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* Btrfs: kill obsolete arguments in btrfs_wait_ordered_extentsLiu Bo2012-10-041-11/+1
| | | | | | nocow_only is now an obsolete argument. Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
* Btrfs: use a slab for ordered extents allocationMiao Xie2012-10-011-2/+21
| | | | | | | | | | | | | | The ordered extent allocation is in the fast path of the IO, so use a slab to improve the speed of the allocation. "Size of the struct is 280, so this will fall into the size-512 bucket, giving 8 objects per page, while own slab will pack 14 objects into a page. Another benefit I see is to check for leaked objects when the module is removed (and the cache destroy takes place)." -- David Sterba Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
* Btrfs: fix file extent discount problem in the, snapshotMiao Xie2012-10-011-44/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If a snapshot is created while we are writing some data into the file, the i_size of the corresponding file in the snapshot will be wrong, it will be beyond the end of the last file extent. And btrfsck will report: root 256 inode 257 errors 100 Steps to reproduce: # mkfs.btrfs <partition> # mount <partition> <mnt> # cd <mnt> # dd if=/dev/zero of=tmpfile bs=4M count=1024 & # for ((i=0; i<4; i++)) > do > btrfs sub snap . $i > done This because the algorithm of disk_i_size update is wrong. Though there are some ordered extents behind the current one which we use to update disk_i_size, it doesn't mean those extents will be dealt with in the same transaction. So We shouldn't use the offset of those extents to update disk_i_size. Or we will get the wrong i_size in the snapshot. We fix this problem by recording the max real i_size. If we find there is a ordered extent which is in front of the current one and doesn't complete, we will record the end of the current one into that ordered extent. Surely, if the current extent holds the end of other extent(it must be greater than the current one because it is behind the current one), we will record the number that the current extent holds. In this way, we can exclude the ordered extents that may not be dealth with in the same transaction, and be easy to know the real disk_i_size. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
* btrfs: nuke pdflush from commentsArtem Bityutskiy2012-08-041-1/+1
| | | | | | | | | | The pdflush thread is long gone, so this patch removes references to pdflush from btrfs comments. Cc: Chris Mason <chris.mason@fusionio.com> Cc: linux-btrfs@vger.kernel.org Signed-off-by: Artem Bityutskiy <artem.bityutskiy@linux.intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Btrfs: call filemap_fdatawrite twice for compressionJosef Bacik2012-06-141-1/+21
| | | | | | | | | | | | | | | | I removed this in an earlier commit and I was wrong. Because compression can return from filemap_fdatawrite() without having actually set any of it's pages as writeback() it can make filemap_fdatawait() do essentially nothing, and then we won't find any ordered extents because they may not have been created yet. So not only does this make fsync() completely useless, but it will also screw up if you truncate on a non-page aligned offset since we zero out the end and then wait on ordered extents and then call drop caches. We can drop the cache before the io completes and then we try to unpin the extent we just wrote we won't find it and everything goes sideways. So fix this by putting it back and put a giant comment there to keep me from trying to remove it in the future. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* Btrfs: finish ordered extents in their own threadJosef Bacik2012-05-301-57/+72
| | | | | | | | | | | | | | We noticed that the ordered extent completion doesn't really rely on having a page and that it could be done independantly of ending the writeback on a page. This patch makes us not do the threaded endio stuff for normal buffered writes and direct writes so we can end page writeback as soon as possible (in irq context) and only start threads to do the ordered work when it is actually done. Compression needs to be reworked some to take advantage of this as well, but atm it has to do a find_get_page in its endio handler so it must be done in its own thread. This makes direct writes quite a bit faster. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* Btrfs: do not check delalloc when updating disk_i_sizeJosef Bacik2012-05-301-16/+3
