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* Merge branch 'for-linus-min' of ↵Linus Torvalds2012-04-141-0/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull the minimal btrfs branch from Chris Mason: "We have a use-after-free in there, along with errors when mount -o discard is enabled, and a BUG_ON(we should compile with UP more often)." * 'for-linus-min' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: use commit root when loading free space cache Btrfs: fix use-after-free in __btrfs_end_transaction Btrfs: check return value of bio_alloc() properly Btrfs: remove lock assert from get_restripe_target() Btrfs: fix eof while discarding extents Btrfs: fix uninit variable in repair_eb_io_failure Revert "Btrfs: increase the global block reserve estimates"
| * Btrfs: check return value of bio_alloc() properlyTsutomu Itoh2012-04-121-0/+2
| | | | | | | | | | | | | | | | bio_alloc() has the possibility of returning NULL. So, it is necessary to check the return value. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* | Merge branch 'for-linus' of ↵Linus Torvalds2012-03-301-20/+18
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes and features from Chris Mason: "We've merged in the error handling patches from SuSE. These are already shipping in the sles kernel, and they give btrfs the ability to abort transactions and go readonly on errors. It involves a lot of churn as they clarify BUG_ONs, and remove the ones we now properly deal with. Josef reworked the way our metadata interacts with the page cache. page->private now points to the btrfs extent_buffer object, which makes everything faster. He changed it so we write an whole extent buffer at a time instead of allowing individual pages to go down,, which will be important for the raid5/6 code (for the 3.5 merge window ;) Josef also made us more aggressive about dropping pages for metadata blocks that were freed due to COW. Overall, our metadata caching is much faster now. We've integrated my patch for metadata bigger than the page size. This allows metadata blocks up to 64KB in size. In practice 16K and 32K seem to work best. For workloads with lots of metadata, this cuts down the size of the extent allocation tree dramatically and fragments much less. Scrub was updated to support the larger block sizes, which ended up being a fairly large change (thanks Stefan Behrens). We also have an assortment of fixes and updates, especially to the balancing code (Ilya Dryomov), the back ref walker (Jan Schmidt) and the defragging code (Liu Bo)." Fixed up trivial conflicts in fs/btrfs/scrub.c that were just due to removal of the second argument to k[un]map_atomic() in commit 7ac687d9e047. * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (75 commits) Btrfs: update the checks for mixed block groups with big metadata blocks Btrfs: update to the right index of defragment Btrfs: do not bother to defrag an extent if it is a big real extent Btrfs: add a check to decide if we should defrag the range Btrfs: fix recursive defragment with autodefrag option Btrfs: fix the mismatch of page->mapping Btrfs: fix race between direct io and autodefrag Btrfs: fix deadlock during allocating chunks Btrfs: show useful info in space reservation tracepoint Btrfs: don't use crc items bigger than 4KB Btrfs: flush out and clean up any block device pages during mount btrfs: disallow unequal data/metadata blocksize for mixed block groups Btrfs: enhance superblock sanity checks Btrfs: change scrub to support big blocks Btrfs: minor cleanup in scrub Btrfs: introduce common define for max number of mirrors Btrfs: fix infinite loop in btrfs_shrink_device() Btrfs: fix memory leak in resolver code Btrfs: allow dup for data chunks in mixed mode Btrfs: validate target profiles only if we are going to use them ...
| * btrfs: replace many BUG_ONs with proper error handlingJeff Mahoney2012-03-221-12/+12
| | | | | | | | | | | | | | | | | | | | | | btrfs currently handles most errors with BUG_ON. This patch is a work-in- progress but aims to handle most errors other than internal logic errors and ENOMEM more gracefully. This iteration prevents most crashes but can run into lockups with the page lock on occasion when the timing "works out." Signed-off-by: Jeff Mahoney <jeffm@suse.com>
| * btrfs: drop gfp_t from lock_extentJeff Mahoney2012-03-221-3/+3
| | | | | | | | | | | | | | lock_extent and unlock_extent are always called with GFP_NOFS, drop the argument and use GFP_NOFS consistently. Signed-off-by: Jeff Mahoney <jeffm@suse.com>
| * btrfs: return void in functions without error conditionsJeff Mahoney2012-03-221-5/+3
| | | | | | | | Signed-off-by: Jeff Mahoney <jeffm@suse.com>
* | btrfs: remove the second argument of k[un]map_atomic()Cong Wang2012-03-201-6/+6
|/ | | | Signed-off-by: Cong Wang <amwang@redhat.com>
* Btrfs: check return value of lookup_extent_mapping() correctlyTsutomu Itoh2012-02-161-0/+2
| | | | | | This patch corrects error checking of lookup_extent_mapping(). Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
* btrfs: separate superblock items out of fs_infoDavid Sterba2011-11-061-1/+2
| | | | | | | | | | | | fs_info has now ~9kb, more than fits into one page. This will cause mount failure when memory is too fragmented. Top space consumers are super block structures super_copy and super_for_commit, ~2.8kb each. Allocate them dynamically. fs_info will be ~3.5kb. (measured on x86_64) Add a wrapper for freeing fs_info and all of it's dynamically allocated members. Signed-off-by: David Sterba <dsterba@suse.cz>
* Btrfs: check the nodatasum flag when writing compressed filesLi Zefan2011-08-011-4/+10
| | | | | | | | | If mounting with nodatasum option, we won't csum file data for general write or direct-io write, and this rule should also be applied when writing compressed files. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Merge branch 'cleanups' of git://repo.or.cz/linux-2.6/btrfs-unstable into ↵Chris Mason2011-05-221-21/+21
|\ | | | | | | | | | | | | | | | | | | | | | | inode_numbers Conflicts: fs/btrfs/extent-tree.c fs/btrfs/free-space-cache.c fs/btrfs/inode.c fs/btrfs/tree-log.c Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * btrfs: rename variables clashing with global function namesDavid Sterba2011-05-021-21/+21
| | | | | | | | | | | | | | reported by gcc -Wshadow: page_index, page_offset, new_inode, dev_name Signed-off-by: David Sterba <dsterba@suse.cz>
* | Btrfs: Always use 64bit inode numberLi Zefan2011-04-251-2/+3
|/ | | | | | | | | | | | | | | | | | There's a potential problem in 32bit system when we exhaust 32bit inode numbers and start to allocate big inode numbers, because btrfs uses inode->i_ino in many places. So here we always use BTRFS_I(inode)->location.objectid, which is an u64 variable. There are 2 exceptions that BTRFS_I(inode)->location.objectid != inode->i_ino: the btree inode (0 vs 1) and empty subvol dirs (256 vs 2), and inode->i_ino will be used in those cases. Another reason to make this change is I'm going to use a special inode to save free ino cache, and the inode number must be > (u64)-256. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* Btrfs: check return value of btrfs_alloc_path()Tsutomu Itoh2011-03-281-4/+7
| | | | | | | | Adding the check on the return value of btrfs_alloc_path() to several places. And, some of callers are modified by this change. Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: fix uncheck memory allocationsYoshinori Sano2011-03-281-0/+6
| | | | | | | | | | To make Btrfs code more robust, several return value checks where memory allocation can fail are introduced. I use BUG_ON where I don't know how to handle the error properly, which increases the number of using the notorious BUG_ON, though. Signed-off-by: Yoshinori Sano <yoshinori.sano@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs: Drop __exit attribute on btrfs_exit_compressAlexey Charkov2011-02-061-1/+1
| | | | | | | | | As this function is called in some error paths while not removing the module, the __exit attribute prevents the kernel image from linking when btrfs is compiled in statically. Signed-off-by: Alexey Charkov <alchark@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs: fix uncheck memory allocation in btrfs_submit_compressed_readliubo2011-01-281-2/+23
| | | | | | | | | | | btrfs_submit_compressed_read() is lack of memory allocation checks and corresponding error route. After this fix, if it comes to "no memory" case, errno will be returned to userland step by step, and tell users this operation cannot go on. Signed-off-by: Liu Bo <liubo2009@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs: Extract duplicate decompress codeLi Zefan2010-12-221-0/+92
| | | | | | | Add a common function to copy decompressed data from working buffer to bio pages. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* btrfs: Add lzo compression supportLi Zefan2010-12-221-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lzo is a much faster compression algorithm than gzib, so would allow more users to enable transparent compression, and some users can choose from compression ratio and speed for different applications Usage: # mount -t btrfs -o compress[=<zlib,lzo>] dev /mnt or # mount -t btrfs -o compress-force[=<zlib,lzo>] dev /mnt "-o compress" without argument is still allowed for compatability. Compatibility: If we mount a filesystem with lzo compression, it will not be able be mounted in old kernels. One reason is, otherwise btrfs will directly dump compressed data, which sits in inline extent, to user. Performance: The test copied a linux source tarball (~400M) from an ext4 partition to the btrfs partition, and then extracted it. (time in second) lzo zlib nocompress copy: 10.6 21.7 14.9 extract: 70.1 94.4 66.6 (data size in MB) lzo zlib nocompress copy: 185.87 108.69 394.49 extract: 193.80 132.36 381.21 Changelog: v1 -> v2: - Select LZO_COMPRESS and LZO_DECOMPRESS in btrfs Kconfig. - Add incompability flag. - Fix error handling in compress code. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com>
* btrfs: Allow to add new compression algorithmLi Zefan2010-12-221-5/+231
| | | | | | | | | | 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: cleanup duplicate bio allocating functionsMiao Xie2010-11-221-14/+1
| | | | | | | | extent_bio_alloc() and compressed_bio_alloc() are similar, cleanup similar source code. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds2010-04-051-18/+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: use add_to_page_cache_lru, use __page_cache_allocNick Piggin2010-04-051-18/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | Pagecache pages should be allocated with __page_cache_alloc, so they obey pagecache memory policies. add_to_page_cache_lru is exported, so it should be used. Benefits over using a private pagevec: neater code, 128 bytes fewer stack used, percpu lru ordering is preserved, and finally don't need to flush pagevec before returning so batching may be shared with other LRU insertions. Signed-off-by: Nick Piggin <npiggin@suse.de>: Signed-off-by: Chris Mason <chris.mason@oracle.com>
* | include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: fix gfp flags masking in the compression codeNick Piggin2010-03-151-1/+1
| | | | | | GFP_FS must be masked out, NOFS can't be or'd in. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Merge branch 'master' of ↵Chris Mason2009-09-121-4/+4
|\ | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
| * Btrfs: switch extent_map to a rw lockChris Mason2009-09-111-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | There are two main users of the extent_map tree. The first is regular file inodes, where it is evenly spread between readers and writers. The second is the chunk allocation tree, which maps blocks from logical addresses to phyiscal ones, and it is 99.99% reads. The mapping tree is a point of lock contention during heavy IO workloads, so this commit switches things to a rw lock. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* | headers: smp_lock.h reduxAlexey Dobriyan2009-07-121-1/+0
|/ | | | | | | | | | | | | * Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSIONChristoph Hellwig2009-06-101-3/+3
| | | | | | | | | | | | | | | | | Add support for the standard attributes set via chattr and read via lsattr. Currently we store the attributes in the flags value in the btrfs inode, but I wonder whether we should split it into two so that we don't have to keep converting between the two formats. Remove the btrfs_clear_flag/btrfs_set_flag/btrfs_test_flag macros as they were confusing the existing code and got in the way of the new additions. Also add the FS_IOC_GETVERSION ioctl for getting i_generation as it's trivial. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: removed unused #include <version.h>'sHuang Weiyi2009-01-211-1/+0
| | | | | | | | Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix checkpatch.pl warningsChris Mason2009-01-061-6/+6
| | | | | | | 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: fix nodatasum handling in balancing codeYan Zheng2008-12-121-6/+3
| | | | | | | | | | | | | | | | | | | | | | Checksums on data can be disabled by mount option, so it's possible some data extents don't have checksums or have invalid checksums. This causes trouble for data relocation. This patch contains following things to make data relocation work. 1) make nodatasum/nodatacow mount option only affects new files. Checksums and COW on data are only controlled by the inode flags. 2) check the existence of checksum in the nodatacow checker. If checksums exist, force COW the data extent. This ensure that checksum for a given block is either valid or does not exist. 3) update data relocation code to properly handle the case of checksum missing. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: move data checksumming into a dedicated treeChris Mason2008-12-081-15/+109
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: compat code fixesChris Mason2008-11-201-1/+1
| | | | | | | | The btrfs git kernel trees is used to build a standalone tree for compiling against older kernels. This commit makes the standalone tree work with 2.6.27 Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fixes for 2.6.28-rc API changesChris Mason2008-11-201-2/+2
| | | | | | | | * open/close_bdev_excl -> open/close_bdev_exclusive * blkdev_issue_discard takes a GFP mask now * Fix blkdev_issue_discard usage now that it is enabled Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix compile warnings on 32 bit machinesChris Mason2008-11-111-1/+2
| | | | | | | Simple casting here and there to fix things up. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix use after free during compressed readsChris Mason2008-11-101-1/+6
| | | | | | | | Yan's fix to use the correct file offset during compressed reads used the extent_map struct pointer after it had been freed. This saves the fields we want for later use instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix csum error for compressed dataYan Zheng2008-11-101-4/+2
| | | | | | | | | | | | | The decompress code doesn't take the logical offset in extent pointer into account. If the logical offset isn't zero, data will be decompressed into wrong pages. The solution used here is to record the starting offset of the extent in the file separately from the logical start of the extent_map struct. This allows us to avoid problems inserting overlapping extents. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: make sure compressed bios don't complete too soonChris Mason2008-11-071-2/+15
| | | | | | | | | | | | | | | | | | When writing a compressed extent, a number of bios are created that point to a single struct compressed_bio. At end_io time an atomic counter in the compressed_bio struct makes sure that all of the bios have finished before final end_io processing is done. But when multiple bios are needed to write a compressed extent, the counter was being incremented after the first bio was sent to submit_bio. It is possible the bio will complete before the counter is incremented, making the end_io handler free the compressed_bio struct before processing is finished. The fix is to increment the atomic counter before bio submission, both for compressed reads and writes. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Optimize compressed writeback and readsChris Mason2008-11-071-5/+145
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Compression corner fixesChris Mason2008-10-311-0/+4
| | | | | | | | | | | | | | | | | | | | | Make sure we keep page->mapping NULL on the pages we're getting via alloc_page. It gets set so a few of the callbacks can do the right thing, but in general these pages don't have a mapping. Don't try to truncate compressed inline items in btrfs_drop_extents. The whole compressed item must be preserved. Don't try to create multipage inline compressed items. When we try to overwrite just the first page of the file, we would have to read in and recow all the pages after it in the same compressed inline items. For now, only create single page inline items. Make sure we lock pages in the correct order during delalloc. The search into the state tree for delalloc bytes can return bytes before the page we already have locked. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: walk compressed pages based on the nr_pages count instead of bytesChris Mason2008-10-301-2/+5
| | | | | | | The byte walk counting was awkward and error prone. This uses the number of pages sent the higher layer to build bios. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add zlib compression supportChris Mason2008-10-291-0/+454
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>