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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: kill max_extent mount optionJosef Bacik
As Yan pointed out, theres not much reason for all this complicated math to account for file extents being split up into max_extent chunks, since they are likely to all end up in the same leaf anyway. Since there isn't much reason to use max_extent, just remove the option altogether so we have one less thing we need to test. Signed-off-by: Josef Bacik <josef@redhat.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>
2010-03-18Merge 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: (30 commits) Btrfs: fix the inode ref searches done by btrfs_search_path_in_tree Btrfs: allow treeid==0 in the inode lookup ioctl Btrfs: return keys for large items to the search ioctl Btrfs: fix key checks and advance in the search ioctl Btrfs: buffer results in the space_info ioctl Btrfs: use __u64 types in ioctl.h Btrfs: fix search_ioctl key advance Btrfs: fix gfp flags masking in the compression code Btrfs: don't look at bio flags after submit_bio btrfs: using btrfs_stack_device_id() get devid btrfs: use memparse Btrfs: add a "df" ioctl for btrfs Btrfs: cache the extent state everywhere we possibly can V2 Btrfs: cache ordered extent when completing io Btrfs: cache extent state in find_delalloc_range Btrfs: change the ordered tree to use a spinlock instead of a mutex Btrfs: finish read pages in the order they are submitted btrfs: fix btrfs_mkdir goto for no free objectids Btrfs: flush data on snapshot creation Btrfs: make df be a little bit more understandable ...
2010-03-15btrfs: use memparseAkinobu Mita
Use memparse() instead of its own private implementation. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Chris Mason <chris.mason@oracle.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: add new defrag-range ioctl.Chris Mason
The btrfs defrag ioctl was limited to doing the entire file. This commit adds a new interface that can defrag a specific range inside the file. It can also force compression on the file, allowing you to selectively compress individual files after they were created, even when mount -o compress isn't turned on. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: add ioctl and incompat flag to set the default mount subvolJosef Bacik
This patch needs to go along with my previous patch. This lets us set the default dir item's location to whatever root we want to use as our default mounting subvol. With this we don't have to use mount -o subvol=<tree id> anymore to mount a different subvol, we can just set the new one and it will just magically work. I've done some moderate testing with this, mostly just switching the default mount around, mounting subvols and the default mount at the same time and such, everything seems to work. Thanks, Older kernels would generally be able to still mount the filesystem with the default subvolume set, but it would result in a different volume being mounted, which could be an even more unpleasant suprise for users. So if you set your default subvolume, you can't go back to older kernels. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: change how we mount subvolumesJosef Bacik
This work is in preperation for being able to set a different root as the default mounting root. There is currently a problem with how we mount subvolumes. We cannot currently mount a subvolume of a subvolume, you can only mount subvolumes/snapshots of the default subvolume. So say you take a snapshot of the default subvolume and call it snap1, and then take a snapshot of snap1 and call it snap2, so now you have / /snap1 /snap1/snap2 as your available volumes. Currently you can only mount / and /snap1, you cannot mount /snap1/snap2. To fix this problem instead of passing subvolid=<name> you must pass in subvolid=<treeid>, where <treeid> is the tree id that gets spit out via the subvolume listing you get from the subvolume listing patches (btrfs filesystem list). This allows us to mount /, /snap1 and /snap1/snap2 as the root volume. In addition to the above, we also now read the default dir item in the tree root to get the root key that it points to. For now this just points at what has always been the default subvolme, but later on I plan to change it to point at whatever root you want to be the new default root, so you can just set the default mount and not have to mount with -o subvolid=<treeid>. I tested this out with the above scenario and it worked perfectly. Thanks, mount -o subvol operates inside the selected subvolid. For example: mount -o subvol=snap1,subvolid=256 /dev/xxx /mnt /mnt will have the snap1 directory for the subvolume with id 256. mount -o subvol=snap /dev/xxx /mnt /mnt will be the snap directory of whatever the default subvolume is. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-15Btrfs: make set/get functions for the super compat_ro flags use compat_roJosef Bacik
