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2009-12-07Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: kernel/irq/chip.c
2009-12-04tree-wide: fix assorted typos all over the placeAndré Goddard Rosa
That is "success", "unknown", "through", "performance", "[re|un]mapping" , "access", "default", "reasonable", "[con]currently", "temperature" , "channel", "[un]used", "application", "example","hierarchy", "therefore" , "[over|under]flow", "contiguous", "threshold", "enough" and others. Signed-off-by: André Goddard Rosa <andre.goddard@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-11Merge 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: fix panic when trying to destroy a newly allocated Btrfs: allow more metadata chunk preallocation Btrfs: fallback on uncompressed io if compressed io fails Btrfs: find ideal block group for caching Btrfs: avoid null deref in unpin_extent_cache() Btrfs: skip btrfs_release_path in btrfs_update_root and btrfs_del_root Btrfs: fix some metadata enospc issues Btrfs: fix how we set max_size for free space clusters Btrfs: cleanup transaction starting and fix journal_info usage Btrfs: fix data allocation hint start
2009-11-11Btrfs: fix panic when trying to destroy a newly allocatedJosef Bacik
There is a problem where iget5_locked will look for an inode, not find it, and then subsequently try to allocate it. Another CPU will have raced in and allocated the inode instead, so when iget5_locked gets the inode spin lock again and does a search, it finds the new inode. So it goes ahead and calls destroy_inode on the inode it just allocated. The problem is we don't set BTRFS_I(inode)->root until the new inode is completely initialized. This patch makes us set root to NULL when alloc'ing a new inode, so when we get to btrfs_destroy_inode and we see that root is NULL we can just free up the memory and continue on. This fixes the panic http://www.kerneloops.org/submitresult.php?number=812690 Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: allow more metadata chunk preallocationChris Mason
On an FS where all of the space has not been allocated into chunks yet, the enospc can return enospc just because the existing metadata chunks are full. We get around this by allowing more metadata chunks to be allocated up to a certain limit, and finding the right limit is a little fuzzy. The problem is the reservations for delalloc would preallocate way too much of the FS as metadata. We need to start saying no and just force some IO to happen. But we also need to let a reasonable amount of the FS become metadata. This bumps the hard limit up, later releases will have a better system. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: fallback on uncompressed io if compressed io failsJosef Bacik
Currently compressed IO does not deal with not having its entire extent able to be allocated. So if we have enough free space to allocate for the extent, but its not contiguous, it will fail spectacularly. This patch fixes this by falling back on uncompressed IO which lets us spread the delalloc extent across multiple extents. I tested this by making us randomly think the reservation had failed to make it fallback on the uncompressed io way and it seemed to work fine. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: find ideal block group for cachingJosef Bacik
This patch changes a few things. Hopefully the comments are helpfull, but I'll try and be as verbose here. Problem: My fedora box was taking 1 minute and 21 seconds to boot with btrfs as root. Part of this problem was we pick the first block group we can find and start caching it, even if it may not have enough free space. The other problem is we only search for cached block groups the first time around, which we won't find any cached block groups because this is a newly mounted fs, so we end up caching several block groups during bootup, which with alot of fragmentation takes around 30-45 seconds to complete, which bogs down the system. So Solution: 1) Don't cache block groups willy-nilly at first. Instead try and figure out which block group has the most free, and therefore will take the least amount of time to cache. 2) Don't be so picky about cached block groups. The other problem is once we've filled up a cluster, if the block group isn't finished caching the next time we try and do the allocation we'll completely ignore the cluster and start searching from the beginning of the space, which makes us cache more block groups, which slows us down even more. So instead of skipping block groups that are not finished caching when we have a hint, only skip the block group if it hasn't started caching yet. There is one other tweak in here. Before if we allocated a chunk and still couldn't find new space, we'd end up switching the space info to force another chunk allocation. This could make us end up with way too many chunks, so keep track of this particular case. With this patch and my previous cluster fixes my fedora box now boots in 43 seconds, and according to the bootchart is not held up by our block group caching at all. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: avoid null deref in unpin_extent_cache()Dan Carpenter
I re-orderred the checks to avoid dereferencing "em" if it was null. Found by smatch static checker. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: skip btrfs_release_path in btrfs_update_root and btrfs_del_rootLi Dongyang
