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path: root/fs/xfs/xfs_buf_item.c
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2020-08-05xfs: delete duplicated words + other fixesRandy Dunlap
Delete repeated words in fs/xfs/. {we, that, the, a, to, fork} Change "it it" to "it is" in one location. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> To: linux-fsdevel@vger.kernel.org Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: linux-xfs@vger.kernel.org Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-28xfs: Remove kmem_zone_zalloc() usageCarlos Maiolino
Use kmem_cache_zalloc() directly. With the exception of xlog_ticket_alloc() which will be dealt on the next patch for readability. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2020-07-14xfs: remove duplicated include from xfs_buf_item.cYueHaibing
Remove duplicated include. Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Chaitanya Kulkarni <chaitanya.kulkarni@wdc.com>
2020-07-07xfs: attach inodes to the cluster buffer when dirtiedDave Chinner
Rather than attach inodes to the cluster buffer just when we are doing IO, attach the inodes to the cluster buffer when they are dirtied. The means the buffer always carries a list of dirty inodes that reference it, and we can use that list to make more fundamental changes to inode writeback that aren't otherwise possible. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-07xfs: pin inode backing buffer to the inode log itemDave Chinner
When we dirty an inode, we are going to have to write it disk at some point in the near future. This requires the inode cluster backing buffer to be present in memory. Unfortunately, under severe memory pressure we can reclaim the inode backing buffer while the inode is dirty in memory, resulting in stalling the AIL pushing because it has to do a read-modify-write cycle on the cluster buffer. When we have no memory available, the read of the cluster buffer blocks the AIL pushing process, and this causes all sorts of issues for memory reclaim as it requires inode writeback to make forwards progress. Allocating a cluster buffer causes more memory pressure, and results in more cluster buffers to be reclaimed, resulting in more RMW cycles to be done in the AIL context and everything then backs up on AIL progress. Only the synchronous inode cluster writeback in the the inode reclaim code provides some level of forwards progress guarantees that prevent OOM-killer rampages in this situation. Fix this by pinning the inode backing buffer to the inode log item when the inode is first dirtied (i.e. in xfs_trans_log_inode()). This may mean the first modification of an inode that has been held in cache for a long time may block on a cluster buffer read, but we can do that in transaction context and block safely until the buffer has been allocated and read. Once we have the cluster buffer, the inode log item takes a reference to it, pinning it in memory, and attaches it to the log item for future reference. This means we can always grab the cluster buffer from the inode log item when we need it. When the inode is finally cleaned and removed from the AIL, we can drop the reference the inode log item holds on the cluster buffer. Once all inodes on the cluster buffer are clean, the cluster buffer will be unpinned and it will be available for memory reclaim to reclaim again. This avoids the issues with needing to do RMW cycles in the AIL pushing context, and hence allows complete non-blocking inode flushing to be performed by the AIL pushing context. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-07-07xfs: unwind log item error flaggingDave Chinner
When an buffer IO error occurs, we want to mark all the log items attached to the buffer as failed. Open code the error handling loop so that we can modify the flagging for the different types of objects directly and independently of each other. This also allows us to remove the ->iop_error method from the log item operations. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-07-07xfs: handle buffer log item IO errors directlyDave Chinner
Currently when a buffer with attached log items has an IO error it called ->iop_error for each attched log item. These all call xfs_set_li_failed() to handle the error, but we are about to change the way log items manage buffers. hence we first need to remove the per-item dependency on buffer handling done by xfs_set_li_failed(). We already have specific buffer type IO completion routines, so move the log item error handling out of the generic error handling and into the log item specific functions so we can implement per-type error handling easily. This requires a more complex return value from the error handling code so that we can take the correct action the failure handling requires. This results in some repeated boilerplate in the functions, but that can be cleaned up later once all the changes cascade through this code. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-07-07xfs: get rid of log item callbacksDave Chinner
They are not used anymore, so remove them from the log item and the buffer iodone attachment interfaces. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-07xfs: clean up the buffer iodone callback functionsDave Chinner
Now that we've sorted inode and dquot buffers, we can apply the same cleanups to dirty buffers with buffer log items. They only have one callback, too, so we don't need the log item callback. Collapse the iodone functions and remove all the now unnecessary infrastructure around callback processing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-06xfs: use direct calls for dquot IO completionDave Chinner
