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path: root/fs/xfs/xfs_buf.h
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2013-01-16xfs: use b_maps[] for discontiguous buffersMark Tinguely1-3/+3
Commits starting at 77c1a08 introduced a multiple segment support to xfs_buf. xfs_trans_buf_item_match() could not find a multi-segment buffer in the transaction because it was looking at the single segment block number rather than the multi-segment b_maps[0].bm.bn. This results on a recursive buffer lock that can never be satisfied. This patch: 1) Changed the remaining b_map accesses to be b_maps[0] accesses. 2) Renames the single segment b_map structure to __b_map to avoid future confusion. Signed-off-by: Mark Tinguely <tinguely@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: convert buffer verifiers to an ops structure.Dave Chinner1-10/+14
To separate the verifiers from iodone functions and associate read and write verifiers at the same time, introduce a buffer verifier operations structure to the xfs_buf. This avoids the need for assigning the write verifier, clearing the iodone function and re-running ioend processing in the read verifier, and gets rid of the nasty "b_pre_io" name for the write verifier function pointer. If we ever need to, it will also be easier to add further content specific callbacks to a buffer with an ops structure in place. We also avoid needing to export verifier functions, instead we can simply export the ops structures for those that are needed outside the function they are defined in. This patch also fixes a directory block readahead verifier issue it exposed. This patch also adds ops callbacks to the inode/alloc btree blocks initialised by growfs. These will need more work before they will work with CRCs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: add buffer pre-write callbackDave Chinner1-0/+3
Add a callback to the buffer write path to enable verification of the buffer and CRC calculation prior to issuing the write to the underlying storage. If the callback function detects some kind of failure or error condition, it must mark the buffer with an error so that the caller can take appropriate action. In the case of xfs_buf_ioapply(), a corrupt metadta buffer willt rigger a shutdown of the filesystem, because something is clearly wrong and we can't allow corrupt metadata to be written to disk. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-11-15xfs: make buffer read verication an IO completion functionDave Chinner1-8/+12
Add a verifier function callback capability to the buffer read interfaces. This will be used by the callers to supply a function that verifies the contents of the buffer when it is read from disk. This patch does not provide callback functions, but simply modifies the interfaces to allow them to be called. The reason for adding this to the read interfaces is that it is very difficult to tell fom the outside is a buffer was just read from disk or whether we just pulled it out of cache. Supplying a callbck allows the buffer cache to use it's internal knowledge of the buffer to execute it only when the buffer is read from disk. It is intended that the verifier functions will mark the buffer with an EFSCORRUPTED error when verification fails. This allows the reading context to distinguish a verification error from an IO error, and potentially take further actions on the buffer (e.g. attempt repair) based on the error reported. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Phil White <pwhite@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-08-29xfs: fix race while discarding buffers [V4]Carlos Maiolino1-17/+24
While xfs_buftarg_shrink() is freeing buffers from the dispose list (filled with buffers from lru list), there is a possibility to have xfs_buf_stale() racing with it, and removing buffers from dispose list before xfs_buftarg_shrink() does it. This happens because xfs_buftarg_shrink() handle the dispose list without locking and the test condition in xfs_buf_stale() checks for the buffer being in *any* list: if (!list_empty(&bp->b_lru)) If the buffer happens to be on dispose list, this causes the buffer counter of lru list (btp->bt_lru_nr) to be decremented twice (once in xfs_buftarg_shrink() and another in xfs_buf_stale()) causing a wrong account usage of the lru list. This may cause xfs_buftarg_shrink() to return a wrong value to the memory shrinker shrink_slab(), and such account error may also cause an underflowed value to be returned; since the counter is lower than the current number of items in the lru list, a decrement may happen when the counter is 0, causing an underflow on the counter. The fix uses a new flag field (and a new buffer flag) to serialize buffer handling during the shrink process. The new flag field has been designed to use btp->bt_lru_lock/unlock instead of xfs_buf_lock/unlock mechanism. dchinner, sandeen, aquini and aris also deserve credits for this. Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-13xfs: do not call xfs_bdstrat_cb in xfs_buf_iodone_callbacksChristoph Hellwig1-1/+0
