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2009-08-21btrfs: fix inode rbtree corruptionFrom: Nick Piggin
Node may not be inserted over existing node. This causes inode tree corruption and I was seeing crashes in inode_tree_del which I can not reproduce after this patch. The other way to fix this would be to tie inode lifetime in the rbtree with inode while not in freeing state. I had a look at this but it is not so trivial at this point. At least this patch gets things working again. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Acked-by: Yan Zheng <zheng.yan@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-08-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: fix balancing oops when invalidate_inode_pages2 returns EBUSY Btrfs: correct error-handling zlib error handling Btrfs: remove superfluous NULL pointer check in btrfs_rename() Btrfs: make sure the async caching thread advances the key Btrfs: fix btrfs_remove_from_free_space corner case
2009-08-07Btrfs: remove superfluous NULL pointer check in btrfs_rename()Bartlomiej Zolnierkiewicz
This takes care of the following entry from Dan's list: fs/btrfs/inode.c +4788 btrfs_rename(36) warning: variable derefenced before check 'old_inode' Reported-by: Dan Carpenter <error27@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Eugene Teo <eteo@redhat.com> Cc: Julia Lawall <julia@diku.dk> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-07-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: (22 commits) Btrfs: Fix async caching interaction with unmount Btrfs: change how we unpin extents Btrfs: Correct redundant test in add_inode_ref Btrfs: find smallest available device extent during chunk allocation Btrfs: clear all space_info->full after removing a block group Btrfs: make flushoncommit mount option correctly wait on ordered_extents Btrfs: Avoid delayed reference update looping Btrfs: Fix ordering of key field checks in btrfs_previous_item Btrfs: find_free_dev_extent doesn't handle holes at the start of the device Btrfs: Remove code duplication in comp_keys Btrfs: async block group caching Btrfs: use hybrid extents+bitmap rb tree for free space Btrfs: Fix crash on read failures at mount Btrfs: remove of redundant btrfs_header_level Btrfs: adjust NULL test Btrfs: Remove broken sanity check from btrfs_rmap_block() Btrfs: convert nested spin_lock_irqsave to spin_lock Btrfs: make sure all dirty blocks are written at commit time Btrfs: fix locking issue in btrfs_find_next_key Btrfs: fix double increment of path->slots[0] in btrfs_next_leaf ...
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>
2009-07-12headers: smp_lock.h reduxAlexey Dobriyan
* Remove smp_lock.h from files which don't need it (including some headers!) * Add smp_lock.h to files which do need it * Make smp_lock.h include conditional in hardirq.h It's needed only for one kernel_locked() usage which is under CONFIG_PREEMPT This will make hardirq.h inclusion cheaper for every PREEMPT=n config (which includes allmodconfig/allyesconfig, BTW) Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-07-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: fix error message formatting Btrfs: fix use after free in btrfs_start_workers fail path Btrfs: honor nodatacow/sum mount options for new files Btrfs: update backrefs while dropping snapshot Btrfs: account for space we may use in fallocate Btrfs: fix the file clone ioctl for preallocated extents Btrfs: don't log the inode in file_write while growing the file
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: 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>
2009-06-24Get "no acls for this inode" right, fix shmem breakageAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-24switch btrfs to inode->i_aclAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-06-11btrfs: remove ->write_super and stop maintaining ->s_dirtChristoph Hellwig
Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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: 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>
2009-05-14Btrfs: remove some WARN_ONs in the IO failure pathChris Mason
These debugging WARN_ONs make too much console noise during regular IO failures. An IO failure will still generate a number of messages as we verify checksums etc, but these two are not needed. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-05-14Btrfs: init inode ordered_data_close flag properlyChris Mason
This flag is used to decide when we need to send a given file through the ordered code to make sure it is fully written before a transaction commits. It was not being properly set to zero when the inode was being setup. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: look for acls during btrfs_read_locked_inodeChris Mason
This changes btrfs_read_locked_inode() to peek ahead in the btree for acl items. If it is certain a given inode has no acls, it will set the in memory acl fields to null to avoid acl lookups completely. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: fix acl cachingChris Mason
