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2018-06-06xfs: convert to SPDX license tagsDave Chinner
Remove the verbose license text from XFS files and replace them with SPDX tags. This does not change the license of any of the code, merely refers to the common, up-to-date license files in LICENSES/ This change was mostly scripted. fs/xfs/Makefile and fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected and modified by the following command: for f in `git grep -l "GNU General" fs/xfs/` ; do echo $f cat $f | awk -f hdr.awk > $f.new mv -f $f.new $f done And the hdr.awk script that did the modification (including detecting the difference between GPL-2.0 and GPL-2.0+ licenses) is as follows: $ cat hdr.awk BEGIN { hdr = 1.0 tag = "GPL-2.0" str = "" } /^ \* This program is free software/ { hdr = 2.0; next } /any later version./ { tag = "GPL-2.0+" next } /^ \*\// { if (hdr > 0.0) { print "// SPDX-License-Identifier: " tag print str print $0 str="" hdr = 0.0 next } print $0 next } /^ \* / { if (hdr > 1.0) next if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 next } /^ \*/ { if (hdr > 0.0) next print $0 next } // { if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 } END { } $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-10xfs: get rid of the log item descriptorDave Chinner
It's just a connector between a transaction and a log item. There's a 1:1 relationship between a log item descriptor and a log item, and a 1:1 relationship between a log item descriptor and a transaction. Both relationships are created and terminated at the same time, so why do we even have the descriptor? Replace it with a specific list_head in the log item and a new log item dirtied flag to replace the XFS_LID_DIRTY flag. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> [darrick: fix up deferred agfl intent finish_item use of LID_DIRTY] Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-10xfs: add tracing to high level transaction operationsDave Chinner
Because currently we have no idea what the transaction context we are operating in is, and I need to know that information to track down bugs in multiple log item joins to transactions. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-04-09xfs: non-scrub - remove unused function parametersEric Sandeen
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-03-11xfs: fall back to vmalloc when allocation log vector buffersDave Chinner
When using large directory blocks, we regularly see memory allocations of >64k being made for the shadow log vector buffer. When we are under memory pressure, kmalloc() may not be able to find contiguous memory chunks large enough to satisfy these allocations easily, and if memory is fragmented we can potentially stall here. TO avoid this problem, switch the log vector buffer allocation to use kmem_alloc_large(). This will allow failed allocations to fall back to vmalloc and so remove the dependency on large contiguous regions of memory being available. This should prevent slowdowns and potential stalls when memory is low and/or fragmented. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-08-04xfs: Fix leak of discard bioJan Kara
The bio describing discard operation is allocated by __blkdev_issue_discard() which returns us a reference to it. That reference is never released and thus we leak this bio. Drop the bio reference once it completes in xlog_discard_endio(). CC: stable@vger.kernel.org Fixes: 4560e78f40cb55bd2ea8f1ef4001c5baa88531c7 Signed-off-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-19xfs: remove lsn relevant fields from xfs_trans structure and its usersShan Hai
The t_lsn is not used anymore and the t_commit_lsn is used as a tmp storage for the checkpoint sequence number only in the current code. And the start/commit lsn are tracked as a transaction group tag in the xfs_cil_ctx instead of a single transaction, so remove them from the xfs_trans structure and their users to match with the design. Signed-off-by: Shan Hai <shan.hai@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-19xfs: dump transaction usage details on log reservation overrunBrian Foster
If a transaction log reservation overrun occurs, the ticket data associated with the reservation is dumped in xfs_log_commit_cil(). This occurs long after the transaction items and details have been removed from the transaction and effectively lost. This limited set of ticket data provides very little information to support debugging transaction overruns based on the typical report. To improve transaction log reservation overrun reporting, create a helper to dump transaction details such as log items, log vector data, etc., as well as the underlying ticket data for the transaction. Move the overrun detection from xfs_log_commit_cil() to xlog_cil_insert_items() so it occurs prior to migration of the logged items to the CIL. Call the new helper such that it is able to dump this transaction data before it is lost. Also, warn on overrun to provide callstack context for the offending transaction and include a few additional messages from xlog_cil_insert_items() to display the reservation consumed locally for overhead such as log vector headers, split region headers and the context ticket. This provides a complete general breakdown of the reservation consumption of a transaction when/if it happens to overrun the reservation. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-19xfs: refactor xlog_cil_insert_items() to facilitate transaction dumpBrian Foster