xfs_bdstrat_cb only adds a check for a shutdown filesystem over xfs_buf_iorequest, but xfs_buf_iodone_callbacks just checked for a shut down filesystem a little earlier. In addition the shutdown handling in xfs_bdstrat_cb is not very suitable for this caller. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-01xfs: add discontiguous buffer map interfaceDave Chinner1-6/+40
With the internal interfaces supporting discontiguous buffer maps, add external lookup, read and get interfaces so they can start to be used. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-01xfs: convert internal buffer functions to pass mapsDave Chinner1-8/+35
While the external interface currently uses separate blockno/length variables, we need to move internal interfaces to passing and parsing vector maps. This will then allow us to add external interfaces to support discontiguous buffer maps as the internal code will already support them. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-07-01xfs: separate buffer indexing from block mapDave Chinner1-4/+23
To support discontiguous buffers in the buffer cache, we need to separate the cache index variables from the I/O map. While this is currently a 1:1 mapping, discontiguous buffer support will break this relationship. However, for caching purposes, we can still treat them the same as a contiguous buffer - the block number of the first block and the length of the buffer - as that is still a unique representation. Also, the only way we will ever access the discontiguous regions of buffers is via bulding the complete buffer in the first place, so using the initial block number and entire buffer length is a sane way to index the buffers. Add a block mapping vector construct to the xfs_buf and use it in the places where we are doing IO instead of the current b_bn/b_length variables. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2012-05-14xfs: make XBF_MAPPED the default behaviourDave Chinner1-2/+2
Rather than specifying XBF_MAPPED for almost all buffers, introduce XBF_UNMAPPED for the couple of users that use unmapped buffers. 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: kill XBF_DONTBLOCKDave Chinner1-2/+0
Just about all callers of xfs_buf_read() and xfs_buf_get() use XBF_DONTBLOCK. This is used to make memory allocation use GFP_NOFS rather than GFP_KERNEL to avoid recursion through memory reclaim back into the filesystem. All the blocking get calls in growfs occur inside a transaction, even though they are no part of the transaction, so all allocation will be GFP_NOFS due to the task flag PF_TRANS being set. The blocking read calls occur during log recovery, so they will probably be unaffected by converting to GFP_NOFS allocations. Hence make XBF_DONTBLOCK behaviour always occur for buffers and kill the flag. 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: kill XBF_LOCKDave Chinner1-3/+1
Buffers are always returned locked from the lookup routines. Hence we don't need to tell the lookup routines to return locked buffers, on to try and lock them. Remove XBF_LOCK from all the callers and from internal buffer cache usage. 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: kill xfs_buf_btocDave Chinner1-5/+0
xfs_buf_btoc and friends are simple macros that do basic block to page index conversion and vice versa. These aren't widely used, and we use open coded masking and shifting everywhere else. Hence remove the macros and open code the work they do. Also, use of PAGE_CACHE_{SIZE|SHIFT|MASK} for these macros is now incorrect - we are using pages directly and not the page cache, so use PAGE_{SIZE|MASK|SHIFT} instead. 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: use blocks for storing the desired IO sizeDave Chinner1-3/+1
Now that we pass block counts everywhere, and index buffers by block number and length in units of blocks, convert the desired IO size into block counts rather than bytes. Convert the code to use block counts, and those that need byte counts get converted at the time of use. Rename the b_desired_count variable to something closer to it's purpose - b_io_length - as it is only used to specify the length of an IO for a subset of the buffer. The only time this is used is for log IO - both writing iclogs and during log recovery. In all other cases, the b_io_length matches b_length, and hence a lot of code confuses the two. e.g. the buf item code uses the io count exclusively when it should be using the buffer length. Fix these apprpriately as they are found. Also, remove the XFS_BUF_{SET_}COUNT() macros that are just wrappers around the desired IO length. They only serve to make the code shouty loud, don't actually add any real value, and are often used incorrectly. 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: use blocks for counting length of buffersDave Chinner1-3/+1
