- 17 Feb, 2017 5 commits
-
-
Darrick J. Wong authored
Fix an uninitialize variable. Reported-by:
Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by:
Brian Foster <bfoster@redhat.com> Signed-off-by:
Darrick J. Wong <darrick.wong@oracle.com>
-
Brian Foster authored
Certain workoads that punch holes into speculative preallocation can cause delalloc indirect reservation splits when the delalloc extent is split in two. If further splits occur, an already short-handed extent can be split into two in a manner that leaves zero indirect blocks for one of the two new extents. This occurs because the shortage is large enough that the xfs_bmap_split_indlen() algorithm completely drains the requested indlen of one of the extents before it honors the existing reservation. This ultimately results in a warning from xfs_bmap_del_extent(). This has been observed during file copies of large, sparse files using 'cp --sparse=always.' To avoid this problem, update xfs_bmap_split_indlen() to explicitly apply the reservation shortage fairly between both extents. This smooths out the overall indlen shortage and defers the situation where we end up with a delalloc extent with zero indlen reservation to extreme circumstances. Reported-by:
Patrick Dung <mpatdung@gmail.com> Signed-off-by:
-
Brian Foster authored
When a delalloc extent is created, it can be merged with pre-existing, contiguous, delalloc extents. When this occurs, xfs_bmap_add_extent_hole_delay() merges the extents along with the associated indirect block reservations. The expectation here is that the combined worst case indlen reservation is always less than or equal to the indlen reservation for the individual extents. This is not always the case, however, as existing extents can less than the expected indlen reservation if the extent was previously split due to a hole punch. If a new extent merges with such an extent, the total indlen requirement may be larger than the sum of the indlen reservations held by both extents. xfs_bmap_add_extent_hole_delay() assumes that the worst case indlen reservation is always available and assigns it to the merged extent without consideration for the indlen held by the pre-existing extent. As a result, the subsequent xfs_mod_fdblocks() call can attempt an unintentional allocation rather than a free (indicated by an ASSERT() failure). Further, if the allocation happens to fail in this context, the failure goes unhandled and creates a filesystem wide block accounting inconsistency. Fix xfs_bmap_add_extent_hole_delay() to function as designed. Cap the indlen reservation assigned to the merged extent to the sum of the indlen reservations held by each of the individual extents. Signed-off-by:
-
Brian Foster authored
A debug mode write failure mechanism was introduced to XFS in commit 801cc4e1 ("xfs: debug mode forced buffered write failure") to facilitate targeted testing of delalloc indirect reservation management from userspace. This code was subsequently rendered ineffective by the move to iomap based buffered writes in commit 68a9f5e7 ("xfs: implement iomap based buffered write path"). This likely went unnoticed because the associated userspace code had not made it into xfstests. Resurrect this mechanism to facilitate effective indlen reservation testing from xfstests. The move to iomap based buffered writes relocated the hook this mechanism needs to return write failure from XFS to generic code. The failure trigger must remain in XFS. Given that limitation, convert this from a write failure mechanism to one that simply drops writes without returning failure to userspace. Rename all "fail_writes" references to "drop_writes" to illustrate the point. This is more hacky than preferred, but still triggers the XFS error handling behavior required to drive the indlen tests. This is only available in DEBUG mode and for testing purposes only. Signed-off-by:
-
Brian Foster authored
The buffered write failure handling code in xfs_file_iomap_end_delalloc() has a couple minor problems. First, if written == 0, start_fsb is not rounded down and it fails to kill off a delalloc block if the start offset is block unaligned. This results in a lingering delalloc block and broken delalloc block accounting detected at unmount time. Fix this by rounding down start_fsb in the unlikely event that written == 0. Second, it is possible for a failed overwrite of a delalloc extent to leave dirty pagecache around over a hole in the file. This is because is possible to hit ->iomap_end() on write failure before the iomap code has attempted to allocate pagecache, and thus has no need to clean it up. If the targeted delalloc extent was successfully written by a previous write, however, then it does still have dirty pages when ->iomap_end() punches out the underlying blocks. This ultimately results in writeback over a hole. To fix this problem, unconditionally punch out the pagecache from XFS before the associated delalloc range. Signed-off-by:
Christoph Hellwig <hch@lst.de> Reviewed-by:
-
- 09 Feb, 2017 6 commits
-
-
Christoph Hellwig authored
Instead we submit the discard requests and use another workqueue to release the extents from the extent busy list. Signed-off-by:
-
Christoph Hellwig authored
Sort busy extents by the full block number instead of just the AGNO so that we can issue consecutive discard requests that the block layer could merge (although we'll need additional block layer fixes for fast devices). Signed-off-by:
-
Christoph Hellwig authored
Currently we force the log and simply try again if we hit a busy extent, but especially with online discard enabled it might take a while after the log force for the busy extents to disappear, and we might have already completed our second pass. So instead we add a new waitqueue and a generation counter to the pag structure so that we can do wakeups once we've removed busy extents, and we replace the single retry with an unconditional one - after all we hold the AGF buffer lock, so no other allocations or frees can be racing with us in this AG. Signed-off-by:
-
Christoph Hellwig authored
We don't just need the structure to track busy extents which can be avoided with a synchronous transaction, but also to keep track of pending discard. Signed-off-by:
-
Bill O'Donnell authored
If pag cannot be allocated, the current error exit path will trip a null pointer deference error when calling xfs_buf_hash_destroy with a null pag. Fix this by adding a new error exit labels and jumping to those accordingly, avoiding the hash destroy and unnecessary kmem_free on pag. Up to three things need to be properly unwound: 1) pag memory allocation 2) xfs_buf_hash_init 3) radix_tree_insert For any given iteration through the loop, any of the above which succeed must be unwound for /this/ pag, and then all prior initialized pags must be unwound. Addresses-Coverity-Id: 1397628 ("Dereference after null check") Reported-by:Colin Ian King <colin.king@canonical.com> Signed-off-by:
Bill O'Donnell <billodo@redhat.com> Reviewed-by:
Eric Sandeen <sandeen@redhat.com> Reviewed-by:
-
Christoph Hellwig authored
We're changing both metadata and data, so we need to update the timestamps for clone operations. Dedupe on the other hand does not change file data, and only changes invisible metadata so the timestamps should not be updated. This follows existing btrfs behavior. Signed-off-by:
-
- 07 Feb, 2017 5 commits
-
-
Christoph Hellwig authored
Instead of preallocating all the required COW blocks in the high-level write code do it inside the iomap code, like we do for all other I/O. Signed-off-by:
-
Christoph Hellwig authored
When we allocate COW fork blocks for direct I/O writes we currently first create a delayed allocation, and then convert it to a real allocation once we've got the delayed one. As there is no good reason for that this patch instead makes use call xfs_bmapi_write from the COW allocation path. The only interesting bits are a few tweaks the low-level allocator to allow for this, most notably the need to remove the call to xfs_bmap_extsize_align for the cowextsize in xfs_bmap_btalloc - for the existing convert case it's a no-op, but for the direct allocation case it would blow up our block reservation way beyond what we reserved for the transaction. Signed-off-by:
-
Christoph Hellwig authored
We'll need it for the direct I/O code. Also rename the function to xfs_reflink_convert_cow_extent to describe it a bit better. Signed-off-by:
-
Christoph Hellwig authored
Factor a helper to calculate the extent-size aligned block out of the iomap code, so that it can be reused by the upcoming reflink dio code. Signed-off-by:
-
Christoph Hellwig authored
We currently fall back from direct to buffered writes if we detect a remaining shared extent in the iomap_begin callback. But by the time iomap_begin is called for the potentially unaligned end block we might have already written most of the data to disk, which we'd now write again using buffered I/O. To avoid this reject all writes to reflinked files before starting I/O so that we are guaranteed to only write the data once. The alternative would be to unshare the unaligned start and/or end block before doing the I/O. I think that's doable, and will actually be required to support reflinks on DAX file system. But it will take a little more time and I'd rather get rid of the double write ASAP. Signed-off-by:
-
- 03 Feb, 2017 1 commit
-
-
Hou Tao authored
After successful IO or permanent error, b_first_retry_time also needs to be cleared, else the invalid first retry time will be used by the next retry check. Signed-off-by:
Hou Tao <houtao1@huawei.com> Reviewed-by:
-
- 02 Feb, 2017 7 commits
-
-
Darrick J. Wong authored