Similar to inodes, we can call the dquot IO completion functions directly from the buffer completion code, removing another user of log item callbacks for IO completion processing. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-07-06xfs: make inode IO completion buffer centricDave Chinner
Having different io completion callbacks for different inode states makes things complex. We can detect if the inode is stale via the XFS_ISTALE flag in IO completion, so we don't need a special callback just for this. This means inodes only have a single iodone callback, and inode IO completion is entirely buffer centric at this point. Hence we no longer need to use a log item callback at all as we can just call xfs_iflush_done() directly from the buffer completions and walk the buffer log item list to complete the all inodes under IO. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-06xfs: clean up whacky buffer log item list reinitDave Chinner
When we've emptied the buffer log item list, it does a list_del_init on itself to reset it's pointers to itself. This is unnecessary as the list is already empty at this point - it was a left-over fragment from the list_head conversion of the buffer log item list. Remove them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-06xfs: call xfs_buf_iodone directlyDave Chinner
All unmarked dirty buffers should be in the AIL and have log items attached to them. Hence when they are written, we will run a callback to remove the item from the AIL if appropriate. Now that we've handled inode and dquot buffers, all remaining calls are to xfs_buf_iodone() and so we can hard code this rather than use an indirect call. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-07-06xfs: mark dquot buffers in cacheDave Chinner
dquot buffers always have write IO callbacks, so by marking them directly we can avoid needing to attach ->b_iodone functions to them. This avoids an indirect call, and makes future modifications much simpler. This is largely a rearrangement of the code at this point - no IO completion functionality changes at this point, just how the code is run is modified. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-07-06xfs: mark inode buffers in cacheDave Chinner
Inode buffers always have write IO callbacks, so by marking them directly we can avoid needing to attach ->b_iodone functions to them. This avoids an indirect call, and makes future modifications much simpler. While this is largely a refactor of existing functionality, we broaden the scope of the flag to beyond where inodes are explicitly attached because future changes need to know what type of log items are attached to the buffer. Adding this buffer flag may invoke the inode iodone callback in cases where it wouldn't have been previously, but this is not a functional change because the callback is identical to the normal buffer write iodone callback when inodes are not attached. Signed-off-by: Dave Chinner <dchinner@redhat.com> 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>
2020-05-07xfs: combine xfs_trans_ail_[remove|delete]()Brian Foster
Now that the functions and callers of xfs_trans_ail_[remove|delete]() have been fixed up appropriately, the only difference between the two is the shutdown behavior. There are only a few callers of the _remove() variant, so make the shutdown conditional on the parameter and combine the two functions. Suggested-by: Dave Chinner <david@fromorbit.com> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: drop unused shutdown parameter from xfs_trans_ail_remove()Brian Foster
The shutdown parameter of xfs_trans_ail_remove() is no longer used. The remaining callers use it for items that legitimately might not be in the AIL or from contexts where AIL state has already been checked. Remove the unnecessary parameter and fix up the callers. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: acquire ->ail_lock from xfs_trans_ail_delete()Brian Foster
Several callers acquire the lock just prior to the call. Callers that require ->ail_lock for other purposes already check IN_AIL state and thus don't require the additional shutdown check in the helper. Push the lock down into xfs_trans_ail_delete(), open code the instances that still acquire it, and remove the unnecessary ailp parameter. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: refactor ratelimited buffer error messages into helperBrian Foster
XFS has some inconsistent log message rate limiting with respect to buffer alerts. The metadata I/O error notification uses the generic ratelimited alert, the buffer push code uses a custom rate limit and the similar quiesce time failure checks are not rate limited at all (when they should be). The custom rate limit defined in the buf item code is specifically crafted for buffer alerts. It is more aggressive than generic rate limiting code because it must accommodate a high frequency of I/O error events in a relative short timeframe. Factor out the custom rate limit state from the buf item code into a per-buftarg rate limit so various alerts are limited based on the target. Define a buffer alert helper function and use it for the buffer alerts that are already ratelimited. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: factor out buffer I/O failure codeBrian Foster
