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path: root/fs/btrfs/file-item.c
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2009-03-24Btrfs: leave btree locks spinning more oftenChris Mason
btrfs_mark_buffer dirty would set dirty bits in the extent_io tree for the buffers it was dirtying. This may require a kmalloc and it was not atomic. So, anyone who called btrfs_mark_buffer_dirty had to set any btree locks they were holding to blocking first. This commit changes dirty tracking for extent buffers to just use a flag in the extent buffer. Now that we have one and only one extent buffer per page, this can be safely done without losing dirty bits along the way. This also introduces a path->leave_spinning flag that callers of btrfs_search_slot can use to indicate they will properly deal with a path returned where all the locks are spinning instead of blocking. Many of the btree search callers now expect spinning paths, resulting in better btree concurrency overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-06Btrfs: tree logging checksum fixesYan Zheng
This patch contains following things. 1) Limit the max size of btrfs_ordered_sum structure to PAGE_SIZE. This struct is kmalloced so we want to keep it reasonable. 2) Replace copy_extent_csums by btrfs_lookup_csums_range. This was duplicated code in tree-log.c 3) Remove replay_one_csum. csum items are replayed at the same time as replaying file extents. This guarantees we only replay useful csums. 4) nbytes accounting fix. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-01-05Btrfs: Fix checkpatch.pl warningsChris Mason
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>
2008-12-17Btrfs: properly check free space for tree balancingYan Zheng
btrfs_insert_empty_items takes the space needed by the btrfs_item structure into account when calculating the required free space. So the tree balancing code shouldn't add sizeof(struct btrfs_item) to the size when checking the free space. This patch removes these superfluous additions. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-16Btrfs: delete checksum items before marking blocks freeChris Mason
Btrfs maintains a cache of blocks available for allocation in ram. The code that frees extents was marking the extents free and then deleting the checksum items. This meant it was possible the extent would be reallocated before the checksum item was actually deleted, leading to races and other problems as the checksums were updated for the newly allocated extent. The fix is to delete the checksum before marking the extent free. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-12Btrfs: fix nodatasum handling in balancing codeYan Zheng
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>
2008-12-10Btrfs: Delete csum items when freeing extentsChris Mason
This finishes off the new checksumming code by removing csum items for extents that are no longer in use. The trick is doing it without racing because a single csum item may hold csums for more than one extent. Extra checks are added to btrfs_csum_file_blocks to make sure that we are using the correct csum item after dropping locks. A new btrfs_split_item is added to split a single csum item so it can be split without dropping the leaf lock. This is used to remove csum bytes from the middle of an item. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-12-08Btrfs: move data checksumming into a dedicated treeChris Mason
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>
2008-12-02Btrfs: add support for multiple csum algorithmsJosef Bacik
This patch gives us the space we will need in order to have different csum algorithims at some point in the future. We save the csum algorithim type in the superblock, and use those instead of define's. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2008-11-10Btrfs: Use invalidatepage when writepage finds a page outside of i_sizeChris Mason
With all the recent fixes to the delalloc locking, it is now safe again to use invalidatepage inside the writepage code for pages outside of i_size. This used to deadlock against some of the code to write locked ranges of pages, but all of that has been fixed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-10-29Btrfs: Add zlib compression supportChris Mason
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>
2008-09-25Btrfs: Fix variable init during csum creationChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Lookup readpage checksums on bio submission againChris Mason
This optimization had been removed because I thought it was triggering csum errors. The real cause of the errors was elsewhere, and so this optimization is back. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Lower contention on the csum mutexChris Mason
This takes the csum mutex deeper in the call chain and releases it more often. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25btrfs_lookup_bio_sums seems broken, go back to the readpage_io_hook for nowChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Hold csum mutex while reading in sums during readpagesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix streaming read performance with checksumming onChris Mason
Large streaming reads make for large bios, which means each entry on the list async work queues represents a large amount of data. IO congestion throttling on the device was kicking in before the async worker threads decided a single thread was busy and needed some help. The end result was that a streaming read would result in a single CPU running at 100% instead of balancing the work off to other CPUs. This patch also changes the pre-IO checksum lookup done by reads to work on a per-bio basis instead of a per-page. This results in many extra btree lookups on large streaming reads. Doing the checksum lookup right before bio submit allows us to reuse searches while processing adjacent offsets. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: implement memory reclaim for leaf reference cacheYan
The memory reclaiming issue happens when snapshot exists. In that case, some cache entries may not be used during old snapshot dropping, so they will remain in the cache until umount. The patch adds a field to struct btrfs_leaf_ref to record create time. Besides, the patch makes all dead roots of a given snapshot linked together in order of create time. After a old snapshot was completely dropped, we check the dead root list and remove all cache entries created before the oldest dead root in the list. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Take the csum mutex while reading checksumsChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Fix btrfs_wait_ordered_extent_range to properly waitChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Keep extent mappings in ram until pending ordered extents are doneChris Mason
It was possible for stale mappings from disk to be used instead of the new pending ordered extent. This adds a flag to the extent map struct to keep it pinned until the pending ordered extent is actually on disk. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Handle data checksumming on bios that span multiple ordered extentsChris Mason
Data checksumming is done right before the bio is sent down the IO stack, which means a single bio might span more than one ordered extent. In this case, the checksumming data is split between two ordered extents. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: New data=ordered implementationChris Mason
The old data=ordered code would force commit to wait until all the data extents from the transaction were fully on disk. This introduced large latencies into the commit and stalled new writers in the transaction for a long time. The new code changes the way data allocations and extents work: * When delayed allocation is filled, data extents are reserved, and the extent bit EXTENT_ORDERED is set on the entire range of the extent. A struct btrfs_ordered_extent is allocated an inserted into a per-inode rbtree to track the pending extents. * As each page is written EXTENT_ORDERED is cleared on the bytes corresponding to that page. * When all of the bytes corresponding to a single struct btrfs_ordered_extent are written, The previously reserved extent is inserted into the FS btree and into the extent allocation trees. The checksums for the file data are also updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Clone file data ioctlSage Weil
Add a new ioctl to clone file data Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Write bio checksumming outside the FS mutexChris Mason
This significantly improves streaming write performance by allowing concurrency in the data checksumming. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Use KM_USERN instead of KM_IRQ during data summingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Make sure bio pages are adjacent during bulk csummingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: While doing checksums on bios, cache the extent_buffer mappingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: checksum file data at bio submission time instead of during writepageChris Mason
When we checkum file data during writepage, the checksumming is done one page at a time, making it difficult to do bulk metadata modifications to insert checksums for large ranges of the file at once. This patch changes btrfs to checksum on a per-bio basis instead. The bios are checksummed before they are handed off to the block layer, so each bio is contiguous and only has pages from the same inode. Checksumming on a bio basis allows us to insert and modify the file checksum items in large groups. It also allows the checksumming to be done more easily by async worker threads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add some extra debugging around file data checksum failuresChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix a number of inline extent problems that Yan Zheng reported.Chris Mason
The fixes do a number of things: 1) Most btrfs_drop_extent callers will try to leave the inline extents in place. It can truncate bytes off the beginning of the inline extent if required. 2) writepage can now update the inline extent, allowing mmap writes to go directly into the inline extent. 3) btrfs_truncate_in_transaction truncates inline extents 4) extent_map.c fixed to not merge inline extent mappings and hole mappings together Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Minor fix for btrfs_csum_file_block.Yan
Execution should goto label 'insert' when 'btrfs_next_leaf' return a non-zero value, otherwise the parameter 'slot' for 'btrfs_item_key_to_cpu' may be out of bounds. The original codes jump to label 'insert' only when 'btrfs_next_leaf' return a negative value. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Optimize csum insertion to create larger items when possibleChris Mason
This reduces the number of calls to btrfs_extend_item and greatly lowers the cpu usage while writing large files. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add back file data checksummingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Allow tree blocks larger than the page sizeChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Create extent_buffer interface for large blocksizesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-07-11Btrfs: trivial include fixupsZach Brown
Almost none of the files including module.h need to do so, remove them. Include sched.h in extent-tree.c to silence a warning about cond_resched() being undeclared. Signed-off-by: Zach Brown <zach.brown@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-22Btrfs: Audit callers and return codes to make sure -ENOSPC gets up the stackChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-18Subject: Rework btrfs_file_write to only allocate while page locks are heldChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-15Btrfs: patch queue: page_mkwriteChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-13btrfs: Code cleanupAneesh
Attaching below is some of the code cleanups that i came across while reading the code. a) alloc_path already calls init_path. b) Mention that btrfs_inode is the in memory copy.Ext4 have ext4_inode_info as the in memory copy ext4_inode as the disk copy Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-12Btrfs: add GPLv2Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-12Btrfs: printk fixesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-12Btrfs: 64 bit div fixesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-05-29Btrfs: fixup various fsx failuresChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-05-24Btrfs: sparse files!Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-05-10Btrfs: switch to crc32c instead of sha256Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-19Btrfs: many file_write fixes, inline dataChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-18Btrfs: working file_write, reorganized key flagsChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-17Btrfs: rework csums and extent item orderingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>