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2010-11-29Merge 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: (24 commits) Btrfs: don't use migrate page without CONFIG_MIGRATION Btrfs: deal with DIO bios that span more than one ordered extent Btrfs: setup blank root and fs_info for mount time Btrfs: fix fiemap Btrfs - fix race between btrfs_get_sb() and umount Btrfs: update inode ctime when using links Btrfs: make sure new inode size is ok in fallocate Btrfs: fix typo in fallocate to make it honor actual size Btrfs: avoid NULL pointer deref in try_release_extent_buffer Btrfs: make btrfs_add_nondir take parent inode as an argument Btrfs: hold i_mutex when calling btrfs_log_dentry_safe Btrfs: use dget_parent where we can UPDATED Btrfs: fix more ESTALE problems with NFS Btrfs: handle NFS lookups properly btrfs: make 1-bit signed fileds unsigned btrfs: Show device attr correctly for symlinks btrfs: Set file size correctly in file clone btrfs: Check if dest_offset is block-size aligned before cloning file Btrfs: handle the space_cache option properly btrfs: Fix early enospc because 'unused' calculated with wrong sign. ...
2010-11-27Btrfs: fix fiemapJosef Bacik
There are two big problems currently with FIEMAP 1) We return extents for holes. This isn't supposed to happen, we just don't return extents for holes and then userspace interprets the lack of an extent as a hole. 2) We sometimes don't set FIEMAP_EXTENT_LAST properly. This is because we wait to see a EXTENT_FLAG_VACANCY flag on the em, but this won't happen if say we ask fiemap to map up to the last extent in a file, and there is nothing but holes up to the i_size. To fix this we need to lookup the last extent in this file and save the logical offset, so if we happen to try and map that extent we can be sure to set FIEMAP_EXTENT_LAST. With this patch we now pass xfstest 225, which we never have before. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21Btrfs: avoid NULL pointer deref in try_release_extent_bufferChris Mason
If we fail to find a pointer in the radix tree, don't try to deref the NULL one we do have. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-11-21btrfs: cleanup duplicate bio allocating functionsMiao Xie
extent_bio_alloc() and compressed_bio_alloc() are similar, cleanup similar source code. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-30Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (39 commits) Btrfs: deal with errors from updating the tree log Btrfs: allow subvol deletion by unprivileged user with -o user_subvol_rm_allowed Btrfs: make SNAP_DESTROY async Btrfs: add SNAP_CREATE_ASYNC ioctl Btrfs: add START_SYNC, WAIT_SYNC ioctls Btrfs: async transaction commit Btrfs: fix deadlock in btrfs_commit_transaction Btrfs: fix lockdep warning on clone ioctl Btrfs: fix clone ioctl where range is adjacent to extent Btrfs: fix delalloc checks in clone ioctl Btrfs: drop unused variable in block_alloc_rsv Btrfs: cleanup warnings from gcc 4.6 (nonbugs) Btrfs: Fix variables set but not read (bugs found by gcc 4.6) Btrfs: Use ERR_CAST helpers Btrfs: use memdup_user helpers Btrfs: fix raid code for removing missing drives Btrfs: Switch the extent buffer rbtree into a radix tree Btrfs: restructure try_release_extent_buffer() Btrfs: use the flusher threads for delalloc throttling Btrfs: tune the chunk allocation to 5% of the FS as metadata ... Fix up trivial conflicts in fs/btrfs/super.c and fs/fs-writeback.c, and remove use of INIT_RCU_HEAD in fs/btrfs/extent_io.c (that init macro was useless and removed in commit 5e8067adfdba: "rcu head remove init")
2010-10-29Btrfs: cleanup warnings from gcc 4.6 (nonbugs)Andi Kleen
These are all the cases where a variable is set, but not read which are not bugs as far as I can see, but simply leftovers. Still needs more review. Found by gcc 4.6's new warnings Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29Btrfs: Fix variables set but not read (bugs found by gcc 4.6)Andi Kleen
