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path: root/fs/xfs/xfs_iomap.c
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2015-01-09xfs: pass a 64-bit count argument to xfs_iomap_write_unwrittenChristoph Hellwig
The code is already ready for it, and the pnfs layout commit code expects to be able to pass a larger than 32-bit argument. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-12-04Merge branch 'xfs-misc-fixes-for-3.19-2' into for-nextDave Chinner
Conflicts: fs/xfs/xfs_iops.c
2014-12-04xfs: fix set-but-unused warningsDave Chinner
The kernel compile doesn't turn on these checks by default, so it's only when I do a kernel-user sync that I find that there are lots of compiler warnings waiting to be fixed. Fix up these set-but-unused warnings. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-12-04xfs: overflow in xfs_iomap_eof_align_last_fsbPeter Watkins
If extsize is set and new_last_fsb is larger than 32 bits, the roundup to extsize will overflow the align variable. Instead, combine alignments by rounding stripe size up to extsize. Signed-off-by: Peter Watkins <treestem@gmail.com> Reviewed-by: Nathaniel W. Turner <nate@houseofnate.net> Reviewed-by: Brian Foster <bfoster@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>
2014-11-28xfs: merge xfs_dinode.h into xfs_format.hChristoph Hellwig
More consolidatation for the on-disk format defintions. Note that the XFS_IS_REALTIME_INODE moves to xfs_linux.h instead as it is not related to the on disk format, but depends on a CONFIG_ option. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-10-02xfs: check for null dquot in xfs_quota_calc_throttle()Eric Sandeen
Coverity spotted this. Granted, we *just* checked xfs_inod_dquot() in the caller (by calling xfs_quota_need_throttle). However, this is the only place we don't check the return value but the check is cheap and future-proof so add it. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-08-04Merge branch 'xfs-quota-eofblocks-scan' into for-nextDave Chinner
2014-07-24xfs: squash prealloc while over quota free space as wellBrian Foster
From: Brian Foster <bfoster@redhat.com> Commit 4d559a3b introduced heavy prealloc. squashing to catch the case of requesting too large a prealloc on smaller filesystems, leading to repeated flush and retry cycles that occur on ENOSPC. Now that we issue eofblocks scans on EDQUOT/ENOSPC, squash the prealloc against the minimum available free space across all applicable quotas as well to avoid a similar problem of repeated eofblocks scans. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-07-15Merge branch 'xfs-libxfs-restructure' into for-nextDave Chinner
2014-07-15xfs: refine the allocation stack switchDave Chinner
The allocation stack switch at xfs_bmapi_allocate() has served it's purpose, but is no longer a sufficient solution to the stack usage problem we have in the XFS allocation path. Whilst the kernel stack size is now 16k, that is not a valid reason for undoing all our "keep stack usage down" modifications. What it does allow us to do is have the freedom to refine and perfect the modifications knowing that if we get it wrong it won't blow up in our faces - we have a safety net now. This is important because we still have the issue of older kernels having smaller stacks and that they are still supported and are demonstrating a wide range of different stack overflows. Red Hat has several open bugs for allocation based stack overflows from directory modifications and direct IO block allocation and these problems still need to be solved. If we can solve them upstream, then distro's won't need to bake their own unique solutions. To that end, I've observed that every allocation based stack overflow report has had a specific characteristic - it has happened during or directly after a bmap btree block split. That event requires a new block to be allocated to the tree, and so we effectively stack one allocation stack on top of another, and that's when we get into trouble. A further observation is that bmap btree block splits are much rarer than writeback allocation - over a range of different workloads I've observed the ratio of bmap btree inserts to splits ranges from 100:1 (xfstests run) to 10000:1 (local VM image server with sparse files that range in the hundreds of thousands to millions of extents). Either way, bmap btree split events are much, much rarer than allocation events. Finally, we have to move the kswapd state to the allocation workqueue work when allocation is done on behalf of kswapd. This is proving to cause significant perturbation in performance under memory pressure and appears to be