We don't need to call btrfs_release_path because btrfs_free_path will do that for us. Signed-off-by: Li Dongyang <Jerry87905@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: fix some metadata enospc issuesJosef Bacik
We weren't reserving metadata space for rename, rmdir and unlink, which could cause problems. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: fix how we set max_size for free space clustersJosef Bacik
This patch fixes a problem where max_size can be set to 0 even though we filled the cluster properly. We set max_size to 0 if we restart the cluster window, but if the new start entry is big enough to be our new cluster then we could return with a max_size set to 0, which will mean the next time we try to allocate from this cluster it will fail. So set max_extent to the entry's size. Tested this on my box and now we actually allocate from the cluster after we fill it. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: cleanup transaction starting and fix journal_info usageJosef Bacik
We use journal_info to tell if we're in a nested transaction to make sure we don't commit the transaction within a nested transaction. We use another method to see if there are any outstanding ioctl trans handles, so if we're starting one do not set current->journal_info, since it will screw with other filesystems. This patch also cleans up the starting stuff so there aren't any magic numbers. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-11-11Btrfs: fix data allocation hint startJosef Bacik
Sometimes our start allocation hint when we cow a file can be either EXTENT_HOLE or some other such place holder, which is not optimal. So if we find that our em->block_start is one of these special values, check to see where the first block of the inode is stored, and use that as a hint. If that block is also a special value, just fallback on a hint of 0 and let the allocator figure out a good place to put the data. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-15Merge 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: always pin metadata in discard mode Btrfs: enable discard support Btrfs: add -o discard option Btrfs: properly wait log writers during log sync Btrfs: fix possible ENOSPC problems with truncate Btrfs: fix btrfs acl #ifdef checks Btrfs: streamline tree-log btree block writeout Btrfs: avoid tree log commit when there are no changes Btrfs: only write one super copy during fsync
2009-10-14Btrfs: always pin metadata in discard modeChris Mason
We have an optimization in btrfs to allow blocks to be immediately freed if they were allocated in this transaction and never written. Otherwise they are pinned and freed when the transaction commits. This isn't optimal for discard mode because immediately freeing them means immediately discarding them. It is better to give the block to the pinning code and letting the (slow) discard happen later. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-14Btrfs: enable discard supportChristoph Hellwig
The discard support code in btrfs currently is guarded by ifdefs for BIO_RW_DISCARD, which is never defines as it's the name of an enum memeber. Just remove the useless ifdefs to actually enable the code. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-14Btrfs: add -o discard optionChristoph Hellwig
Enable discard by default is not a good idea given the the trim speed of SSD prototypes we've seen, and the carecteristics for many high-end arrays. Turn of discards by default and require the -o discard option to enable them on. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-14Btrfs: properly wait log writers during log syncYan, Zheng
A recently fsync optimization make btrfs_sync_log skip calling wait_for_writer in the single log writer case. This is incorrect since the writer count can also be increased by btrfs_pin_log. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-14Btrfs: fix possible ENOSPC problems with truncateJosef Bacik
There's a problem where we don't do any space reservation for truncates, which can cause you to OOPs because you will be allowed to go off in the weeds a bit since we don't account for the delalloc bytes that are created as a result of the truncate. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13Btrfs: fix btrfs acl #ifdef checksChris Mason
The btrfs acl code was #ifdefing for a define that didn't exist. This correctly matches it to the values used by the Kconfig file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13Btrfs: streamline tree-log btree block writeoutChris Mason
Syncing the tree log is a 3 phase operation. 1) write and wait for all the tree log blocks for a given root. 2) write and wait for all the tree log blocks for the tree of tree log roots. 3) write and wait for the super blocks (barriers here) This isn't as efficient as it could be because there is no requirement to wait for the blocks from step one to hit the disk before we start writing the blocks from step two. This commit changes the sequence so that we don't start waiting until all the tree blocks from both steps one and two have been sent to disk. We do this by breaking up btrfs_write_wait_marked_extents into two functions, which is trivial because it was already broken up into two parts. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13Btrfs: avoid tree log commit when there are no changesChris Mason