These are all the cases where a variable is set, but not read which are really bugs. - Couple of incorrect error handling fixed. - One incorrect use of a allocation policy - Some other things Still needs more review. Found by gcc 4.6's new warnings. [akpm@linux-foundation.org: fix build. Might have been bitrot] Signed-off-by: Andi Kleen <ak@linux.intel.com> Cc: Chris Mason <chris.mason@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29Btrfs: Switch the extent buffer rbtree into a radix treeMiao Xie
This patch reduces the CPU time spent in the extent buffer search by using the radix tree instead of the rbtree and using the rcu lock instead of the spin lock. I did a quick test by the benchmark tool[1] and found the patch improve the file creation/deletion performance problem that I have reported[2]. Before applying this patch: Create files: Total files: 50000 Total time: 0.971531 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.366761 Average time: 0.000027 After applying this patch: Create files: Total files: 50000 Total time: 0.927455 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.292280 Average time: 0.000026 [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3 [2] http://marc.info/?l=linux-btrfs&m=128212635122920&w=2 Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-10-29Btrfs: restructure try_release_extent_buffer()Miao Xie
restructure try_release_extent_buffer() and write a function to release the extent buffer. It will be used later. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-07-06writeback: remove writeback_inodes_wbcChristoph Hellwig
This was just an odd wrapper around writeback_inodes_wb. Removing this also allows to get rid of the bdi member of struct writeback_control which was rather out of place there. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-05-25Btrfs: rework O_DIRECT enospc handlingChris Mason
This changes O_DIRECT write code to mark extents as delalloc while it is processing them. Yan Zheng has reworked the enospc accounting based on tracking delalloc extents and this makes it much easier to track enospc in the O_DIRECT code. There are a few space cases with the O_DIRECT code though, it only sets the EXTENT_DELALLOC bits, instead of doing EXTENT_DELALLOC | EXTENT_DIRTY | EXTENT_UPTODATE, because we don't want to mess with clearing the dirty and uptodate bits when things go wrong. This is important because there are no pages in the page cache, so any extent state structs that we put in the tree won't get freed by releasepage. We have to clear them ourselves as the DIO ends. With this commit, we reserve space at in btrfs_file_aio_write, and then as each btrfs_direct_IO call progresses it sets EXTENT_DELALLOC on the range. btrfs_get_blocks_direct is responsible for clearing the delalloc at the same time it drops the extent lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: use async helpers for DIO write checksummingChris Mason
The async helper threads offload crc work onto all the CPUs, and make streaming writes much faster. This changes the O_DIRECT write code to use them. The only small complication was that we need to pass in the logical offset in the file for each bio, because we can't find it in the bio's pages. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: do aio_write instead of writeJosef Bacik
In order for AIO to work, we need to implement aio_write. This patch converts our btrfs_file_write to btrfs_aio_write. I've tested this with xfstests and nothing broke, and the AIO stuff magically started working. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-05-25Btrfs: Update metadata reservation for delayed allocationYan, Zheng
Introduce metadata reservation context for delayed allocation and update various related functions. This patch also introduces EXTENT_FIRST_DELALLOC control bit for set/clear_extent_bit. It tells set/clear_bit_hook whether they are processing the first extent_state with EXTENT_DELALLOC bit set. This change is important if set/clear_extent_bit involves multiple extent_state. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> 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.