Linus noticed the btrfs code to cache acls wasn't properly caching a NULL acl when the inode didn't have any acls. This meant the common case of no acls resulted in expensive btree searches every time the kernel checked permissions (which is quite often). This is a modified version of Linus' original patch: Properly set initial acl fields to BTRFS_ACL_NOT_CACHED in the inode. This forces an acl lookup when permission checks are done. Fix btrfs_get_acl to avoid lookups and locking when the inode acls fields are set to null. Fix btrfs_get_acl to use the right return value from __btrfs_getxattr when deciding to cache a NULL acl. It was storing a NULL acl when __btrfs_getxattr return -ENOENT, but __btrfs_getxattr was actually returning -ENODATA for this case. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: remove unused btrfs_bit_radix slabChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-27Btrfs: ratelimit IO error printksChris Mason
Btrfs has printks for various IO errors, including bad checksums and mismatches between what we expect the block headers to contain and what we actually find on the disk. Longer term we need a real reporting mechanism for this, but for now printk is going to have to do. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: fix fallocate deadlock on inode extent lockChris Mason
The btrfs fallocate call takes an extent lock on the entire range being fallocated, and then runs through insert_reserved_extent on each extent as they are allocated. The problem with this is that btrfs_drop_extents may decide to try and take the same extent lock fallocate was already holding. The solution used here is to push down knowledge of the range that is already locked going into btrfs_drop_extents. It turns out that at least one other caller had the same bug. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-24Btrfs: kill btrfs_cache_createChristoph Hellwig
Just use kmem_cache_create directly. Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-21Btrfs: fix btrfs fallocate oops and deadlockChris Mason
Btrfs fallocate was incorrectly starting a transaction with a lock held on the extent_io tree for the file, which could deadlock. Strictly speaking it was using join_transaction which would be safe, but it is better to move the transaction outside of the lock. When preallocated extents are overwritten, btrfs_mark_buffer_dirty was being called on an unlocked buffer. This was triggering an assertion and oops because the lock is supposed to be held. The bug was calling btrfs_mark_buffer_dirty on a leaf after btrfs_del_item had been run. btrfs_del_item takes care of dirtying things, so the solution is a to skip the btrfs_mark_buffer_dirty call in this case. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: BUG to BUG_ON changes Btrfs: remove dead code Btrfs: remove dead code Btrfs: fix typos in comments Btrfs: remove unused ftrace include Btrfs: fix __ucmpdi2 compile bug on 32 bit builds Btrfs: free inode struct when btrfs_new_inode fails Btrfs: fix race in worker_loop Btrfs: add flushoncommit mount option Btrfs: notreelog mount option Btrfs: introduce btrfs_show_options Btrfs: rework allocation clustering Btrfs: Optimize locking in btrfs_next_leaf() Btrfs: break up btrfs_search_slot into smaller pieces Btrfs: kill the pinned_mutex Btrfs: kill the block group alloc mutex Btrfs: clean up find_free_extent Btrfs: free space cache cleanups Btrfs: unplug in the async bio submission threads Btrfs: keep processing bios for a given bdev if our proc is batching
2009-04-02Btrfs: free inode struct when btrfs_new_inode failsShen Feng
btrfs_new_inode doesn't call iput to free the inode when it fails. Signed-off-by: Shen Feng <shen@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-04-01Merge git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstableLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-unstable: Btrfs: try to free metadata pages when we free btree blocks Btrfs: add extra flushing for renames and truncates Btrfs: make sure btrfs_update_delayed_ref doesn't increase ref_mod Btrfs: optimize fsyncs on old files Btrfs: tree logging unlink/rename fixes Btrfs: Make sure i_nlink doesn't hit zero too soon during log replay Btrfs: limit balancing work while flushing delayed refs Btrfs: readahead checksums during btrfs_finish_ordered_io Btrfs: leave btree locks spinning more often Btrfs: Only let very young transactions grow during commit Btrfs: Check for a blocking lock before taking the spin Btrfs: reduce stack in cow_file_range Btrfs: reduce stalls during transaction commit Btrfs: process the delayed reference queue in clusters Btrfs: try to cleanup delayed refs while freeing extents Btrfs: reduce stack usage in some crucial tree balancing functions Btrfs: do extent allocation and reference count updates in the background Btrfs: don't preallocate metadata blocks during btrfs_search_slot
2009-04-01fs: fix page_mkwrite error cases in core code and btrfsNick Piggin
page_mkwrite is called with neither the page lock nor the ptl held. This means a page can be concurrently truncated or invalidated out from underneath it. Callers are supposed to prevent truncate races themselves, however previously the only thing they can do in case they hit one is to raise a SIGBUS. A sigbus is wrong for the case that the page has been invalidated or truncated within i_size (eg. hole punched). Callers may also have to perform memory allocations in this path, where again, SIGBUS would be wrong. The previous patch ("mm: page_mkwrite change prototype to match fault") made it possible to properly specify errors. Convert the generic buffer.c code and btrfs to return sane error values (in the case of page removed from pagecache, VM_FAULT_NOPAGE will cause the fault handler to exit without doing anything, and the fault will be retried properly). This fixes core code, and converts btrfs as a template/example. All other filesystems defining their own page_mkwrite should be fixed in a similar manner. Acked-by: Chris Mason <chris.mason@oracle.com> Signed-off-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-04-01mm: page_mkwrite change prototype to match faultNick Piggin
