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path: root/fs/btrfs/inode.c
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* Btrfs: mount ro and remount supportYan Zheng2008-11-12
| | | | | | | | | | | This patch adds mount ro and remount support. The main changes in patch are: adding btrfs_remount and related helper function; splitting the transaction related code out of close_ctree into btrfs_commit_super; updating allocator to properly handle read only block group. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: Fix compile warnings on 32 bit machinesChris Mason2008-11-11
| | | | | | | Simple casting here and there to fix things up. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix usage of struct extent_map->orig_startChris Mason2008-11-10
| | | | | | | This makes sure the orig_start field in struct extent_map gets set everywhere the extent_map structs are created or modified. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix csum error for compressed dataYan Zheng2008-11-10
| | | | | | | | | | | | | 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: Optimize compressed writeback and readsChris Mason2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 ordered async work queuesChris Mason2008-11-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs uses kernel threads to create async work queues for cpu intensive operations such as checksumming and decompression. These work well, but they make it difficult to keep IO order intact. A single writepages call from pdflush or fsync will turn into a number of bios, and each bio is checksummed in parallel. Once the checksum is computed, the bio is sent down to the disk, and since we don't control the order in which the parallel operations happen, they might go down to the disk in almost any order. The code deals with this somewhat by having deep work queues for a single kernel thread, making it very likely that a single thread will process all the bios for a single inode. This patch introduces an explicitly ordered work queue. As work structs are placed into the queue they are put onto the tail of a list. They have three callbacks: ->func (cpu intensive processing here) ->ordered_func (order sensitive processing here) ->ordered_free (free the work struct, all processing is done) The work struct has three callbacks. The func callback does the cpu intensive work, and when it completes the work struct is marked as done. Every time a work struct completes, the list is checked to see if the head is marked as done. If so the ordered_func callback is used to do the order sensitive processing and the ordered_free callback is used to do any cleanup. Then we loop back and check the head of the list again. This patch also changes the checksumming code to use the ordered workqueues. One a 4 drive array, it increases streaming writes from 280MB/s to 350MB/s. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Compression corner fixesChris Mason2008-10-31
| | | | | | | | | | | | | | | | | | | | | 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: Add fallocate support v2Yan Zheng2008-10-30
| | | | | | | | | | | | 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 Zheng2008-10-30
| | | | | | | | | | 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: Fix bookend extent race v2Yan Zheng2008-10-30
| | | | | | | | | | | | | When dropping middle part of an extent, btrfs_drop_extents truncates the extent at first, then inserts a bookend extent. Since truncation and insertion can't be done atomically, there is a small period that the bookend extent isn't in the tree. This causes problem for functions that search the tree for file extent item. The way to fix this is lock the range of the bookend extent before truncation. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: update hole handling v2Yan Zheng2008-10-30
| | | | | | | | | This patch splits the hole insertion code out of btrfs_setattr into btrfs_cont_expand and updates btrfs_get_extent to properly handle the case that file extent items are not continuous. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: Fix logic to avoid reading checksums for -o nodatasum,compressChris Mason2008-10-30
| | | | | | | | When compression was on, we were improperly ignoring -o nodatasum. This reworks the logic a bit to properly honor all the flags. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: walk compressed pages based on the nr_pages count instead of bytesChris Mason2008-10-30
| | | | | | | 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 Mason2008-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Fix subvolume creation locking rulesChristoph Hellwig2008-10-09
| | | | | | | | | | | | | | | | | Creating a subvolume is in many ways like a normal VFS ->mkdir, and we really need to play with the VFS topology locking rules. So instead of just creating the snapshot on disk and then later getting rid of confliting aliases do it correctly from the start. This will become especially important once we allow for subvolumes anywhere in the tree, and not just below a hidden root. Note that snapshots will need the same treatment, but do to the delay in creating them we can't do it currently. Chris promised to fix that issue, so I'll wait on that. Signed-off-by: Christoph Hellwig <hch@lst.de>
* Btrfs: Fix leaf reference cache missYan Zheng2008-10-09
| | | | | | | | | | | | Due to the optimization for truncate, tree leaves only containing checksum items can be deleted without being COW'ed first. This causes reference cache misses. The way to fix the miss is create cache entries for tree leaves only contain checksum. This patch also fixes a -EEXIST issue in shared reference cache. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: Remove offset field from struct btrfs_extent_refYan Zheng2008-10-09
| | | | | | | | | | | | | | The offset field in struct btrfs_extent_ref records the position inside file that file extent is referenced by. In the new back reference system, tree leaves holding references to file extent are recorded explicitly. We can scan these tree leaves very quickly, so the offset field is not required. This patch also makes the back reference system check the objectid when extents are in deleting. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: Count space allocated to file in bytesYan Zheng2008-10-09
| | | | | | | | | | | This patch makes btrfs count space allocated to file in bytes instead of 512 byte sectors. Everything else in btrfs uses a byte count instead of sector sizes or blocks sizes, so this fits better. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: cast bio->bi_sector to a u64 before shiftingChris Mason2008-10-03
| | | | | | | | On 32 bit machines without CONFIG_LBD, the bi_sector field is only 32 bits. Btrfs needs to cast it before shifting up, or we end up doing IO into the wrong place. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: don't read leaf blocks containing only checksums during truncateChris Mason2008-10-01
| | | | | | | | | | | | | | | | | | Checksum items take up a significant portion of the metadata for large files. It is possible to avoid reading them during truncates by checking the keys in the higher level nodes. If a given leaf is followed by another leaf where the lowest key is a checksum item from the same file, we know we can safely delete the leaf without reading it. For a 32GB file on a 6 drive raid0 array, Btrfs needs 8s to delete the file with a cold cache. It is read bound during the run. With this change, Btrfs is able to delete the file in 0.5s Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: add and improve commentsChris Mason2008-09-29
| | | | | | | | | | | 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: Wait for IO on the block device inodes of newly added devicesChris Mason2008-09-29
| | | | | | | | | | | | | | | | | | | btrfs-vol -a /dev/xxx will zero the first and last two MB of the device. The kernel code needs to wait for this IO to finish before it adds the device. btrfs metadata IO does not happen through the block device inode. A separate address space is used, allowing the zero filled buffer heads in the block device inode to be written to disk after FS metadata starts going down to the disk via the btrfs metadata inode. The end result is zero filled metadata blocks after adding new devices into the filesystem. The fix is a simple filemap_write_and_wait on the block device inode before actually inserting it into the pool of available devices. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: extent_map and data=ordered fixes for space balancingZheng Yan2008-09-26
| | | | | | | | | | | | | | | | | | | | | * 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>
* Remove Btrfs compat code for older kernelsChris Mason2008-09-25
| | | | | | | | Btrfs had compatibility code for kernels back to 2.6.18. These have been removed, and will be maintained in a separate backport git tree from now on. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix race against disk_i_size updatesChris Mason2008-09-25
| | | | | | | | | | | | | | The code to update the on disk i_size happens before the ordered_extent record is removed. So, it is possible for multiple ordered_extent completion routines to run at the same time, and to find each other in the ordered tree. The end result is they both decide not to update disk_i_size, leaving it too small. This temporary fix just puts the updates inside the extent_mutex. A real solution would be stronger ordering of disk_i_size updates against removing the ordered extent from the tree. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Full back reference supportZheng Yan2008-09-25
| | | | | | | | | | This patch makes the back reference system to explicit record the location of parent node for all types of extents. The location of parent node is placed into the offset field of backref key. Every time a tree block is balanced, the back references for the affected lower level extents are updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: free space accounting redoJosef Bacik2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 1) replace the per fs_info extent_io_tree that tracked free space with two rb-trees per block group to track free space areas via offset and size. The reason to do this is because most allocations come with a hint byte where to start, so we can usually find a chunk of free space at that hint byte to satisfy the allocation and get good space packing. If we cannot find free space at or after the given offset we fall back on looking for a chunk of the given size as close to that given offset as possible. When we fall back on the size search we also try to find a slot as close to the size we want as possible, to avoid breaking small chunks off of huge areas if possible. 2) remove the extent_io_tree that tracked the block group cache from fs_info and replaced it with an rb-tree thats tracks block group cache via offset. also added a per space_info list that tracks the block group cache for the particular space so we can lookup related block groups easily. 3) cleaned up the allocation code to make it a little easier to read and a little less complicated. Basically there are 3 steps, first look from our provided hint. If we couldn't find from that given hint, start back at our original search start and look for space from there. If that fails try to allocate space if we can and start looking again. If not we're screwed and need to start over again. 4) small fixes. there were some issues in volumes.c where we wouldn't allocate the rest of the disk. fixed cow_file_range to actually pass the alloc_hint, which has helped a good bit in making the fs_mark test I run have semi-normal results as we run out of space. Generally with data allocations we don't track where we last allocated from, so everytime we did a data allocation we'd search through every block group that we have looking for free space. Now searching a block group with no free space isn't terribly time consuming, it was causing a slight degradation as we got more data block groups. The alloc_hint has fixed this slight degredation and made things semi-normal. There is still one nagging problem I'm working on where we will get ENOSPC when there is definitely plenty of space. This only happens with metadata allocations, and only when we are almost full. So you generally hit the 85% mark first, but sometimes you'll hit the BUG before you hit the 85% wall. I'm still tracking it down, but until then this seems to be pretty stable and make a significant performance gain. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Dir fsync optimizationsChris Mason2008-09-25
| | | | | | | | | | | Drop i_mutex during the commit Don't bother doing the fsync at all unless the dir is marked as dirtied and needing fsync in this transaction. For directories, this means that someone has unlinked a file from the dir without fsyncing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix releasepage to properly keep dirty and writeback pagesChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Update the highest objectid in a root after log replay is doneChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* remove unused function btrfs_ilookupChristoph Hellwig2008-09-25
| | | | | | | | btrfs_ilookup is unused, which is good because a normal filesystem should never have to use ilookup anyway. Remove it. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Add a write ahead tree log to optimize synchronous operationsChris Mason2008-09-25
| | | | | | | | | | | File syncs and directory syncs are optimized by copying their items into a special (copy-on-write) log tree. There is one log tree per subvolume and the btrfs super block points to a tree of log tree roots. After a crash, items are copied out of the log tree and back into the subvolume. See tree-log.c for all the details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: optimize btrget/set/removexattrChristoph Hellwig2008-09-25
| | | | | | | | | | | | btrfs actually stores the whole xattr name, including the prefix ondisk, so using the generic resolver that strips off the prefix is not very helpful. Instead do the real ondisk xattrs manually and only use the generic resolver for synthetic xattrs like ACLs. (Sorry Josef for guiding you towards the wrong direction here intially) Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Optimise NFS readdir hack slightly; don't call readdir() again when doneDavid Woodhouse2008-09-25
| | | | | | Date: Sun, 17 Aug 2008 17:12:56 +0100 Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Minor cleanup of btrfs_real_readdir()David Woodhouse2008-09-25
| | | | | | Date: Sun, 17 Aug 2008 17:08:36 +0100 Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Remove special cases for "." and ".."David Woodhouse2008-09-25
| | | | | | | | | Date: Sun, 17 Aug 2008 15:14:48 +0100 We never get asked by the VFS to lookup either of them, and we can handle the readdir() case a lot more simply, too. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Implement our own copy of the nfsd readdir hack, for older kernelsDavid Woodhouse2008-09-25
| | | | | | Date: Wed, 6 Aug 2008 19:42:33 +0100 Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Introduce btrfs_iget helperBalaji Rao2008-09-25
| | | | | | | | | Date: Mon, 21 Jul 2008 02:01:04 +0530 This patch introduces a btrfs_iget helper to be used in NFS support. Signed-off-by: Balaji Rao <balajirrao@gmail.com> Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Lookup readpage checksums on bio submission againChris Mason2008-09-25
| | | | | | | | 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>
* Btrfs: Fix add_extent_mapping to check for duplicates across the whole rangeChris Mason2008-09-25
| | | | | | | | | | | | add_extent_mapping was allowing the insertion of overlapping extents. This never used to happen because it only inserted the extents from disk and those were never overlapping. But, with the data=ordered code, the disk and memory representations of the file are not the same. add_extent_mapping needs to ensure a new extent does not overlap before it inserts. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Lower contention on the csum mutexChris Mason2008-09-25
| | | | | | | This takes the csum mutex deeper in the call chain and releases it more often. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Init address_space->writeback_index properlyChris Mason2008-09-25
| | | | | | | | | | | The writeback_index field is used by write_cache_pages to pick up where writeback on a given inode left off. But, it is never set to a sane value, so writeback can often start at a random offset in the file. Kernels 2.6.28 and higher will have this fixed, but for everyone else, we also fill in the value in btrfs. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Avoid calling into the FS for the final iput on fake root inodesChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix nodatacow for the new data=ordered modeYan Zheng2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Get rid of BTRFS_I(inode)->index and use local vars insteadChris Mason2008-09-25
| | | | | | | | rename and link don't always have a lock on the source inode, and our use of a per-inode index variable was racy. This changes things to store the index in a local variable instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* btrfs_lookup_bio_sums seems broken, go back to the readpage_io_hook for nowChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Maintain a list of inodes that are delalloc and a way to wait on themChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Hold csum mutex while reading in sums during readpagesChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Drop some debugging around the extent_map pinned flagChris Mason2008-09-25
| | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Fix streaming read performance with checksumming onChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | 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>