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path: root/fs/ocfs2/extent_map.h
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2011-07-25ocfs2: Implement llseek()Sunil Mushran
ocfs2 implements its own llseek() to provide the SEEK_HOLE/SEEK_DATA functionality. SEEK_HOLE sets the file pointer to the start of either a hole or an unwritten (preallocated) extent, that is greater than or equal to the supplied offset. SEEK_DATA sets the file pointer to the start of an allocated extent (not unwritten) that is greater than or equal to the supplied offset. If the supplied offset is on a desired region, then the file pointer is set to it. Offsets greater than or equal to the file size return -ENXIO. Unwritten (preallocated) extents are considered holes because the file system treats reads to such regions in the same way as it does to holes. Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
2009-09-22ocfs2: Return extent flags for xattr value tree.Tao Ma
With the new refcount tree, xattr value can also be refcounted among multiple files. So return the appropriate extent flags so that CoW can used it later. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-09-22ocfs2: Add support for incrementing refcount in the tree.Tao Ma
Given a physical cpos and length, increment the refcount in the tree. If the extent has not been seen before, a refcount record is created for it. Refcount records may be merged or split by this operation. Signed-off-by: Tao Ma <tao.ma@oracle.com>
2009-01-05ocfs2: Wrap virtual block reads in ocfs2_read_virt_blocks()Joel Becker
The ocfs2_read_dir_block() function really maps an inode's virtual blocks to physical ones before calling ocfs2_read_blocks(). Let's extract that to common code, because other places might want to do that. Other than the block number being virtual, ocfs2_read_virt_blocks() takes the same arguments as ocfs2_read_blocks(). It converts those virtual block numbers to physical before calling ocfs2_read_blocks() directly. If the blocks asked for are discontiguous, this can mean multiple calls to ocfs2_read_blocks(), but this is mostly hidden from the caller. Like ocfs2_read_blocks(), the caller can pass in an existing buffer_head. This is usually done to pick up some readahead I/O. ocfs2_read_virt_blocks() checks the buffer_head's block number against the extent map - it must match. Signed-off-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-13ocfs2: Add extent tree operation for xattr value btreesTao Ma
Add some thin wrappers around ocfs2_insert_extent() for each of the 3 different btree types, ocfs2_inode_insert_extent(), ocfs2_xattr_value_insert_extent() and ocfs2_xattr_tree_insert_extent(). The last is for the xattr index btree, which will be used in a followup patch. All the old callers in file.c etc will call ocfs2_dinode_insert_extent(), while the other two handle the xattr issue. And the init of extent tree are handled by these functions. When storing xattr value which is too large, we will allocate some clusters for it and here ocfs2_extent_list and ocfs2_extent_rec will also be used. In order to re-use the b-tree operation code, a new parameter named "private" is added into ocfs2_extent_tree and it is used to indicate the root of ocfs2_exent_list. The reason is that we can't deduce the root from the buffer_head now. It may be in an inode, an ocfs2_xattr_block or even worse, in any place in an ocfs2_xattr_bucket. Signed-off-by: Tao Ma <tao.ma@oracle.com> Signed-off-by: Mark Fasheh <mfasheh@suse.com>
2008-10-03ocfs2: fiemap supportMark Fasheh
Plug ocfs2 into ->fiemap. Some portions of ocfs2_get_clusters() had to be refactored so that the extent cache can be skipped in favor of going directly to the on-disk records. This makes it easier for us to determine which extent is the last one in the btree. Also, I'm not sure we want to be caching fiemap lookups anyway as they're not directly related to data read/write. Signed-off-by: Mark Fasheh <mfasheh@suse.com> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: ocfs2-devel@oss.oracle.com Cc: linux-fsdevel@vger.kernel.org
2007-04-26ocfs2: Cache extent recordsMark Fasheh
The extent map code was ripped out earlier because of an inability to deal with holes. This patch adds back a simpler caching scheme requiring far less code. Our old extent map caching was designed back when meta data block caching in Ocfs2 didn't work very well, resulting in many disk reads. These days our metadata caching is much better, resulting in no un-necessary disk reads. As a result, extent caching doesn't have to be as fancy, nor does it have to cache as many extents. Keeping the last 3 extents seen should be sufficient to give us a small performance boost on some streaming workloads. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-04-26ocfs2: Fix extent lookup to return true size of holesMark Fasheh
Initially, we had wired things to return a size '1' of holes. Cook up a small amount of code to find the next extent and calculate the number of clusters between the virtual offset and the next allocated extent. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-04-26ocfs2: Read from an unwritten extent returns zerosMark Fasheh
Return an optional extent flags field from our lookup functions and wire up callers to treat unwritten regions as holes for the purpose of returning zeros to the user. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-04-26ocfs2: teach ocfs2_file_aio_write() about sparse filesMark Fasheh
Unfortunately, ocfs2 can no longer make use of generic_file_aio_write_nlock() because allocating writes will require zeroing of pages adjacent to the I/O for cluster sizes greater than page size. Implement a custom file write here, which can order page locks for zeroing. This also has the advantage that cluster locks can easily be ordered outside of the page locks. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2007-04-26ocfs2: temporarily remove extent map cachingMark Fasheh
The code in extent_map.c is not prepared to deal with a subtree being rotated between lookups. This can happen when filling holes in sparse files. Instead of a lengthy patch to update the code (which would likely lose the benefit of caching subtree roots), we remove most of the algorithms and implement a simple path based lookup. A less ambitious extent caching scheme will be added in a later patch. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
2006-01-03[PATCH] OCFS2: The Second Oracle Cluster FilesystemMark Fasheh
The OCFS2 file system module. Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com> Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>