- 08 Dec, 2020 40 commits
-
-
Qu Wenruo authored
The pitfall here is, if the parameter @bits has multiple bits set, we will return the first range which just has one of the specified bits set. This is a little tricky if we want an exact match. Anyway, update the comment to make that clear. Signed-off-by:
Qu Wenruo <wqu@suse.com> Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
-
Qu Wenruo authored
The return value of that function is completely wrong. That function only returns 0 if the extent buffer doesn't need to be submitted. The "ret = 1" and "ret = 0" are determined by the return value of "test_and_clear_bit(EXTENT_BUFFER_DIRTY, &eb->bflags)". And if we get ret == 1, it's because the extent buffer is dirty, and we set its status to EXTENT_BUFFER_WRITE_BACK, and continue to page locking. While if we get ret == 0, it means the extent is not dirty from the beginning, so we don't need to write it back. The caller also follows this, in btree_write_cache_pages(), if lock_extent_buffer_for_io() returns 0, we just skip the extent buffer completely. So the comment is completely wrong. Since we're here, also change the description a little. The write bio flushing won't be visible to the caller, thus it's not an major feature. In the main description, only describe the locking part to make the point more clear. For reference, added in commit 2e3c2513 ("btrfs: extent_io: add proper error handling to lock_extent_buffer_for_io()") Signed-off-by:
-
David Sterba authored
Long time ago the explicit casts were necessary for u64 but we don't need it. Remove casts where the type matches, leaving only cases that cast sector_t or loff_t. Reviewed-by:
Josef Bacik <josef@toxicpanda.com> Signed-off-by:
-
David Sterba authored
The drop_level member is used directly unlike all the other int types in root_item. Add the definition and use it everywhere. The type is u8 so there's no conversion necessary and the helpers are properly inlined, this is for consistency. Reviewed-by:
-
David Sterba authored
For consistency use the available helpers to set flags and limit. Reviewed-by:
-
David Sterba authored
There's one raw use of le->cpu conversion but we have a helper to do that for us, so use it. Reviewed-by:
-
David Sterba authored
We have helpers to access the on-disk item members, use that for root_item::ctransid instead of raw le64_to_cpu. Reviewed-by:
-
David Sterba authored
The names in btrfs_lockdep_keysets are generated from a simple pattern using snprintf but we can generate them directly with some macro magic and remove the helpers. Reviewed-by:
-
David Sterba authored
BTRFS_MAX_LEVEL is 8 and the keyset table is supposed to have a key for each level, but we'll never have more than 8 levels. The values passed to btrfs_set_buffer_lockdep_class are always derived from a valid extent buffer. Set the array sizes to the right value. Reviewed-by:
-
Goldwyn Rodrigues authored
This effectively reverts 09745ff88d93 ("btrfs: dio iomap DSYNC workaround") now that the iomap API has been updated to allow iomap_dio_complete() not to be called under i_rwsem anymore. Reviewed-by:Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by:
-
Goldwyn Rodrigues authored
If direct writes are called with O_DIRECT | O_DSYNC, it will result in a deadlock because iomap_dio_rw() is called under i_rwsem which calls: iomap_dio_complete() generic_write_sync() btrfs_sync_file() btrfs_sync_file() requires i_rwsem, so call __iomap_dio_rw() with the i_rwsem locked, and call iomap_dio_complete() after unlocking i_rwsem. Reviewed-by: -
Goldwyn Rodrigues authored
The inode dio_sem can be eliminated because all DIO synchronization is now performed through inode->i_rwsem that provides the same guarantees. This reduces btrfs_inode size by 40 bytes. Reviewed-by:
-
Goldwyn Rodrigues authored
Direct writes within EOF are safe to be performed with inode shared lock to improve parallelization with other direct writes or reads because EOF is not changed and there is no race with truncate(). Direct reads are already performed under shared inode lock. This patch is precursor to removing btrfs_inode->dio_sem. Signed-off-by:
-
Goldwyn Rodrigues authored
Push inode locking and unlocking closer to where we perform the I/O. For this we need to move the write checks inside the respective functions as well. pos is evaluated after generic_write_checks because O_APPEND can change iocb->ki_pos. Reviewed-by:
-
Goldwyn Rodrigues authored
btrfs_inode_lock/unlock() are wrappers around inode locks, separating the type of lock and actual locking. - 0 - default, exclusive lock - BTRFS_ILOCK_SHARED - for shared locks, for possible parallel DIO - BTRFS_ILOCK_TRY - for the RWF_NOWAIT sequence The bits SHARED and TRY can be combined together. Reviewed-by:
-
Goldwyn Rodrigues authored
btrfs_write_check() checks write parameters in one place before beginning a write. This does away with inode_unlock() after every check. In the later patches, it will help push inode_lock/unlock() in buffered and direct write functions respectively. generic_write_checks needs to be called before as it could truncate iov_iter and its return used as count. Signed-off-by:
-
Goldwyn Rodrigues authored
fs_info::fs_state is a filesystem bit check as opposed to inode and can be performed before we begin with write checks. This eliminates inode lock/unlock in case the error bit is set. Reviewed-by:
-
Goldwyn Rodrigues authored
