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path: root/fs/btrfs/volumes.c
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2010-08-07block: unify flags for struct bio and struct requestChristoph Hellwig
Remove the current bio flags and reuse the request flags for the bio, too. This allows to more easily trace the type of I/O from the filesystem down to the block driver. There were two flags in the bio that were missing in the requests: BIO_RW_UNPLUG and BIO_RW_AHEAD. Also I've renamed two request flags that had a superflous RW in them. Note that the flags are in bio.h despite having the REQ_ name - as blkdev.h includes bio.h that is the only way to go for now. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-25Btrfs: Integrate metadata reservation with start_transactionYan, Zheng
Besides simplify the code, this change makes sure all metadata reservation for normal metadata operations are released after committing transaction. Changes since V1: Add code that check if unlink and rmdir will free space. Add ENOSPC handling for clone ioctl. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-04-12Merge branch 'master' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: make sure the chunk allocator doesn't create zero length chunks Btrfs: fix data enospc check overflow
2010-04-06Btrfs: make sure the chunk allocator doesn't create zero length chunksChris Mason
A recent commit allowed for smaller chunks to be created, but didn't make sure they were always bigger than a stripe. After some divides, this led to zero length stripes. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-04-05Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: add check for changed leaves in setup_leaf_for_split Btrfs: create snapshot references in same commit as snapshot Btrfs: fix small race with delalloc flushing waitqueue's Btrfs: use add_to_page_cache_lru, use __page_cache_alloc Btrfs: fix chunk allocate size calculation Btrfs: kill max_extent mount option Btrfs: fail to mount if we have problems reading the block groups Btrfs: check btrfs_get_extent return for IS_ERR() Btrfs: handle kmalloc() failure in inode lookup ioctl Btrfs: dereferencing freed memory Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk() Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree() Btrfs: Remove unnecessary finish_wait() in wait_current_trans() Btrfs: add NULL check for do_walk_down() Btrfs: remove duplicate include in ioctl.c Fix trivial conflict in fs/btrfs/compression.c due to slab.h include cleanups.
2010-03-30Btrfs: fix chunk allocate size calculationJosef Bacik
If the amount of free space left in a device is less than what we think should be the minimum size, just ignore the minimum size and use the amount we have. I ran into this running tests on a 600mb volume, the chunk allocator wouldn't let me allocate the last 52mb of the disk for data because we want to have at least 64mb chunks for data. This patch fixes that problem. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30Btrfs: Simplify num_stripes's calculation logical for __btrfs_alloc_chunk()Zhao Lei
We can use this simple method to make source more readable. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30Btrfs: Add error handle for btrfs_search_slot() in btrfs_read_chunk_tree()Zhao Lei
We need to check return value of btrfs_search_slot() in btrfs_read_chunk_tree() and do corresponding error handing. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-30include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo
implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-15Btrfs: don't look at bio flags after submit_bioChris Mason
After callling submit_bio, the bio can be freed at any time. The btrfs submission thread helper was checking the bio flags too late, which might not give the correct answer. When CONFIG_DEBUG_PAGE_ALLOC is turned on, it can lead to oopsen. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15btrfs: using btrfs_stack_device_id() get devidXiao Guangrong
We can use btrfs_stack_device_id() to get dev_item->devid Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15btrfs: Update existing btrfs_device for renaming deviceTARUISI Hiroaki
When we scan devices in a multi-device filesystem, we memorize the original name. If the device gets a new name, later scans don't update the in-kernel structures related to it, and we're not able to mount the filesystem. This patch updates device name during scaning. Signed-off-by: TARUISI Hiroaki <taruishi.hiroak@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: run the backing dev more often in the submit_bio helperChris Mason
The submit_bio helper thread can decide to loop back around to service more bios. This commit forces it to unplug first, which helps reduce the latency seen by submitters. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-28Btrfs: check total number of devices when removing missingJosef Bacik
If you have a disk failure in RAID1 and then add a new disk to the array, and then try to remove the missing volume, it will fail. The reason is the sanity check only looks at the total number of rw devices, which is just 2 because we have 2 good disks and 1 bad one. Instead check the total number of devices in the array to make sure we can actually remove the device. Tested this with a failed disk setup and with this test we can now run btrfs-vol -r missing /mount/point and it works fine. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-28Btrfs: check return value of open_bdev_exclusive properlyJosef Bacik
Hit this problem while testing RAID1 failure stuff. open_bdev_exclusive returns ERR_PTR(), not NULL. So change the return value properly. This is important if you accidently specify a device that doesn't exist when trying to add a new device to an array, you will panic the box dereferencing bdev. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-28Btrfs: do not mark the chunk as readonly if in degraded modeJosef Bacik