Christoph Hellwig pointed out that there's a potentially nasty race when performing simultaneous nearby directio cow writes: "Thread 1 writes a range from B to c " B --------- C p "a little later thread 2 writes from A to B " A --------- B p [editor's note: the 'p' denote cowextsize boundaries, which I added to make this more clear] "but the code preallocates beyond B into the range where thread "1 has just written, but ->end_io hasn't been called yet. "But once ->end_io is called thread 2 has already allocated "up to the extent size hint into the write range of thread 1, "so the end_io handler will splice the unintialized blocks from "that preallocation back into the file right after B." We can avoid this race by ensuring that thread 1 cannot accidentally remap the blocks that thread 2 allocated (as part of speculative preallocation) as part of t2's write preparation in t1's end_io handler. The way we make this happen is by taking advantage of the unwritten extent flag as an intermediate step. Recall that when we begin the process of writing data to shared blocks, we create a delayed allocation extent in the CoW fork: D: --RRRRRRSSSRRRRRRRR--- C: ------DDDDDDD--------- When a thread prepares to CoW some dirty data out to disk, it will now convert the delalloc reservation into an /unwritten/ allocated extent in the cow fork. The da conversion code tries to opportunistically allocate as much of a (speculatively prealloc'd) extent as possible, so we may end up allocating a larger extent than we're actually writing out: D: --RRRRRRSSSRRRRRRRR--- U: ------UUUUUUU--------- Next, we convert only the part of the extent that we're actively planning to write to normal (i.e. not unwritten) status: D: --RRRRRRSSSRRRRRRRR--- U: ------UURRUUU--------- If the write succeeds, the end_cow function will now scan the relevant range of the CoW fork for real extents and remap only the real extents into the data fork: D: --RRRRRRRRSRRRRRRRR--- U: ------UU--UUU--------- This ensures that we never obliterate valid data fork extents with unwritten blocks from the CoW fork. Signed-off-by: -
Darrick J. Wong authored
In the data fork, we only allow extents to perform the following state transitions: delay -> real <-> unwritten There's no way to move directly from a delalloc reservation to an /unwritten/ allocated extent. However, for the CoW fork we want to be able to do the following to each extent: delalloc -> unwritten -> written -> remapped to data fork This will help us to avoid a race in the speculative CoW preallocation code between a first thread that is allocating a CoW extent and a second thread that is remapping part of a file after a write. In order to do this, however, we need two things: first, we have to be able to transition from da to unwritten, and second the function that converts between real and unwritten has to be made aware of the cow fork. Do both of those things. Signed-off-by:
-
Darrick J. Wong authored
Perform basic sanity checking of the directory free block header fields so that we avoid hanging the system on invalid data. (Granted that just means that now we shutdown on directory write, but that seems better than hanging...) Signed-off-by:
-
Darrick J. Wong authored
We can't handle a bmbt that's taller than BTREE_MAXLEVELS, and there's no such thing as a zero-level bmbt (for that we have extents format), so if we see this, send back an error code. Signed-off-by:
-
Darrick J. Wong authored
Don't let anybody load an obviously bad btree pointer. Since the values come from disk, we must return an error, not just ASSERT. Signed-off-by:
-
Darrick J. Wong authored
When we open a directory, we try to readahead block 0 of the directory on the assumption that we're going to need it soon. If the bmbt is corrupt, the directory will never be usable and the readahead fails immediately, so we might as well prevent the directory from being opened at all. This prevents a subsequent read or modify operation from hitting it and taking the fs offline. NOTE: We're only checking for early failures in the block mapping, not the readahead directory block itself. Signed-off-by:
-
Darrick J. Wong authored
We use di_format and if_flags to decide whether we're grabbing the ilock in btree mode (btree extents not loaded) or shared mode (anything else), but the state of those fields can be changed by other threads that are also trying to load the btree extents -- IFEXTENTS gets set before the _bmap_read_extents call and cleared if it fails. We don't actually need to have IFEXTENTS set until after the bmbt records are successfully loaded and validated, which will fix the race between multiple threads trying to read the same directory. The next patch strengthens directory bmbt validation by refusing to open the directory if reading the bmbt to start directory readahead fails. Signed-off-by:
-
- 31 Jan, 2017 9 commits
-
-
Eric Sandeen authored
The "full" argument was used only by the fiemap formatter, which is now gone with the iomap updates. Remove the unused arg. Signed-off-by:
Alex Elder <elder@linaro.org> Reviewed-by:
-
Brian Foster authored
