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2009-07-24Btrfs: make flushoncommit mount option correctly wait on ordered_extentsSage Weil
The commit_transaction call to wait_ordered_extents when snap_pending passes nocow_only=1 to process only NOCOW or PREALLOC extents. This isn't correct for the 'flushoncommit' mode, as it skips extents we just started IO on in start_delalloc_inodes. So, in the flushoncommit case, wait on all ordered extents. Otherwise, only pass the nocow_only flag to wait_ordered_extents if snap_pending. Signed-off-by: Sage Weil <sage@newdream.net> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: Avoid delayed reference update loopingYan Zheng
btrfs_split_leaf and btrfs_del_items can end up in a loop where one is constantly spliting a given leaf and the other is constantly merging it back with the adjacent nodes. There is a better fix for this, but in the interest of something small, this patch just changes btrfs_del_items back to balancing less often. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: Fix ordering of key field checks in btrfs_previous_itemYan Zheng
Check objectid of item before checking the item type, otherwise we may return zero for a key that is actually too low. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: find_free_dev_extent doesn't handle holes at the start of the deviceYan Zheng
find_free_dev_extent does not properly handle the case where the device is not complete free, and there is a free extent at the beginning of the device. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: Remove code duplication in comp_keysDiego Calleja
comp_keys is duplicating what is done in btrfs_comp_cpu_keys, so just call it. Signed-off-by: Diego Calleja <diegocg@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: async block group cachingJosef Bacik
This patch moves the caching of the block group off to a kthread in order to allow people to allocate sooner. Instead of blocking up behind the caching mutex, we instead kick of the caching kthread, and then attempt to make an allocation. If we cannot, we wait on the block groups caching waitqueue, which the caching kthread will wake the waiting threads up everytime it finds 2 meg worth of space, and then again when its finished caching. This is how I tested the speedup from this mkfs the disk mount the disk fill the disk up with fs_mark unmount the disk mount the disk time touch /mnt/foo Without my changes this took 11 seconds on my box, with these changes it now takes 1 second. Another change thats been put in place is we lock the super mirror's in the pinned extent map in order to keep us from adding that stuff as free space when caching the block group. This doesn't really change anything else as far as the pinned extent map is concerned, since for actual pinned extents we use EXTENT_DIRTY, but it does mean that when we unmount we have to go in and unlock those extents to keep from leaking memory. I've also added a check where when we are reading block groups from disk, if the amount of space used == the size of the block group, we go ahead and mark the block group as cached. This drastically reduces the amount of time it takes to cache the block groups. Using the same test as above, except doing a dd to a file and then unmounting, it used to take 33 seconds to umount, now it takes 3 seconds. This version uses the commit_root in the caching kthread, and then keeps track of how many async caching threads are running at any given time so if one of the async threads is still running as we cross transactions we can wait until its finished before handling the pinned extents. Thank you, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-24Btrfs: use hybrid extents+bitmap rb tree for free spaceJosef Bacik
Currently btrfs has a problem where it can use a ridiculous amount of RAM simply tracking free space. As free space gets fragmented, we end up with thousands of entries on an rb-tree per block group, which usually spans 1 gig of area. Since we currently don't ever flush free space cache back to disk this gets to be a bit unweildly on large fs's with lots of fragmentation. This patch solves this problem by using PAGE_SIZE bitmaps for parts of the free space cache. Initially we calculate a threshold of extent entries we can handle, which is however many extent entries we can cram into 16k of ram. The maximum amount of RAM that should ever be used to track 1 gigabyte of diskspace will be 32k of RAM, which scales much better than we did before. Once we pass the extent threshold, we start adding bitmaps and using those instead for tracking the free space. This patch also makes it so that any free space thats less than 4 * sectorsize we go ahead and put into a bitmap. This is nice since we try and allocate out of the front of a block group, so if the front of a block group is heavily fragmented and then has a huge chunk of free space at the end, we go ahead and add the fragmented areas to bitmaps and use a normal extent entry to track the big chunk at the back of the block group. I've also taken the opportunity to revamp how we search for free space. Previously we indexed free space via an offset indexed rb tree and a bytes indexed rb tree. I've dropped the bytes indexed rb tree and use only the offset indexed rb tree. This cuts the number of tree operations we were doing previously down by half, and gives us a little bit of a better allocation pattern since we will always start from a specific offset and search forward from there, instead of searching for the size we need and try and get it as close as possible to the offset we want. I've given this a healthy amount of testing pre-new format stuff, as well as post-new format stuff. I've booted up my fedora box which is installed on btrfs with this patch and ran with it for a few days without issues. I've not seen any performance regressions in any of my tests. Since the last patch Yan Zheng fixed a problem where we could have overlapping entries, so updating their offset inline would cause problems. Thanks, Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: Fix crash on read failures at mountDavid Woodhouse