Now that we pass block counts everywhere, and index buffers by block number, track the length of the buffer in units of blocks rather than bytes. Convert the code to use block counts, and those that need byte counts get converted at the time of use. Also, remove the XFS_BUF_{SET_}SIZE() macros that are just wrappers around the buffer length. They only serve to make the code shouty loud and don't actually add any real value. 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: kill b_file_offsetDave Chinner1-4/+1
Seeing as we pass block numbers around everywhere in the buffer cache now, it makes no sense to index everything by byte offset. Replace all the byte offset indexing with block number based indexing, and replace all uses of the byte offset with direct conversion from the block index. 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: clean up buffer get/read call APIDave Chinner1-17/+21
The xfs_buf_get/read API is not consistent in the units it uses, and does not use appropriate or consistent units/types for the variables. Convert the API to use disk addresses and block counts for all buffer get and read calls. Use consistent naming for all the functions and their declarations, and convert the internal functions to use disk addresses and block counts to avoid need to convert them from one type to another and back again. Fix all the callers to use disk addresses and block counts. In many cases, this removes an additional conversion from the function call as the callers already have a block count. 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: check for buffer errors before waitingDave Chinner1-1/+1
If we call xfs_buf_iowait() on a buffer that failed dispatch due to an IO error, it will wait forever for an Io that does not exist. This is hndled in xfs_buf_read, but there is other code that calls xfs_buf_iowait directly that doesn't. Rather than make the call sites have to handle checking for dispatch errors and then checking for completion errors, make xfs_buf_iowait() check for dispatch errors on the buffer before waiting. This means we handle both dispatch and completion errors with one set of error handling at the caller sites. 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: on-stack delayed write buffer listsChristoph Hellwig1-22/+6
Queue delwri buffers on a local on-stack list instead of a per-buftarg one, and write back the buffers per-process instead of by waking up xfsbufd. This is now easily doable given that we have very few places left that write delwri buffers: - log recovery: Only done at mount time, and already forcing out the buffers synchronously using xfs_flush_buftarg - quotacheck: Same story. - dquot reclaim: Writes out dirty dquots on the LRU under memory pressure. We might want to look into doing more of this via xfsaild, but it's already more optimal than the synchronous inode reclaim that writes each buffer synchronously. - xfsaild: This is the main beneficiary of the change. By keeping a local list of buffers to write we reduce latency of writing out buffers, and more importably we can remove all the delwri list promotions which were hitting the buffer cache hard under sustained metadata loads. The implementation is very straight forward - xfs_buf_delwri_queue now gets a new list_head pointer that it adds the delwri buffers to, and all callers need to eventually submit the list using xfs_buf_delwi_submit or xfs_buf_delwi_submit_nowait. Buffers that already are on a delwri list are skipped in xfs_buf_delwri_queue, assuming they already are on another delwri list. The biggest change to pass down the buffer list was done to the AIL pushing. Now that we operate on buffers the trylock, push and pushbuf log item methods are merged into a single push routine, which tries to lock the item, and if possible add the buffer that needs writeback to the buffer list. This leads to much simpler code than the previous split but requires the individual IOP_PUSH instances to unlock and reacquire the AIL around calls to blocking routines. Given that xfsailds now also handle writing out buffers, the conditions for log forcing and the sleep times needed some small changes. The most important one is that we consider an AIL busy as long we still have buffers to push, and the other one is that we do increment the pushed LSN for buffers that are under flushing at this moment, but still count them towards the stuck items for restart purposes. Without this we could hammer on stuck items without ever forcing the log and not make progress under heavy random delete workloads on fast flash storage devices. [ Dave Chinner: - rebase on previous patches. - improved comments for XBF_DELWRI_Q handling - fix XBF_ASYNC handling in queue submission (test 106 failure) - rename delwri submit function buffer list parameters for clarity - xfs_efd_item_push() should return XFS_ITEM_PINNED ] 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>