2010-04-05Btrfs: use add_to_page_cache_lru, use __page_cache_allocNick Piggin
Pagecache pages should be allocated with __page_cache_alloc, so they obey pagecache memory policies. add_to_page_cache_lru is exported, so it should be used. Benefits over using a private pagevec: neater code, 128 bytes fewer stack used, percpu lru ordering is preserved, and finally don't need to flush pagevec before returning so batching may be shared with other LRU insertions. Signed-off-by: Nick Piggin <npiggin@suse.de>: 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: cache the extent state everywhere we possibly can V2Josef Bacik
This patch just goes through and fixes everybody that does lock_extent() blah unlock_extent() to use lock_extent_bits() blah unlock_extent_cached() and pass around a extent_state so we only have to do the searches once per function. This gives me about a 3 mb/s boots on my random write test. I have not converted some things, like the relocation and ioctl's, since they aren't heavily used and the relocation stuff is in the middle of being re-written. I also changed the clear_extent_bit() to only unset the cached state if we are clearing EXTENT_LOCKED and related stuff, so we can do things like this lock_extent_bits() clear delalloc bits unlock_extent_cached() without losing our cached state. I tested this thoroughly and turned on LEAK_DEBUG to make sure we weren't leaking extent states, everything worked out fine. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: cache extent state in find_delalloc_rangeJosef Bacik
This patch makes us cache the extent state we find in find_delalloc_range since we'll have to lock the extent later on in the function. This will keep us from re-searching for the rang when we try to lock the extent. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: finish read pages in the order they are submittedChris Mason
The endio is done at reverse order of bio vectors. That means for a sequential read, the page first submitted will finish last in a bio. Considering we will do checksum (making cache hot) for every page, this does introduce delay (and chance to squeeze cache used soon) for pages submitted at the begining. I don't observe obvious performance difference with below patch at my simple test, but seems more natural to finish read in the order they are submitted. Signed-off-by: Shaohua Li <shaohua.li@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-08Btrfs: use RB_ROOT to intialize rb_trees instead of setting rb_node to NULLEric Paris
btrfs inialize rb trees in quite a number of places by settin rb_node = NULL; The problem with this is that 17d9ddc72fb8bba0d4f678 in the linux-next tree adds a new field to that struct which needs to be NULL for the new rbtree library code to work properly. This patch uses RB_ROOT as the intializer so all of the relevant fields will be NULL'd. Without the patch I get a panic. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-02-04Btrfs: fix race between allocate and release extent buffer.Yan, Zheng
Increase extent buffer's reference count while holding the lock. Otherwise it can race with try_release_extent_buffer. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08Btrfs: release delalloc reservations on extent item insertionJosef Bacik
This patch fixes an issue with the delalloc metadata space reservation code. The problem is we used to free the reservation as soon as we allocated the delalloc region. The problem with this is if we are not inserting an inline extent, we don't actually insert the extent item until after the ordered extent is written out. This patch does 3 things, 1) It moves the reservation clearing stuff into the ordered code, so when we remove the ordered extent we remove the reservation. 2) It adds a EXTENT_DO_ACCOUNTING flag that gets passed when we clear delalloc bits in the cases where we want to clear the metadata reservation when we clear the delalloc extent, in the case that we do an inline extent or we invalidate the page. 3) It adds another waitqueue to the space info so that when we start a fs wide delalloc flush, anybody else who also hits that area will simply wait for the flush to finish and then try to make their allocation. This has been tested thoroughly to make sure we did not regress on performance. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08Btrfs: cleanup extent_clear_unlock_delalloc flagsChris Mason
extent_clear_unlock_delalloc has a growing set of ugly parameters that is very difficult to read and maintain. This switches to a flag field and well named flag defines. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-28Btrfs: proper -ENOSPC handlingJosef Bacik