generating allocation deadlock warnings under some workloads, so avoiding the use of a workqueue for the majority of kswapd writeback allocation will minimise the impact of such behaviour. Hence it makes sense to move the stack switch to xfs_btree_split() and only do it for bmap btree splits. Stack switches during allocation will be much rarer, so there won't be significant performacne overhead caused by switching stacks. The worse case stack from all allocation paths will be split, not just writeback. And the majority of memory allocations will be done in the correct context (e.g. kswapd) without causing additional latency, and so we simplify the memory reclaim interactions between processes, workqueues and kswapd. The worst stack I've been able to generate with this patch in place is 5600 bytes deep. It's very revealing because we exit XFS at: 37) 1768 64 kmem_cache_alloc+0x13b/0x170 about 1800 bytes of stack consumed, and the remaining 3800 bytes (and 36 functions) is memory reclaim, swap and the IO stack. And this occurs in the inode allocation from an open(O_CREAT) syscall, not writeback. The amount of stack being used is much less than I've previously be able to generate - fs_mark testing has been able to generate stack usage of around 7k without too much trouble; with this patch it's only just getting to 5.5k. This is primarily because the metadata allocation paths (e.g. directory blocks) are no longer causing double splits on the same stack, and hence now stack tracing is showing swapping being the worst stack consumer rather than XFS. Performance of fs_mark inode create workloads is unchanged. Performance of fs_mark async fsync workloads is consistently good with context switches reduced by around 150,000/s (30%). Performance of dbench, streaming IO and postmark is unchanged. Allocation deadlock warnings have not been seen on the workloads that generated them since adding this patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-25xfs: 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>
2014-04-14xfs: remove unused tp arg from xfs_bmap_last_offset() and callersEric Sandeen
remove unused transaction pointer from various callchains leading to xfs_bmap_last_offset(). Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-02-10xfs: always use unwritten extents for direct I/O writesChristoph Hellwig
To allow aio writes beyond i_size we need to create unwritten extents for newly allocated blocks, similar to how we already do inside i_size. Instead of adding another special case we now use unwritten extents unconditionally. This also marks the end of directly allocation data extents in all of XFS - we now always use either delalloc or unwritten extents. 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 inode and bmap btree header filesDave Chinner
Currently the xfs_inode.h header has a dependency on the definition of the BMAP btree records as the inode fork includes an array of xfs_bmbt_rec_host_t objects in it's definition. Move all the btree format definitions from xfs_btree.h, xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to xfs_format.h to continue the process of centralising the on-disk format definitions. With this done, the xfs inode definitions are no longer dependent on btree header files. The enables a massive culling of unnecessary includes, with close to 200 #include directives removed from the XFS kernel code base. 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: 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: remove newlines from strings passed to __xfs_printkEric Sandeen
__xfs_printk adds its own "\n". Having it in the original string leads to unintentional blank lines from these messages. Most format strings have no newline, but a few do, leading to i.e.: [ 7347.119911] XFS (sdb2): Access to block zero in inode 132 start_block: 0 start_off: 0 blkcnt: 0 extent-state: 0 lastx: 1a05 [ 7347.119911] [ 7347.119919] XFS (sdb2): Access to block zero in inode 132 start_block: 0 start_off: 0 blkcnt: 0 extent-state: 0 lastx: 1a05 [ 7347.119919] Fix them all. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-01xfs: get rid of count from xfs_iomap_write_allocate()Jie Liu
Get rid of function variable count from xfs_iomap_write_allocate() as it is unused. Additionally, checkpatch warn me of the following for this change: WARNING: extern prototypes should be avoided in .h files +extern int xfs_iomap_write_allocate(struct xfs_inode *, xfs_off_t, So this patch also remove all extern function prototypes at xfs_iomap.h to suppress it to make this code style in consistent manner in this file. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: refactor xfs_trans_reserve() interfaceJie Liu