Our set/get functions for compat_ro_flags actually look at compat_flags. This will mess any attempt to use compat flags up. The fix is obvious. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2010-03-05pass writeback_control to ->write_inodeChristoph Hellwig
This gives the filesystem more information about the writeback that is happening. Trond requested this for the NFS unstable write handling, and other filesystems might benefit from this too by beeing able to distinguish between the different callers in more detail. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-01-28Btrfs: Add mount -o compress-forceChris Mason
The default btrfs mount -o compress mode will quickly back off compressing a file if it notices that compression does not reduce the size of the data being written. This can save considerable CPU because all future writes to the file go through uncompressed. But some files are both very large and have mixed data stored in them. In that case, we want to add the ability to always try compressing data before writing it. This commit adds mount -o compress-force. A later commit will add a new inode flag that does the same thing. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Fix per root used space accountingYan, Zheng
The bytes_used field in root item was originally planned to trace the amount of used data and tree blocks. But it never worked right since we can't trace freeing of data accurately. This patch changes it to only trace the amount of tree blocks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Add delayed iputYan, Zheng
iput() can trigger new transactions if we are dropping the final reference, so calling it in btrfs_commit_transaction may end up deadlock. This patch adds delayed iput to avoid the issue. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Pass transaction handle to security and ACL initialization functionsYan, Zheng
Pass transaction handle down to security and ACL initialization functions, so we can avoid starting nested transactions Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-17Btrfs: Avoid orphan inodes cleanup while replaying logYan, Zheng
We do log replay in a single transaction, so it's not good to do unbound operations. This patch cleans up orphan inodes cleanup after replaying the log. It also avoids doing other unbound operations such as truncating a file during replaying log. These unbound operations are postponed to the orphan inode cleanup stage. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-15Btrfs: Rewrite btrfs_drop_extentsYan, Zheng
Rewrite btrfs_drop_extents by using btrfs_duplicate_item, so we can avoid calling lock_extent within transaction. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-12-15Btrfs: Add btrfs_duplicate_itemYan, Zheng
btrfs_duplicate_item duplicates item with new key, guaranteeing the source item and the new items are in the same tree leaf and contiguous. It allows us to split file extent in place, without using lock_extent to prevent bookend extent race. Signed-off-by: Yan Zheng <zheng.yan@oracle.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: 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>
2009-10-13Btrfs: 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: 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>
2009-10-11Merge 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: constify dentry_operationsAlexey Dobriyan
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>
2009-10-05Btrfs: 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>
2009-09-29Btrfs: 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>
2009-09-28Btrfs: 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>
2009-09-21Btrfs: account for space used by the super mirrorsJosef Bacik
As we get closer to proper -ENOSPC handling in btrfs, we need more accurate space accounting for the space info's. Currently we exclude the free space for the super mirrors, but the space they take up isn't accounted for in any of the counters. This patch introduces bytes_super, which keeps track of the amount of bytes used for a super mirror in the block group cache and space info. This makes sure that our free space caclucations will be completely accurate. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
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>
2009-09-21Btrfs: add snapshot/subvolume destroy ioctlYan, Zheng
This patch adds snapshot/subvolume destroy ioctl. A subvolume that isn't being used and doesn't contains links to other subvolumes can be destroyed. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21Btrfs: change how subvolumes are organizedYan, Zheng
