- 14 Mar, 2022 40 commits
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Josef Bacik authored
If we fail to submit a bio for whatever reason, we may not have setup a mirror_num for that bio. This means we shouldn't try to do the repair workflow, if we do we'll hit an BUG_ON(!failrec->this_mirror) in clean_io_failure. Instead simply skip the repair workflow if we have no mirror set, and add an assert to btrfs_check_repairable() to make it easier to catch what is happening in the future. Reviewed-by: Boris Burkov <boris@bur.io> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
I hit some weird panics while fixing up the error handling from btrfs_lookup_bio_sums(). Turns out the compression path will complete the bio we use if we set up any of the compression bios and then return an error, and then btrfs_submit_data_bio() will also call bio_endio() on the bio. Fix this by making btrfs_submit_compressed_read() responsible for calling bio_endio() on the bio if there are any errors. Currently it was only doing it if we created the compression bios, otherwise it was depending on btrfs_submit_data_bio() to do the right thing. This creates the above problem, so fix up btrfs_submit_compressed_read() to always call bio_endio() in case of an error, and then simply return from btrfs_submit_data_bio() if we had to call btrfs_submit_compressed_read(). Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
Right now we just have a binary "errors" flag, so any error we get on the compressed bio's gets translated to EIO. This isn't necessarily a bad thing, but if we get an ENOMEM it may be nice to know that's what happened instead of an EIO. Track our errors as a blk_status_t, and do the appropriate setting of the errors accordingly. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
This bio is usually one of the compressed bio's, and we don't actually need it in this function, so remove the argument and stop passing it around. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
Commit c09abff8 ("btrfs: cloned bios must not be iterated by bio_for_each_segment_all") added ASSERT()'s to make sure we weren't calling bio_for_each_segment_all() on a RAID5/6 bio. However it was checking the bio that the compression code passed in, not the cb->orig_bio that we actually iterate over, so adjust this ASSERT() to check the correct bio. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
Currently any error we get while trying to lookup csums during reads shows up as a missing csum, and then on the read completion side we print an error saying there was a csum mismatch and we increase the device corruption count. However we could have gotten an EIO from the lookup. We could also be inside of a memory constrained container and gotten a ENOMEM while trying to do the read. In either case we don't want to make this look like a file system corruption problem, we want to make it look like the actual error it is. Capture any negative value, convert it to the appropriate blk_status_t, free the csum array if we have one and bail. Note: a possible improvement would be to make the relocation code look up the owning inode and see if it's marked as NODATASUM and set EXTENT_NODATASUM there, that way if there's corruption and there isn't a checksum when we want it we can fail here rather than later. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
We can either fail to find a csum entry at all and return -ENOENT, or we can find a range that is close, but return -EFBIG. In essence these both mean the same thing when we are doing a lookup for a csum in an existing range, we didn't find a csum. We want to treat both of these errors the same way, complain loudly that there wasn't a csum. This currently happens anyway because we do count = search_csum_tree(); if (count <= 0) { // reloc and error handling } However it forces us to incorrectly treat EIO or ENOMEM errors as on disk corruption. Fix this by returning 0 if we get either -ENOENT or -EFBIG from btrfs_lookup_csum() so we can do proper error handling. Reviewed-by: Boris Burkov <boris@bur.io> Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
The implementation resembles direct I/O: we have to flush any ordered extents, invalidate the page cache, and do the io tree/delalloc/extent map/ordered extent dance. From there, we can reuse the compression code with a minor modification to distinguish the write from writeback. This also creates inline extents when possible. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
