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path: root/fs/btrfs/btrfs_inode.h
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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>
2009-02-20Btrfs: 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>
2008-12-11Btrfs: fix leaking block group on balanceYan Zheng
The block group structs are referenced in many different places, and it's not safe to free while balancing. So, those block group structs were simply leaked instead. This patch replaces the block group pointer in the inode with the starting byte offset of the block group and adds reference counting to the block group struct. Signed-off-by: Yan Zheng <zheng.yan@oracle.com>
2008-12-08Btrfs: Add inode sequence number for NFS and reserved space in a few structsChris Mason
This adds a sequence number to the btrfs inode that is increased on every update. NFS will be able to use that to detect when an inode has changed, without relying on inaccurate time fields. While we're here, this also: Puts reserved space into the super block and inode Adds a log root transid to the super so we can pick the newest super based on the fsync log as well as the main transaction ID. For now the log root transid is always zero, but that'll get fixed. Adds a starting offset to the dev_item. This will let us do better alignment calculations if we know the start of a partition on the disk. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-29Btrfs: add and improve commentsChris Mason
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>
2008-09-25Btrfs: Dir fsync optimizationsChris Mason
Drop i_mutex during the commit Don't bother doing the fsync at all unless the dir is marked as dirtied and needing fsync in this transaction. For directories, this means that someone has unlinked a file from the dir without fsyncing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add a write ahead tree log to optimize synchronous operationsChris Mason
File syncs and directory syncs are optimized by copying their items into a special (copy-on-write) log tree. There is one log tree per subvolume and the btrfs super block points to a tree of log tree roots. After a crash, items are copied out of the log tree and back into the subvolume. See tree-log.c for all the details. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Get rid of BTRFS_I(inode)->index and use local vars insteadChris Mason
rename and link don't always have a lock on the source inode, and our use of a per-inode index variable was racy. This changes things to store the index in a local variable instead. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Maintain a list of inodes that are delalloc and a way to wait on themChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Create orphan inode records to prevent lost files after a crashJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add ACL supportJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Implement new dir index formatJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Add a per-inode lock around btrfs_drop_extentsChris Mason
btrfs_drop_extents is always called with a range lock held on the inode. But, it may operate on extents outside that range as it drops and splits them. This patch adds a per-inode mutex that is held while calling btrfs_drop_extents and while inserting new extents into the tree. It prevents races from two procs working against adjacent ranges in the tree. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Update on disk i_size only after pending ordered extents are doneChris Mason
This changes the ordered data code to update i_size after the extent is on disk. An on disk i_size is maintained in the in-memory btrfs inode structures, and this is updated as extents finish. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: New data=ordered implementationChris Mason
The old data=ordered code would force commit to wait until all the data extents from the transaction were fully on disk. This introduced large latencies into the commit and stalled new writers in the transaction for a long time. The new code changes the way data allocations and extents work: * When delayed allocation is filled, data extents are reserved, and the extent bit EXTENT_ORDERED is set on the entire range of the extent. A struct btrfs_ordered_extent is allocated an inserted into a per-inode rbtree to track the pending extents. * As each page is written EXTENT_ORDERED is cleared on the bytes corresponding to that page. * When all of the bytes corresponding to a single struct btrfs_ordered_extent are written, The previously reserved extent is inserted into the FS btree and into the extent allocation trees. The checksums for the file data are also updated. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add a per-inode csum mutex to avoid races creating csum itemsChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Throttle file_write when data=ordered is flushing the inodeChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Handle checksumming errors while reading data blocksChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Fix i_blocks accountingChris Mason
Now that delayed allocation accounting works, i_blocks accounting is changed to only modify i_blocks when extents inserted or removed. The fillattr call is changed to include the delayed allocation byte count in the i_blocks result. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Split the extent_map code into two partsChris Mason
There is now extent_map for mapping offsets in the file to disk and extent_io for state tracking, IO submission and extent_bufers. The new extent_map code shifts from [start,end] pairs to [start,len], and pushes the locking out into the caller. This allows a few performance optimizations and is easier to use. A number of extent_map usage bugs were fixed, mostly with failing to remove extent_map entries when changing the file. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add inode flags supportYan
This patch adds NODATASUM & NODATACOW inode flags support. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2008-09-25Btrfs: Add data=ordered supportChris Mason
This forces file data extents down the disk along with the metadata that references them. The current implementation is fairly simple, and just writes out all of the dirty pages in an inode before the commit. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-27Btrfs: Extent based page cache code. This uses an rbtree of extents and testsChris Mason
instead of buffer heads. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-08-10Btrfs: delay commits during fsync to allow more writersJosef Bacik
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-13btrfs: Code cleanupAneesh
Attaching below is some of the code cleanups that i came across while reading the code. a) alloc_path already calls init_path. b) Mention that btrfs_inode is the in memory copy.Ext4 have ext4_inode_info as the in memory copy ext4_inode as the disk copy Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-06-12Btrfs: add GPLv2Chris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-30Btrfs: allocator improvements, inode block groupsChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-10Btrfs: drop the inode map treeChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-06Btrfs: start of support for many FS volumesChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>
2007-04-02Btrfs: still corruption huntingChris Mason
Signed-off-by: Chris Mason <chris.mason@oracle.com>