If a RAID setup has chunks that span multiple disks, and one of those disks has failed, btrfs_chunk_readonly will return 1 since one of the disks in that chunk's stripes is dead and therefore not writeable. So instead if we are in degraded mode, return 0 so we can go ahead and allocate stuff. Without this patch all of the block groups in a RAID1 setup will end up read-only, which will mean we can't add new disks to the array since we won't be able to make allocations. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-01-17Btrfs, fix memory leaks in error pathsJiri Slaby
Stanse found 2 memory leaks in relocate_block_group and __btrfs_map_block. cluster and multi are not freed/assigned on all paths. Fix that. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: make metadata chunks smallerJosef Bacik
This patch makes us a bit less zealous about making sure we have enough free metadata space by pearing down the size of new metadata chunks to 256mb instead of 1gb. Also, we used to try an allocate metadata chunks when allocating data, but that sort of thing is done elsewhere now so we can just remove it. With my -ENOSPC test I used to have 3gb reserved for metadata out of 75gb, now I have 1.7gb. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-01Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus
2009-09-29Btrfs: introduce missing kfreeJulia Lawall
Error handling code following a kzalloc should free the allocated data. The semantic match that finds the problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r exists@ local idexpression x; statement S; expression E; identifier f,f1,l; position p1,p2; expression *ptr != NULL; @@ x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...); ... if (x == NULL) S <... when != x when != if (...) { <+...x...+> } ( x->f1 = E | (x->f1 == NULL || ...) | f(...,x->f1,...) ) ...> ( return \(0\|<+...x...+>\|ptr\); | return@p2 ...; ) @script:python@ p1 << r.p1; p2 << r.p2; @@ print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-24Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus Conflicts: fs/btrfs/super.c
2009-09-21Btrfs: make balance code choose more wisely when relocatingJosef Bacik
Currently, we can panic the box if the first block group we go to move is of a type where there is no space left to move those extents. For example, if we fill the disk up with data, and then we try to balance and we have no room to move the data nor room to allocate new chunks, we will panic. Change this by checking to see if we have room to move this chunk around, and if not, return -ENOSPC and move on to the next chunk. This will make sure we remove block groups that are moveable, like if we have alot of empty metadata block groups, and then that way we make room to be able to balance our data chunks as well. Tested this with an fs that would panic on btrfs-vol -b normally, but no longer panics with this patch. V1->V2: -actually search for a free extent on the device to make sure we can allocate a chunk if need be. -fix btrfs_shrink_device to make sure we actually try to relocate all the chunks, and then if we can't return -ENOSPC so if we are doing a btrfs-vol -r we don't remove the device with data still on it. -check to make sure the block group we are going to relocate isn't the last one in that particular space -fix a bug in btrfs_shrink_device where we would change the device's size and not fix it if we fail to do our relocate Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: switch extent_map to a rw lockChris Mason
There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: tweak congestion backoffChris Mason
The btrfs io submission thread tries to back off congested devices in favor of rotating off to another disk. But, it tries to make sure it submits at least some IO before rotating on (the others may be congested too), and so it has a magic number of requests it tries to write before it hops. This makes the magic number smaller. Testing shows that we're spending too much time on congested devices and leaving the other devices idle. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11bio: first step in sanitizing the bio->bi_rw flag testingJens Axboe
Get rid of any functions that test for these bits and make callers use bio_rw_flagged() directly. Then it is at least directly apparent what variable and flag they check. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-07-24Btrfs: find smallest available device extent during chunk allocationChris Mason
Allocating new block group is easy when the disk has plenty of space. But things get difficult as the disk fills up, especially if the FS has been run through btrfs-vol -b. The balance operation is likely to make the total bytes available on the device greater than the largest extent we'll actually be able to allocate. But the device extent allocation code incorrectly assumes that a device with 5G free will be able to allocate a 5G extent. It isn't normally a problem because device extents don't get freed unless btrfs-vol -b is run. This fixes the device extent allocator to remember the largest free extent it can find, and then uses that value as a fallback. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: find_free_dev_extent doesn't handle holes at the start of the deviceYan Zheng
find_free_dev_extent does not properly handle the case where the device is not complete free, and there is a free extent at the beginning of the device. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: Remove broken sanity check from btrfs_rmap_block()David Woodhouse
It was never actually doing anything anyway (see the loop condition), and it would be difficult to make it work for RAID[56]. Even if it was actually working, it's checking for the wrong thing anyway. Instead of checking whether we list a block which _doesn't_ land at the relevant physical location, it should be checking that we _have_ listed all the logical blocks which refer to the required physical location on all devices. This function is only called from remove_sb_from_cache() to ensure that we reserve the logical blocks which would reside at the same physical location as the superblock copies. So listing more blocks than we need is actually OK. With RAID[56] we're going to throw away an entire stripe for each block we have to ignore, so we _are_ going to list blocks other than the ones which actually contain the superblock. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: properly update space information after shrinking device.Yan Zheng