There are 4 main cases: 1. Inline extents: we copy the data straight out of the extent buffer. 2. Hole/preallocated extents: we fill in zeroes. 3. Regular, uncompressed extents: we read the sectors we need directly from disk. 4. Regular, compressed extents: we read the entire compressed extent from disk and indicate what subset of the decompressed extent is in the file. This initial implementation simplifies a few things that can be improved in the future: - Cases 1, 3, and 4 allocate temporary memory to read into before copying out to userspace. - We don't do read repair, because it turns out that read repair is currently broken for compressed data. - We hold the inode lock during the operation. Note that we don't need to hold the mmap lock. We may race with btrfs_page_mkwrite() and read the old data from before the page was dirtied: btrfs_page_mkwrite btrfs_encoded_read --------------------------------------------------- (enter) (enter) btrfs_wait_ordered_range lock_extent_bits btrfs_page_set_dirty unlock_extent_cached (exit) lock_extent_bits read extent (dirty page hasn't been flushed, so this is the old data) unlock_extent_cached (exit) we read the old data from before the page was dirtied. But, that's true even if we were to hold the mmap lock: btrfs_page_mkwrite btrfs_encoded_read ------------------------------------------------------------------- (enter) (enter) btrfs_inode_lock(BTRFS_ILOCK_MMAP) down_read(i_mmap_lock) (blocked) btrfs_wait_ordered_range lock_extent_bits read extent (page hasn't been dirtied, so this is the old data) unlock_extent_cached btrfs_inode_unlock(BTRFS_ILOCK_MMAP) down_read(i_mmap_lock) returns lock_extent_bits btrfs_page_set_dirty unlock_extent_cached In other words, this is inherently racy, so it's fine that we return the old data in this tiny window. Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
In order to allow sending and receiving compressed data without decompressing it, we need an interface to write pre-compressed data directly to the filesystem and the matching interface to read compressed data without decompressing it. This adds the definitions for ioctls to do that and detailed explanations of how to use them. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
Currently, an inline extent is always created after i_size is extended from btrfs_dirty_pages(). However, for encoded writes, we only want to update i_size after we successfully created the inline extent. Add an update_i_size parameter to cow_file_range_inline() and insert_inline_extent() and pass in the size of the extent rather than determining it from i_size. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> [ reformat comment ] Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
The start parameter to cow_file_range_inline() (and insert_inline_extent()) is always 0, so get rid of it and simplify the logic in those two functions. Pass btrfs_inode to insert_inline_extent() and remove the redundant root parameter. Also document the requirements for creating an inline extent. No functional change. Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
Currently, we always reserve the same extent size in the file and extent size on disk for delalloc because the former is the worst case for the latter. For BTRFS_IOC_ENCODED_WRITE writes, we know the exact size of the extent on disk, which may be less than or greater than (for bookends) the size in the file. Add a disk_num_bytes parameter to btrfs_delalloc_reserve_metadata() so that we can reserve the correct amount of csum bytes. No functional change. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
Currently, we only create ordered extents when ram_bytes == num_bytes and offset == 0. However, BTRFS_IOC_ENCODED_WRITE writes may create extents which only refer to a subset of the full unencoded extent, so we need to plumb these fields through the ordered extent infrastructure and pass them down to insert_reserved_file_extent(). Since we're changing the btrfs_add_ordered_extent* signature, let's get rid of the trivial wrappers and add a kernel-doc. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
btrfs_csum_one_bio() loops over each filesystem block in the bio while keeping a cursor of its current logical position in the file in order to look up the ordered extent to add the checksums to. However, this doesn't make much sense for compressed extents, as a sector on disk does not correspond to a sector of decompressed file data. It happens to work because: 1) the compressed bio always covers one ordered extent 2) the size of the bio is always less than the size of the ordered extent However, the second point will not always be true for encoded writes. Let's add a boolean parameter to btrfs_csum_one_bio() to indicate that it can assume that the bio only covers one ordered extent. Since we're already changing the signature, let's get rid of the contig parameter and make it implied by the offset parameter, similar to the change we recently made to btrfs_lookup_bio_sums(). Additionally, let's rename nr_sectors to blockcount to make it clear that it's the number of filesystem blocks, not the number of 512-byte sectors. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