Transaction reservation overrun detection currently occurs too late to print useful information about the offending transaction. Ideally, the transaction data is printed before the associated log items are moved from the transaction to the CIL, which occurs in xlog_cil_insert_items(), such that details of the items logged by the transaction are available for analysis. Refactor xlog_cil_insert_items() to facilitate moving tx overrun detection to this function. Update the function to track each bit of extra log reservation stolen from the transaction (i.e., such as for the CIL context ticket) and perform the log item migration as the last operation before the CIL lock is released. This creates a context where the transaction reservation consumption has been fully calculated when the log items are moved to the CIL. This patch makes no functional changes. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-06-19xfs: separate shutdown from ticket reservation print helperBrian Foster
xlog_print_tic_res() pre-dates delayed logging and the committed items list (CIL) and thus retains some factoring warts, such as hard coded function names in the output and the fact that it induces a shutdown. In preparation for more detailed logging of regular transaction overrun situations, refactor xlog_print_tic_res() to be slightly more generic. Reword some of the warning messages and pull the shutdown into the callers. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-02-09xfs: don't block the log commit handler for discardsChristoph Hellwig
Instead we submit the discard requests and use another workqueue to release the extents from the extent busy list. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-07-22xfs: allocate log vector buffers outside CIL context lockDave Chinner
One of the problems we currently have with delayed logging is that under serious memory pressure we can deadlock memory reclaim. THis occurs when memory reclaim (such as run by kswapd) is reclaiming XFS inodes and issues a log force to unpin inodes that are dirty in the CIL. The CIL is pushed, but this will only occur once it gets the CIL context lock to ensure that all committing transactions are complete and no new transactions start being committed to the CIL while the push switches to a new context. The deadlock occurs when the CIL context lock is held by a committing process that is doing memory allocation for log vector buffers, and that allocation is then blocked on memory reclaim making progress. Memory reclaim, however, is blocked waiting for a log force to make progress, and so we effectively deadlock at this point. To solve this problem, we have to move the CIL log vector buffer allocation outside of the context lock so that memory reclaim can always make progress when it needs to force the log. The problem with doing this is that a CIL push can take place while we are determining if we need to allocate a new log vector buffer for an item and hence the current log vector may go away without warning. That means we canot rely on the existing log vector being present when we finally grab the context lock and so we must have a replacement buffer ready to go at all times. To ensure this, introduce a "shadow log vector" buffer that is always guaranteed to be present when we gain the CIL context lock and format the item. This shadow buffer may or may not be used during the formatting, but if the log item does not have an existing log vector buffer or that buffer is too small for the new modifications, we swap it for the new shadow buffer and format the modifications into that new log vector buffer. The result of this is that for any object we modify more than once in a given CIL checkpoint, we double the memory required to track dirty regions in the log. For single modifications then we consume the shadow log vectorwe allocate on commit, and that gets consumed by the checkpoint. However, if we make multiple modifications, then the second transaction commit will allocate a shadow log vector and hence we will end up with double the memory usage as only one of the log vectors is consumed by the CIL checkpoint. The remaining shadow vector will be freed when th elog item is freed. This can probably be optimised in future - access to the shadow log vector is serialised by the object lock (as opposited to the active log vector, which is controlled by the CIL context lock) and so we can probably free shadow log vector from some objects when the log item is marked clean on removal from the AIL. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-04-06xfs: remove transaction typesChristoph Hellwig
These aren't used for CIL-style logging and can be dropped. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-07-29xfs: close xc_cil list_empty() races with cil commit sequenceBrian Foster