With the new xfs_trans_res structure has been introduced, the log reservation size, log count as well as log flags are pre-initialized at mount time. So it's time to refine xfs_trans_reserve() interface to be more neat. Also, introduce a new helper M_RES() to return a pointer to the mp->m_resv structure to simplify the input. Signed-off-by: Jie Liu <jeff.liu@oracle.com> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: consolidate xfs_utils.cDave Chinner
There are a few small helper functions in xfs_util, all related to xfs_inode modifications. Move them all to xfs_inode.c so all xfs_inode operations are consiolidated in the one place. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: create xfs_bmap_util.[ch]Dave Chinner
There is a bunch of code in xfs_bmap.c that is kernel specific and not shared with userspace. To minimise the difference between the kernel and userspace code, shift this unshared code to xfs_bmap_util.c, and the declarations to xfs_bmap_util.h. The biggest issue here is xfs_bmap_finish() - userspace has it's own definition of this function, and so we need to move it out of xfs_bmap.[ch]. This means several other files need to include xfs_bmap_util.h as well. It also introduces and interesting dance for the stack switching code in xfs_bmapi_allocate(). The stack switching/workqueue code is actually moved to xfs_bmap_util.c, so that userspace can simply use a #define in a header file to connect the dots without needing to know about the stack switch code at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-12xfs: separate dquot on disk format definitions out of xfs_quota.hDave Chinner
The on disk format definitions of the on-disk dquot, log formats and quota off log formats are all intertwined with other definitions for quotas. Separate them out into their own header file so they can easily be shared with userspace. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-06-27xfs: don't use speculative prealloc for small filesDave Chinner
Dedicated small file workloads have been seeing significant free space fragmentation causing premature inode allocation failure when large inode sizes are in use. A particular test case showed that a workload that runs to a real ENOSPC on 256 byte inodes would fail inode allocation with ENOSPC about about 80% full with 512 byte inodes, and at about 50% full with 1024 byte inodes. The same workload, when run with -o allocsize=4096 on 1024 byte inodes would run to being 100% full before giving ENOSPC. That is, no freespace fragmentation at all. The issue was caused by the specific IO pattern the application had - the framework it was using did not support direct IO, and so it was emulating it by using fadvise(DONT_NEED). The result was that the data was getting written back before the speculative prealloc had been trimmed from memory by the close(), and so small single block files were being allocated with 2 blocks, and then having one truncated away. The result was lots of small 4k free space extents, and hence each new 8k allocation would take another 8k from contiguous free space and turn it into 4k of allocated space and 4k of free space. Hence inode allocation, which requires contiguous, aligned allocation of 16k (256 byte inodes), 32k (512 byte inodes) or 64k (1024 byte inodes) can fail to find sufficiently large freespace and hence fail while there is still lots of free space available. There's a simple fix for this, and one that has precendence in the allocator code already - don't do speculative allocation unless the size of the file is larger than a certain size. In this case, that size is the minimum default preallocation size: mp->m_writeio_blocks. And to keep with the concept of being nice to people when the files are still relatively small, cap the prealloc to mp->m_writeio_blocks until the file goes over a stripe unit is size, at which point we'll fall back to the current behaviour based on the last extent size. This will effectively turn off speculative prealloc for very small files, keep preallocation low for small files, and behave as it currently does for any file larger than a stripe unit. This completely avoids the freespace fragmentation problem this particular IO pattern was causing. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-22xfs: xfs_iomap_prealloc_size() tracepointBrian Foster
Add a tracepoint to provide some feedback on preallocation size calculation. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-22xfs: add quota-driven speculative preallocation throttlingBrian Foster