Encoded I/O in Btrfs needs to check a write with a given logical size without an iov_iter that matches that size (because the iov_iter we have is for the compressed data). So, factor out the parts of generic_write_check() that don't need an iov_iter into a new generic_write_checks_count() function and export that. Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Omar Sandoval authored
I'm adding btrfs ioctls to read and write compressed data, and rather than duplicating the checks in rw_verify_area(), let's just export it. Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Omar Sandoval <osandov@fb.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Sidong Yang authored
These comments are old, outdated and not very specific. It seems that it doesn't help to inspire anybody to work on that. So we remove them. Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Sidong Yang <realwakka@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Sidong Yang authored
Removes duplicated check when adding qgroup relations. btrfs_add_qgroup_relations function adds relations by calling add_relation_rb(). add_relation_rb() checks that member/parentid exists in current qgroup_tree. But it already checked before calling the function. It seems that we don't need to double check. Add new function __add_relation_rb() that adds relations with qgroup structures and makes old function use the new one. And it makes btrfs_add_qgroup_relation() function work without double checks by calling the new function. Signed-off-by: Sidong Yang <realwakka@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comments ] Signed-off-by: David Sterba <dsterba@suse.com>
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Dāvis Mosāns authored
It makes it more readable for length checking and is be used repeatedly. Signed-off-by: Dāvis Mosāns <davispuh@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Qu Wenruo authored
When btrfs_get_extent() tries to get some file extent from disk, it never populates extent_map::generation, leaving the value to be 0. On the other hand, for extent map generated by IO, it will get its generation properly set at finish_ordered_io() finish_ordered_io() |- unpin_extent_cache(gen = trans->transid) |- em->generation = gen; [CAUSE] Since extent_map::generation is mostly used by fsync code, and for fsync they only care about modified extents, which all have their em::generation > 0. Thus it's fine to not populate em read from disk for fsync. [CORNER CASE] However autodefrag also relies on em::generation to determine if one extent needs to be defragged. This unpopulated extent_map::generation can prevent the following autodefrag case from working: mkfs.btrfs -f $dev mount $dev $mnt -o autodefrag # initial write to queue the inode for autodefrag xfs_io -f -c "pwrite 0 4k" $mnt/file sync # Real fragmented write xfs_io -f -s -c "pwrite -b 4096 0 32k" $mnt/file sync echo "=== before autodefrag ===" xfs_io -c "fiemap -v" $mnt/file # Drop cache to force em to be read from disk echo 3 > /proc/sys/vm/drop_caches mount -o remount,commit=1 $mnt sleep 3 sync echo "=== After autodefrag ===" xfs_io -c "fiemap -v" $mnt/file umount $mnt The result looks like this: === before autodefrag === /mnt/btrfs/file: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..15]: 26672..26687 16 0x0 1: [16..31]: 26656..26671 16 0x0 2: [32..47]: 26640..26655 16 0x0 3: [48..63]: 26624..26639 16 0x1 === After autodefrag === /mnt/btrfs/file: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..15]: 26672..26687 16 0x0 1: [16..31]: 26656..26671 16 0x0 2: [32..47]: 26640..26655 16 0x0 3: [48..63]: 26624..26639 16 0x1 This fragmented 32K will not be defragged by autodefrag. [FIX] To make things less weird, just populate extent_map::generation when reading file extents from disk. This would make above fragmented extents to be properly defragged: == before autodefrag === /mnt/btrfs/file: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..15]: 26672..26687 16 0x0 1: [16..31]: 26656..26671 16 0x0 2: [32..47]: 26640..26655 16 0x0 3: [48..63]: 26624..26639 16 0x1 === After autodefrag === /mnt/btrfs/file: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..63]: 26688..26751 64 0x1 Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
Removing or replacing an extent map requires holding a write lock on the extent map's tree. We currently do that everywhere, except in one of the self tests, where it's harmless since there's no concurrency. In order to catch possible races in the future, assert that we are holding a write lock on the extent map tree before removing or replacing an extent map in the tree, and update the self test to obtain a write lock before removing extent maps. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