| | | | | | | | | | | | | | | | | | | | | We are checking delalloc to see if it is ok to update the i_size. There are 2 cases it stops us from updating 1) If there is delalloc between our current disk_i_size and this ordered extent 2) If there is delalloc between our current ordered extent and the next ordered extent These tests are racy however since we can set delalloc for these ranges at any time. Also for the first case if we notice there is delalloc between disk_i_size and our ordered extent we will not update disk_i_size and assume that when that delalloc bit gets written out it will update everything properly. However if we crash before that we will have file extents outside of our i_size, which is not good, so this test is dangerous as well as racy. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* Btrfs: remove useless waiting and extra filemap workJosef Bacik2012-05-301-15/+2
| | | | | | | | | | | | | | | | | | | | | | | In btrfs_wait_ordered_range we have been calling filemap_fdata_write() twice because compression does strange things and then waiting. Then we look up ordered extents and if we find any we will always schedule_timeout(); once and then loop back around and do it all again. We will even check to see if there is delalloc pages on this range and loop again. So this patch gets rid of the multipe fdata_write() calls and just does filemap_write_and_wait(). In the case of compression we will still find the ordered extents and start those individually if we need to so that is ok, but in the normal buffered case we avoid all this weird overhead. Then in the case of the schedule_timeout(1), we don't need it. All callers either 1) don't care, they just want to make sure what they just wrote maeks it to disk or 2) are doing the lock()->lookup ordered->unlock->flush thing in which case it will lock and check for ordered extents _anyway_ so get back to them as quickly as possible. The delaloc check is simply not needed, this only catches the case where we write to the file again since doing the filemap_write_and_wait() and if the caller truly cares about that it will take care of everything itself. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com>
* btrfs: return void in functions without error conditionsJeff Mahoney2012-03-221-31/+17
| | | | Signed-off-by: Jeff Mahoney <jeffm@suse.com>
* btrfs: Panic on bad rbtree operationsJeff Mahoney2012-03-221-2/+10
| | | | | | | | | The ordered data and relocation trees have BUG_ONs to protect against bad tree operations. This patch replaces them with a panic that will report the problem. Signed-off-by: Jeff Mahoney <jeffm@suse.com>
* Btrfs: add initial tracepoint support for btrfsliubo2011-03-281-0/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Tracepoints can provide insight into why btrfs hits bugs and be greatly helpful for debugging, e.g dd-7822 [000] 2121.641088: btrfs_inode_request: root = 5(FS_TREE), gen = 4, ino = 256, blocks = 8, disk_i_size = 0, last_trans = 8, logged_trans = 0 dd-7822 [000] 2121.641100: btrfs_inode_new: root = 5(FS_TREE), gen = 8, ino = 257, blocks = 0, disk_i_size = 0, last_trans = 0, logged_trans = 0 btrfs-transacti-7804 [001] 2146.935420: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29368320 (orig_level = 0), cow_buf = 29388800 (cow_level = 0) btrfs-transacti-7804 [001] 2146.935473: btrfs_cow_block: root = 1(ROOT_TREE), refs = 2, orig_buf = 29364224 (orig_level = 0), cow_buf = 29392896 (cow_level = 0) btrfs-transacti-7804 [001] 2146.972221: btrfs_transaction_commit: root = 1(ROOT_TREE), gen = 8 flush-btrfs-2-7821 [001] 2155.824210: btrfs_chunk_alloc: root = 3(CHUNK_TREE), offset = 1103101952, size = 1073741824, num_stripes = 1, sub_stripes = 0, type = DATA flush-btrfs-2-7821 [001] 2155.824241: btrfs_cow_block: root = 2(EXTENT_TREE), refs = 2, orig_buf = 29388800 (orig_level = 0), cow_buf = 29396992 (cow_level = 0) flush-btrfs-2-7821 [001] 2155.824255: btrfs_cow_block: root = 4(DEV_TREE), refs = 2, orig_buf = 29372416 (orig_level = 0), cow_buf = 29401088 (cow_level = 0) flush-btrfs-2-7821 [000] 2155.824329: btrfs_cow_block: root = 3(CHUNK_TREE), refs = 2, orig_buf = 20971520 (orig_level = 0), cow_buf = 20975616 (cow_level = 0) btrfs-endio-wri-7800 [001] 2155.898019: btrfs_cow_block: root = 5(FS_TREE), refs = 2, orig_buf = 29384704 (orig_level = 0), cow_buf = 29405184 (cow_level = 0) btrfs-endio-wri-7800 [001] 2155.898043: btrfs_cow_block: root = 7(CSUM_TREE), refs = 2, orig_buf = 29376512 (orig_level = 0), cow_buf = 29409280 (cow_level = 0) Here is what I have added: 1) ordere_extent: btrfs_ordered_extent_add btrfs_ordered_extent_remove btrfs_ordered_extent_start btrfs_ordered_extent_put These provide critical information to understand how ordered_extents are updated. 