btrfs allows subvolumes and snapshots anywhere in the directory tree. If we snapshot a subvolume that contains a link to other subvolume called subvolA, subvolA can be accessed through both the original subvolume and the snapshot. This is similar to creating hard link to directory, and has the very similar problems. The aim of this patch is enforcing there is only one access point to each subvolume. Only the first directory entry (the one added when the subvolume/snapshot was created) is treated as valid access point. The first directory entry is distinguished by checking root forward reference. If the corresponding root forward reference is missing, we know the entry is not the first one. This patch also adds snapshot/subvolume rename support, the code allows rename subvolume link across subvolumes. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-21Btrfs: do not reuse objectid of deleted snapshot/subvolYan, Zheng
The new back reference format does not allow reusing objectid of deleted snapshot/subvol. So we use ++highest_objectid to allocate objectid for new snapshot/subvol. Now we use ++highest_objectid to allocate objectid for both new inode and new snapshot/subvolume, so this patch removes 'find hole' code in btrfs_find_free_objectid. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-17Btrfs: improve async block group cachingYan Zheng
This patch gets rid of two limitations of async block group caching. The old code delays handling pinned extents when block group is in caching. To allocate logged file extents, the old code need wait until block group is fully cached. To get rid of the limitations, This patch introduces a data structure to track the progress of caching. Base on the caching progress, we know which extents should be added to the free space cache when handling the pinned extents. The logged file extents are also handled in a similar way. This patch also changes how pinned extents are tracked. The old code uses one tree to track pinned extents, and copy the pinned extents tree at transaction commit time. This patch makes it use two trees to track pinned extents. One tree for extents that are pinned in the running transaction, one tree for extents that can be unpinned. At transaction commit time, we swap the two trees. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-09-11Merge branch 'master' of ↵Chris Mason
git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
2009-09-11Btrfs: Fix extent replacment raceChris Mason
Data COW means that whenever we write to a file, we replace any old extent pointers with new ones. There was a window where a readpage might find the old extent pointers on disk and cache them in the extent_map tree in ram in the middle of a given write replacing them. Even though both the readpage and the write had their respective bytes in the file locked, the extent readpage inserts may cover more bytes than it had locked down. This commit closes the race by keeping the new extent pinned in the extent map tree until after the on-disk btree is properly setup with the new extent pointers. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-30Merge 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: be more polite in the async caching threads Btrfs: preserve commit_root for async caching
2009-07-30Btrfs: preserve commit_root for async cachingYan Zheng
The async block group caching code uses the commit_root pointer to get a stable version of the extent allocation tree for scanning. This copy of the tree root isn't going to change and it significantly reduces the complexity of the scanning code. During a commit, we have a loop where we update the extent allocation tree root. We need to loop because updating the root pointer in the tree of tree roots may allocate blocks which may change the extent allocation tree. Right now the commit_root pointer is changed inside this loop. It is more correct to change the commit_root pointer only after all the looping is done. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-28Merge 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: (22 commits) Btrfs: Fix async caching interaction with unmount Btrfs: change how we unpin extents Btrfs: Correct redundant test in add_inode_ref Btrfs: find smallest available device extent during chunk allocation Btrfs: clear all space_info->full after removing a block group Btrfs: make flushoncommit mount option correctly wait on ordered_extents Btrfs: Avoid delayed reference update looping Btrfs: Fix ordering of key field checks in btrfs_previous_item Btrfs: find_free_dev_extent doesn't handle holes at the start of the device Btrfs: Remove code duplication in comp_keys Btrfs: async block group caching Btrfs: use hybrid extents+bitmap rb tree for free space Btrfs: Fix crash on read failures at mount Btrfs: remove of redundant btrfs_header_level Btrfs: adjust NULL test Btrfs: Remove broken sanity check from btrfs_rmap_block() Btrfs: convert nested spin_lock_irqsave to spin_lock Btrfs: make sure all dirty blocks are written at commit time Btrfs: fix locking issue in btrfs_find_next_key Btrfs: fix double increment of path->slots[0] in btrfs_next_leaf ...