We use the same buffer I/O failure code in a few different places. It's not much code, but it's not necessarily self-explanatory. Factor it into a helper and document it in one place. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-05-07xfs: refactor failed buffer resubmission into xfsaildBrian Foster
Flush locked log items whose underlying buffers fail metadata writeback are tagged with a special flag to indicate that the flush lock is already held. This is currently implemented in the type specific ->iop_push() callback, but the processing required for such items is not type specific because we're only doing basic state management on the underlying buffer. Factor the failed log item handling out of the inode and dquot ->iop_push() callbacks and open code the buffer resubmit helper into a single helper called from xfsaild_push_item(). This provides a generic mechanism for handling failed metadata buffer writeback with a bit less code. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-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>
2020-03-19xfs: add a new xfs_sb_version_has_v3inode helperChristoph Hellwig
Add a new wrapper to check if a file system supports the v3 inode format with a larger dinode core. Previously we used xfs_sb_version_hascrc for that, which is technically correct but a little confusing to read. Also move xfs_dinode_good_version next to xfs_sb_version_has_v3inode so that we have one place that documents the superblock version to inode version relationship. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Chandan Rajendra <chandanrlinux@gmail.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-26xfs: fix xfs_buf_ioerror_alert location reportingxfs-5.6-merge-8xfs-5.6-merge-7Darrick J. Wong
Instead of passing __func__ to the error reporting function, let's use the return address builtins so that the messages actually tell you which higher level function called the buffer functions. This was previously true for the xfs_buf_read callers, but not for the xfs_trans_read_buf callers. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-16xfs: check log iovec size to make sure it's plausibly a buffer log formatDarrick J. Wong
When log recovery is processing buffer log items, we should check that the incoming iovec actually describes a region of memory large enough to contain the log format and the dirty map. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-16xfs: complain if anyone tries to create a too-large buffer log itemDarrick J. Wong
Complain if someone calls xfs_buf_item_init on a buffer that is larger than the dirty bitmap can handle, or tries to log a region that's past the end of the dirty bitmap. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-16xfs: clean up xfs_buf_item_get_format return valueDarrick J. Wong
The only thing that can cause a nonzero return from xfs_buf_item_get_format is if the kmem_alloc fails, which it can't. Get rid of all the unnecessary error handling. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-12-19xfs: use bitops interface for buf log item AIL flag checkBrian Foster
The xfs_log_item flags were converted to atomic bitops as of commit 22525c17ed ("xfs: log item flags are racy"). The assert check for AIL presence in xfs_buf_item_relse() still uses the old value based check. This likely went unnoticed as XFS_LI_IN_AIL evaluates to 0 and causes the assert to unconditionally pass. Fix up the check. Signed-off-by: Brian Foster <bfoster@redhat.com> Fixes: 22525c17ed ("xfs: log item flags are racy") Reviewed-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>
2019-11-18xfs: Remove kmem_zone_free() wrapperCarlos Maiolino
We can remove it now, without needing to rework the KM_ flags. Use kmem_cache_free() directly. Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-07xfs: "optimize" buffer item log segment bitmap settingDarrick J. Wong
Optimize the setting of full words of bits in xfs_buf_item_log_segment. The optimization is purely within the bug triage process. No functional changes. Coverity-id: 1446793 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-08-26fs: xfs: Remove KM_NOSLEEP and KM_SLEEP.Tetsuo Handa
Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP, we can remove KM_NOSLEEP and replace KM_SLEEP with 0. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28xfs: remove unused header filesEric Sandeen
There are many, many xfs header files which are included but unneeded (or included twice) in the xfs code, so remove them. nb: xfs_linux.h includes about 9 headers for everyone, so those explicit includes get removed by this. I'm not sure what the preference is, but if we wanted explicit includes everywhere, a followup patch could remove those xfs_*.h includes from xfs_linux.h and move them into the files that need them. Or it could be left as-is. 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>
2019-06-28xfs: remove a pointless comment duplicated above all xfs_item_ops instancesChristoph Hellwig
Signed-off-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>
2019-06-28xfs: remove the xfs_log_item_t typedefChristoph Hellwig
Signed-off-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>
2019-06-28xfs: split iop_unlockChristoph Hellwig