2) extent_map: btrfs_get_extent extent_map is used in both read and write cases, and it is useful for tracking how btrfs specific IO is running. 3) writepage: __extent_writepage btrfs_writepage_end_io_hook Pages are cirtical resourses and produce a lot of corner cases during writeback, so it is valuable to know how page is written to disk. 4) inode: btrfs_inode_new btrfs_inode_request btrfs_inode_evict These can show where and when a inode is created, when a inode is evicted. 5) sync: btrfs_sync_file btrfs_sync_fs These show sync arguments. 6) transaction: btrfs_transaction_commit In transaction based filesystem, it will be useful to know the generation and who does commit. 7) back reference and cow: btrfs_delayed_tree_ref btrfs_delayed_data_ref btrfs_delayed_ref_head btrfs_cow_block Btrfs natively supports back references, these tracepoints are helpful on understanding btrfs's COW mechanism. 8) chunk: btrfs_chunk_alloc btrfs_chunk_free Chunk is a link between physical offset and logical offset, and stands for space infomation in btrfs, and these are helpful on tracing space things. 9) reserved_extent: btrfs_reserved_extent_alloc btrfs_reserved_extent_free These can show how btrfs uses its space. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: avoid uninit variable warnings in ordered-data.cChris Mason2011-01-311-1/+1
| | | | | | | This one isn't really an uninit variable, but for pretty obscure reasons. Let's make it clearly correct. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs: Allow to add new compression algorithmLi Zefan2010-12-221-3/+15
| | | | | | | | | | Make the code aware of compression type, instead of always assuming zlib compression. Also make the zlib workspace function as common code for all compression types. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* Btrfs: deal with DIO bios that span more than one ordered extentChris Mason2010-11-281-0/+67
| | | | | | | | | | | | | The new DIO bio splitting code has problems when the bio spans more than one ordered extent. This will happen as the generic DIO code merges our get_blocks calls together into a bigger single bio. This fixes things by walking forward in the ordered extent code finding all the overlapping ordered extents and completing them all at once. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: cleanup warnings from gcc 4.6 (nonbugs)Andi Kleen2010-10-291-2/+0
| | | | | | | | | | | | | | 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>
* Btrfs: add basic DIO read/write supportJosef Bacik2010-05-251-3/+72
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This provides basic DIO support for reading and writing. It does not do the work to recover from mismatching checksums, that will come later. A few design changes have been made from Jim's code (sorry Jim!) 1) Use the generic direct-io code. Jim originally re-wrote all the generic DIO code in order to account for all of BTRFS's oddities, but thanks to that work it seems like the best bet is to just ignore compression and such and just opt to fallback on buffered IO. 2) Fallback on buffered IO for compressed or inline extents. Jim's code did it's own buffering to make dio with compressed extents work. Now we just fallback onto normal buffered IO. 3) Use ordered extents for the writes so that all of the lock_extent() lookup_ordered() type checks continue to work. 4) Do the lock_extent() lookup_ordered() loop in readpage so we don't race with DIO writes. I've tested this with fsx and everything works great. This patch depends on my dio and filemap.c patches to work. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Update metadata reservation for delayed allocationYan, Zheng2010-05-251-7/+0
| | | | | | | | | | | | | | 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds2010-04-051-2/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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.