Change 'goto done' to 'break' for the case of all device extents have been freed, so that the code updates space information will be execute. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: avoid races between super writeout and device list updatesChris Mason
On multi-device filesystems, btrfs writes supers to all of the devices before considering a sync complete. There wasn't any additional locking between super writeout and the device list management code because device management was done inside a transaction and super writeout only happened with no transation writers running. With the btrfs fsync log and other async transaction updates, this has been racey for some time. This adds a mutex to protect the device list. The existing volume mutex could not be reused due to transaction lock ordering requirements. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: autodetect SSD devicesChris Mason
During mount, btrfs will check the queue nonrot flag for all the devices found in the FS. If they are all non-rotating, SSD mode is enabled by default. If the FS was mounted with -o nossd, the non-rotating flag is ignored. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: avoid IO stalls behind congested devices in a multi-device FSChris Mason
The btrfs IO submission threads try to service a bunch of devices with a small number of threads. They do a congestion check to try and avoid waiting on requests for a busy device. The checks make sure we've sent a few requests down to a given device just so that we aren't bouncing between busy devices without actually sending down any IO. The counter used to decide if we can switch to the next device is somewhat overloaded. It is also being used to decide if we've done a good batch of requests between the WRITE_SYNC or regular priority lists. It may get reset to zero often, leaving us hammering on a busy device instead of moving on to another disk. This commit adds a new counter for the number of bios sent while servicing a device. It doesn't get reset or fiddled with. On multi-device filesystems, this fixes IO stalls in streaming write workloads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: don't allow WRITE_SYNC bios to starve out regular writesChris Mason
Btrfs uses dedicated threads to submit bios when checksumming is on, which allows us to make sure the threads dedicated to checksumming don't get stuck waiting for requests. For each btrfs device, there are two lists of bios. One list is for WRITE_SYNC bios and the other is for regular priority bios. The IO submission threads used to process all of the WRITE_SYNC bios first and then switch to the regular bios. This commit makes sure we don't completely starve the regular bios by rotating between the two lists. WRITE_SYNC bios are still favored 2:1 over the regular bios, and this tries to run in batches to avoid seeking. Benchmarking shows this eliminates stalls during streaming buffered writes on both multi-device and single device filesystems. If the regular bios starve, the system can end up with a large amount of ram pinned down in writeback pages. If we are a little more fair between the two classes, we're able to keep throughput up and make progress on the bulk of our dirty ram. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)Yan Zheng
This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-04Btrfs: set device->total_disk_bytes when adding new deviceYan Zheng
It was not being properly initialized, and so the size saved to disk was not correct. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: When shrinking, only update disk size on successChris Ball
Previously, we updated a device's size prior to attempting a shrink operation. This patch moves the device resizing logic to only happen if the shrink completes successfully. In the process, it introduces a new field to btrfs_device -- disk_total_bytes -- to track the on-disk size. Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20Btrfs: use WRITE_SYNC for synchronous writesChris Mason
Part of reducing fsync/O_SYNC/O_DIRECT latencies is using WRITE_SYNC for writes we plan on waiting on in the near future. This patch mirrors recent changes in other filesystems and the generic code to use WRITE_SYNC when WB_SYNC_ALL is passed and to use WRITE_SYNC for other latency critical writes. Btrfs uses async worker threads for checksumming before the write is done, and then again to actually submit the bios. The bio submission code just runs a per-device list of bios that need to be sent down the pipe. This list is split into low priority and high priority lists so the WRITE_SYNC IO happens first. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03Btrfs: unplug in the async bio submission threadsChris Mason
Btrfs pages being written get set to writeback, and then may go through a number of steps before they hit the block layer. This includes compression, checksumming and async bio submission. The end result is that someone who writes a page and then does wait_on_page_writeback is likely to unplug the queue before the bio they cared about got there. We could fix this by marking bios sync, or by doing more frequent unplugs, but this commit just changes the async bio submission code to unplug after it has processed all the bios for a device. The async bio submission does a fair job of collection bios, so this shouldn't be a huge problem for reducing merging at the elevator. For streaming O_DIRECT writes on a 5 drive array, it boosts performance from 386MB/s to 460MB/s. Thanks to Hisashi Hifumi for helping with this work. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03Btrfs: keep processing bios for a given bdev if our proc is batchingChris Mason