We have seen somewhat rare reports of the following assert from xlog_cil_push_background() failing during ltp tests or somewhat innocuous desktop root fs workloads (e.g., virt operations, initramfs construction): ASSERT(!list_empty(&cil->xc_cil)); The reasoning behind the assert is that the transaction has inserted items to the CIL and hit background push codepath all with cil->xc_ctx_lock held for reading. This locks out background commit from emptying the CIL, which acquires the lock for writing. Therefore, the reasoning is that the items previously inserted in the CIL should still be present. The cil->xc_ctx_lock read lock is not sufficient to protect the xc_cil list, however, due to how CIL insertion is handled. xlog_cil_insert_items() inserts and reorders the dirty transaction items to the tail of the CIL under xc_cil_lock. It uses list_move_tail() to achieve insertion and reordering in the same block of code. This function removes and reinserts an item to the tail of the list. If a transaction commits an item that was already logged and thus already resides in the CIL, and said item is the sole item on the list, the removal and reinsertion creates a temporary state where the list is actually empty. This state is not valid and thus should never be observed by concurrent transaction commit-side checks in the circumstances outlined above. We do not want to acquire the xc_cil_lock in all of these instances as it was previously removed and replaced with a separate push lock for performance reasons. Therefore, close any races with list_empty() on the insertion side by ensuring that the list is never in a transient empty state. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04xfs: fix xfs_log_done interfaceChristoph Hellwig
Instead of the confusing flags argument pass a boolean flag to indicate if we want to release or regrant a log reservation. Also ensure that xfs_log_done always drop the reference on the log ticket, to both simplify the code and make the logic in xfs_trans_roll easier to understand. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04xfs: saner xfs_trans_commit interfaceChristoph Hellwig
The flags argument to xfs_trans_commit is not useful for most callers, as a commit of a transaction without a permanent log reservation must pass 0 here, and all callers for a transaction with a permanent log reservation except for xfs_trans_roll must pass XFS_TRANS_RELEASE_LOG_RES. So remove the flags argument from the public xfs_trans_commit interfaces, and introduce low-level __xfs_trans_commit variant just for xfs_trans_roll that regrants a log reservation instead of releasing it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-06-04xfs: pass a boolean flag to xfs_trans_free_itemsChristoph Hellwig
The flags value always was 0 or XFS_TRANS_ABORT. Switch to a bool parameter to allow further cleanups. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: move most of xfs_sb.h to xfs_format.hChristoph Hellwig
More on-disk format consolidation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: merge xfs_ag.h into xfs_format.hChristoph Hellwig
More on-disk format consolidation. A few declarations that weren't on-disk format related move into better suitable spots. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-09-23xfs: xlog_cil_force_lsn doesn't always wait correctlyDave Chinner
When running a tight mount/unmount loop on an older kernel, RedHat QE found that unmount would occasionally hang in xfs_buf_unpin_wait() on the superblock buffer. Tracing and other debug work by Eric Sandeen indicated that it was hanging on the writing of the superblock during unmount immediately after logging the superblock counters in a synchronous transaction. Further debug indicated that the synchronous transaction was not waiting for completion correctly, and we narrowed it down to xlog_cil_force_lsn() returning NULLCOMMITLSN and hence not pushing the transaction in the iclog buffer to disk correctly. While this unmount superblock write code is now very different in mainline kernels, the xlog_cil_force_lsn() code is identical, and it was bisected to the backport of commit f876e44 ("xfs: always do log forces via the workqueue"). This commit made the CIL push asynchronous for log forces and hence exposed a race condition that couldn't occur on a synchronous push. Essentially, the xlog_cil_force_lsn() relied implicitly on the fact that the sequence push would be complete by the time xlog_cil_push_now() returned, resulting in the context being pushed being in the committing list. When it was made asynchronous, it was recognised that there was a race condition in detecting whether an asynchronous push has started or not and code was added to handle it. Unfortunately, the fix was not quite right and left a race condition where it it would detect an empty CIL while a push was in progress before the context had been added to the committing list. This was incorrectly seen as a "nothing to do" condition and so would tell xfs_log_force_lsn() that there is nothing to wait for, and hence it would push the iclogbufs in memory. The fix is simple, but explaining the logic and the race condition is a lot more complex. The fix is to add the context to the committing list before we start emptying the CIL. This allows us to detect the difference between an empty "do nothing" push and a push that has not started by adding a discrete "emptying the CIL" state to avoid the transient, incorrect "empty" condition that the (unchanged) waiting code was seeing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-24xfs: fix cil push sequence after log recoveryMark Tinguely
When the CIL checkpoint is fully written to the log, the LSN of the checkpoint commit record is written into the CIL context structure. This allows log force waiters to correctly detect when the checkpoint they are waiting on have been fully written into the log buffers. However, the initial context after mount is initialised with a non-zero commit LSN, so appears to waiters as though it is complete even though it may not have even been pushed, let alone written to the log buffers. Hence a log force immediately after a filesystem is mounted may not behave correctly, nor does commit record ordering if multiple CIL pushes interleave immediately after mount. To fix this, make sure the initial context commit LSN is not touched until the first checkpointis actually pushed. [dchinner: rewrite commit message] Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-25xfs: global error sign conversionDave Chinner