While we do this, correct the call to pagecache_isize_extended: - pagecache_isize_extended needs to be called to the start of the write as opposed to i_size - we don't need to check range before the call, this is done in the function Reviewed-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
-
Goldwyn Rodrigues authored
The read and write DIO don't have anything in common except for the call to iomap_dio_rw. Extract the write call into a new function to get rid of conditional statements for direct write. Reviewed-by:
-
Anand Jain authored
Add /sys/fs/btrfs/UUID/read_policy attribute so that the read policy for the raid1, raid1c34 and raid10 can be tuned. When this attribute is read, it will show all available policies, with active policy in [ ]. The read_policy attribute can be written using one of the items listed in there. For example: $ cat /sys/fs/btrfs/UUID/read_policy [pid] $ echo pid > /sys/fs/btrfs/UUID/read_policy Reviewed-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
-
Anand Jain authored
As of now, we use the pid method to read striped mirrored data, which means process id determines the stripe id to read. This type of routing typically helps in a system with many small independent processes tying to read random data. On the other hand, the pid based read IO policy is inefficient because if there is a single process trying to read a large file, the overall disk bandwidth remains underutilized. So this patch introduces a read policy framework so that we could add more read policies, such as IO routing based on the device's wait-queue or manual when we have a read-preferred device or a policy based on the target storage caching. Reviewed-by:
-
Anand Jain authored
Add a generic helper to match the string in a given buffer, and ignore the leading and trailing whitespace. Reviewed-by:
-
Filipe Manana authored
We do not need anymore to start writeback for delalloc of roots that are being snapshotted and wait for it to complete. This was done in commit 609e804d ("Btrfs: fix file corruption after snapshotting due to mix of buffered/DIO writes") to fix a type of file corruption where files in a snapshot end up having their i_size updated in a non-ordered way, leaving implicit file holes, when buffered IO writes that increase a file's size are followed by direct IO writes that also increase the file's size. This is not needed anymore because we now have a more generic mechanism to prevent a non-ordered i_size update since commit 9ddc959e ("btrfs: use the file extent tree infrastructure"), which addresses this scenario involving snapshots as well. Reviewed-by:
Filipe Manana <fdmanana@suse.com> Reviewed-by:
-
Josef Bacik authored
Historically we've implemented our own locking because we wanted to be able to selectively spin or sleep based on what we were doing in the tree. For instance, if all of our nodes were in cache then there's rarely a reason to need to sleep waiting for node locks, as they'll likely become available soon. At the time this code was written the rw_semaphore didn't do adaptive spinning, and thus was orders of magnitude slower than our home grown locking. However now the opposite is the case. There are a few problems with how we implement blocking locks, namely that we use a normal waitqueue and simply wake everybody up in reverse sleep order. This leads to some suboptimal performance behavior, and a lot of context switches in highly contended cases. The rw_semaphores actually do this properly, and also have adaptive spinning that works relatively well. The locking code is also a bit of a bear to understand, and we lose the benefit of lockdep for the most part because the blocking states of the lock are simply ad-hoc and not mapped into lockdep. So rework the locking code to drop all of this custom locking stuff, and simply use a rw_semaphore for everything. This makes the locking much simpler for everything, as we can now drop a lot of cruft and blocking transitions. The performance numbers vary depending on the workload, because generally speaking there doesn't tend to be a lot of contention on the btree. However, on my test system which is an 80 core single socket system with 256GiB of RAM and a 2TiB NVMe drive I get the following results (with all debug options off): dbench 200 baseline Throughput 216.056 MB/sec 200 clients 200 procs max_latency=1471.197 ms dbench 200 with patch Throughput 737.188 MB/sec 200 clients 200 procs max_latency=714.346 ms Previously we also used fs_mark to test this sort of contention, and those results are far less impressive, mostly because there's not enough tasks to really stress the locking fs_mark -d /d[0-15] -S 0 -L 20 -n 100000 -s 0 -t 16 baseline Average Files/sec: 160166.7 p50 Files/sec: 165832 p90 Files/sec: 123886 p99 Files/sec: 123495 real 3m26.527s user 2m19.223s sys 48m21.856s patched Average Files/sec: 164135.7 p50 Files/sec: 171095 p90 Files/sec: 122889 p99 Files/sec: 113819 real 3m29.660s user 2m19.990s sys 44m12.259s Signed-off-by: -
Nikolay Borisov authored
Just open code it in its sole caller and remove a level of indirection. Reviewed-by:
Nikolay Borisov <nborisov@suse.com> Reviewed-by:
-
Josef Bacik authored
Now that we have the building blocks for some better recovery options with corrupted file systems, add a rescue=all option to enable all of the relevant rescue options. This will allow distros to simply default to rescue=all for the "oh dear lord the world's on fire" recovery without needing to know all the different options that we have and may add in the future. Reviewed-by:
