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path: root/fs/xfs/xfs_dir2_readdir.c
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2013-12-19xfs: reinstate the ilock in xfs_readdirBen Myers1-0/+4
Although it was removed in commit 051e7cd44ab8, ilock needs to be taken in xfs_readdir because we might have to read the extent list in from disk. This keeps other threads from reading from or writing to the extent list while it is being read in and is still in a transitional state. This has been associated with "Access to block zero" messages on directories with large numbers of extents resulting from excessive filesytem fragmentation, as well as extent list corruption. Unfortunately no test case at this point. Signed-off-by: Ben Myers <bpm@sgi.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2013-10-30xfs: convert directory vector functions to constantsDave Chinner1-3/+3
Many of the vectorised function calls now take no parameters and return a constant value. There is no reason for these to be vectored functions, so convert them to constants Binary sizes: text data bss dec hex filename 794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig 792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1 792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2 789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3 789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4 789061 96802 1096 886959 d88af fs/xfs/xfs.o.p5 789733 96802 1096 887631 d8b4f fs/xfs/xfs.o.p6 791421 96802 1096 889319 d91e7 fs/xfs/xfs.o.p7 791701 96802 1096 889599 d92ff fs/xfs/xfs.o.p8 791205 96802 1096 889103 d91cf fs/xfs/xfs.o.p9 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30xfs: vectorise directory data operations part 2Dave Chinner1-3/+3
Convert the rest of the directory data block encode/decode operations to vector format. This further reduces the size of the built binary: text data bss dec hex filename 794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig 792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1 792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2 789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3 789005 96802 1096 886903 d8997 fs/xfs/xfs.o.p4 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30xfs: vectorise directory data operationsDave Chinner1-7/+7
Following from the initial patches to vectorise the shortform directory encode/decode operations, convert half the data block operations to use the vector. The rest will be done in a second patch. This further reduces the size of the built binary: text data bss dec hex filename 794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig 792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1 792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2 789293 96802 1096 887191 d8997 fs/xfs/xfs.o.p3 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30xfs: vectorise remaining shortform dir2 opsDave Chinner1-3/+3
Following from the initial patch to introduce the directory operations vector, convert the rest of the shortform directory operations to use vectored ops rather than superblock feature checks. This further reduces the size of the built binary: text data bss dec hex filename 794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig 792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1 792350 96802 1096 890248 d9588 fs/xfs/xfs.o.p2 Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-30xfs: abstract the differences in dir2/dir3 via an ops vectorDave Chinner1-2/+2
Lots of the dir code now goes through switches to determine what is the correct on-disk format to parse. It generally involves a "xfs_sbversion_hasfoo" check, deferencing the superblock version and feature fields and hence touching several cache lines per operation in the process. Some operations do multiple checks because they nest conditional operations and they don't pass the information in a direct fashion between each other. Hence, add an ops vector to the xfs_inode structure that is configured when the inode is initialised to point to all the correct decode and encoding operations. This will significantly reduce the branchiness and cacheline footprint of the directory object decoding and encoding. This is the first patch in a series of conversion patches. It will introduce the ops structure, the setup of it and add the first operation to the vector. Subsequent patches will convert directory ops one at a time to keep the changes simple and obvious. Just this patch shows the benefit of such an approach on code size. Just converting the two shortform dir operations as this patch does decreases the built binary size by ~1500 bytes: $ size fs/xfs/xfs.o.orig fs/xfs/xfs.o.p1 text data bss dec hex filename 794490 96802 1096 892388 d9de4 fs/xfs/xfs.o.orig 792986 96802 1096 890884 d9804 fs/xfs/xfs.o.p1 $ That's a significant decrease in the instruction cache footprint of the directory code for such a simple change, and indicates that this approach is definitely worth pursuing further. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-24xfs: decouple inode and bmap btree header filesDave Chinner1-2/+2