After commit 92082d40 ("btrfs: integrate page status update for data read path into begin/end_page_read"), the 'nr' counter at btrfs_do_readpage() is no longer used, we increment it but we never read from it. So just remove it. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
At btrfs_do_readpage(), if we get an error when trying to lookup for an extent map, we end up marking the page with the error bit, clearing the uptodate bit on it, and doing everything else that should be done. However we return success (0) to the caller, when we should return the error encoded in the extent map pointer. So fix that by returning the error encoded in the pointer. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
At extent_io.c, in the read page and write page code paths, we are testing if the return value from btrfs_get_extent() can be NULL. However that is not possible, as btrfs_get_extent() always returns either an error pointer or a (non-NULL) pointer to an extent map structure. Everywhere else outside extent_io.c we never check for NULL, we always treat any returned value as a non-NULL pointer if it does not encode an error. So check only for the IS_ERR() case at extent_io.c. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
When we want to log an extent, in the fast fsync path, we obtain a path to the leaf that will hold the file extent item either through a deletion search, via btrfs_drop_extents(), or through an insertion search using btrfs_insert_empty_item(). After that we fill the file extent item's fields one by one directly on the leaf. Instead of doing that, we could prepare the file extent item before obtaining a btree path, and then copy the prepared extent item with a single operation once we get the path. This helps avoid some contention on the log tree, since we are holding write locks for longer than necessary, especially in the case where the path is obtained via btrfs_drop_extents() through a deletion search, which always keeps a write lock on the nodes at levels 1 and 2 (besides the leaf). This change does that, we prepare the file extent item that is going to be inserted before acquiring a path, and then copy it into a leaf using a single copy operation once we get a path. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path The following test was run to measure the impact of the whole patchset: $ cat test.sh #!/bin/bash DEV=/dev/sdi MNT=/mnt/sdi MOUNT_OPTIONS="-o ssd" MKFS_OPTIONS="-R free-space-tree -O no-holes" NUM_JOBS=8 FILE_SIZE=128M RUN_TIME=200 cat <<EOF > /tmp/fio-job.ini [writers] rw=randwrite fsync=1 fallocate=none group_reporting=1 direct=0 bssplit=4k/20:8k/20:16k/20:32k/10:64k/10:128k/5:256k/5:512k/5:1m/5 ioengine=sync filesize=$FILE_SIZE runtime=$RUN_TIME time_based directory=$MNT numjobs=$NUM_JOBS thread EOF echo "performance" | \ tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor echo echo "Using config:" echo cat /tmp/fio-job.ini echo umount $MNT &> /dev/null mkfs.btrfs -f $MKFS_OPTIONS $DEV mount $MOUNT_OPTIONS $DEV $MNT fio /tmp/fio-job.ini umount $MNT The test ran inside a VM (8 cores, 32G of RAM) with the target disk mapping to a raw NVMe device, and using a non-debug kernel config (Debian's default config). Before the patchset: WRITE: bw=116MiB/s (122MB/s), 116MiB/s-116MiB/s (122MB/s-122MB/s), io=22.7GiB (24.4GB), run=200013-200013msec After the patchset: WRITE: bw=125MiB/s (131MB/s), 125MiB/s-125MiB/s (131MB/s-131MB/s), io=24.3GiB (26.1GB), run=200007-200007msec A 7.8% gain on throughput and +7.0% more IO done in the same period of time (200 seconds). Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
There's no point in calling btrfs_release_path() after finishing the loop that logs the modified extents, since log_one_extent() returns with the path released. In case the list of extents is empty, the path is already released, so there's no need for that case as well. So just remove that unnecessary btrfs_release_path() call. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path The last patch in the series has some performance test result in its changelog. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
At btrfs_drop_extents(), we try to replace a range of file extent items with a new file extent in a single btree search, to avoid the need to do a search for deletion, followed by a path release and followed by yet another search for insertion. When I originally added that optimization, in commit 1acae57b ("Btrfs: faster file extent item replace operations"), I left a constraint to do the fast replace only if we visited a single leaf. That was because in the most common case we find all file extent items that need to be deleted (or trimmed) in a single leaf, however it can work for other common cases like when we need to delete a few file extent items located at the end of a leaf and a few more located at the beginning of the next leaf. The key for the new file extent item is greater than the key of any deleted or trimmed file extent item from previous leaves, so we are fine to use the last leaf that we found as long as we are holding a write lock on it - even if the new key ends up at slot 0, as if that's the case, the btree search has obtained a write lock on any upper nodes that need to have a key pointer updated. So removed the constraint that limits the optimization to the case where we visited only a single leaf. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path The last patch in the series has some performance test result in its changelog. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