| * Btrfs: kill max_extent mount optionJosef Bacik2010-03-301-2/+4
| | | | | | | | | | | | | | | | | | | | | | 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>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-1/+0
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Btrfs: cache ordered extent when completing ioJosef Bacik2010-03-151-1/+6
| | | | | | | | | | | | | When finishing io we run btrfs_dec_test_ordered_pending, and then immediately run btrfs_lookup_ordered_extent, but btrfs_dec_test_ordered_pending does that already, so we're searching twice when we don't have to. This patch lets us pass a btrfs_ordered_extent in to btrfs_dec_test_ordered_pending so if we do complete io on that ordered extent we can just use the one we found then instead of having to do another btrfs_lookup_ordered_extent. This made my fio job with the other patch go from 24 mb/s to 29 mb/s. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: change the ordered tree to use a spinlock instead of a mutexJosef Bacik2010-03-151-17/+17
| | | | | | | | | | The ordered tree used to need a mutex, but currently all we use it for is to protect the rb_tree, and a spin_lock is just fine for that. Using a spin_lock instead makes dbench run a little faster, 58 mb/s instead of 51 mb/s, and have less latency, 3445.138 ms instead of 3820.633 ms. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: align offsets for btrfs_ordered_update_i_sizeYan, Zheng2010-01-171-0/+2
| | | | | | | | | Some callers of btrfs_ordered_update_i_size can now pass in a NULL for the ordered extent to update against. This makes sure we properly align the offset they pass in when deciding how much to bump the on disk i_size. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add delayed iputYan, Zheng2009-12-171-3/+7
| | | | | | | | | | 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>
* Btrfs: Fix disk_i_size update corner caseYan, Zheng2009-12-171-24/+81
| | | | | | | | | | There are some cases file extents are inserted without involving ordered struct. In these cases, we update disk_i_size directly, without checking pending ordered extent and DELALLOC bit. This patch extends btrfs_ordered_update_i_size() to handle these cases. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds2009-10-111-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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
| * Btrfs: release delalloc reservations on extent item insertionJosef Bacik2009-10-081-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Btrfs: remove duplicates of filemap_ helpersChristoph Hellwig2009-10-011-89/+4
| | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'master' of ↵Chris Mason2009-09-241-16/+17
|\ \ | |/ | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable into for-linus Conflicts: fs/btrfs/super.c
| * Btrfs: Use PagePrivate2 to track pages in the data=ordered code.Chris Mason2009-09-111-14/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * Btrfs: use a cached state for extent state operations during delallocChris Mason2009-09-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | 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>
* | writeback: get rid of wbc->for_writepagesJens Axboe2009-09-161-1/+0
|/ | | | | | | It's only set, it's never checked. Kill it. Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* Btrfs: use WRITE_SYNC for synchronous writesChris Mason2009-04-201-1/+1
| | | | | | | | | | | | | | | | | 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>
* Btrfs: add extra flushing for renames and truncatesChris Mason2009-03-311-0/+118
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Renames and truncates are both common ways to replace old data with new data. The filesystem can make an effort to make sure the new data is on disk before actually replacing the old data. This is especially important for rename, which many application use as though it were atomic for both the data and the metadata involved. The current btrfs code will happily replace a file that is fully on disk with one that was just created and still has pending IO. If we crash after transaction commit but before the IO is done, we'll end up replacing a good file with a zero length file. The solution used here is to create a list of inodes that need special ordering and force them to disk before the commit is done. This is similar to the ext3 style data=ordering, except it is only done on selected files. Btrfs is able to get away with this because it does not wait on commits very often, even for fsync (which use a sub-commit). For renames, we order the file when it wasn't already on disk and when it is replacing an existing file. Larger files are sent to filemap_flush right away (before the transaction handle is opened). For truncates, we order if the file goes from non-zero size down to zero size. This is a little different, because at the time of the truncate the file has no dirty bytes to order. But, we flag the inode so that it is added to the ordered list on close (via release method). We also immediately add it to the ordered list of the current transaction so that we can try to flush down any writes the application sneaks in before commit. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: simplify iteration codesQinghuang Feng2009-01-211-3/+1
| | | | | | | | Merge list_for_each* and list_entry to list_for_each_entry* Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix checkpatch.pl warningsChris Mason2009-01-051-19/+15