Change the page_mkwrite prototype to take a struct vm_fault, and return VM_FAULT_xxx flags. There should be no functional change. This makes it possible to return much more detailed error information to the VM (and also can provide more information eg. virtual_address to the driver, which might be important in some special cases). This is required for a subsequent fix. And will also make it easier to merge page_mkwrite() with fault() in future. Signed-off-by: Nick Piggin <npiggin@suse.de> Cc: Chris Mason <chris.mason@oracle.com> Cc: Trond Myklebust <trond.myklebust@fys.uio.no> Cc: Miklos Szeredi <miklos@szeredi.hu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <joel.becker@oracle.com> Cc: Artem Bityutskiy <dedekind@infradead.org> Cc: Felix Blyakher <felixb@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-03-31Btrfs: add extra flushing for renames and truncatesChris Mason
Renames and truncates are both common ways to replace old data with new data. The filesystem can make an effort to make sure the new data is on disk before actually replacing the old data. This is especially important for rename, which many application use as though it were atomic for both the data and the metadata involved. The current btrfs code will happily replace a file that is fully on disk with one that was just created and still has pending IO. If we crash after transaction commit but before the IO is done, we'll end up replacing a good file with a zero length file. The solution used here is to create a list of inodes that need special ordering and force them to disk before the commit is done. This is similar to the ext3 style data=ordering, except it is only done on selected files. Btrfs is able to get away with this because it does not wait on commits very often, even for fsync (which use a sub-commit). For renames, we order the file when it wasn't already on disk and when it is replacing an existing file. Larger files are sent to filemap_flush right away (before the transaction handle is opened). For truncates, we order if the file goes from non-zero size down to zero size. This is a little different, because at the time of the truncate the file has no dirty bytes to order. But, we flag the inode so that it is added to the ordered list on close (via release method). We also immediately add it to the ordered list of the current transaction so that we can try to flush down any writes the application sneaks in before commit. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: tree logging unlink/rename fixesChris Mason
The tree logging code allows individual files or directories to be logged without including operations on other files and directories in the FS. It tries to commit the minimal set of changes to disk in order to fsync the single file or directory that was sent to fsync or O_SYNC. The tree logging code was allowing files and directories to be unlinked if they were part of a rename operation where only one directory in the rename was in the fsync log. This patch adds a few new rules to the tree logging. 1) on rename or unlink, if the inode being unlinked isn't in the fsync log, we must force a full commit before doing an fsync of the directory where the unlink was done. The commit isn't done during the unlink, but it is forced the next time we try to log the parent directory. Solution: record transid of last unlink/rename per directory when the directory wasn't already logged. For renames this is only done when renaming to a different directory. mkdir foo/some_dir normal commit rename foo/some_dir foo2/some_dir mkdir foo/some_dir fsync foo/some_dir/some_file The fsync above will unlink the original some_dir without recording it in its new location (foo2). After a crash, some_dir will be gone unless the fsync of some_file forces a full commit 2) we must log any new names for any file or dir that is in the fsync log. This way we make sure not to lose files that are unlinked during the same transaction. 2a) we must log any new names for any file or dir during rename when the directory they are being removed from was logged. 2a is actually the more important variant. Without the extra logging a crash might unlink the old name without recreating the new one 3) after a crash, we must go through any directories with a link count of zero and redo the rm -rf mkdir f1/foo normal commit rm -rf f1/foo fsync(f1) The directory f1 was fully removed from the FS, but fsync was never called on f1, only its parent dir. After a crash the rm -rf must be replayed. This must be able to recurse down the entire directory tree. The inode link count fixup code takes care of the ugly details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: readahead checksums during btrfs_finish_ordered_ioChris Mason
This reads in blocks in the checksum btree before starting the transaction in btrfs_finish_ordered_io. It makes it much more likely we'll be able to do operations inside the transaction without needing any btree reads, which limits transaction latencies overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: leave btree locks spinning more oftenChris Mason