2012-03-28Remove all #inclusions of asm/system.hDavid Howells1-1/+0
Remove all #inclusions of asm/system.h preparatory to splitting and killing it. Performed with the following command: perl -p -i -e 's!^#\s*include\s*<asm/system[.]h>.*\n!!' `grep -Irl '^#\s*include\s*<asm/system[.]h>' *` Signed-off-by: David Howells <dhowells@redhat.com>
2011-12-16xfs: remove unused XBT_FORCE_SLEEP bitEric Sandeen1-2/+1
XBT_FORCE_SLEEP is no longer ever tested; it is only set and cleared. Remove it. Signed-off-by: Eric Sandeen <sandeen@sandeen.net> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2011-10-11xfs: remove XFS_bflushChristoph Hellwig1-2/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove xfs_buf_target_nameChristoph Hellwig1-9/+0
The calling convention that returns a pointer to a static buffer is fairly nasty, so just opencode it in the only caller that is left. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: clean up xfs_ioerror_alertChristoph Hellwig1-0/+1
Instead of passing the block number and mount structure explicitly get them off the bp and fix make the argument order more natural. Also move it to xfs_buf.c and stop printing the device name given that we already get the fs name as part of xfs_alert, and we know what device is operates on because of the caller that gets printed, finally rename it to xfs_buf_ioerror_alert and pass __func__ as argument where it makes sense. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: clean up buffer allocationChristoph Hellwig1-1/+2
Change _xfs_buf_initialize to allocate the buffer directly and rename it to xfs_buf_alloc now that is the only buffer allocation routine. Also remove the xfs_buf_deallocate wrapper around the kmem_zone_free calls for buffers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove XFS_BUF_STALE and XFS_BUF_SUPER_STALEChristoph Hellwig1-6/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove XFS_BUF_SET_VTYPE and XFS_BUF_SET_VTYPE_REFChristoph Hellwig1-6/+1
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove XFS_BUF_FINISH_IOWAITChristoph Hellwig1-2/+0
Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: remove xfs_get_buftarg_listChristoph Hellwig1-4/+0
The code is unused and under a config option that doesn't exist, remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: fix buffer flushing during unmountChristoph Hellwig1-1/+0
The code to flush buffers in the umount code is a bit iffy: we first flush all delwri buffers out, but then might be able to queue up a new one when logging the sb counts. On a normal shutdown that one would get flushed out when doing the synchronous superblock write in xfs_unmountfs_writesb, but we skip that one if the filesystem has been shut down. Fix this by moving the delwri list flushing until just before unmounting the log, and while we're at it also remove the superflous delwri list and buffer lru flusing for the rt and log device that can never have cached or delwri buffers. Signed-off-by: Christoph Hellwig <hch@lst.de> Reported-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Tested-by: Amit Sahrawat <amit.sahrawat83@gmail.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: use the "delwri" terminology consistentlyChristoph Hellwig1-2/+2
And also remove the strange local lock and delwri list pointers in a few functions. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: let xfs_bwrite callers handle the xfs_buf_relseChristoph Hellwig1-1/+1
Remove the xfs_buf_relse from xfs_bwrite and let the caller handle it to mirror the delwri and read paths. Also remove the mount pointer passed to xfs_bwrite, which is superflous now that we have a mount pointer in the buftarg. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-10-11xfs: call xfs_buf_delwri_queue directlyChristoph Hellwig1-5/+3
Unify the ways we add buffers to the delwri queue by always calling xfs_buf_delwri_queue directly. The xfs_bdwrite functions is removed and opencoded in its callers, and the two places setting XBF_DELWRI while a buffer is locked and expecting xfs_buf_unlock to pick it up are converted to call xfs_buf_delwri_queue directly, too. Also replace the XFS_BUF_UNDELAYWRITE macro with direct calls to xfs_buf_delwri_dequeue to make the explicit queuing/dequeuing more obvious. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Alex Elder <aelder@sgi.com>
2011-08-12xfs: remove subdirectoriesChristoph Hellwig1-0/+326
Use the move from Linux 2.6 to Linux 3.x as an excuse to kill the annoying subdirectories in the XFS source code. Besides the large amount of file rename the only changes are to the Makefile, a few files including headers with the subdirectory prefix, and the binary sysctl compat code that includes a header under fs/xfs/ from kernel/. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Alex Elder <aelder@sgi.com>