| | | | | | | There were many, most are fixed now. struct-funcs.c generates some warnings but these are bogus. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: move data checksumming into a dedicated treeChris Mason2008-12-081-3/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs stores checksums for each data block. Until now, they have been stored in the subvolume trees, indexed by the inode that is referencing the data block. This means that when we read the inode, we've probably read in at least some checksums as well. But, this has a few problems: * The checksums are indexed by logical offset in the file. When compression is on, this means we have to do the expensive checksumming on the uncompressed data. It would be faster if we could checksum the compressed data instead. * If we implement encryption, we'll be checksumming the plain text and storing that on disk. This is significantly less secure. * For either compression or encryption, we have to get the plain text back before we can verify the checksum as correct. This makes the raid layer balancing and extent moving much more expensive. * It makes the front end caching code more complex, as we have touch the subvolume and inodes as we cache extents. * There is potentitally one copy of the checksum in each subvolume referencing an extent. The solution used here is to store the extent checksums in a dedicated tree. This allows us to index the checksums by phyiscal extent start and length. It means: * The checksum is against the data stored on disk, after any compression or encryption is done. * The checksum is stored in a central location, and can be verified without following back references, or reading inodes. This makes compression significantly faster by reducing the amount of data that needs to be checksummed. It will also allow much faster raid management code in general. The checksums are indexed by a key with a fixed objectid (a magic value in ctree.h) and offset set to the starting byte of the extent. This allows us to copy the checksum items into the fsync log tree directly (or any other tree), without having to invent a second format for them. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Optimize compressed writeback and readsChris Mason2008-11-061-5/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading compressed extents, try to put pages into the page cache for any pages covered by the compressed extent that readpages didn't already preload. Add an async work queue to handle transformations at delayed allocation processing time. Right now this is just compression. The workflow is: 1) Find offsets in the file marked for delayed allocation 2) Lock the pages 3) Lock the state bits 4) Call the async delalloc code The async delalloc code clears the state lock bits and delalloc bits. It is important this happens before the range goes into the work queue because otherwise it might deadlock with other work queue items that try to lock those extent bits. The file pages are compressed, and if the compression doesn't work the pages are written back directly. An ordered work queue is used to make sure the inodes are written in the same order that pdflush or writepages sent them down. This changes extent_write_cache_pages to let the writepage function update the wbc nr_written count. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add fallocate support v2Yan Zheng2008-10-301-2/+3
| | | | | | | | | | | | This patch updates btrfs-progs for fallocate support. fallocate is a little different in Btrfs because we need to tell the COW system that a given preallocated extent doesn't need to be cow'd as long as there are no snapshots of it. This leverages the -o nodatacow checks. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: update nodatacow code v2Yan Zheng2008-10-301-6/+3
| | | | | | | | | | This patch simplifies the nodatacow checker. If all references were created after the latest snapshot, then we can avoid COW safely. This patch also updates run_delalloc_nocow to do more fine-grained checking. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: Add zlib compression supportChris Mason2008-10-291-2/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is a large change for adding compression on reading and writing, both for inline and regular extents. It does some fairly large surgery to the writeback paths. Compression is off by default and enabled by mount -o compress. Even when the -o compress mount option is not used, it is possible to read compressed extents off the disk. If compression for a given set of pages fails to make them smaller, the file is flagged to avoid future compression attempts later. * While finding delalloc extents, the pages are locked before being sent down to the delalloc handler. This allows the delalloc handler to do complex things such as cleaning the pages, marking them writeback and starting IO on their behalf. * Inline extents are inserted at delalloc time now. This allows us to compress the data before inserting the inline extent, and it allows us to insert an inline extent that spans multiple pages. * All of the in-memory extent representations (extent_map.c, ordered-data.c etc) are changed to record both an in-memory size and an on disk size, as well as a flag for compression. From a disk format point of view, the extent pointers in the file are changed to record the on disk size of a given extent and some encoding flags. Space in the disk format is allocated for compression encoding, as well as encryption and a generic 'other' field. Neither the encryption or the 'other' field are currently used. In order to limit the amount of data read for a single random read in the file, the size of a compressed extent is limited to 