btrfs_mark_buffer dirty would set dirty bits in the extent_io tree for the buffers it was dirtying. This may require a kmalloc and it was not atomic. So, anyone who called btrfs_mark_buffer_dirty had to set any btree locks they were holding to blocking first. This commit changes dirty tracking for extent buffers to just use a flag in the extent buffer. Now that we have one and only one extent buffer per page, this can be safely done without losing dirty bits along the way. This also introduces a path->leave_spinning flag that callers of btrfs_search_slot can use to indicate they will properly deal with a path returned where all the locks are spinning instead of blocking. Many of the btree search callers now expect spinning paths, resulting in better btree concurrency overall. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: reduce stack in cow_file_rangeChris Mason
The fs/btrfs/inode.c code to run delayed allocation during writout needed some stack usage optimization. This is the first pass, it does the check for compression earlier on, which allows us to do the common (no compression) case higher up in the call chain. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-03-24Btrfs: reduce stalls during transaction commitChris Mason
To avoid deadlocks and reduce latencies during some critical operations, some transaction writers are allowed to jump into the running transaction and make it run a little longer, while others sit around and wait for the commit to finish. This is a bit unfair, especially when the callers that jump in do a bunch of IO that makes all the others procs on the box wait. This commit reduces the stalls this produces by pre-reading file extent pointers during btrfs_finish_ordered_io before the transaction is joined. It also tunes the drop_snapshot code to politely wait for transactions that have started writing out their delayed refs to finish. This avoids new delayed refs being flooded into the queue while we're trying to close off the transaction. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-20Btrfs: add better -ENOSPC handlingJosef Bacik
This is a step in the direction of better -ENOSPC handling. Instead of checking the global bytes counter we check the space_info bytes counters to make sure we have enough space. If we don't we go ahead and try to allocate a new chunk, and then if that fails we return -ENOSPC. This patch adds two counters to btrfs_space_info, bytes_delalloc and bytes_may_use. bytes_delalloc account for extents we've actually setup for delalloc and will be allocated at some point down the line. bytes_may_use is to keep track of how many bytes we may use for delalloc at some point. When we actually set the extent_bit for the delalloc bytes we subtract the reserved bytes from the bytes_may_use counter. This keeps us from not actually being able to allocate space for any delalloc bytes. Signed-off-by: Josef Bacik <jbacik@redhat.com>
2009-02-12Btrfs: remove btrfs_init_pathJeff Mahoney
btrfs_init_path was initially used when the path objects were on the stack. Now all the work is done by btrfs_alloc_path and btrfs_init_path isn't required. This patch removes it, and just uses kmem_cache_zalloc to zero out the object. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-12Btrfs: Avoid using __GFP_HIGHMEM with slab allocatorYan Zheng
btrfs_releasepage may call kmem_cache_alloc indirectly, and provide same GFP flags it gets to kmem_cache_alloc. So it's possible to use __GFP_HIGHMEM with the slab allocator. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2009-02-06Btrfs: Make sure dir is non-null before doing S_ISGID checksChris Mason
The S_ISGID check in btrfs_new_inode caused an oops during subvol creation because sometimes the dir is null. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Change btrfs_truncate_inode_items to stop when it hits the inodeChris Mason
btrfs_truncate_inode_items is setup to stop doing btree searches when it has finished removing the items for the inode. It used to detect the end of the inode by looking for an objectid that didn't match the one we were searching for. But, this would result in an extra search through the btree, which adds extra balancing and cow costs to the operation. This commit adds a check to see if we found the inode item, which means we can stop searching early. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Don't try to compress pages past i_sizeChris Mason
The compression code had some checks to make sure we were only compressing bytes inside of i_size, but it wasn't catching every case. To make things worse, some incorrect math about the number of bytes remaining would make it try to compress more pages than the file really had. The fix used here is to fall back to the non-compression code in this case, which does all the proper cleanup of delalloc and other accounting. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Handle SGID bit when creating inodesChris Ball
Before this patch, new files/dirs would ignore the SGID bit on their parent directory and always be owned by the creating user's uid/gid. Signed-off-by: Chris Ball <cjb@laptop.org> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Make btrfs_drop_snapshot work in larger and more efficient chunksChris Mason