At the start of a transaction we do a btrfs_reserve_metadata_space() and specify how many items we plan on modifying. Then once we've done our modifications and such, just call btrfs_unreserve_metadata_space() for the same number of items we reserved. For keeping track of metadata needed for data I've had to add an extent_io op for when we merge extents. This lets us track space properly when we are doing sequential writes, so we don't end up reserving way more metadata space than what we need. The only place where the metadata space accounting is not done is in the relocation code. This is because Yan is going to be reworking that code in the near future, so running btrfs-vol -b could still possibly result in a ENOSPC related panic. This patch also turns off the metadata_ratio stuff in order to allow users to more efficiently use their disk space. This patch makes it so we track how much metadata we need for an inode's delayed allocation extents by tracking how many extents are currently waiting for allocation. It introduces two new callbacks for the extent_io tree's, merge_extent_hook and split_extent_hook. These help us keep track of when we merge delalloc extents together and split them up. Reservations are handled prior to any actually dirty'ing occurs, and then we unreserve after we dirty. btrfs_unreserve_metadata_for_delalloc() will make the appropriate unreservations as needed based on the number of reservations we currently have and the number of extents we currently have. Doing the reservation outside of doing any of the actual dirty'ing lets us do things like filemap_flush() the inode to try and force delalloc to happen, or as a last resort actually start allocation on all delalloc inodes in the fs. This has survived dbench, fs_mark and an fsx torture test. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-23Btrfs: fix releasepage to avoid unlocking extents we haven't lockedChris Mason
During releasepage, we try to drop any extent_state structs for the bye offsets of the page we're releaseing. But the code was incorrectly telling clear_extent_bit to delete the state struct unconditionallly. Normally this would be fine because we have the page locked, but other parts of btrfs will lock down an entire extent, the most common place being IO completion. releasepage was deleting the extent state without first locking the extent, which may result in removing a state struct that another process had locked down. The fix here is to leave the NODATASUM and EXTENT_LOCKED bits alone in releasepage. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-23Btrfs: Fix test_range_bit for whole file extentsChris Mason
If test_range_bit finds an extent that goes all the way to (u64)-1, it can incorrectly wrap the u64 instead of treaing it like the end of the address space. This just adds a check for the highest possible offset so we don't wrap. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-23Btrfs: fix errors handling cached state in set/clear_extent_bitChris Mason
Both set and clear_extent_bit allow passing a cached state struct to reduce rbtree search times. clear_extent_bit was improperly bypassing some of the checks around making sure the extent state fields were correct for a given operation. The fix used here (from Yan Zheng) is to use the hit_next goto target instead of jumping all the way down to start clearing bits without making sure the cached state was exactly correct for the operation we were doing. This also fixes up the setting of the start variable for both ops in the case where we find an overlapping extent that begins before the range we want to change. In both cases we were incorrectly going backwards from the original requested change. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-18Btrfs: properly honor wbc->nr_to_write changesChris Mason
When btrfs fills a delayed allocation, it tries to increase the wbc nr_to_write to cover a big part of allocation. The theory is that we're doing contiguous IO and writing a few more blocks will save seeks overall at a very low cost. The problem is that extent_write_cache_pages could ignore the new higher nr_to_write if nr_to_write had already gone down to zero. We fix that by rechecking the nr_to_write for every page that is processed in the pagevec. This updates the math around bumping the nr_to_write value to make sure we don't leave a tiny amount of IO hanging around for the very end of a new extent. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: Use PagePrivate2 to track pages in the data=ordered code.Chris Mason
Btrfs writes go through delalloc to the data=ordered code. This makes sure that all of the data is on disk before the metadata that references it. The tracking means that we have to make sure each page in an extent is fully written before we add that extent into the on-disk btree. This was done in the past by setting the EXTENT_ORDERED bit for the range of an extent when it was added to the data=ordered code, and then clearing the EXTENT_ORDERED bit in the extent state tree as each page finished IO. One of the reasons we had to do this was because sometimes pages are magically dirtied without page_mkwrite being called. The EXTENT_ORDERED bit is checked at writepage time, and if it isn't there, our page become dirty without going through the proper path. These bit operations make for a number of rbtree searches for each page, and can cause considerable lock contention. This commit switches from the EXTENT_ORDERED bit to use PagePrivate2. As pages go into the ordered code, PagePrivate2 is set on each one. This is a cheap operation because we already have all the pages locked and ready to go. As IO finishes, the PagePrivate2 bit is cleared and the ordered accoutning is updated for each page. At writepage time, if the PagePrivate2 bit is missing, we go into the writepage fixup code to handle improperly dirtied pages. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: use a cached state for extent state operations during delallocChris Mason