Convert all the errors the core XFs code to negative error signs like the rest of the kernel and remove all the sign conversion we do in the interface layers. Errors for conversion (and comparison) found via searches like: $ git grep " E" fs/xfs $ git grep "return E" fs/xfs $ git grep " E[A-Z].*;$" fs/xfs Negation points found via searches like: $ git grep "= -[a-z,A-Z]" fs/xfs $ git grep "return -[a-z,A-D,F-Z]" fs/xfs $ git grep " -[a-z].*;" fs/xfs [ with some bits I missed from Brian Foster ] Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-22xfs: Nuke XFS_ERROR macroEric Sandeen
XFS_ERROR was designed long ago to trap return values, but it's not runtime configurable, it's not consistently used, and we can do similar error trapping with ftrace scripts and triggers from userspace. Just nuke XFS_ERROR and associated bits. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-05-20Merge branch 'xfs-misc-fixes-2-for-3.16' into for-nextDave Chinner
Conflicts: fs/xfs/xfs_ialloc.c
2014-05-20xfs: log vector rounding leaks log spaceDave Chinner
The addition of direct formatting of log items into the CIL linear buffer added alignment restrictions that the start of each vector needed to be 64 bit aligned. Hence padding was added in xlog_finish_iovec() to round up the vector length to ensure the next vector started with the correct alignment. This adds a small number of bytes to the size of the linear buffer that is otherwise unused. The issue is that we then use the linear buffer size to determine the log space used by the log item, and this includes the unused space. Hence when we account for space used by the log item, it's more than is actually written into the iclogs, and hence we slowly leak this space. This results on log hangs when reserving space, with threads getting stuck with these stack traces: Call Trace: [<ffffffff81d15989>] schedule+0x29/0x70 [<ffffffff8150d3a2>] xlog_grant_head_wait+0xa2/0x1a0 [<ffffffff8150d55d>] xlog_grant_head_check+0xbd/0x140 [<ffffffff8150ee33>] xfs_log_reserve+0x103/0x220 [<ffffffff814b7f05>] xfs_trans_reserve+0x2f5/0x310 ..... The 4 bytes is significant. Brain Foster did all the hard work in tracking down a reproducable leak to inode chunk allocation (it went away with the ikeep mount option). His rough numbers were that creating 50,000 inodes leaked 11 log blocks. This turns out to be roughly 800 inode chunks or 1600 inode cluster buffers. That works out at roughly 4 bytes per cluster buffer logged, and at that I started looking for a 4 byte leak in the buffer logging code. What I found was that a struct xfs_buf_log_format structure for an inode cluster buffer is 28 bytes in length. This gets rounded up to 32 bytes, but the vector length remains 28 bytes. Hence the CIL ticket reservation is decremented by 32 bytes (via lv->lv_buf_len) for that vector rather than 28 bytes which are written into the log. The fix for this problem is to separately track the bytes used by the log vectors in the item and use that instead of the buffer length when accounting for the log space that will be used by the formatted log item. Again, thanks to Brian Foster for doing all the hard work and long hours to isolate this leak and make finding the bug relatively simple. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-05-07xfs: don't sleep in xlog_cil_force_lsn on shutdownDave Chinner
Reports of a shutdown hang when fsyncing a directory have surfaced, such as this: [ 3663.394472] Call Trace: [ 3663.397199] [<ffffffff815f1889>] schedule+0x29/0x70 [ 3663.402743] [<ffffffffa01feda5>] xlog_cil_force_lsn+0x185/0x1a0 [xfs] [ 3663.416249] [<ffffffffa01fd3af>] _xfs_log_force_lsn+0x6f/0x2f0 [xfs] [ 3663.429271] [<ffffffffa01a339d>] xfs_dir_fsync+0x7d/0xe0 [xfs] [ 3663.435873] [<ffffffff811df8c5>] do_fsync+0x65/0xa0 [ 3663.441408] [<ffffffff811dfbc0>] SyS_fsync+0x10/0x20 [ 3663.447043] [<ffffffff815fc7d9>] system_call_fastpath+0x16/0x1b If we trigger a shutdown in xlog_cil_push() from xlog_write(), we will never wake waiters on the current push sequence number, so anything waiting in xlog_cil_force_lsn() for that push sequence number to come up will not get woken and hence stall the shutdown. Fix this by ensuring we call wake_up_all(&cil->xc_commit_wait) in the push abort handling, in the log shutdown code when waking all waiters, and adding a shutdown check in the sequence completion wait loops to ensure they abort when a wakeup due to a shutdown occurs. Reported-by: Boris Ranto <branto@redhat.com> Reported-by: Eric Sandeen <esandeen@redhat.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-03-13Merge branch 'xfs-stack-fixes' into for-nextDave Chinner
2014-02-27xfs: always do log forces via the workqueueDave Chinner