Every transaction in btrfs creates a new snapshot, and then schedules the snapshot from the last transaction for deletion. Snapshot deletion works by walking down the btree and dropping the reference counts on each btree block during the walk. If if a given leaf or node has a reference count greater than one, the reference count is decremented and the subtree pointed to by that node is ignored. If the reference count is one, walking continues down into that node or leaf, and the references of everything it points to are decremented. The old code would try to work in small pieces, walking down the tree until it found the lowest leaf or node to free and then returning. This was very friendly to the rest of the FS because it didn't have a huge impact on other operations. But it wouldn't always keep up with the rate that new commits added new snapshots for deletion, and it wasn't very optimal for the extent allocation tree because it wasn't finding leaves that were close together on disk and processing them at the same time. This changes things to walk down to a level 1 node and then process it in bulk. All the leaf pointers are sorted and the leaves are dropped in order based on their extent number. The extent allocation tree and commit code are now fast enough for this kind of bulk processing to work without slowing the rest of the FS down. Overall it does less IO and is better able to keep up with snapshot deletions under high load. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: Change btree locking to use explicit blocking pointsChris Mason
Most of the btrfs metadata operations can be protected by a spinlock, but some operations still need to schedule. So far, btrfs has been using a mutex along with a trylock loop, most of the time it is able to avoid going for the full mutex, so the trylock loop is a big performance gain. This commit is step one for getting rid of the blocking locks entirely. btrfs_tree_lock takes a spinlock, and the code explicitly switches to a blocking lock when it starts an operation that can schedule. We'll be able get rid of the blocking locks in smaller pieces over time. Tracing allows us to find the most common cause of blocking, so we can start with the hot spots first. The basic idea is: btrfs_tree_lock() returns with the spin lock held btrfs_set_lock_blocking() sets the EXTENT_BUFFER_BLOCKING bit in the extent buffer flags, and then drops the spin lock. The buffer is still considered locked by all of the btrfs code. If btrfs_tree_lock gets the spinlock but finds the blocking bit set, it drops the spin lock and waits on a wait queue for the blocking bit to go away. Much of the code that needs to set the blocking bit finishes without actually blocking a good percentage of the time. So, an adaptive spin is still used against the blocking bit to avoid very high context switch rates. btrfs_clear_lock_blocking() clears the blocking bit and returns with the spinlock held again. btrfs_tree_unlock() can be called on either blocking or spinning locks, it does the right thing based on the blocking bit. ctree.c has a helper function to set/clear all the locked buffers in a path as blocking. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-02-04Btrfs: selinux supportJim Owens
Add call to LSM security initialization and save resulting security xattr for new inodes. Add xattr support to symlink inode ops. Set inode->i_op for existing special files. Signed-off-by: jim owens <jowens@hp.com>
2009-01-28Btrfs: fix readdir on 32 bit machinesChris Mason
After btrfs_readdir has gone through all the directory items, it sets the directory f_pos to the largest possible int. This way applications that mix readdir with creating new files don't end up in an endless loop finding the new directory items as they go. It was a workaround for a bug in git, but the assumption was that if git could make this looping mistake than it would be a common problem. The largest possible int chosen was INT_LIMIT(typeof(file->f_pos), and it is possible for that to be a larger number than 32 bit glibc expects to come out of readdir. This patches switches that to INT_LIMIT(off_t), which should keep applications happy on 32 and 64 bit machines. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: fiemap supportYehuda Sadeh
Now that bmap support is gone, this is the only way to get extent mappings for userland. These are still not valid for IO, but they can tell us if a file has holes or how much fragmentation there is. Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
2009-01-21Btrfs: stop providing a bmap operation to avoid swapfile corruptionsChris Mason
Swapfiles use bmap to build a list of extents belonging to the file, and they assume these extents won't change over the life of the file. They also use resulting list to do IO directly to the block device. This causes problems for btrfs in a few ways: btrfs returns logical block numbers through bmap, and these are not suitable for IO. They might translate to different devices, raid etc. COW means that file block mappings are going to change frequently. Using swapfiles on btrfs will lead to corruption, so we're avoiding the problem for now by dropping bmap support entirely. A later commit will add fiemap support for people that really want to know how a file is laid out. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: simplify iteration codesQinghuang Feng
Merge list_for_each* and list_entry to list_for_each_entry* Signed-off-by: Qinghuang Feng <qhfeng.kernel@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-21Btrfs: removed unused #include <version.h>'sHuang Weiyi
Removed unused #include <version.h>'s in btrfs Signed-off-by: Huang Weiyi <weiyi.huang@gmail.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2009-01-07Btrfs: kmap_atomic(KM_USER0) is safe for btrfs_readpage_end_io_hookChris Mason
None of the checksum verification code schedules, so we can use the faster kmap_atomic Signed-off-by: Chris Mason <chris.mason@oracle.com>