If the tree roots hit read errors during mount, btrfs is not properly erroring out. We need to check the uptodate bits after reading in the tree root node. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: remove of redundant btrfs_header_levelDaniel Cadete
This removes the continues call's of btrfs_header_level. One call of btrfs_header_level(c) its enough. Signed-off-by Daniel Cadete <danielncadete10@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: adjust NULL testJulia Lawall
Move the call to BUG_ON to before the dereference of the tested value. Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: Remove broken sanity check from btrfs_rmap_block()David Woodhouse
It was never actually doing anything anyway (see the loop condition), and it would be difficult to make it work for RAID[56]. Even if it was actually working, it's checking for the wrong thing anyway. Instead of checking whether we list a block which _doesn't_ land at the relevant physical location, it should be checking that we _have_ listed all the logical blocks which refer to the required physical location on all devices. This function is only called from remove_sb_from_cache() to ensure that we reserve the logical blocks which would reside at the same physical location as the superblock copies. So listing more blocks than we need is actually OK. With RAID[56] we're going to throw away an entire stripe for each block we have to ignore, so we _are_ going to list blocks other than the ones which actually contain the superblock. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: convert nested spin_lock_irqsave to spin_lockJulia Lawall
If spin_lock_irqsave is called twice in a row with the same second argument, the interrupt state at the point of the second call overwrites the value saved by the first call. Indeed, the second call does not need to save the interrupt state, so it is changed to a simple spin_lock. Signed-off-by: Julia Lawall <julia@diku.dk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: make sure all dirty blocks are written at commit timeYan Zheng
Write dirty block groups may allocate new block, and so may add new delayed back ref. btrfs_run_delayed_refs may make some block groups dirty. commit_cowonly_roots does not handle the recursion properly, and some dirty blocks can be left unwritten at commit time. This patch moves btrfs_run_delayed_refs into the loop that writes dirty block groups, and makes the code not break out of the loop until there are no dirty block groups or delayed back refs. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: fix locking issue in btrfs_find_next_keyYan Zheng
When walking up the tree, btrfs_find_next_key assumes the upper level tree block is properly locked. This isn't always true even path->keep_locks is 1. This is because btrfs_find_next_key may advance path->slots[] several times instead of only once. When 'path->slots[level] >= btrfs_header_nritems(path->nodes[level])' is found, we can't guarantee the original value of 'path->slots[level]' is 'btrfs_header_nritems(path->nodes[level]) - 1'. If it's not, the tree block at 'level + 1' isn't locked. This patch fixes the issue by explicitly checking the locking state, re-searching the tree if it's not locked. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: fix double increment of path->slots[0] in btrfs_next_leafYan Zheng
if 1 is returned by btrfs_search_slot, the path already points to the first item with 'key > searching key'. So increasing path->slots[0] by one is superfluous in that case. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: properly update space information after shrinking device.Yan Zheng
Change 'goto done' to 'break' for the case of all device extents have been freed, so that the code updates space information will be execute. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-22Btrfs: fix definition of struct btrfs_extent_inline_refYan Zheng
use __le64 instead of u64 in on-disk structure definition. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: fix error message formattingHu Tao
Make an error msg look nicer by inserting a space between number and word. Signed-off-by: Hu Tao <hu.taoo@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: fix use after free in btrfs_start_workers fail pathJiri Slaby
worker memory is already freed on one fail path in btrfs_start_workers, but is still dereferenced. Switch the dereference and kfree. Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: honor nodatacow/sum mount options for new filesChris Mason