-
Josef Bacik authored
There are cases where you can end up with bad data csums because of misbehaving applications. This happens when an application modifies a buffer in-flight when doing an O_DIRECT write. In order to recover the file we need a way to turn off data checksums so you can copy the file off, and then you can delete the file and restore it properly later. Reviewed-by:
-
Josef Bacik authored
In the face of extent root corruption, or any other core fs wide root corruption we will fail to mount the file system. This makes recovery kind of a pain, because you need to fall back to userspace tools to scrape off data. Instead provide a mechanism to gracefully handle bad roots, so we can at least mount read-only and possibly recover data from the file system. Signed-off-by:
-
Josef Bacik authored
The standalone option usebackuproot was intended as one-time use and it was not necessary to keep it in the option list. Now that we're going to have more rescue options, it's desirable to keep them intact as it could be confusing why the option disappears. Signed-off-by:
-
Josef Bacik authored
We're going to have a lot of rescue options, add a helper to collapse the /proc/mounts output to rescue=option1:option2:option3 format. Reviewed-by:
Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by:
-
Josef Bacik authored
We're going to be adding a variety of different rescue options, we should advertise which ones we support to make user spaces life easier in the future. Reviewed-by:
-
Josef Bacik authored
When we move to being able to handle NULL csum_roots it'll be cleaner to just check in btrfs_lookup_bio_sums instead of at all of the caller locations, so push the NODATASUM check into it as well so it's unified. Reviewed-by:
-
Josef Bacik authored
We're going to be adding more options that require RDONLY, so add a helper to do the check and error out if we don't have RDONLY set. Reviewed-by:
-
Filipe Manana authored
When scrubbing a stripe of a block group we always start readahead for the checksums btree and wait for it to complete, however when the blockgroup is not a data block group (or a mixed block group) it is a waste of time to do it, since there are no checksums for metadata extents in that btree. So skip that when the block group does not have the data flag set, saving some time doing memory allocations, queueing a job in the readahead work queue, waiting for it to complete and potentially avoiding some IO as well (when csum tree extents are not in memory already). Reviewed-by:
-
Filipe Manana authored
When we drop the last reference of a zone, we end up releasing it through the callback reada_zone_release(), which deletes the zone from a device's reada_zones radix tree. This tree is protected by the global readahead lock at fs_info->reada_lock. Currently all places that are sure that they are dropping the last reference on a zone, are calling kref_put() in a critical section delimited by this lock, while all other places that are sure they are not dropping the last reference, do not bother calling kref_put() while holding that lock. When working on the previous fix for hangs and use-after-frees in the readahead code, my initial attempts were different and I actually ended up having reada_zone_release() called when not holding the lock, which resulted in weird and unexpected problems. So just add an assertion there to detect such problem more quickly and make the dependency more obvious. Reviewed-by:
-
Goldwyn Rodrigues authored
Set the extent bits EXTENT_NORESERVE inside btrfs_dirty_pages() as opposed to calling set_extent_bits again later. Fold check for written length within the function. Note: EXTENT_NORESERVE is set before unlocking extents. Reviewed-by:
-
Goldwyn Rodrigues authored
round_down looks prettier than the bit mask operations. Reviewed-by:
-
Goldwyn Rodrigues authored
While using compression, a submitted bio is mapped with a compressed bio which performs the read from disk, decompresses and returns uncompressed data to original bio. The original bio must reflect the uncompressed size (iosize) of the I/O to be performed, or else the page just gets the decompressed I/O length of data (disk_io_size). The compressed bio checks the extent map and gets the correct length while performing the I/O from disk. This came up in subpage work when only compressed length of the original bio was filled in the page. This worked correctly for pagesize == sectorsize because both compressed and uncompressed data are at pagesize boundaries, and would end up filling the requested page. Reviewed-by:
-
Goldwyn Rodrigues authored
write_bytes can change in btrfs_check_nocow_lock(). Calculate variables such as num_pages and reserve_bytes once we are sure of the value of write_bytes so there is no need to re-calculate. Reviewed-by:
-
Nikolay Borisov authored
If transaction_kthread is woken up before btrfs_fs_info::commit_interval seconds have elapsed it will sleep for a fixed period of 5 seconds. This is not a problem per-se but is not accurate. Instead the code should sleep for an interval which guarantees on next wakeup commit_interval would have passed. Since time tracking is not precise subtract 1 second from delta to ensure the delay we end up waiting will be longer than than the wake up period. Signed-off-by:
-