It's possible for post-eof blocks to end up being used for direct I/O writes. dio write performs an upfront unwritten extent allocation, sends the dio and then updates the inode size (if necessary) on write completion. If a file release occurs while a file extending dio write is in flight, it is possible to mistake the post-eof blocks for speculative preallocation and incorrectly truncate them from the inode. This means that the resulting dio write completion can discover a hole and allocate new blocks rather than perform unwritten extent conversion. This requires a strange mix of I/O and is thus not likely to reproduce in real world workloads. It is intermittently reproduced by generic/299. The error manifests as an assert failure due to transaction overrun because the aforementioned write completion transaction has only reserved enough blocks for btree operations: XFS: Assertion failed: tp->t_blk_res_used <= tp->t_blk_res, \ file: fs/xfs//xfs_trans.c, line: 309 The root cause is that xfs_free_eofblocks() uses i_size to truncate post-eof blocks from the inode, but async, file extending direct writes do not update i_size until write completion, long after inode locks are dropped. Therefore, xfs_free_eofblocks() effectively truncates the inode to the incorrect size. Update xfs_free_eofblocks() to serialize against dio similar to how extending writes are serialized against i_size updates before post-eof block zeroing. Specifically, wait on dio while under the iolock. This ensures that dio write completions have updated i_size before post-eof blocks are processed. Signed-off-by:
-
Brian Foster authored
The xfs_eofblocks.eof_scan_owner field is an internal field to facilitate invoking eofb scans from the kernel while under the iolock. This is necessary because the eofb scan acquires the iolock of each inode. Synchronous scans are invoked on certain buffered write failures while under iolock. In such cases, the scan owner indicates that the context for the scan already owns the particular iolock and prevents a double lock deadlock. eofblocks scans while under iolock are still livelock prone in the event of multiple parallel scans, however. If multiple buffered writes to different inodes fail and invoke eofblocks scans at the same time, each scan avoids a deadlock with its own inode by virtue of the eof_scan_owner field, but will never be able to acquire the iolock of the inode from the parallel scan. Because the low free space scans are invoked with SYNC_WAIT, the scan will not return until it has processed every tagged inode and thus both scans will spin indefinitely on the iolock being held across the opposite scan. This problem can be reproduced reliably by generic/224 on systems with higher cpu counts (x16). To avoid this problem, simplify the semantics of eofblocks scans to never invoke a scan while under iolock. This means that the buffered write context must drop the iolock before the scan. It must reacquire the lock before the write retry and also repeat the initial write checks, as the original state might no longer be valid once the iolock was dropped. Signed-off-by:
-
Brian Foster authored
xfs_free_eofblocks() requires the IOLOCK_EXCL lock, but is called from different contexts where the lock may or may not be held. The need_iolock parameter exists for this reason, to indicate whether xfs_free_eofblocks() must acquire the iolock itself before it can proceed. This is ugly and confusing. Simplify the semantics of xfs_free_eofblocks() to require the caller to acquire the iolock appropriately and kill the need_iolock parameter. While here, the mp param can be removed as well as the xfs_mount is accessible from the xfs_inode structure. This patch does not change behavior. Signed-off-by:
-
Eric Sandeen authored
After scratching my head looking for "xfs_busy_extent" I realized it's not used; it's xfs_extent_busy, and the declaration for the other name is bogus. Remove that and a few others as well. (struct xfs_log_callback is used, but the 2nd declaration is unnecessary). Signed-off-by:
-
Christoph Hellwig authored
Signed-off-by:
-
Eric Sandeen authored
Now that xfs_btree_init_block_int is able to determine crc status from the passed-in mp, we can determine the proper magic as well if we are given a btree number, rather than an explicit magic value. Change xfs_btree_init_block[_int] callers to pass in the btree number, and let xfs_btree_init_block_int use the xfs_magics array via the xfs_btree_magic macro to determine which magic value is needed. This makes all of the if (crc) / else stanzas identical, and the if/else can be removed, leading to a single, common init_block call. Signed-off-by:
-
Eric Sandeen authored
Right now the xfs_btree_magic() define takes only a cursor; change this to take crc and btnum args to make it more generically useful, and move to a function. This will allow xfs_btree_init_block_int callers which don't have a cursor to make use of the xfs_magics array, which will happen in the next patch. Signed-off-by:
-
Eric Sandeen authored