This changes the btrfs code to find delalloc ranges in the extent state tree to use the new state caching code from set/test bit. It reduces one of the biggest causes of rbtree searches in the writeback path. test_range_bit is also modified to take the cached state as a starting point while searching. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: don't lock bits in the extent tree during writepageChris Mason
At writepage time, we have the page locked and we have the extent_map entry for this extent pinned in the extent_map tree. So, the page can't go away and its mapping can't change. There is no need for the extra extent_state lock bits during writepage. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: cache values for locking extentsChris Mason
Many of the btrfs extent state tree users follow the same pattern. They lock an extent range in the tree, do some operation and then unlock. This translates to at least 2 rbtree searches, and maybe more if they are doing operations on the extent state tree. A locked extent in the tree isn't going to be merged or changed, and so we can safely return the extent state structure as a cached handle. This changes set_extent_bit to give back a cached handle, and also changes both set_extent_bit and clear_extent_bit to use the cached handle if it is available. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: reduce CPU usage in the extent_state treeChris Mason
Btrfs is currently mirroring some of the page state bits into its extent state tree. The goal behind this was to use it in supporting blocksizes other than the page size. But, we don't currently support that, and we're using quite a lot of CPU on the rb tree and its spin lock. This commit starts a series of cleanups to reduce the amount of work done in the extent state tree as part of each IO. This commit: * Adds the ability to lock an extent in the state tree and also set other bits. The idea is to do locking and delalloc in one call * Removes the EXTENT_WRITEBACK and EXTENT_DIRTY bits. Btrfs is using a combination of the page bits and the ordered write code for this instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: Fix new state initialization orderChris Mason
As the extent state tree is manipulated, there are call backs that are used to take extra actions when different state bits are set or cleared. One example of this is a counter for the total number of delayed allocation bytes in a single inode and in the whole FS. When new states are inserted, this callback is being done before we properly setup the new state. This hasn't caused problems before because the lock bit was always done first, and the existing call backs don't care about the lock bit. This patch makes sure the state is properly setup before using the callback, which is important for later optimizations that do more work without using the lock bit. 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: use larger nr_to_write for larger extentsChris Mason
When btrfs fills a large delayed allocation extent, it is a good idea to try and convince the write_cache_pages caller to go ahead and write a good chunk of that extent. The extra IO is basically free because we know it is contiguous. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Btrfs: optimize set extent bitChris Mason
The Btrfs set_extent_bit call currently searches the rbtree every time it needs to find more extent_state objects to fill the requested operation. This adds a simple test with rb_next to see if the next object in the tree was adjacent to the one we just found. If so, we skip the search and just use the next object. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10btrfs: Fix set/clear_extent_bit for 'end == (u64)-1'Yan Zheng
There are some 'start = state->end + 1;' like code in set_extent_bit and clear_extent_bit. They overflow when end == (u64)-1. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: remove #if 0 codeChris Mason
Btrfs had some old code sitting around under #if 0, this drops it. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: kill btrfs_cache_createChristoph Hellwig
Just use kmem_cache_create directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20Btrfs: fix oops on page->mapping->host during writepageChris Mason
The extent_io writepage call updates the writepage index in the inode as it makes progress. But, it was doing the update after unlocking the page, which isn't legal because page->mapping can't be trusted once the page is unlocked. This lead to an oops, especially common with compression turned on. The fix here is to update the writeback index before unlocking the page. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-20Btrfs: add a priority queue to the async thread helpersChris Mason