When deleting items from a leaf, we always compute the sum of the data sizes of the items that are going to be deleted. However we only use that sum when the last item to delete is behind the last item in the leaf. This unnecessarily wastes CPU time when we are deleting either the whole leaf or from some slot > 0 up to the last item in the leaf, and both of these cases are common (e.g. truncation operation, either as a result of truncate(2) or when logging inodes, deleting checksums after removing a large enough extent, etc). So compute only the sum of the data sizes if the last item to be deleted does not match the last item in the leaf. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path The last patch in the series has some performance test result in its changelog. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
When we delete items from a leaf, if we end up with more than two thirds of unused leaf space, we try to delete the leaf by moving all its items into its left and right neighbour leaves. Sometimes that is not possible because there is not enough free space in the left and right leaves, and in that case we end up not deleting our leaf. The way we are doing this is not ideal and can be improved in the following ways: 1) When we call push_leaf_left(), we pass a value of 1 byte to the data size parameter of push_leaf_left(). This is not realistic value because no item can have a size less than 25 bytes, which is the size of struct btrfs_item. This means that means that if the left leaf has not enough free space to push any item, we end up COWing it even if we end up not changing its content at all. COWing that leaf means allocating a new metadata extent, marking it dirty and doing more IO when committing a transaction or when syncing a log tree. For a log tree case, it's particularly more important to avoid the useless COW operation, as more IO can imply a higher latency for an fsync operation. So instead of passing 1 as the minimum data size for push_leaf_left(), pass the size of the first item in our leaf, as we don't want to COW the left leaf if we can't at least push the first item of our leaf; 2) When we call push_leaf_right(), we also pass a value of 1 byte as the data size parameter of push_leaf_right(). Like the previous case, it will also result in COWing the right leaf even if we are not able to move any items into it, since there can't be any item with a size smaller than 25 bytes (the size of struct btrfs_item). So instead of passing 1 as the minimum data size to push_leaf_right(), pass a size that corresponds to the sum of the size of all the remaining items in our leaf. We are not interested in moving less than that, because if we do, we are not able to delete our leaf and we have COWed the right leaf for nothing. Plus, moving only some of the items of our leaf, it means an even less balanced tree. Just like the previous case, we want to avoid the useless COW of the right leaf, this way we don't have to spend time allocating one new metadata extent, and doing more IO when committing a transaction or syncing a log tree. For the log tree case it's specially more important because more IO can result in a higher latency for a fsync operation. So adjust the minimum data size passed to push_leaf_left() and push_leaf_right() as mentioned above. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path Not being able to delete a leaf that became less than 1/3 full after deleting items from it is actually common. For example, for the fio test mentioned in the changelog of patch 6/6, we are only able to delete a leaf at btrfs_del_items() about 5.3% of the time, due to its left and right neighbour leaves not having enough free space to push all the remaining items into them. The last patch in the series has some performance test result in its changelog. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Filipe Manana authored