xfs_btree_init_block_int() can determine whether crcs are in effect without the passed-in XFS_BTREE_CRC_BLOCKS flag; the mp argument allows us to determine this from the superblock. Remove the flag from callers, and use xfs_sb_version_hascrc(&mp->m_sb) internally instead. This removes one difference between the if & else cases in the callers. Signed-off-by:
-
- 29 Jan, 2017 3 commits
-
-
Linus Torvalds authored
-
Linus Torvalds authored
I've seen this trigger twice now, where the i915_gem_object_to_ggtt() call in intel_unpin_fb_obj() returns NULL, resulting in an oops immediately afterwards as the (inlined) call to i915_vma_unpin_fence() tries to dereference it. It seems to be some race condition where the object is going away at shutdown time, since both times happened when shutting down the X server. The call chains were different: - VT ioctl(KDSETMODE, KD_TEXT): intel_cleanup_plane_fb+0x5b/0xa0 [i915] drm_atomic_helper_cleanup_planes+0x6f/0x90 [drm_kms_helper] intel_atomic_commit_tail+0x749/0xfe0 [i915] intel_atomic_commit+0x3cb/0x4f0 [i915] drm_atomic_commit+0x4b/0x50 [drm] restore_fbdev_mode+0x14c/0x2a0 [drm_kms_helper] drm_fb_helper_restore_fbdev_mode_unlocked+0x34/0x80 [drm_kms_helper] drm_fb_helper_set_par+0x2d/0x60 [drm_kms_helper] intel_fbdev_set_par+0x18/0x70 [i915] fb_set_var+0x236/0x460 fbcon_blank+0x30f/0x350 do_unblank_screen+0xd2/0x1a0 vt_ioctl+0x507/0x12a0 tty_ioctl+0x355/0xc30 do_vfs_ioctl+0xa3/0x5e0 SyS_ioctl+0x79/0x90 entry_SYSCALL_64_fastpath+0x13/0x94 - i915 unpin_work workqueue: intel_unpin_work_fn+0x58/0x140 [i915] process_one_work+0x1f1/0x480 worker_thread+0x48/0x4d0 kthread+0x101/0x140 and this patch purely papers over the issue by adding a NULL pointer check and a WARN_ON_ONCE() to avoid the oops that would then generally make the machine unresponsive. Other callers of i915_gem_object_to_ggtt() seem to also check for the returned pointer being NULL and warn about it, so this clearly has happened before in other places. [ Reported it originally to the i915 developers on Jan 8, applying the ugly workaround on my own now after triggering the problem for the second time with no feedback. This is likely to be the same bug reported as https://bugs.freedesktop.org/show_bug.cgi?id=98829 https://bugs.freedesktop.org/show_bug.cgi?id=99134 which has a patch for the underlying problem, but it hasn't gotten to me, so I'm applying the workaround. ] Cc: Daniel Vetter <daniel.vetter@intel.com> Cc: Jani Nikula <jani.nikula@linux.intel.com> Cc: Ville Syrjälä <ville.syrjala@linux.intel.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Tvrtko Ursulin <tvrtko.ursulin@intel.com> Cc: Imre Deak <imre.deak@intel.com> Signed-off-by:Linus Torvalds <torvalds@linux-foundation.org>
-
git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linuxLinus Torvalds authored
Pull two parisc fixes from Helge Deller: "One fix to avoid usage of BITS_PER_LONG in user-space exported swab.h header which breaks compiling qemu, and one trivial fix for printk continuation in the parisc parport driver" * 'parisc-4.10-3' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux: parisc: Don't use BITS_PER_LONG in userspace-exported swab.h header parisc, parport_gsc: Fixes for printk continuation lines
-
- 28 Jan, 2017 4 commits
-
-
git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linuxLinus Torvalds authored
Pull i2c fixes from Wolfram Sang: "Two I2C driver bugfixes. The 'VLLS mode support' patch should have been entitled 'reconfigure pinctrl after suspend' to make the bugfix more clear. Sorry, I missed that, yet didn't want to rebase" * 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux: i2c: imx-lpi2c: add VLLS mode support i2c: i2c-cadence: Initialize configuration before probing devices
-
Helge Deller authored
In swab.h the "#if BITS_PER_LONG > 32" breaks compiling userspace programs if BITS_PER_LONG is #defined by userspace with the sizeof() compiler builtin. Solve this problem by using __BITS_PER_LONG instead. Since we now #include asm/bitsperlong.h avoid further potential userspace pollution by moving the #define of SHIFT_PER_LONG to bitops.h which is not exported to userspace. This patch unbreaks compiling qemu on hppa/parisc. Signed-off-by:Helge Deller <deller@gmx.de> Cc: <stable@vger.kernel.org>
-
Helge Deller authored
Signed-off-by: -
git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds authored
Pull NFS client bugfixes from Trond Myklebust: "Stable patches: - NFSv4.1: Fix a deadlock in layoutget - NFSv4 must not bump sequence ids on NFS4ERR_MOVED errors - NFSv4 Fix a regression with OPEN EXCLUSIVE4 mode - Fix a memory leak when removing the SUNRPC module Bugfixes: - Fix a reference leak in _pnfs_return_layout" * tag 'nfs-for-4.10-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: pNFS: Fix a reference leak in _pnfs_return_layout nfs: Fix "Don't increment lock sequence ID after NFS4ERR_MOVED" SUNRPC: cleanup ida information when removing sunrpc module NFSv4.0: always send mode in SETATTR after EXCLUSIVE4 nfs: Don't increment lock sequence ID after NFS4ERR_MOVED NFSv4.1: Fix a deadlock in layoutget
-