128k. This is a software only limit, the disk format supports u64 sized compressed extents. In order to limit the ram consumed while processing extents, the uncompressed size of a compressed extent is limited to 256k. This is a software only limit and will be subject to tuning later. Checksumming is still done on compressed extents, and it is done on the uncompressed version of the data. This way additional encodings can be layered on without having to figure out which encoding to checksum. Compression happens at delalloc time, which is basically singled threaded because it is usually done by a single pdflush thread. This makes it tricky to spread the compression load across all the cpus on the box. We'll have to look at parallel pdflush walks of dirty inodes at a later time. Decompression is hooked into readpages and it does spread across CPUs nicely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: O_DIRECT writes via buffered writes + invaldiateChris Mason2008-10-031-1/+2
| | | | | | | | | | | | | This reworks the btrfs O_DIRECT write code a bit. It had always fallen back to buffered IO and done an invalidate, but needed to be updated for the data=ordered code. The invalidate wasn't actually removing pages because they were still inside an ordered extent. This also combines the O_DIRECT/O_SYNC paths where possible, and kicks off IO in the main btrfs_file_write loop to keep the pipe down the the disk full as we process long writes. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: add and improve commentsChris Mason2008-09-291-1/+18
| | | | | | | | | | | This improves the comments at the top of many functions. It didn't dive into the guts of functions because I was trying to avoid merging problems with the new allocator and back reference work. extent-tree.c and volumes.c were both skipped, and there is definitely more work todo in cleaning and commenting the code. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: extent_map and data=ordered fixes for space balancingZheng Yan2008-09-261-13/+13
| | | | | | | | | | | | | | | | | | | | | * Add an EXTENT_BOUNDARY state bit to keep the writepage code from merging data extents that are in the process of being relocated. This allows us to do accounting for them properly. * The balancing code relocates data extents indepdent of the underlying inode. The extent_map code was modified to properly account for things moving around (invalidating extent_map caches in the inode). * Don't take the drop_mutex in the create_subvol ioctl. It isn't required. * Fix walking of the ordered extent list to avoid races with sys_unlink * Change the lock ordering rules. Transaction start goes outside the drop_mutex. This allows btrfs_commit_transaction to directly drop the relocation trees. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix nodatacow for the new data=ordered modeYan Zheng2008-09-251-3/+13
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Various small fixes.Yan Zheng2008-09-251-2/+2
| | | | | | | | This trivial patch contains two locking fixes and a off by one fix. --- Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix the defragmention code and the block relocation code for data=orderedChris Mason2008-09-251-2/+54
| | | | | | | | | | | Before setting an extent to delalloc, the code needs to wait for pending ordered extents. Also, the relocation code needs to wait for ordered IO before scanning the block group again. This is because the extents are not removed until the IO for the new extents is finished Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Search data ordered extents first for checksums on readChris Mason2008-09-251-0/+1
| | | | | | | | | | | | | | | | | | | | | | Checksum items are not inserted into the tree until all of the io from a given extent is complete. This means one dirty page from an extent may be written, freed, and then read again before the entire extent is on disk and the checksum item is inserted. The checksums themselves are stored in the ordered extent so they can be inserted in bulk when IO is complete. On read, if a checksum item isn't found, the ordered extents were being searched for a checksum record. This all worked most of the time, but the checksum insertion code tries to reduce the number of tree operations by pre-inserting checksum items based on i_size and a few other factors. This means the read code might find a checksum item that hasn't yet really been filled in. This commit changes things to check the ordered extents first and only dive into the btree if nothing was found. This removes the need for extra locking and is more reliable. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Take the csum mutex while reading checksumsChris Mason2008-09-251-1/+1
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix some data=ordered related data corruptionsChris Mason2008-09-251-18/+97
| | | | | | | | | | | | | | | | | | Stress testing was showing data checksum errors, most of which were caused by a lookup bug in the extent_map tree. The tree was caching the last pointer returned, and searches would check the last pointer first. But, search callers also expect the search to return the very first matching extent in the range, which wasn't always true with the last pointer usage. For now, the code to cache the last return value is just removed. It is easy to fix, but I think lookups are rare enough that it isn't required anymore. This commit also replaces do_sync_mapping_range with a local copy of the related functions. Signed-off-by: Chris Mason <chris.mason@oracle.com>
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