The btrfs attr patches unconditionally inherited the inode flags field without honoring nodatacow and nodatasum. This fix makes sure we properly record the nodatacow/sum mount options in new inodes. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: update backrefs while dropping snapshotYan Zheng
The new backref format has restriction on type of backref item. If a tree block isn't referenced by its owner tree, full backrefs must be used for the pointers in it. When a tree block loses its owner tree's reference, backrefs for the pointers in it should be updated to full backrefs. Current btrfs_drop_snapshot misses the code that updates backrefs, so it's unsafe for general use. This patch adds backrefs update code to btrfs_drop_snapshot. It isn't a problem in the restricted form btrfs_drop_snapshot is used today, but for general snapshot deletion this update is required. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: account for space we may use in fallocateJosef Bacik
Using Eric Sandeen's xfstest for fallocate, you can easily trigger a ENOSPC panic on btrfs. This is because we do not account for data we may use when doing the fallocate. This patch fixes the problem by properly reserving space, and then just freeing it when we are done. The reservation stuff was made with delalloc in mind, so its a little crude for this case, but it keeps the box from panicing. Signed-off-by: Josef Bacik <jbacik@redhat.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-02Btrfs: fix the file clone ioctl for preallocated extentsChris Mason
2009-07-02Btrfs: don't log the inode in file_write while growing the fileChris Mason
2009-06-15Btrfs: always update root items for fs trees at commit timeYan Zheng
commit_fs_roots skips updating root items for fs trees that aren't modified. This is unsafe now that relocation code modifies root item's last_snapshot field without modifying corresponding fs tree. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11Btrfs: fix extent_buffer leak during tree log replayChris Mason
During tree log replay, we read in the tree log roots, process them and then free them. A recent change takes an extra reference on the root node of the tree when the root is read in, and stores that reference in root->commit_root. This reference was not being freed, leaving us with one buffer pinned in ram for each subvol with a tree log root after a crash. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11Btrfs: fix oops when btrfs_inherit_iflags called with a NULL dirChris Mason
This happens during subvol creation. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11Btrfs: fix -o nodatasum printk spellingChris Mason
It was printing nodatacsum, which was not the correct option name. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-11Btrfs: check duplicate backrefs for both data and metadataYan Zheng
lookup_inline_extent_backref only checks for duplicate backref for data extents. It assumes backrefs for tree block never conflict. This patch makes lookup_inline_extent_backref check for duplicate backrefs for both data and tree block, so that we can detect potential bug earlier. This is a safety check, strictly speaking it is not required. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: init worker struct fields before kthread-runShin Hong
This patch fixes a bug which may result race condition between btrfs_start_workers() and worker_loop(). btrfs_start_workers() executed in a parent thread writes on workers->worker and worker_loop() in a child thread reads workers->worker. However, there is no synchronization enforcing the order of two operations. This patch makes btrfs_start_workers() fill workers->worker before it starts a child thread with worker_loop() Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: pin buffers during write_dev_supersHisashi Hifumi
write_dev_supers is called in sequence. First is it called with wait == 0, which starts IO on all of the super blocks for a given device. Then it is called with wait == 1 to make sure they all reach the disk. It doesn't currently pin the buffers between the two calls, and it also assumes the buffers won't go away between the two calls, leading to an oops if the VM manages to free the buffers in the middle of the sync. This fixes that assumption and updates the code to return an error if things are not up to date when the wait == 1 run is done. Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: avoid races between super writeout and device list updatesChris Mason
On multi-device filesystems, btrfs writes supers to all of the devices before considering a sync complete. There wasn't any additional locking between super writeout and the device list management code because device management was done inside a transaction and super writeout only happened with no transation writers running. With the btrfs fsync log and other async transaction updates, this has been racey for some time. This adds a mutex to protect the device list. The existing volume mutex could not be reused due to transaction lock ordering requirements. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Fix btrfs when ACLs are configured outAl Viro
... otherwise generic_permission() will allow *anything* for all files you don't own and that have some group permissions. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: fdatasync should skip metadata writeoutHisashi Hifumi
In btrfs, fdatasync and fsync are identical, but fdatasync should skip committing transaction when inode->i_state is set just I_DIRTY_SYNC and this indicates only atime or/and mtime updates. Following patch improves fdatasync throughput. --file-block-size=4K --file-total-size=16G --file-test-mode=rndwr --file-fsync-mode=fdatasync run Results: -2.6.30-rc8 Test execution summary: total time: 1980.6540s total number of events: 10001 total time taken by event execution: 1192.9804 per-request statistics: min: 0.0000s avg: 0.1193s max: 15.3720s approx. 95 percentile: 0.7257s Threads fairness: events (avg/stddev): 625.0625/151.32 execution time (avg/stddev): 74.5613/9.46 -2.6.30-rc8-patched Test execution summary: total time: 1695.9118s total number of events: 10000 total time taken by event execution: 871.3214 per-request statistics: min: 0.0000s avg: 0.0871s max: 10.4644s approx. 95 percentile: 0.4787s Threads fairness: events (avg/stddev): 625.0000/131.86 execution time (avg/stddev): 54.4576/8.98 Signed-off-by: Hisashi Hifumi <hifumi.hisashi@oss.ntt.co.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: remove crc32c.h and use libcrc32c directly.David Woodhouse
There's no need to preserve this abstraction; it used to let us use hardware crc32c support directly, but libcrc32c is already doing that for us through the crypto API -- so we're already using the Intel crc32c acceleration where appropriate. Signed-off-by: David Woodhouse <David.Woodhouse@intel.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: implement FS_IOC_GETFLAGS/SETFLAGS/GETVERSIONChristoph Hellwig
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>
2009-06-10Btrfs: autodetect SSD devicesChris Mason
During mount, btrfs will check the queue nonrot flag for all the devices found in the FS. If they are all non-rotating, SSD mode is enabled by default. If the FS was mounted with -o nossd, the non-rotating flag is ignored. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: add mount -o ssd_spread to spread allocations outChris Mason
Some SSDs perform best when reusing block numbers often, while others perform much better when clustering strictly allocates big chunks of unused space. The default mount -o ssd will find rough groupings of blocks where there are a bunch of free blocks that might have some allocated blocks mixed in. mount -o ssd_spread will make sure there are no allocated blocks mixed in. It should perform better on lower end SSDs. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: avoid allocation clusters that are too spread outChris Mason
In SSD mode for data, and all the time for metadata the allocator will try to find a cluster of nearby blocks for allocations. This commit adds extra checks to make sure that each free block in the cluster is close to the last one. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: Add mount -o nossdChris Mason
This allows you to turn off the ssd mode via remount. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: avoid IO stalls behind congested devices in a multi-device FSChris Mason
The btrfs IO submission threads try to service a bunch of devices with a small number of threads. They do a congestion check to try and avoid waiting on requests for a busy device. The checks make sure we've sent a few requests down to a given device just so that we aren't bouncing between busy devices without actually sending down any IO. The counter used to decide if we can switch to the next device is somewhat overloaded. It is also being used to decide if we've done a good batch of requests between the WRITE_SYNC or regular priority lists. It may get reset to zero often, leaving us hammering on a busy device instead of moving on to another disk. This commit adds a new counter for the number of bios sent while servicing a device. It doesn't get reset or fiddled with. On multi-device filesystems, this fixes IO stalls in streaming write workloads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: don't allow WRITE_SYNC bios to starve out regular writesChris Mason
Btrfs uses dedicated threads to submit bios when checksumming is on, which allows us to make sure the threads dedicated to checksumming don't get stuck waiting for requests. For each btrfs device, there are two lists of bios. One list is for WRITE_SYNC bios and the other is for regular priority bios. The IO submission threads used to process all of the WRITE_SYNC bios first and then switch to the regular bios. This commit makes sure we don't completely starve the regular bios by rotating between the two lists. WRITE_SYNC bios are still favored 2:1 over the regular bios, and this tries to run in batches to avoid seeking. Benchmarking shows this eliminates stalls during streaming buffered writes on both multi-device and single device filesystems. If the regular bios starve, the system can end up with a large amount of ram pinned down in writeback pages. If we are a little more fair between the two classes, we're able to keep throughput up and make progress on the bulk of our dirty ram. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: fix metadata dirty throttling limitsChris Mason
Once a metadata block has been written, it must be recowed, so the btrfs dirty balancing call has a check to make sure a fair amount of metadata was actually dirty before it started writing it back to disk. A previous commit had changed the dirty tracking for metadata without updating the btrfs dirty balancing checks. This commit switches it to use the correct counter. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: reduce mount -o ssd CPU usageChris Mason
The block allocator in SSD mode will try to find groups of free blocks that are close together. This commit makes it loop less on a given group size before bumping it. The end result is that we are less likely to fill small holes in the available free space, but we don't waste as much CPU building the large cluster used by ssd mode. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: balance btree more oftenChris Mason
With the new back reference code, the cost of a balance has gone down in terms of the number of back reference updates done. This commit makes us more aggressively balance leaves and nodes as they become less full. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: stop avoiding balancing at the end of the transaction.Chris Mason
When the delayed reference code was added, some checks were added to avoid extra balancing while the delayed references were being flushed. This made for less efficient btrees, but it reduced the chances of loops where no forward progress was made because the balances made more delayed ref updates. With the new dead root removal code and the mixed back references, the extent allocation tree is no longer using precise back refs, and the delayed reference updates don't carry the risk of looping forever anymore. So, the balance avoidance is no longer required. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10Btrfs: Mixed back reference (FORWARD ROLLING FORMAT CHANGE)Yan Zheng
This commit introduces a new kind of back reference for btrfs metadata. Once a filesystem has been mounted with this commit, IT WILL NO LONGER BE MOUNTABLE BY OLDER KERNELS. When a tree block in subvolume tree is cow'd, the reference counts of all extents it points to are increased by one. At transaction commit time, the old root of the subvolume is recorded in a "dead root" data structure, and the btree it points to is later walked, dropping reference counts and freeing any blocks where the reference count goes to 0. The increments done during cow and decrements done after commit cancel out, and the walk is a very expensive way to go about freeing the blocks that are no longer referenced by the new btree root. This commit reduces the transaction overhead by avoiding the need for dead root records. When a non-shared tree block is cow'd, we free the old block at once, and the new block inherits old block's references. When a tree block with reference count > 1 is cow'd, we increase the reference counts of all extents the new block points to by one, and decrease the old block's reference count by one. This dead tree avoidance code removes the need to modify the reference counts of lower level extents when a non-shared tree block is cow'd. But we still need to update back ref for all pointers in the block. This is because the location of the block is recorded in the back ref item. We can solve this by introducing a new type of back ref. The new back ref provides information about pointer's key, level and in which tree the pointer lives. This information allow us to find the pointer by searching the tree. The shortcoming of the new back ref is that it only works for pointers in tree blocks referenced by their owner trees. This is mostly a problem for snapshots, where resolving one of these fuzzy back references would be O(number_of_snapshots) and quite slow. The solution used here is to use the fuzzy back references in the common case where a given tree block is only referenced by one root, and use the full back references when multiple roots have a reference on a given block. This commit adds per subvolume red-black tree to keep trace of cached inodes. The red-black tree helps the balancing code to find cached inodes whose inode numbers within a given range. This commit improves the balancing code by introducing several data structures to keep the state of balancing. The most important one is the back ref cache. It caches how the upper level tree blocks are referenced. This greatly reduce the overhead of checking back ref. The improved balancing code scales significantly better with a large number of snapshots. This is a very large commit and was written in a number of pieces. But, they depend heavily on the disk format change and were squashed together to make sure git bisect didn't end up in a bad state wrt space balancing or the format change. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-10btrfs: Fix set/clear_extent_bit for 'end == (u64)-1'Yan Zheng
There are some 'start = state->end + 1;' like code in set_extent_bit and clear_extent_bit. They overflow when end == (u64)-1. Signed-off-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-06-09Linux 2.6.30Linus Torvalds
2009-06-09char: mxser, fix ISA board lookupPeter Botha
There's a bug in the mxser kernel module that still appears in the 2.6.29.4 kernel. mxser_get_ISA_conf takes a ioaddress as its first argument, by passing the not of the ioaddr, you're effectively passing 0 which means it won't be able to talk to an ISA card. I have tested this, and removing the ! fixes the problem. Cc: "Peter Botha" <peterb@goldcircle.co.za> Signed-off-by: Jiri Slaby <jirislaby@gmail.com> Acked-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>