The iop_unlock method is called when comitting or cancelling a transaction. In the latter case, the transaction may or may not be aborted. While there is no known problem with the current code in practice, this implementation is limited in that any log item implementation that might want to differentiate between a commit and a cancellation must rely on the aborted state. The aborted bit is only set when the cancelled transaction is dirty, however. This means that there is no way to distinguish between a commit and a clean transaction cancellation. For example, intent log items currently rely on this distinction. The log item is either transferred to the CIL on commit or released on transaction cancel. There is currently no possibility for a clean intent log item in a transaction, but if that state is ever introduced a cancel of such a transaction will immediately result in memory leaks of the associated log item(s). This is an interface deficiency and landmine. To clean this up, replace the iop_unlock method with an iop_release method that is specific to transaction cancel. The existing iop_committing method occurs at the same time as iop_unlock in the commit path and there is no need for two separate callbacks here. Overload the iop_committing method with the current commit time iop_unlock implementations to eliminate the need for the latter and further simplify the interface. Signed-off-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>
2019-06-28xfs: don't require log items to implement optional methodsChristoph Hellwig
Just check if they are present first. Signed-off-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>
2019-06-28xfs: add struct xfs_mount pointer to struct xfs_bufChristoph Hellwig
We need to derive the mount pointer from a buffer in a lot of place. Add a direct pointer to short cut the pointer chasing. 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>
2019-06-28xfs: move xfs_ino_geometry to xfs_shared.hDarrick J. Wong
The inode geometry structure isn't related to ondisk format; it's support for the mount structure. Move it to xfs_shared.h. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-04-14xfs: fix use after free in buf log item unlock assertBrian Foster
The xfs_buf_log_item ->iop_unlock() callback asserts that the buffer is unlocked when either non-stale or aborted. This assert occurs after the bli refcount has been dropped and the log item potentially freed. The aborted check is thus a potential use after free. This problem has been reproduced with KASAN enabled via generic/475. Fix up xfs_buf_item_unlock() to query aborted state before the bli reference is dropped to prevent a potential use after free. 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>
2018-11-20xfs: fix transient reference count error in xfs_buf_resubmit_failed_buffersDave Chinner
When retrying a failed inode or dquot buffer, xfs_buf_resubmit_failed_buffers() clears all the failed flags from the inde/dquot log items. In doing so, it also drops all the reference counts on the buffer that the failed log items hold. This means it can drop all the active references on the buffer and hence free the buffer before it queues it for write again. Putting the buffer on the delwri queue takes a reference to the buffer (so that it hangs around until it has been written and completed), but this goes bang if the buffer has already been freed. Hence we need to add the buffer to the delwri queue before we remove the failed flags from the log items attached to the buffer to ensure it always remains referenced during the resubmit process. Reported-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-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>
2018-09-29xfs: refactor xfs_buf_log_item reference count handlingBrian Foster
The xfs_buf_log_item structure has a reference counter with slightly tricky semantics. In the common case, a buffer is logged and committed in a transaction, committed to the on-disk log (added to the AIL) and then finally written back and removed from the AIL. The bli refcount covers two potentially overlapping timeframes: 1. the bli is held in an active transaction 2. the bli is pinned by the log The caveat to this approach is that the reference counter does not purely dictate the lifetime of the bli. IOW, when a dirty buffer is physically logged and unpinned, the bli refcount may go to zero as the log item is inserted into the AIL. Only once the buffer is written back can the bli finally be freed. The above semantics means that it is not enough for the various refcount decrementing contexts to release the bli on decrement to zero. xfs_trans_brelse(), transaction commit (->iop_unlock()) and unpin (->iop_unpin()) must all drop the associated reference and make additional checks to determine if the current context is responsible for freeing the item. For example, if a transaction holds but does not dirty a particular bli, the commit may drop the refcount to zero. If the bli itself is clean, it is also not AIL resident and must be freed at this time. The same is true for xfs_trans_brelse(). If the transaction dirties a bli and then aborts or an unpin results in an abort due to a log I/O error, the last reference count holder is expected to explicitly remove the item from the AIL and release it (since an abort means filesystem shutdown and metadata writeback will never occur). This leads to fairly complex checks being replicated in a few different places. Since ->iop_unlock() and xfs_trans_brelse() are nearly identical, refactor the logic into a common helper that implements and documents the semantics in one place. This patch does not change behavior. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29xfs: don't unlock invalidated buf on aborted tx commitBrian Foster