2009-07-27Btrfs: change how we unpin extentsJosef Bacik
We are racy with async block caching and unpinning extents. This patch makes things much less complicated by only unpinning the extent if the block group is cached. We check the block_group->cached var under the block_group->lock spin lock. If it is set to BTRFS_CACHE_FINISHED then we update the pinned counters, and unpin the extent and add the free space back. If it is not set to this, we start the caching of the block group so the next time we unpin extents we can unpin the extent. This keeps us from racing with the async caching threads, lets us kill the fs wide async thread counter, and keeps us from having to set DELALLOC bits for every extent we hit if there are caching kthreads going. One thing that needed to be changed was btrfs_free_super_mirror_extents. Now instead of just looking for LOCKED extents, we also look for DIRTY extents, since we could have left some extents pinned in the previous transaction that will never get freed now that we are unmounting, which would cause us to leak memory. So btrfs_free_super_mirror_extents has been changed to btrfs_free_pinned_extents, and it will clear the extents locked for the super mirror, and any remaining pinned extents that may be present. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: async block group cachingJosef Bacik
This patch moves the caching of the block group off to a kthread in order to allow people to allocate sooner. Instead of blocking up behind the caching mutex, we instead kick of the caching kthread, and then attempt to make an allocation. If we cannot, we wait on the block groups caching waitqueue, which the caching kthread will wake the waiting threads up everytime it finds 2 meg worth of space, and then again when its finished caching. This is how I tested the speedup from this mkfs the disk mount the disk fill the disk up with fs_mark unmount the disk mount the disk time touch /mnt/foo Without my changes this took 11 seconds on my box, with these changes it now takes 1 second. Another change thats been put in place is we lock the super mirror's in the pinned extent map in order to keep us from adding that stuff as free space when caching the block group. This doesn't really change anything else as far as the pinned extent map is concerned, since for actual pinned extents we use EXTENT_DIRTY, but it does mean that when we unmount we have to go in and unlock those extents to keep from leaking memory. I've also added a check where when we are reading block groups from disk, if the amount of space used == the size of the block group, we go ahead and mark the block group as cached. This drastically reduces the amount of time it takes to cache the block groups. Using the same test as above, except doing a dd to a file and then unmounting, it used to take 33 seconds to umount, now it takes 3 seconds. This version uses the commit_root in the caching kthread, and then keeps track of how many async caching threads are running at any given time so if one of the async threads is still running as we cross transactions we can wait until its finished before handling the pinned extents. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: use hybrid extents+bitmap rb tree for free spaceJosef Bacik
Currently btrfs has a problem where it can use a ridiculous amount of RAM simply tracking free space. As free space gets fragmented, we end up with thousands of entries on an rb-tree per block group, which usually spans 1 gig of area. Since we currently don't ever flush free space cache back to disk this gets to be a bit unweildly on large fs's with lots of fragmentation. This patch solves this problem by using PAGE_SIZE bitmaps for parts of the free space cache. Initially we calculate a threshold of extent entries we can handle, which is however many extent entries we can cram into 16k of ram. The maximum amount of RAM that should ever be used to track 1 gigabyte of diskspace will be 32k of RAM, which scales much better than we did before. Once we pass the extent threshold, we start adding bitmaps and using those instead for tracking the free space. This patch also makes it so that any free space thats less than 4 * sectorsize we go ahead and put into a bitmap. This is nice since we try and allocate out of the front of a block group, so if the front of a block group is heavily fragmented and then has a huge chunk of free space at the end, we go ahead and add the fragmented areas to bitmaps and use a normal extent entry to track the big chunk at the back of the block group. I've also taken the opportunity to revamp how we search for free space. Previously we indexed free space via an offset indexed rb tree and a bytes indexed rb tree. I've dropped the bytes indexed rb tree and use only the offset indexed rb tree. This cuts the number of tree operations we were doing previously down by half, and gives us a little bit of a better allocation pattern since we will always start from a specific offset and search forward from there, instead of searching for the size we need and try and get it as close as possible to the offset we want. I've given this a healthy amount of testing pre-new format stuff, as well as post-new format stuff. I've booted up my fedora box which is installed on btrfs with this patch and ran with it for a few days without issues. I've not seen any performance regressions in any of my tests. Since the last patch Yan Zheng fixed a problem where we could have overlapping entries, so updating their offset inline would cause problems. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: fix definition of struct btrfs_extent_inline_refYan Zheng
use __le64 instead of u64 in on-disk structure definition. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Merge 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 error message formatting Btrfs: fix use after free in btrfs_start_workers fail path Btrfs: honor nodatacow/sum mount options for new files Btrfs: update backrefs while dropping snapshot Btrfs: account for space we may use in fallocate Btrfs: fix the file clone ioctl for preallocated extents Btrfs: don't log the inode in file_write while growing the file
2009-07-02Btrfs: update backrefs while dropping snapshotYan Zheng
The new backref format has restriction on type of backref item. If a tree block isn't referenced by its owner tree, full backrefs must be used for the pointers in it. When a tree block loses its owner tree's reference, backrefs for the pointers in it should be updated to full backrefs. Current btrfs_drop_snapshot misses the code that updates backrefs, so it's unsafe for general use. This patch adds backrefs update code to btrfs_drop_snapshot. It isn't a problem in the restricted form btrfs_drop_snapshot is used today, but for general snapshot deletion this update is required. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-24switch btrfs to inode->i_aclAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>