Introduce the need_throttle() and calc_throttle() functions to independently check whether throttling is required for a particular dquot and if so, calculate the associated throttling metrics based on the state of the quota. We use the same general algorithm to calculate the throttle shift as for global free space with the exception of using three stages rather than five. Update xfs_iomap_prealloc_size() to use the smallest available prealloc size based on each of the constraints and apply the maximum shift to obtain the throttled preallocation size. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-22xfs: push rounddown_pow_of_two() to after prealloc throttleBrian Foster
The round down occurs towards the beginning of the function. Push it down after throttling has occurred. This is to support adding further transformations to 'alloc_blocks' that might not preserve power-of-two alignment (and thus could lead to rounding down multiple times). Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-22xfs: reorganize xfs_iomap_prealloc_size to remove indentationBrian Foster
The majority of xfs_iomap_prealloc_size() executes within the check for lack of default I/O size. Reverse the logic to remove the extra indentation. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-07xfs: fix xfs_iomap_eof_prealloc_initial_size typeMark Tinguely
Fix the return type of xfs_iomap_eof_prealloc_initial_size() to xfs_fsblock_t to reflect the fact that the return value may be an unsigned 64 bits if XFS_BIG_BLKNOS is defined. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-07xfs: increase prealloc size to double that of the previous extentBrian Foster
The updated speculative preallocation algorithm for handling sparse files can becomes less effective in situations with a high number of concurrent, sequential writers. The number of writers and amount of available RAM affect the writeback bandwidth slicing algorithm, which in turn affects the block allocation pattern of XFS. For example, running 32 sequential writers on a system with 32GB RAM, preallocs become fixed at a value of around 128MB (instead of steadily increasing to the 8GB maximum as sequential writes proceed). Update the speculative prealloc heuristic to base the size of the next prealloc on double the size of the preceding extent. This preserves the original aggressive speculative preallocation behavior and continues to accomodate sparse files at a slight cost of increasing the size of preallocated data regions following holes of sparse files. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-03-07xfs: fix potential infinite loop in xfs_iomap_prealloc_size()Brian Foster
If freesp == 0, we could end up in an infinite loop while squashing the preallocation. Break the loop when we've killed the prealloc entirely. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-02-14xfs: limit speculative prealloc size on sparse filesDave Chinner
Speculative preallocation based on the current file size works well for contiguous files, but is sub-optimal for sparse files where the EOF preallocation can fill holes and result in large amounts of zeros being written when it is not necessary. The algorithm is modified to prevent EOF speculative preallocation from triggering larger allocations on IO patterns of truncate--to-zero-seek-write-seek-write-.... which results in non-sparse files for large files. This, unfortunately, is the way cp now behaves when copying sparse files and so needs to be fixed. What this code does is that it looks at the existing extent adjacent to the current EOF and if it determines that it is a hole we disable speculative preallocation altogether. To avoid the next write from doing a large prealloc, it takes the size of subsequent preallocations from the current size of the existing EOF extent. IOWs, if you leave a hole in the file, it resets preallocation behaviour to the same as if it was a zero size file. Example new behaviour: $ xfs_io -f -c "pwrite 0 31m" \ -c "pwrite 33m 1m" \ -c "pwrite 128m 1m" \ -c "fiemap -v" /mnt/scratch/blah wrote 32505856/32505856 bytes at offset 0 31 MiB, 7936 ops; 0.0000 sec (1.608 GiB/sec and 421432.7439 ops/sec) wrote 1048576/1048576 bytes at offset 34603008 1 MiB, 256 ops; 0.0000 sec (1.462 GiB/sec and 383233.5329 ops/sec) wrote 1048576/1048576 bytes at offset 134217728 1 MiB, 256 ops; 0.0000 sec (1.719 GiB/sec and 450704.2254 ops/sec) /mnt/scratch/blah: EXT: FILE-OFFSET BLOCK-RANGE TOTAL FLAGS 0: [0..65535]: 96..65631 65536 0x0 1: [65536..67583]: hole 2048 2: [67584..69631]: 67680..69727 2048 0x0 3: [69632..262143]: hole 192512 4: [262144..264191]: 262240..264287 2048 0x1 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-01-24xfs: limit speculative prealloc near ENOSPC thresholdsDave Chinner