rpm has a habit of running fdatasync when the file hasn't changed. We already detect if a file hasn't been changed in the current transaction but it might have been sent to the tree-log in this transaction and not changed since the last call to fsync. In this case, we want to avoid a tree log sync, which includes a number of synchronous writes and barriers. This commit extends the existing tracking of the last transaction to change a file to also track the last sub-transaction. The end result is that rpm -ivh and -Uvh are roughly twice as fast, and on par with ext3. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-13Btrfs: only write one super copy during fsyncChris Mason
During a tree-log commit for fsync, we've been writing at least two copies of the super block and forcing them to disk. The other filesystems write only one, and this change brings us on par with them. A full transaction commit will write all the super copies, so we still have redundant info written on a regular basis. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-11Merge 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: fix file clone ioctl for bookend extents Btrfs: fix uninit compiler warning in cow_file_range_nocow Btrfs: constify dentry_operations Btrfs: optimize back reference update during btrfs_drop_snapshot Btrfs: remove negative dentry when deleting subvolumne Btrfs: optimize fsync for the single writer case Btrfs: async delalloc flushing under space pressure Btrfs: release delalloc reservations on extent item insertion Btrfs: delay clearing EXTENT_DELALLOC for compressed extents Btrfs: cleanup extent_clear_unlock_delalloc flags Btrfs: fix possible softlockup in the allocator Btrfs: fix deadlock on async thread startup
2009-10-09Btrfs: fix file clone ioctl for bookend extentsChris Mason
The file clone ioctl was incorrectly taking the offset into the extent on disk into account when calculating the length of the cloned extent. The length never changes based on the offset into the physical extent. Test case: fallocate -l 1g image mke2fs image bcp image image2 e2fsck -f image2 (errors on image2) The math bug ends up wrapping the length of the extent, and things go wrong from there. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: fix uninit compiler warning in cow_file_range_nocowChris Mason
The extent_type variable was exposed uninit via a goto. It should be impossible to trigger because it is protected by a check on another variable, but this makes sure. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: constify dentry_operationsAlexey Dobriyan
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: optimize back reference update during btrfs_drop_snapshotYan, Zheng
This patch reading level 0 tree blocks that already use full backrefs. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-09Btrfs: remove negative dentry when deleting subvolumneYan, Zheng
The use of btrfs_dentry_delete is removing dentries from the dcache when deleting subvolumne. btrfs_dentry_delete ignores negative dentries. This is incorrect since if we don't remove the negative dentry, its parent dentry can't be removed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08Btrfs: optimize fsync for the single writer caseJosef Bacik
This patch optimizes the tree logging stuff so it doesn't always wait 1 jiffie for new people to join the logging transaction if there is only ever 1 writer. This helps a little bit with latency where we have something like RPM where it will fdatasync every file it writes, and so waiting the 1 jiffie for every fdatasync really starts to add up. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-08Btrfs: async delalloc flushing under space pressureJosef Bacik
This patch moves the delalloc flushing that occurs when we are under space pressure off to a async thread pool. This helps since we only free up metadata space when we actually insert the extent item, which means it takes quite a while for space to be free'ed up if we wait on all ordered extents. However, if space is freed up due to inline extents being inserted, we can wake people who are waiting up early, and they can finish their work. Signed-off-by: Josef Bacik <jbacik@redhat.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: delay clearing EXTENT_DELALLOC for compressed extentsChris Mason
When compression is on, the cow_file_range code is farmed off to worker threads. This allows us to do significant CPU work in parallel on SMP machines. But it is a delicate balance around when we clear flags and how. In the past we cleared the delalloc flag immediately, which was safe because the pages stayed locked. But this is causing problems with the newest ENOSPC code, and with the recent extent state cleanups we can now clear the delalloc bit at the same time the uncompressed code does. 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>
2009-10-06Btrfs: fix possible softlockup in the allocatorJosef Bacik