Btrfs is using WRITE_SYNC_PLUG to send down synchronous IOs with a higher priority. But, the checksumming helper threads prevent it from being fully effective. There are two problems. First, a big queue of pending checksumming will delay the synchronous IO behind other lower priority writes. Second, the checksumming uses an ordered async work queue. The ordering makes sure that IOs are sent to the block layer in the same order they are sent to the checksumming threads. Usually this gives us less seeky IO. But, when we start mixing IO priorities, the lower priority IO can delay the higher priority IO. This patch solves both problems by adding a high priority list to the async helper threads, and a new btrfs_set_work_high_prio(), which is used to make put a new async work item onto the higher priority list. The ordering is still done on high priority IO, but all of the high priority bios are ordered separately from the low priority bios. This ordering is purely an IO optimization, it is not involved in data or metadata integrity. 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: fix __ucmpdi2 compile bug on 32 bit buildsHeiko Carstens
We get this on 32 builds: fs/built-in.o: In function `extent_fiemap': (.text+0x1019f2): undefined reference to `__ucmpdi2' Happens because of a switch statement with a 64 bit argument. Convert this to an if statement to fix this. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: leave btree locks spinning more oftenChris Mason
btrfs_mark_buffer dirty would set dirty bits in the extent_io tree for the buffers it was dirtying. This may require a kmalloc and it was not atomic. So, anyone who called btrfs_mark_buffer_dirty had to set any btree locks they were holding to blocking first. This commit changes dirty tracking for extent buffers to just use a flag in the extent buffer. Now that we have one and only one extent buffer per page, this can be safely done without losing dirty bits along the way. This also introduces a path->leave_spinning flag that callers of btrfs_search_slot can use to indicate they will properly deal with a path returned where all the locks are spinning instead of blocking. Many of the btree search callers now expect spinning paths, resulting in better btree concurrency overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: remove unused code in split_state()Qinghuang Feng
These two lines are not used, remove them. Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: don't return congestion in write_cache_pages as oftenChris Mason
On fast devices that go from congested to uncongested very quickly, pdflush is waiting too often in congestion_wait, and the FS is backing off to easily in write_cache_pages. For now, fix this on the btrfs side by only checking congestion after some bios have already gone down. Longer term a real fix is needed for pdflush, but that is a larger project. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Change btree locking to use explicit blocking pointsChris Mason
Most of the btrfs metadata operations can be protected by a spinlock, but some operations still need to schedule. So far, btrfs has been using a mutex along with a trylock loop, most of the time it is able to avoid going for the full mutex, so the trylock loop is a big performance gain. This commit is step one for getting rid of the blocking locks entirely. btrfs_tree_lock takes a spinlock, and the code explicitly switches to a blocking lock when it starts an operation that can schedule. We'll be able get rid of the blocking locks in smaller pieces over time. Tracing allows us to find the most common cause of blocking, so we can start with the hot spots first. The basic idea is: btrfs_tree_lock() returns with the spin lock held btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in the extent buffer flags, and then drops the spin lock. The buffer is still considered locked by all of the btrfs code. If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops the spin lock and waits on a wait queue for the blocking bit to go away. Much of the code that needs to set the blocking bit finishes without actually blocking a good percentage of the time. So, an adaptive spin is still used against the blocking bit to avoid very high context switch rates. btrfs_clear_lock_blocking() clears the blocking bit and returns with the spinlock held again. btrfs_tree_unlock() can be called on either blocking or spinning locks, it does the right thing based on the blocking bit. ctree.c has a helper function to set/clear all the locked buffers in a path as blocking. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: disable leak debugging checks in extent_io.cChris Mason
extent_io.c has debugging code to report and free leaked extent_state and extent_buffer objects at rmmod time. This helps track down leaks and it saves you from rebooting just to properly remove the kmem_cache object. But, the code runs under a fairly expensive spinlock and the checks to see if it is currently enabled are not entirely consistent. Some use #ifdef and some #if. This changes everything to #if and disables the leak checking. Signed-off-by: Chris Mason <chris.mason@oracle.com>