There is a window on small filesytsems where specualtive preallocation can be larger than that ENOSPC throttling thresholds, resulting in specualtive preallocation trying to reserve more space than there is space available. This causes immediate ENOSPC to be triggered, prealloc to be turned off and flushing to occur. One the next write (i.e. next 4k page), we do exactly the same thing, and so effective drive into synchronous 4k writes by triggering ENOSPC flushing on every page while in the window between the prealloc size and the ENOSPC prealloc throttle threshold. Fix this by checking to see if the prealloc size would consume all free space, and throttle it appropriately to avoid premature ENOSPC... Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-08xfs: add EOFBLOCKS inode tagging/untaggingBrian Foster
Add the XFS_ICI_EOFBLOCKS_TAG inode tag to identify inodes with speculatively preallocated blocks beyond EOF. An inode is tagged when speculative preallocation occurs and untagged either via truncate down or when post-EOF blocks are freed via release or reclaim. The tag management is intentionally not aggressive to prefer simplicity over the complexity of handling all the corner cases under which post-EOF blocks could be freed (i.e., forward truncation, fallocate, write error conditions, etc.). This means that a tagged inode may or may not have post-EOF blocks after a period of time. The tag is eventually cleared when the inode is released or reclaimed. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-18xfs: introduce XFS_BMAPI_STACK_SWITCHDave Chinner
Certain allocation paths through xfs_bmapi_write() are in situations where we have limited stack available. These are almost always in the buffered IO writeback path when convertion delayed allocation extents to real extents. The current stack switch occurs for userdata allocations, which means we also do stack switches for preallocation, direct IO and unwritten extent conversion, even those these call chains have never been implicated in a stack overrun. Hence, let's target just the single stack overun offended for stack switches. To do that, introduce a XFS_BMAPI_STACK_SWITCH flag that the caller can pass xfs_bmapi_write() to indicate it should switch stacks if it needs to do allocation. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-10-17xfs: xfs_sync_data is redundant.Dave Chinner
We don't do any data writeback from XFS any more - the VFS is completely responsible for that, including for freeze. We can replace the remaining caller with a VFS level function that achieves the same thing, but without conflicting with current writeback work. This means we can remove the flush_work and xfs_flush_inodes() - the VFS functionality completely replaces the internal flush queue for doing this writeback work in a separate context to avoid stack overruns. This does have one complication - it cannot be called with page locks held. Hence move the flushing of delalloc space when ENOSPC occurs back up into xfs_file_aio_buffered_write when we don't hold any locks that will stall writeback. Unfortunately, writeback_inodes_sb_if_idle() is not sufficient to trigger delalloc conversion fast enough to prevent spurious ENOSPC whent here are hundreds of writers, thousands of small files and GBs of free RAM. Hence we need to use sync_sb_inodes() to block callers while we wait for writeback like the previous xfs_flush_inodes implementation did. That means we have to hold the s_umount lock here, but because this call can nest inside i_mutex (the parent directory in the create case, held by the VFS), we have to use down_read_trylock() to avoid potential deadlocks. In practice, this trylock will succeed on almost every attempt as unmount/remount type operations are exceedingly rare. Note: we always need to pass a count of zero to generic_file_buffered_write() as the previously written byte count. We only do this by accident before this patch by the virtue of ret always being zero when there are no errors. Make this explicit rather than needing to specifically zero ret in the ENOSPC retry case. Signed-off-by: Dave Chinner <dchinner@redhat.com> Tested-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-07-31xfs: Convert to new freezing codeJan Kara
Generic code now blocks all writers from standard write paths. So we add blocking of all writers coming from ioctl (we get a protection of ioctl against racing remount read-only as a bonus) and convert xfs_file_aio_write() to a non-racy freeze protection. We also keep freeze protection on transaction start to block internal filesystem writes such as removal of preallocated blocks. CC: Ben Myers <bpm@sgi.com> CC: Alex Elder <elder@kernel.org> CC: xfs@oss.sgi.com Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-06-14xfs: make largest supported offset less shoutyDave Chinner