Like the cluster allocating stuff, we can lockup the box with the normal allocation path. This happens when we 1) Start to cache a block group that is severely fragmented, but has a decent amount of free space. 2) Start to commit a transaction 3) Have the commit try and empty out some of the delalloc inodes with extents that are relatively large. The inodes will not be able to make the allocations because they will ask for allocations larger than a contiguous area in the free space cache. So we will wait for more progress to be made on the block group, but since we're in a commit the caching kthread won't make any more progress and it already has enough free space that wait_block_group_cache_progress will just return. So, if we wait and fail to make the allocation the next time around, just loop and go to the next block group. This keeps us from getting stuck in a softlockup. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-05Btrfs: fix deadlock on async thread startupChris Mason
The btrfs async worker threads are used for a wide variety of things, including processing bio end_io functions. This means that when the endio threads aren't running, the rest of the FS isn't able to do the final processing required to clear PageWriteback. The endio threads also try to exit as they become idle and start more as the work piles up. The problem is that starting more threads means kthreadd may need to allocate ram, and that allocation may wait until the global number of writeback pages on the system is below a certain limit. The result of that throttling is that end IO threads wait on kthreadd, who is waiting on IO to end, which will never happen. This commit fixes the deadlock by handing off thread startup to a dedicated thread. It also fixes a bug where the on-demand thread creation was creating far too many threads because it didn't take into account threads being started by other procs. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-01Merge 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: Btrfs: fix data space leak fix Btrfs: remove duplicates of filemap_ helpers Btrfs: take i_mutex before generic_write_checks Btrfs: fix arguments to btrfs_wait_on_page_writeback_range Btrfs: fix deadlock with free space handling and user transactions Btrfs: fix error cases for ioctl transactions Btrfs: Use CONFIG_BTRFS_POSIX_ACL to enable ACL code Btrfs: introduce missing kfree Btrfs: Fix setting umask when POSIX ACLs are not enabled Btrfs: proper -ENOSPC handling
2009-10-01const: constify remaining file_operationsAlexey Dobriyan
[akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-01Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus
2009-10-01Btrfs: fix data space leak fixJosef Bacik
There is a problem where page_mkwrite can be called on a dirtied page that already has a delalloc range associated with it. The fix is to clear any delalloc bits for the range we are dirtying so the space accounting gets handled properly. This is the same thing we do in the normal write case, so we are consistent across the board. With this patch we no longer leak reserved space. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-01Btrfs: remove duplicates of filemap_ helpersChristoph Hellwig
Use filemap_fdatawrite_range and filemap_fdatawait_range instead of local copies of the functions. For filemap_fdatawait_range that also means replacing the awkward old wait_on_page_writeback_range calling convention with the regular filemap byte offsets. Signed-off-by: Christoph Hellwig <hch@lst.de> 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
2009-10-01Btrfs: take i_mutex before generic_write_checksChris Mason
btrfs_file_write was incorrectly calling generic_write_checks without taking i_mutex. This lead to problems with racing around i_size when doing O_APPEND writes. The fix here is to move i_mutex higher. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-10-01Btrfs: fix arguments to btrfs_wait_on_page_writeback_rangeChristoph Hellwig
wait_on_page_writeback_range/btrfs_wait_on_page_writeback_range takes a pagecache offset, not a byte offset into the file. Shift the arguments around to wait for the correct range Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-29Btrfs: fix deadlock with free space handling and user transactionsSage Weil
If an ioctl-initiated transaction is open, we can't force a commit during the free space checks in order to free up pinned extents or else we deadlock. Just ENOSPC instead. A more satisfying solution that reserves space for the entire user transaction up front is forthcoming... Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-29Btrfs: fix error cases for ioctl transactionsSage Weil
Fix leak of vfsmount write reference and open_ioctl_trans reference on ENOMEM. Clean up the error paths while we're at it. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-29Btrfs: Use CONFIG_BTRFS_POSIX_ACL to enable ACL codeChris Ball
We've already defined CONFIG_BTRFS_POSIX_ACL in Kconfig, but we're currently not using it and are testing CONFIG_FS_POSIX_ACL instead. CONFIG_FS_POSIX_ACL states "Never use this symbol for ifdefs". Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
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>
2009-09-29Btrfs: Fix setting umask when POSIX ACLs are not enabledChris Ball
We currently set sb->s_flags |= MS_POSIXACL unconditionally, which is incorrect -- it tells the VFS that it shouldn't set umask because we will, yet we don't set it ourselves if we aren't using POSIX ACLs, so the umask ends up ignored. Signed-off-by: Chris Ball <cjb@laptop.org> 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>