- 25 Sep, 2008 40 commits
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Sage Weil authored
Commit 597:466b27332893 (btrfs_start_transaction: wait for commits in progress) breaks the transaction start/stop ioctls by making btrfs_start_transaction conditionally wait for the next transaction to start. If an application artificially is holding a transaction open, things deadlock. This workaround maintains a count of open ioctl-initiated transactions in fs_info, and avoids wait_current_trans() if any are currently open (in start_transaction() and btrfs_throttle()). The start transaction ioctl uses a new btrfs_start_ioctl_transaction() that _does_ call wait_current_trans(), effectively pushing the join/wait decision to the outer ioctl-initiated transaction. This more or less neuters btrfs_throttle() when ioctl-initiated transactions are in use, but that seems like a pretty fundamental consequence of wrapping lots of write()'s in a transaction. Btrfs has no way to tell if the application considers a given operation as part of it's transaction. Obviously, if the transaction start/stop ioctls aren't being used, there is no effect on current behavior. Signed-off-by:
Sage Weil <sage@newdream.net> --- ctree.h | 1 + ioctl.c | 12 +++++++++++- transaction.c | 18 +++++++++++++----- transaction.h | 2 ++ 4 files changed, 27 insertions(+), 6 deletions(-) Signed-off-by:
Chris Mason <chris.mason@oracle.com>
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Chris Mason authored
Intel doesn't yet ship hardware to the public with this enabled, but when they do, they will be ready. Original code from: Austin Zhang <austin_zhang@linux.intel.com> It is currently disabled, but edit crc32c.h to turn it on. Signed-off-by: -
Chris Mason authored
Signed-off-by: -
Chris Mason authored
* Make walk_down_tree wake up throttled tasks more often * Make walk_down_tree call cond_resched during long loops * As the size of the ref cache grows, wait longer in throttle * Get rid of the reada code in walk_down_tree, the leaves don't get read anymore, thanks to the ref cache. Signed-off-by: -
Chris Mason authored
A btree block cow has two parts, the first is to allocate a destination block and the second is to copy the old bock over. The first part needs locks in the extent allocation tree, and may need to do IO. This changeset splits that into a separate function that can be called without any tree locks held. btrfs_search_slot is changed to drop its path and start over if it has to COW a contended block. This often means that many writers will pre-alloc a new destination for a the same contended block, but they cache their prealloc for later use on lower levels in the tree. Signed-off-by: -
Chris Mason authored
Signed-off-by: -
Chris Mason authored
While dropping snapshots, walk_down_tree does most of the work of checking reference counts and limiting tree traversal to just the blocks that we are freeing. It dropped and held the allocation mutex in strange and confusing ways, this commit changes it to only hold the mutex while actually freeing a block. The rest of the checks around reference counts should be safe without the lock because we only allow one process in btrfs_drop_snapshot at a time. Other processes dropping reference counts should not drop it to 1 because their tree roots already have an extra ref on the block. Signed-off-by: -
Chris Mason authored
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Chris Mason authored
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Chris Mason authored
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 authored
This avoids waiting for transactions with pages locked by breaking out the code to wait for the current transaction to close into a function called by btrfs_throttle. It also lowers the limits for where we start throttling. Signed-off-by: -
Chris Mason authored
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Sven Wegener authored
Add a couple of #if's to follow API changes. Signed-off-by:
Sven Wegener <sven.wegener@stealer.net> Signed-off-by:
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Yan authored
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 authored
It was incorrectly clearing the up to date flag on the buffer even when the buffer properly verified. Signed-off-by: -
Yan Zheng authored
To check whether a given file extent is referenced by multiple snapshots, the checker walks down the fs tree through dead root and checks all tree blocks in the path. We can easily detect whether a given tree block is directly referenced by other snapshot. We can also detect any indirect reference from other snapshot by checking reference's generation. The checker can always detect multiple references, but can't reliably detect cases of single reference. So btrfs may do file data cow even there is only one reference. Signed-off-by: -
Li Zefan authored
When kthread_run() returns failure, this worker hasn't been added to the list, so btrfs_stop_workers() won't free it. Signed-off-by:
Li Zefan <lizf@cn.fujitsu.com> Signed-off-by:
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Chris Mason authored
A large reference cache is directly related to a lot of work pending for the cleaner thread. This throttles back new operations based on the size of the reference cache so the cleaner thread will be able to keep up. Overall, this actually makes the FS faster because the cleaner thread will be more likely to find things in cache. Signed-off-by: -
Chris Mason authored
Signed-off-by: -
Chris Mason authored
This changes the reference cache to make a single cache per root instead of one cache per transaction, and to key by the byte number of the disk block instead of the keys inside. This makes it much less likely to have cache misses if a snapshot or something has an extra reference on a higher node or a leaf while the first transaction that added the leaf into the cache is dropping. Some throttling is added to functions that free blocks heavily so they wait for old transactions to drop. Signed-off-by: -
Yan Zheng authored
Much of the IO done while dropping snapshots is done looking up leaves in the filesystem trees to see if they point to any extents and to drop the references on any extents found. This creates a cache so that IO isn't required. Signed-off-by: -
Chris Mason authored
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Mark Fasheh authored
The 'char name[BTRFS_PATH_NAME_MAX]' member of struct btrfs_ioctl_vol_args is passed directly to strlen() after being copied from user. I haven't verified this, but in theory a userspace program could pass in an unterminated string and cause a kernel crash as strlen walks off the end of the array. This patch terminates the ->name string in all btrfs ioctl functions which currently use a 'struct btrfs_ioctl_vol_args'. Since the string is now properly terminated, it's length will never be longer than BTRFS_PATH_NAME_MAX so that error check has been removed. By the way, it might be better overall to just have the ioctl pass an unterminated string + length structure but I didn't bother with that since it'd change the kernel/user interface. Signed-off-by:
Mark Fasheh <mfasheh@suse.com> Signed-off-by:
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Yan authored
We should decrease the found slot by one as btrfs_search_slot does when bin_search return 1 and node level > 0. Signed-off-by: -
Yan authored
Inode ref item can be in the next leaf when we find "path->slots[0] == btrfs_header_nritems(...)". Signed-off-by: -
Yan authored
When buffer isn't uptodate, pin_down_bytes may leave the tree locked after it returns. Signed-off-by: -
Balaji Rao authored
Remove a unused variable 'path' in fixup_tree_root_location. Signed-off-by:
Balaji Rao <balajirrao@gmail.com> Signed-off-by:
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Josef Bacik authored
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Josef Bacik authored
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Josef Bacik authored
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Josef Bacik authored
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Josef Bacik authored
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Chris Mason authored
Before setting an extent to delalloc, the code needs to wait for pending ordered extents. Also, the relocation code needs to wait for ordered IO before scanning the block group again. This is because the extents are not removed until the IO for the new extents is finished Signed-off-by: -
David Woodhouse authored
On UP systems spin_trylock always succeeds Signed-off-by: -
Chris Mason authored
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Chris Mason authored
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Chris Mason authored
Checksum items are not inserted into the tree until all of the io from a given extent is complete. This means one dirty page from an extent may be written, freed, and then read again before the entire extent is on disk and the checksum item is inserted. The checksums themselves are stored in the ordered extent so they can be inserted in bulk when IO is complete. On read, if a checksum item isn't found, the ordered extents were being searched for a checksum record. This all worked most of the time, but the checksum insertion code tries to reduce the number of tree operations by pre-inserting checksum items based on i_size and a few other factors. This means the read code might find a checksum item that hasn't yet really been filled in. This commit changes things to check the ordered extents first and only dive into the btree if nothing was found. This removes the need for extra locking and is more reliable. Signed-off-by: -
Chris Mason authored
The ordered extents have to fit in memory, so an unsigned long is sufficient. Signed-off-by: -
Chris Mason authored
Signed-off-by: -
Chris Mason authored
This releases the alloc_mutex in a few places that hold it for over long operations. btrfs_lookup_block_group is changed so that it doesn't need the mutex at all. Signed-off-by:
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