Log forces can occur deep in the call chain when we have relatively little stack free. Log forces can also happen at close to the call chain leaves (e.g. xfs_buf_lock()) and hence we can trigger IO from places where we really don't want to add more stack overhead. This stack overhead occurs because log forces do foreground CIL pushes (xlog_cil_push_foreground()) rather than waking the background push wq and waiting for the for the push to complete. This foreground push was done to avoid confusing the CFQ Io scheduler when fsync()s were issued, as it has trouble dealing with dependent IOs being issued from different process contexts. Avoiding blowing the stack is much more critical than performance optimisations for CFQ, especially as we've been recommending against the use of CFQ for XFS since 3.2 kernels were release because of it's problems with multi-threaded IO workloads. Hence convert xlog_cil_push_foreground() to move the push work to the CIL workqueue. We already do the waiting for the push to complete in xlog_cil_force_lsn(), so there's nothing else we need to modify to make this work. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-02-20Merge branch 'xfs-fixes-for-3.15' into for-nextDave Chinner
2014-02-10xfs: ensure correct log item buffer alignmentDave Chinner
On 32 bit platforms, the log item vector headers are not 64 bit aligned or sized. hence if we don't take care to align them correctly or pad the buffer appropriately for 8 byte alignment, we can end up with alignment issues when accessing the user buffer directly as a structure. To solve this, simply pad the buffer headers to 64 bit offset so that the data section is always 8 byte aligned. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reported-by: Michael L. Semon <mlsemon35@gmail.com> Tested-by: Michael L. Semon <mlsemon35@gmail.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-02-07xfs: convert xfs_log_commit_cil() to voidJie Liu
Convert xfs_log_commit_cil() to a void function since it return nothing but 0 in any case, after that we can simplify the relative code logic in xfs_trans_commit() accordingly. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2013-12-13xfs: format log items write directly into the linear CIL bufferChristoph Hellwig
Instead of setting up pointers to memory locations in iop_format which then get copied into the CIL linear buffer after return move the copy into the individual inode items. This avoids the need to always have a memory block in the exact same layout that gets written into the log around, and allow the log items to be much more flexible in their in-memory layouts. The only caveat is that we need to properly align the data for each iovec so that don't have structures misaligned in subsequent iovecs. Note that all log item format routines now need to be careful to modify the copy of the item that was placed into the CIL after calls to xlog_copy_iovec instead of the in-memory copy. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2013-12-13xfs: remove duplicate code in xlog_cil_insert_format_itemsChristoph Hellwig
Share code that was previously duplicated in two branches. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2013-10-23xfs: decouple log and transaction headersDave Chinner
xfs_trans.h has a dependency on xfs_log.h for a couple of structures. Most code that does transactions doesn't need to know anything about the log, but this dependency means that they have to include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header files and clean up the includes to be in dependency order. In doing this, remove the direct include of xfs_trans_reserve.h from xfs_trans.h so that we remove the dependency between xfs_trans.h and xfs_mount.h. Hence the xfs_trans.h include can be moved to the indicate the actual dependencies other header files have on it. Note that these are kernel only header files, so this does not translate to any userspace changes at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-23xfs: create a shared header file for format-related informationDave Chinner
All of the buffer operations structures are needed to be exported for xfs_db, so move them all to a common location rather than spreading them all over the place. They are verifying the on-disk format, so while xfs_format.h might be a good place, it is not part of the on disk format. Hence we need to create a new header file that we centralise these related definitions. Start by moving the bffer operations structures, and then also move all the other definitions that have crept into xfs_log_format.h and xfs_format.h as there was no other shared header file to put them in. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-17xfs: prevent deadlock trying to cover an active logDave Chinner
Recent analysis of a deadlocked XFS filesystem from a kernel crash dump indicated that the filesystem was stuck waiting for log space. The short story of the hang on the RHEL6 kernel is this: - the tail of the log is pinned by an inode - the inode has been pushed by the xfsaild - the inode has been flushed to it's backing buffer and is currently flush locked and hence waiting for backing buffer IO to complete and remove it from the AIL - the backing buffer is marked for write - it is on the delayed write queue - the inode buffer has been modified directly and logged recently due to unlinked inode list modification - the backing buffer is pinned in memory as it is in the active CIL context. - the xfsbufd won't start buffer writeback because it is pinned - xfssyncd won't force the log because it sees the log as needing to be covered and hence wants to issue a dummy transaction to move the log covering state machine along. Hence there is no trigger to force the CIL to the log and hence unpin the inode buffer and therefore complete the inode IO, remove it from the AIL and hence move the tail of the log along, allowing transactions to start again. Mainline kernels also have the same deadlock, though the signature is slightly different - the inode buffer never reaches the delayed write lists because xfs_buf_item_push() sees that it is pinned and hence never adds it to the delayed write list that the xfsaild flushes. There are two possible solutions here. The first is to simply force the log before trying to cover the log and so ensure that the CIL is emptied before we try to reserve space for the dummy transaction in the xfs_log_worker(). While this might work most of the time, it is still racy and is no guarantee that we don't get stuck in xfs_trans_reserve waiting for log space to come free. Hence it's not the best way to solve the problem. The second solution is to modify xfs_log_need_covered() to be aware of the CIL. We only should be attempting to cover the log if there is no current activity in the log - covering the log is the process of ensuring that the head and tail in the log on disk are identical (i.e. the log is clean and at idle). Hence, by definition, if there are items in the CIL then the log is not at idle and so we don't need to attempt to cover it. When we don't need to cover the log because it is active or idle, we issue a log force from xfs_log_worker() - if the log is idle, then this does nothing. However, if the log is active due to there being items in the CIL, it will force the items in the CIL to the log and unpin them. In the case of the above deadlock scenario, instead of xfs_log_worker() getting stuck in xfs_trans_reserve() attempting to cover the log, it will instead force the log, thereby unpinning the inode buffer, allowing IO to be issued and complete and hence removing the inode that was pinning the tail of the log from the AIL. At that point, everything will start moving along again. i.e. the xfs_log_worker turns back into a watchdog that can alleviate deadlocks based around pinned items that prevent the tail of the log from being moved... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: split the CIL lockDave Chinner
The xc_cil_lock is used for two purposes - to protect the CIL itself, and to protect the push/commit state and lists. These are two logically separate structures and operations, so can have their own locks. This means that pushing on the CIL and the commit wait ordering won't contend for a lock with other transactions that are completing concurrently. As the CIL insertion is the hottest path throught eh CIL, this is a big win. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: Combine CIL insert and prepare passesDave Chinner
Now that all the log item preparation and formatting is done under the CIL lock, we can get rid of the intermediate log vector chain used to track items to be inserted into the CIL. We can already find all the items to be committed from the transaction handle, so as long as we attach the log vectors to the item before we insert the items into the CIL, we don't need to create a log vector chain to pass around. This means we can move all the item insertion code into and optimise it into a pair of simple passes across all the items in the transaction. The first pass does the formatting and accounting, the second inserts them all into the CIL. We keep this two pass split so that we can separate the CIL insertion - which must be done under the CIL spinlock - from the formatting. We could insert each item into the CIL with a single pass, but that massively increases the number of times we have to grab the CIL spinlock. It is much more efficient (and hence scalable) to do a batch operation and insert all objects in a single lock grab. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: avoid CIL allocation during insertDave Chinner
Now that we have the size of the log vector that has been allocated, we can determine if we need to allocate a new log vector for formatting and insertion. We only need to allocate a new vector if it won't fit into the existing buffer. However, we need to hold the CIL context lock while we do this so that we can't race with a push draining the currently queued log vectors. It is safe to do this as long as we do GFP_NOFS allocation to avoid avoid memory allocation recursing into the filesystem. Hence we can safely overwrite the existing log vector on the CIL if it is large enough to hold all the dirty regions of the current item. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: Reduce allocations during CIL insertionDave Chinner
Now that we have the size of the object before the formatting pass is called, we can allocation the log vector and it's buffer in a single allocation rather than two separate allocations. Store the size of the allocated buffer in the log vector so that we potentially avoid allocation for future modifications of the object. While touching this code, remove the IOP_FORMAT definition. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: return log item size in IOP_SIZEDave Chinner
To begin optimising the CIL commit process, we need to have IOP_SIZE return both the number of vectors and the size of the data pointed to by the vectors. This enables us to calculate the size ofthe memory allocation needed before the formatting step and reduces the number of memory allocations per item by one. While there, kill the IOP_SIZE macro. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-27xfs: Introduce ordered log vector supportDave Chinner
And "ordered log vector" is a log vector that is used for tracking a log item through the CIL and into the AIL as part of the log checkpointing. These ordered log vectors are special in that they are not written to to journal in any way, and are not accounted to the checkpoint being written. The reason for this behaviour is to allow operations to attach items to transactions and have them follow the normal transactional lifecycle without actually having to write them to the journal. This allows logging of items that track high level logical changes and writing them to the log, while the physical items being modified pass through into the AIL and pin the tail of the log (and therefore the logical item in the log) until all the modified items are physically written to disk. IOWs, it allows us to write metadata without physically logging every individual change but still maintain the full transactional integrity guarantees we currently have w.r.t. crash recovery. This change modifies some of the CIL item insertion loops, as ordered log vectors introduce some new constraints as they don't track any data. One advantage of this change is that it combines two log vector chain walks into a single pass, so there is less overhead in the transaction commit pass as well. It also kills some unused code in the log vector walk loop when committing the CIL. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-05-20xfs: fix missing KM_NOFS tags to keep lockdep happyDave Chinner
There are several places where we use KM_SLEEP allocation contexts and use the fact that they are called from transaction context to add KM_NOFS where appropriate. Unfortunately, there are several places where the code makes this assumption but can be called from outside transaction context but with filesystem locks held. These places need explicit KM_NOFS annotations to avoid lockdep complaining about reclaim contexts. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-04-16xfs: Update xfs_log_commit_cil() commentsJeff Liu
xfs_log_commit_iclog() function has been removed by commits 93b8a585: xfs: remove the deprecated nodelaylog option Beginning from Linux 3.3, only delayed logging is supported so that we call xfs_log_commit_cil() at xfs_trans_commit() only, remove the useless comments so. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-21xfs: rename log structure to xlogMark Tinguely
Rename the XFS log structure to xlog to help crash distinquish it from the other logs in Linux. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: clean up xfs_bit.h includesDave Chinner
With the removal of xfs_rw.h and other changes over time, xfs_bit.h is being included in many files that don't actually need it. Clean up the includes as necessary. Also move the only-used-once xfs_ialloc_find_free() static inline function out of a header file that is widely included to reduce the number of needless dependencies on xfs_bit.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: clean up busy extent namingDave Chinner
Now that the busy extent tracking has been moved out of the allocation files, clean up the namespace it uses to "xfs_extent_busy" rather than a mix of "xfs_busy" and "xfs_alloc_busy". Signed-off-by: Dave Chinner<dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move busy extent handling to it's own fileDave Chinner
To make it easier to handle userspace code merges, move all the busy extent handling out of the allocation code and into it's own file. The userspace code does not need the busy extent code, so this simplifies the merging of the kernel code into the userspace xfsprogs library. Because the busy extent code has been almost completely rewritten over the past couple of years, also update the copyright on this new file to include the authors that made all those changes. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: move xfsagino_t to xfs_types.hDave Chinner
Untangle the header file includes a bit by moving the definition of xfs_agino_t to xfs_types.h. This removes the dependency that xfs_ag.h has on xfs_inum.h, meaning we don't need to include xfs_inum.h everywhere we include xfs_ag.h. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: Do background CIL flushes via a workqueueDave Chinner
Doing background CIL flushes adds significant latency to whatever async transaction that triggers it. To avoid blocking async transactions on things like waiting for log buffer IO to complete, move the CIL push off into a workqueue. By moving the push work into a workqueue, we remove all the latency that the commit adds from the foreground transaction commit path. This also means that single threaded workloads won't do the CIL push procssing, leaving them more CPU to do more async transactions. To do this, we need to keep track of the sequence number we have pushed work for. This avoids having many transaction commits attempting to schedule work for the same sequence, and ensures that we only ever have one push (background or forced) in progress at a time. It also means that we don't need to take the CIL lock in write mode to check for potential background push races, which reduces lock contention. To avoid potential issues with "smart" IO schedulers, don't use the workqueue for log force triggered flushes. Instead, do them directly so that the log IO is done directly by the process issuing the log force and so doesn't get stuck on IO elevator queue idling incorrectly delaying the log IO from the workqueue. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>