xfstests generic/388,475 occasionally reproduce assertion failures in xfs_buf_item_unpin() when the final bli reference is dropped on an invalidated buffer and the buffer is not locked as it is expected to be. Invalidated buffers should remain locked on transaction commit until the final unpin, at which point the buffer is removed from the AIL and the bli is freed since stale buffers are not written back. The assert failures are associated with filesystem shutdown, typically due to log I/O errors injected by the test. The problematic situation can occur if the shutdown happens to cause a race between an active transaction that has invalidated a particular buffer and an I/O error on a log buffer that contains the bli associated with the same (now stale) buffer. Both transaction and log contexts acquire a bli reference. If the transaction has already invalidated the buffer by the time the I/O error occurs and ends up aborting due to shutdown, the transaction and log hold the last two references to a stale bli. If the transaction cancel occurs first, it treats the buffer as non-stale due to the aborted state: the bli reference is dropped and the buffer is released/unlocked. The log buffer I/O error handling eventually calls into xfs_buf_item_unpin(), drops the final reference to the bli and treats it as stale. The buffer wasn't left locked by xfs_buf_item_unlock(), however, so the assert fails and the buffer is double unlocked. The latter problem is mitigated by the fact that the fs is shutdown and no further damage is possible. ->iop_unlock() of an invalidated buffer should behave consistently with respect to the bli refcount, regardless of aborted state. If the refcount remains elevated on commit, we know the bli is awaiting an unpin (since it can't be in another transaction) and will be handled appropriately on log buffer completion. If the final bli reference of an invalidated buffer is dropped in ->iop_unlock(), we can assume the transaction has aborted because invalidation implies a dirty transaction. In the non-abort case, the log would have acquired a bli reference in ->iop_pin() and prevented bli release at ->iop_unlock() time. In the abort case the item must be freed and buffer unlocked because it wasn't pinned by the log. Rework xfs_buf_item_unlock() to simplify the currently circuitous and duplicate logic and leave invalidated buffers locked based on bli refcount, regardless of aborted state. This ensures that a pinned, stale buffer is always found locked when eventually unpinned. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-06-08xfs: clean up MIN/MAXDave Chinner
Get rid of the MIN/MAX macros and just use the native min/max macros directly in the XFS code. Signed-Off-By: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-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>
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 some more debug checks to buffer log item reuseDave Chinner
Just to make sure the item isn't associated with another transaction when we try to reuse it. 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>
2018-05-10xfs: log item flags are racyDave Chinner
The log item flags contain a field that is protected by the AIL lock - the XFS_LI_IN_AIL flag. We use non-atomic RMW operations to set and clear these flags, but most of the updates and checks are not done with the AIL lock held and so are susceptible to update races. Fix this by changing the log item flags to use atomic bitops rather than be reliant on the AIL lock for update serialisation. 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>
2018-03-11xfs: Rename xa_ elements to ail_Matthew Wilcox
This is a simple rename, except that xa_ail becomes ail_head. Signed-off-by: Matthew Wilcox <mawilcox@microsoft.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-29Use list_head infra-structure for buffer's log items listCarlos Maiolino
Now that buffer's b_fspriv has been split, just replace the current singly linked list of xfs_log_items, by the list_head infrastructure. Also, remove the xfs_log_item argument from xfs_buf_resubmit_failed_buffers(), there is no need for this argument, once the log items can be walked through the list_head in the buffer. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: minor style cleanups] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-29Split buffer's b_fspriv fieldCarlos Maiolino
By splitting the b_fspriv field into two different fields (b_log_item and b_li_list). It's possible to get rid of an old ABI workaround, by using the new b_log_item field to store xfs_buf_log_item separated from the log items attached to the buffer, which will be linked in the new b_li_list field. This way, there is no more need to reorder the log items list to place the buf_log_item at the beginning of the list, simplifying a bit the logic to handle buffer IO. This also opens the possibility to change buffer's log items list into a proper list_head. b_log_item field is still defined as a void *, because it is still used by the log buffers to store xlog_in_core structures, and there is no need to add an extra field on xfs_buf just for xlog_in_core. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> [darrick: minor style changes] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-29Get rid of xfs_buf_log_item_t typedefCarlos Maiolino
Take advantage of the rework on xfs_buf log items list, to get rid of ths typedef for xfs_buf_log_item. This patch also fix some indentation alignment issues found along the way. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>