lwn.git/fs/xfs/xfs_inode.h, branch docs-5.6

xfs: merge the projid fields in struct xfs_icdinode

2019-11-13T19:13:45+00:00

There is no point in splitting the fields like this in an purely in-memory structure. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: remove the now unused dir ops infrastructure

2019-11-11T00:54:24+00:00

Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: add a xfs_inode_buftarg helper

2019-10-28T15:37:54+00:00

Add a new xfs_inode_buftarg helper that gets the data I/O buftarg for a given inode. Replace the existing xfs_find_bdev_for_inode and xfs_find_daxdev_for_inode helpers with this new general one and cleanup some of the callers. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: widen inode delalloc block counter to 64-bits

2019-04-23T15:36:23+00:00

Widen the incore inode's i_delayed_blks counter to be a 64-bit integer. This is necessary to fix an integer overflow problem that can be reproduced easily now that we use the counter to track blocks that are assigned to the inode in memory but not on disk. This includes actual delalloc reservations as well as real extents in the COW fork that are waiting to be remapped into the data fork. These 'delayed mapping' blocks can easily exceed 2^32 blocks if one creates a very large sparse file of size approximately 2^33 bytes with one byte written every 2^23 bytes, sets a very large COW extent size hint of 2^23 blocks, reflinks the first file into a second file, and then writes a single byte every 2^23 blocks in the original file. When this happens, we'll try to create approximately 1024 2^23 extent reservations in the COW fork, which will overflow the counter and cause problems. Note that on x64 we end up filling a 4-byte gap in the structure so this doesn't increase the incore size. Signed-off-by: Darrick J. Wong Reviewed-by: Allison Collins Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig

xfs: implement per-inode writeback completion queues

2019-04-16T17:01:57+00:00

When scheduling writeback of dirty file data in the page cache, XFS uses IO completion workqueue items to ensure that filesystem metadata only updates after the write completes successfully. This is essential for converting unwritten extents to real extents at the right time and performing COW remappings. Unfortunately, XFS queues each IO completion work item to an unbounded workqueue, which means that the kernel can spawn dozens of threads to try to handle the items quickly. These threads need to take the ILOCK to update file metadata, which results in heavy ILOCK contention if a large number of the work items target a single file, which is inefficient. Worse yet, the writeback completion threads get stuck waiting for the ILOCK while holding transaction reservations, which can use up all available log reservation space. When that happens, metadata updates to other parts of the filesystem grind to a halt, even if the filesystem could otherwise have handled it. Even worse, if one of the things grinding to a halt happens to be a thread in the middle of a defer-ops finish holding the same ILOCK and trying to obtain more log reservation having exhausted the permanent reservation, we now have an ABBA deadlock - writeback completion has a transaction reserved and wants the ILOCK, and someone else has the ILOCK and wants a transaction reservation. Therefore, we create a per-inode writeback io completion queue + work item. When writeback finishes, it can add the ioend to the per-inode queue and let the single worker item process that queue. This dramatically cuts down on the number of kworkers and ILOCK contention in the system, and seems to have eliminated an occasional deadlock I was seeing while running generic/476. Testing with a program that simulates a heavy random-write workload to a single file demonstrates that the number of kworkers drops from approximately 120 threads per file to 1, without dramatically changing write bandwidth or pagecache access latency. Note that we leave the xfs-conv workqueue's max_active alone because we still want to be able to run ioend processing for as many inodes as the system can handle. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster

xfs: track metadata health status

2019-04-15T01:15:57+00:00

Add the necessary in-core metadata fields to keep track of which parts of the filesystem have been observed and which parts were observed to be unhealthy, and print a warning at unmount time if we have unfixed problems. Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster

xfs: cache unlinked pointers in an rhashtable

2019-02-12T00:07:01+00:00

Use a rhashtable to cache the unlinked list incore. This should speed up unlinked processing considerably when there are a lot of inodes on the unlinked list because iunlink_remove no longer has to traverse an entire bucket list to find which inode points to the one being removed. The incore list structure records "X.next_unlinked = Y" relations, with the rhashtable using Y to index the records. This makes finding the inode X that points to a inode Y very quick. If our cache fails to find anything we can always fall back on the old method. FWIW this drastically reduces the amount of time it takes to remove inodes from the unlinked list. I wrote a program to open a lot of O_TMPFILE files and then close them in the same order, which takes a very long time if we have to traverse the unlinked lists. With the ptach, I see: + /d/t/tmpfile/tmpfile Opened 193531 files in 6.33s. Closed 193531 files in 5.86s real 0m12.192s user 0m0.064s sys 0m11.619s + cd / + umount /mnt real 0m0.050s user 0m0.004s sys 0m0.030s And without the patch: + /d/t/tmpfile/tmpfile Opened 193588 files in 6.35s. Closed 193588 files in 751.61s real 12m38.853s user 0m0.084s sys 12m34.470s + cd / + umount /mnt real 0m0.086s user 0m0.000s sys 0m0.060s Signed-off-by: Darrick J. Wong Reviewed-by: Brian Foster

xfs: fold dfops into the transaction

2018-08-03T06:05:14+00:00

struct xfs_defer_ops has now been reduced to a single list_head. The external dfops mechanism is unused and thus everywhere a (permanent) transaction is accessible the associated dfops structure is as well. Remove the xfs_defer_ops structure and fold the list_head into the transaction. Also remove the last remnant of external dfops in xfs_trans_dup(). Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong

xfs: introduce a new xfs_inode_has_cow_data helper

2018-07-30T14:57:48+00:00

We have a few places that already check if an inode has actual data in the COW fork to avoid work on reflink inodes that do not actually have outstanding COW blocks. There are a few more places that can avoid working if doing the same check, so add a documented helper for this condition and use it in all places where it makes sense. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

xfs: remove the xfs_ifork_t typedef

2018-07-30T14:57:48+00:00

We only have a few more callers left, so seize the opportunity and kill it off. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong