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* 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: prevent looping forever in finish_current_insert and del_pending_extentsChris Mason2008-10-30
| | | | | | | | | | | | | | | | | finish_current_insert and del_pending_extents process extent tree modifications that build up while we are changing the extent tree. It is a confusing bit of code that prevents recursion. Both functions run through a list of pending operations and both funcs add to the list of pending operations. If you have two procs in either one of them, they can end up looping forever making more work for each other. This patch makes them walk forward through the list of pending changes instead of always trying to process the entire list. At transaction commit time, we catch any changes that were left over. Signed-off-by: Chris Mason <chris.mason@oracle.com>
* Btrfs: Rev the disk format for compression and root pointer generation fieldsChris Mason2008-10-29
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* Btrfs: Add root tree pointer transaction idsYan Zheng2008-10-29
| | | | | | | | | | | This patch adds transaction IDs to root tree pointers. Transaction IDs in tree pointers are compared with the generation numbers in block headers when reading root blocks of trees. This can detect some types of IO errors. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
* Btrfs: nuke fs wide allocation mutex V2Josef Bacik2008-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch removes the giant fs_info->alloc_mutex and replaces it with a bunch of little locks. There is now a pinned_mutex, which is used when messing with the pinned_extents extent io tree, and the extent_ins_mutex which is used with the pending_del and extent_ins extent io trees. The locking for the extent tree stuff was inspired by a patch that Yan Zheng wrote to fix a race condition, I cleaned it up some and changed the locking around a little bit, but the idea remains the same. Basically instead of holding the extent_ins_mutex throughout the processing of an extent on the extent_ins or pending_del trees, we just hold it while we're searching and when we clear the bits on those trees, and lock the extent for the duration of the operations on the extent. Also to keep from getting hung up waiting to lock an extent, I've added a try_lock_extent so if we cannot lock the extent, move on to the next one in the tree and we'll come back to that one. I have tested this heavily and it does not appear to break anything. This has to be applied on top of my find_free_extent redo patch. I tested this patch on top of Yan's space reblancing code and it worked fine. The only thing that has changed since the last version is I pulled out all my debugging stuff, apparently I forgot to run guilt refresh before I sent the last patch out. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com>
* Btrfs: fix enospc when there is plenty of spaceJosef Bacik2008-10-29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So there is an odd case where we can possibly return -ENOSPC when there is in fact space to be had. It only happens with Metadata writes, and happens _very_ infrequently. What has to happen is we have to allocate have allocated out of the first logical byte on the disk, which would set last_alloc to first_logical_byte(root, 0), so search_start == orig_search_start. We then need to allocate for normal metadata, so BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DUP. We will do a block lookup for the given search_start, block_group_bits() won't match and we'll go to choose another block group. However because search_start matches orig_search_start we go to see if we can allocate a chunk. If we are in the situation that we cannot allocate a chunk, we fail and ENOSPC. This is kind of a big flaw of the way find_free_extent works, as it along with find_free_space loop through _all_ of the block groups, not just the ones that we want to allocate out of. This patch completely kills find_free_space and rolls it into find_free_extent. I've introduced a sort of state machine into this, which will make it easier to get cache miss information out of the allocator, and will work well with my locking changes. The basic flow is this: We have the variable loop which is 0, meaning we are in the hint phase. We lookup the block group for the hint, and lookup the space_info for what we want to allocate out of. If the block group we were pointed at by the hint either isn't of the correct type, or just doesn't have the space we need, we set head to space_info->block_groups, so we start at the beginning of the block groups for this particular space info, and loop through. This is also where we add the empty_cluster to total_needed. At this point loop is set to 1 and we just loop through all of the block groups for this particular space_info looking for the space we need, just as find_free_space would have done, except we only hit the block groups we want and not _all_ of the block groups. If we come full circle we see if we can allocate a chunk. If we cannot of course we exit with -ENOSPC and we are good. If not we start over at space_info->block_groups and loop through again, with loop == 2. If we come full circle and haven't found what we need then we exit with -ENOSPC. I've been running this for a couple of days now and it seems stable, and I haven't yet hit a -ENOSPC when there was plenty of space left. Also I've made a groups_sem to handle the group list for the space_info. This is part of my locking changes, but is relatively safe and seems better than holding the space_info spinlock over that entire search time. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com>
* Btrfs: Improve space balancing codeYan Zheng2008-10-29
| | | | | | | | | | | | | | | | | | | | | This patch improves the space balancing code to keep more sharing of tree blocks. The only case that breaks sharing of tree blocks is data extents get fragmented during balancing. The main changes in this patch are: Add a 'drop sub-tree' function. This solves the problem in old code that BTRFS_HEADER_FLAG_WRITTEN check breaks sharing of tree block. Remove relocation mapping tree. Relocation mappings are stored in struct btrfs_ref_path and updated dynamically during walking up/down the reference path. This reduces CPU usage and simplifies code. This patch also fixes a bug. Root items for reloc trees should be updated in btrfs_free_reloc_root. Signed-off-by: Yan Zheng <zheng.yan@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>
* Merge branch 'master' of ↵Chris Mason2008-10-16
|\ | | | | | | ssh://mason@master.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable
| * Btrfs: make tree_search_offset more flexible in its searchingJosef Bacik2008-10-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Sometimes we end up freeing a reserved extent because we don't need it, however this means that its possible for transaction->last_alloc to point to the middle of a free area. When we search for free space in find_free_space we do a tree_search_offset with contains set to 0, because we want it to find the next best free area if we do not have an offset starting on the given offset. Unfortunately that currently means that if the offset we were given as a hint points to the middle of a free area, we won't find anything. This is especially bad if we happened to last allocate from the big huge chunk of a newly formed block group, since we won't find anything and have to go back and search the long way around. This fixes this problem by making it so that we return the free space area regardless of the contains variable. This made cache missing happen _alot_ less, and speeds things up considerably. Signed-off-by: Josef Bacik <jbacik@redhat.com>
| * Btrfs: Don't call security_inode_mkdir during subvol creationChris Mason2008-10-10
| | | | | | | | | | | | | | | | Subvol creation already requires privs, and security_inode_mkdir isn't exported. For now we don't need it. 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: Rev the disk format for the new back reference formatChris Mason2008-10-09
| | | | | | | | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: Fix makefile for builing btrfs staticSage Weil2008-10-09
| | | | | | | | | | | | | | | | This fixes the btrfs makefile for building in the tree and out of the tree both as a module and static. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * 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: remove last_log_alloc allocator optimizationChris Mason2008-10-03
| | | | | | | | | | | | | | | | | | | | | | | | | | The tree logging code was trying to separate tree log allocations from normal metadata allocations to improve writeback patterns during an fsync. But, the code was not effective and ended up just mixing tree log blocks with regular metadata. That seems to be working fairly well, so the last_log_alloc code can be removed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: O_DIRECT writes via buffered writes + invaldiateChris Mason2008-10-03
| | | | | | | | | | | | | | | | | | | | | | | | | | 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: 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: fix deadlock between alloc_mutex/chunk_mutexJosef Bacik2008-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes a deadlock that happens between the alloc_mutex and chunk_mutex. Process A comes in, decides to do a do_chunk_alloc, which takes the chunk_mutex, and is holding the alloc_mutex because the only way you get to do_chunk_alloc is by holding the alloc_mutex. btrfs_alloc_chunk does its thing and goes to insert a new item, which results in a cow of the block. We get into del_pending_extents from there, where if we need to be rescheduled we drop the alloc_mutex and schedule. At this point process B comes in to do an allocation and gets the alloc_mutex, and because process A did not do the chunk allocation completely it thinks its a good time to do a chunk allocation as well, and hangs on the chunk_mutex. Process A wakes up and tries to take the alloc_mutex and cannot. The way to fix this is do a mutex_trylock() on chunk_mutex. If we return 0 we didn't get the lock, and if this is just a "hey it may be a good time to allocate a chunk" then we just exit. If we are trying to force an allocation then we reschedule and keep trying to acquire the chunk_mutex. If once we acquire it the space is already full then we can just exit, otherwise we can continue with the chunk allocation. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com>
| * Btrfs: disk-io.c (open_ctree): avoid leaks upon allocation failureJim Meyering2008-10-01
| | | | | | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: disk-io.c (open_ctree): Don't deref. NULL upon failed kzallocJim Meyering2008-10-01
| | | | | | | | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: fix multi-device code to use raid policies set by mkfsChris Mason2008-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When reading in block groups, a global mask of the available raid policies should be adjusted based on the types of block groups found on disk. This global mask is then used to decide which raid policy to use for new block groups. The recent allocator changes dropped the call that updated the global mask, making all the block groups allocated at run time single striped onto a single drive. This also fixes the async worker threads to set any thread that uses the requeue mechanism as busy. This allows us to avoid blocking on get_request_wait for the async bio submission threads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: fix seekiness due to finding the wrong block groupJosef Bacik2008-09-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch fixes a problem where we end up seeking too much when *last_ptr is valid. This happens because btrfs_lookup_first_block_group only returns a block group that starts on or after the given search start, so if the search_start is in the middle of a block group it will return the block group after the given search_start, which is suboptimal. This patch fixes that by doing a btrfs_lookup_block_group, which will return the block group that contains the given search start. If we fail to find a block group, we fall back on btrfs_lookup_first_block_group so we can find the next block group, not sure if this is absolutely needed, but better safe than sorry. Also if we can't find the block group that we need, or it happens to not be of the right type, we need to add empty_cluster since *last_ptr could point to a mismatched block group, which means we need to start over with empty_cluster added to total needed. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com> 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: drop WARN_ON from btrfs_add_leaf_refChris Mason2008-09-29
| | | | | | | | | | | | | | | | | | | | | | | | btrfs_add_leaf_ref was doing checks on the objects it found in the rbtree to make sure they were properly linked into the tree. But, the field it was checking can be safely changed outside of the tree spin lock. The WARN_ON was for debugging the initial implementation and can be safely removed. 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: update space balancing codeZheng Yan2008-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch updates the space balancing code to utilize the new backref format. Before, btrfs-vol -b would break any COW links on data blocks or metadata. This was slow and caused the amount of space used to explode if a large number of snapshots were present. The new code can keeps the sharing of all data extents and most of the tree blocks. To maintain the sharing of data extents, the space balance code uses a seperate inode hold data extent pointers, then updates the references to point to the new location. To maintain the sharing of tree blocks, the space balance code uses reloc trees to relocate tree blocks in reference counted roots. There is one reloc tree for each subvol, and all reloc trees share same root key objectid. Reloc trees are snapshots of the latest committed roots of subvols (root->commit_root). To relocate a tree block referenced by a subvol, there are two steps. COW the block through subvol's reloc tree, then update block pointer in the subvol to point to the new block. Since all reloc trees share same root key objectid, doing special handing for tree blocks owned by them is easy. Once a tree block has been COWed in one reloc tree, we can use the resulting new block directly when the same block is required to COW again through other reloc trees. In this way, relocated tree blocks are shared between reloc trees, so they are also shared between subvols. 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>
| * Btrfs: Add shared reference cacheZheng Yan2008-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs has a cache of reference counts in leaves, allowing it to avoid reading tree leaves while deleting snapshots. To reduce contention with multiple subvolumes, this cache is private to each subvolume. This patch adds shared reference cache support. The new space balancing code plays with multiple subvols at the same time, So the old per-subvol reference cache is not well suited. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: allocator fixes for space balancing updateZheng Yan2008-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | * Reserved extent accounting: reserved extents have been allocated in the rbtrees that track free space but have not been allocated on disk. They were never properly accounted for in the past, making it hard to know how much space was really free. * btrfs_find_block_group used to return NULL for block groups that had been removed by the space balancing code. This made it hard to account for space during the final stages of a balance run. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: Raise thresholds for metadata writebackChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | | | Btrfs metadata writeback is fairly expensive. Once a tree block is written it must be cowed before it can be changed again. The btree writepages code has a threshold based on a count of dirty btree bytes which is updated as IO is sent out. This changes btree_writepages to skip the writeout if there are less than 32MB of dirty bytes from the btrees, improving performance across many workloads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Btrfs: fix sleep with spinlock held during unmountChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | The code to free block groups needs to drop the space info spin lock before calling btrfs_remove_free_space_cache (which can schedule). This is safe because at unmount time, nobody else is going to play with the block groups. 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 allocation completions in tree log replayChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | After a crash, the tree log code uses btrfs_alloc_logged_extent to record allocations of data extents that it finds in the log tree. These come in basically random order, which does not fit how btrfs_remove_free_space() expects to be called. btrfs_remove_free_space was changed to support recording an extent allocation in the middle of a region of free space. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Add Btrfs to fs/Kconfig and fs/MakefileChris Mason2008-09-25
| | | | | | | | Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Update Btrfs files for in-kernel usageChris Mason2008-09-25
| | | | | | | | | | | | | | | | btrfs had magic to put the chagneset id into a printk on module load. This removes that from the Makefile and hardcodes the printk to print "Btrfs" Signed-off-by: Chris Mason <chris.mason@oracle.com>
| * Merge Btrfs into fs/btrfsChris Mason2008-09-25
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| | * 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>
| | * Add check for tree-log roots in btrfs_alloc_reserved_extentsChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | Tree log blocks are only reserved, and should not ever get fully allocated on disk. This check makes sure they stay out of the extent tree. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * Btrfs: Checksum tree blocks in the backgroundChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | Tree blocks were using async bio submission, but the sum was still being done directly during writepage. This moves the checksumming into the worker thread. 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: fix cache_block_group error handlingJosef Bacik2008-09-25
| | | | | | | | | | | | | | | | | | | | | | | | cache block group had a few bugs in the error handling code, this makes sure paths get properly released and the correct return value goes out. Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * Fix leaf overflow check in btrfs_insert_empty_itemsChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | It was incorrectly adding an extra sizeof(struct btrfs_item) and causing false positives (oops) Signed-off-by: Chris Mason <chris.mason@oracle.com>
| | * Btrfs: Fix mismerge in block header checksChris Mason2008-09-25
| | | | | | | | | | | | | | | | | | | | | I had incorrectly disabled the check for the block number being correct in the header block. Signed-off-by: Chris Mason <chris.mason@oracle.com>