When trying to push items from a leaf into its left and right neighbours, we lock the left or right leaf, check if it has the required minimum free space, COW the leaf and then check again if it has the minimum required free space. This second check is pointless: 1) Most and foremost because it's not needed. We have a write lock on the leaf and on its parent node, so no one can come in and change either the pre-COW or post-COW version of the leaf for the whole duration of the push_leaf_left() and push_leaf_right() calls; 2) The call to btrfs_leaf_free_space() is not trivial, it has a fair amount of arithmetic operations and access to fields in the leaf's header and items, so it's not very cheap. So remove the duplicated free space checks. This change if part of a patchset that is comprised of the following patches: 1/6 btrfs: remove unnecessary leaf free space checks when pushing items 2/6 btrfs: avoid unnecessary COW of leaves when deleting items from a leaf 3/6 btrfs: avoid unnecessary computation when deleting items from a leaf 4/6 btrfs: remove constraint on number of visited leaves when replacing extents 5/6 btrfs: remove useless path release in the fast fsync path 6/6 btrfs: prepare extents to be logged before locking a log tree path The last patch in the series has some performance test result in its changelog. Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Johannes Thumshirn authored
In get_extent_skip_holes() we're checking the return of btrfs_get_extent_fiemap() for an error pointer or NULL, but btrfs_get_extent_fiemap() will never return NULL, only error pointers or a valid extent_map. The other caller of btrfs_get_extent_fiemap(), find_desired_extent(), correctly only checks for error-pointers. Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Pankaj Raghav authored
Remove the redundant assignment to zone_info variable in btrfs_check_zoned_mode function. Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Signed-off-by: David Sterba <dsterba@suse.com>
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David Sterba authored
The static_assert introduced in 6bab69c6 ("build_bug.h: add wrapper for _Static_assert") has been supported by compilers for a long time (gcc 4.6, clang 3.0) and can be used in header files. We don't need to put BUILD_BUG_ON to random functions but rather keep it next to the definition. The exception here is the UAPI header btrfs_tree.h that could be potentially included by userspace code and the static assert is not defined (nor used in any other header). Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Johannes Thumshirn authored
Allow creating or reading block-groups on a zoned device with DUP as a meta-data profile. This works because we're using the zoned_meta_io_lock and REQ_OP_WRITE operations for meta-data on zoned btrfs, so all writes to meta-data zones are aligned to the zone's write-pointer. Upon loading of the block-group, it is ensured both zones do have the same zone capacity and write-pointer offsets, so no extra machinery is needed to keep the write-pointers in sync for the meta-data zones. If this prerequisite is not met, loading of the block-group is refused. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Johannes Thumshirn authored
Allow for a block-group to be placed on more than one physical zone. This is a preparation for allowing DUP profiles for meta-data on a zoned file-system. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Johannes Thumshirn authored
Currently finishing of a zone only works if the block group isn't spanning more than one zone. This limitation is purely artificial and can be easily expanded to block groups being places across multiple zones. This is a preparation for allowing DUP and later more complex block-group profiles on zoned btrfs. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Johannes Thumshirn authored
Currently activation of a zone only works if the block group isn't spanning more than one zone. This limitation is purely artificial and can be easily expanded to block groups being places across multiple zones. This is a preparation for allowing DUP and later more complex block-group profiles on zoned btrfs. Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
With extent tree v2 you will be able to create multiple csum, extent, and free space trees. They will be used based on the block group, which will now use the block_group_item->chunk_objectid to point to the set of global roots that it will use. When allocating new block groups we'll simply mod the gigabyte offset of the block group against the number of global roots we have and that will be the block groups global id. >From there we can take the bytenr that we're modifying in the respective tree, look up the block group and get that block groups corresponding global root id. From there we can get to the appropriate global root for that bytenr. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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Josef Bacik authored
This code adds the on disk structures for the block group root, which will hold the block group items for extent tree v2. Signed-off-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: David Sterba <dsterba@suse.com>
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