Btrfs uses async helper threads to submit write bios so the checksumming helper threads don't block on the disk. The submit bio threads may process bios for more than one block device, so when they find one device congested they try to move on to other devices instead of blocking in get_request_wait for one device. This does a pretty good job of keeping multiple devices busy, but the congested flag has a number of problems. A congested device may still give you a request, and other procs that aren't backing off the congested device may starve you out. This commit uses the io_context stored in current to decide if our process has been made a batching process by the block layer. If so, it keeps sending IO down for at least one batch. This helps make sure we do a good amount of work each time we visit a bdev, and avoids large IO stalls in multi-device workloads. It's also very ugly. A better solution is in the works with Jens Axboe. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10Btrfs: Clear space_info full when adding new devicesChris Mason
The full flag on the space info structs tells the allocator not to try and allocate more chunks because the devices in the FS are fully allocated. When more devices are added, we need to clear the full flag so the allocator knows it has more space available. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-10Btrfs: Fix locking around adding new space_infoChris Mason
Storage allocated to different raid levels in btrfs is tracked by a btrfs_space_info structure, and all of the current space_infos are collected into a list_head. Most filesystems have 3 or 4 of these structs total, and the list is only changed when new raid levels are added or at unmount time. This commit adds rcu locking on the list head, and properly frees things at unmount time. It also clears the space_info->full flag whenever new space is added to the FS. The locking for the space info list goes like this: reads: protected by rcu_read_lock() writes: protected by the chunk_mutex At unmount time we don't need special locking because all the readers are gone. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: make a lockdep class for the extent buffer locksChris Mason
Btrfs is currently using spin_lock_nested with a nested value based on the tree depth of the block. But, this doesn't quite work because the max tree depth is bigger than what spin_lock_nested can deal with, and because locks are sometimes taken before the level field is filled in. The solution here is to use lockdep_set_class_and_name instead, and to set the class before unlocking the pages when the block is read from the disk and just after init of a freshly allocated tree block. btrfs_clear_path_blocking is also changed to take the locks in the proper order, and it also makes sure all the locks currently held are properly set to blocking before it tries to retake the spinlocks. Otherwise, lockdep gets upset about bad lock orderin. The lockdep magic cam from Peter Zijlstra <peterz@infradead.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: fs/btrfs/volumes.c: remove useless kzallocJulia Lawall
The call to kzalloc is followed by a kmalloc whose result is stored in the same variable. The semantic match that finds the problem is as follows: (http://www.emn.fr/x-info/coccinelle/) // <smpl> @r exists@ local idexpression x; statement S; expression E; identifier f,l; position p1,p2; expression *ptr != NULL; @@ ( if ((x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...)) == NULL) S | x@p1 = \(kmalloc\|kzalloc\|kcalloc\)(...); ... if (x == NULL) S ) <... when != x when != if (...) { <+...x...+> } x->f = E ...> ( return \(0\|<+...x...+>\|ptr\); | return@p2 ...; ) @script:python@ p1 << r.p1; p2 << r.p2; @@ print "* file: %s kmalloc %s return %s" % (p1[0].file,p1[0].line,p2[0].line) // </smpl> Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Catch missed bios in the async bio submission threadChris Mason
The async bio submission thread was missing some bios that were added after it had decided there was no work left to do. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: simplify iteration codesQinghuang Feng
Merge list_for_each* and list_entry to list_for_each_entry* Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: Remove extra KERN_INFO in the middle of a lineRoland Dreier
The "devid <xxx> transid <xxx>" printk in btrfs_scan_one_device() actually follows another printk that doesn't end in a newline (since the intention is for the two printks to make one line of output), so the KERN_INFO just ends up messing up the output: device label exp <6>devid 1 transid 9 /dev/sda5 Fix this by changing the extra KERN_INFO to KERN_CONT. Signed-off-by: Roland Dreier <rolandd@cisco.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: removed unused #include <version.h>'sHuang Weiyi
Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-16Btrfs: Clear the device->running_pending flag before bailing on congestionChris Mason
Btrfs maintains a queue of async bio submissions so the checksumming threads don't have to wait on get_request_wait. In order to avoid extra wakeups, this code has a running_pending flag that is used to tell new submissions they don't need to wake the thread. When the threads notice congestion on a single device, they may decide to requeue the job and move on to other devices. This makes sure the running_pending flag is cleared before the job is requeued. It should help avoid IO stalls by making sure the task is woken up when new submissions come in. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-05Btrfs: Fix checkpatch.pl warningsChris Mason
There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-12Btrfs: shared seed deviceYan Zheng
This patch makes seed device possible to be shared by multiple mounted file systems. The sharing is achieved by cloning seed device's btrfs_fs_devices structure. Thanks you, Signed-off-by: Yan Zheng <zheng.yan@oracle.com>