XFS_MAXIOFFSET() is just a simple macro that resolves to mp->m_maxioffset. It doesn't need to exist, and it just makes the code unnecessarily loud and shouty. Make it quiet and easy to read. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-06-14xfs: m_maxioffset is redundantDave Chinner
The m_maxioffset field in the struct xfs_mount contains the same value as the superblock s_maxbytes field. There is no need to carry two copies of this limit around, so use the VFS superblock version. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-21xfs: fix delalloc quota accounting on failureDave Chinner
xfstest 270 was causing quota reservations way beyond what was sane (ten to hundreds of TB) for a 4GB filesystem. There's a sign problem in the error handling path of xfs_bmapi_reserve_delalloc() because xfs_trans_unreserve_quota_nblks() simple negates the value passed - which doesn't work for an unsigned variable. This causes reservations of close to 2^32 block instead of removing a reservation of a handful of blocks. Fix the same problem in the other xfs_trans_unreserve_quota_nblks() callers where unsigned integer variables are used, too. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Eric Sandeen <sandeen@redhat.com> 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: move xfs_get_extsz_hint() and kill xfs_rw.hDave Chinner
The only thing left in xfs_rw.h is a function prototype for an inode function. Move that to xfs_inode.h, and kill xfs_rw.h. Also move the function implementing the prototype from xfs_rw.c to xfs_inode.c so we only have one function left in xfs_rw.c Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Christoph Hellwig <hch@lst.de> 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: limit specualtive delalloc to maxioffsetDave Chinner
Speculative delayed allocation beyond EOF near the maximum supported file offset can result in creating delalloc extents beyond mp->m_maxioffset (8EB). These can never be trimmed during xfs_free_eof_blocks() because they are beyond mp->m_maxioffset, and that results in assert failures in xfs_fs_destroy_inode() due to delalloc blocks still being present. xfstests 071 exposes this problem. Limit speculative delalloc to mp->m_maxioffset to avoid this problem. Signed-off-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: use shared ilock mode for direct IO writes by defaultDave Chinner
For the direct IO write path, we only really need the ilock to be taken in exclusive mode during IO submission if we need to do extent allocation instead of all the time. Change the block mapping code to take the ilock in shared mode for the initial block mapping, and only retake it exclusively when we actually have to perform extent allocations. We were already dropping the ilock for the transaction allocation, so this doesn't introduce new race windows. Based on an earlier patch from Dave Chinner. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-03-05xfs: log file size updates as part of unwritten extent conversionChristoph Hellwig
If we convert and unwritten extent past the current i_size log the size update as part of the extent manipulation transactions instead of doing an unlogged metadata update later. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-01-17xfs: remove the i_size field in struct xfs_inodeChristoph Hellwig
There is no fundamental need to keep an in-memory inode size copy in the XFS inode. We already have the on-disk value in the dinode, and the separate in-memory copy that we need for regular files only in the XFS inode. Remove the xfs_inode i_size field and change the XFS_ISIZE macro to use the VFS inode i_size field for regular files. Switch code that was directly accessing the i_size field in the xfs_inode to XFS_ISIZE, or in cases where we are limited to regular files direct access of the VFS inode i_size field. This also allows dropping some fairly complicated code in the write path which dealt with keeping the xfs_inode i_size uptodate with the VFS i_size that is getting updated inside ->write_end. Note that we do not bother resetting the VFS i_size when truncating a file that gets freed to zero as there is no point in doing so because the VFS inode is no longer in use at this point. Just relax the assert in xfs_ifree to only check the on-disk size instead. Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>