrfs: Cleanup the "_struct" suffix in btrfs_workequeueQu Wenruo
Since the "_struct" suffix is mainly used for distinguish the differnt btrfs_work between the original and the newly created one, there is no need using the suffix since all btrfs_workers are changed into btrfs_workqueue. Also this patch fixed some codes whose code style is changed due to the too long "_struct" suffix. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Tested-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10btrfs: Replace fs_info->flush_workers with btrfs_workqueue.Qu Wenruo
Replace the fs_info->submit_workers with the newly created btrfs_workqueue. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Tested-by: David Sterba <dsterba@suse.cz> Signed-off-by: Josef Bacik <jbacik@fb.com>
2014-03-10Btrfs: don't mix the ordered extents of all files together during logging ↵Miao Xie
the inodes There was a problem in the old code: If we failed to log the csum, we would free all the ordered extents in the log list including those ordered extents that were logged successfully, it would make the log committer not to wait for the completion of the ordered extents. This patch doesn't insert the ordered extents that is about to be logged into a global list, instead, we insert them into a local list. If we log the ordered extents successfully, we splice them with the global list, or we will throw them away, then do full sync. It can also reduce the lock contention and the traverse time of list. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fb.com>