Currently the xfs_inode.h header has a dependency on the definition of the BMAP btree records as the inode fork includes an array of xfs_bmbt_rec_host_t objects in it's definition. Move all the btree format definitions from xfs_btree.h, xfs_bmap_btree.h, xfs_alloc_btree.h and xfs_ialloc_btree.h to xfs_format.h to continue the process of centralising the on-disk format definitions. With this done, the xfs inode definitions are no longer dependent on btree header files. The enables a massive culling of unnecessary includes, with close to 200 #include directives removed from the XFS kernel code base. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-24xfs: decouple log and transaction headersDave Chinner1-3/+3
xfs_trans.h has a dependency on xfs_log.h for a couple of structures. Most code that does transactions doesn't need to know anything about the log, but this dependency means that they have to include xfs_log.h. Decouple the xfs_trans.h and xfs_log.h header files and clean up the includes to be in dependency order. In doing this, remove the direct include of xfs_trans_reserve.h from xfs_trans.h so that we remove the dependency between xfs_trans.h and xfs_mount.h. Hence the xfs_trans.h include can be moved to the indicate the actual dependencies other header files have on it. Note that these are kernel only header files, so this does not translate to any userspace changes at all. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-23xfs: unify directory/attribute format definitionsDave Chinner1-1/+1
The on-disk format definitions for the directory and attribute structures are spread across 3 header files right now, only one of which is dedicated to defining on-disk structures and their manipulation (xfs_dir2_format.h). Pull all the format definitions into a single header file - xfs_da_format.h - and switch all the code over to point at that. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-10-01xfs: dirent dtype presence is dependent on directory magic numbersDave Chinner1-2/+2
The determination of whether a directory entry contains a dtype field originally was dependent on the filesystem having CRCs enabled. This meant that the format for dtype beign enabled could be determined by checking the directory block magic number rather than doing a feature bit check. This was useful in that it meant that we didn't need to pass a struct xfs_mount around to functions that were already supplied with a directory block header. Unfortunately, the introduction of dtype fields into the v4 structure via a feature bit meant this "use the directory block magic number" method of discriminating the dirent entry sizes is broken. Hence we need to convert the places that use magic number checks to use feature bit checks so that they work correctly and not by chance. The current code works on v4 filesystems only because the dirent size roundup covers the extra byte needed by the dtype field in the places where this problem occurs. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Ben Myers <bpm@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-22xfs: Add read-only support for dirent filetype fieldDave Chinner1-10/+59
Add support for the file type field in directory entries so that readdir can return the type of the inode the dirent points to to userspace without first having to read the inode off disk. The encoding of the type field is a single byte that is added to the end of the directory entry name length. For all intents and purposes, it appends a "hidden" byte to the name field which contains the type information. As the directory entry is already of dynamic size, helpers are already required to access and decode the direct entry structures. Hence the relevent extraction and iteration helpers are updated to understand the hidden byte. Helpers for reading and writing the filetype field from the directory entries are also added. Only the read helpers are used by this patch. It also adds all the code necessary to read the type information out of the dirents on disk. Further we add the superblock feature bit and helpers to indicate that we understand the on-disk format change. This is not a compatible change - existing kernels cannot read the new format successfully - so an incompatible feature flag is added. We don't yet allow filesystems to mount with this flag yet - that will be added once write support is added. Finally, the code to take the type from the VFS, convert it to an XFS on-disk type and put it into the xfs_name structures passed around is added, but the directory code does not use this field yet. That will be in the next patch. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: reshuffle dir2 definitions around for userspaceDave Chinner1-0/+1
Many of the definitions within xfs_dir2_priv.h are needed in userspace outside libxfs. Definitions within xfs_dir2_priv.h are wholly contained within libxfs, so we need to shuffle some of the definitions around to keep consistency across files shared between user and kernel space. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>
2013-08-13xfs: move getdents code into it's own fileDave Chinner1-0/+645
The directory readdir code is not used by userspace, but it is intermingled with files that are shared with userspace. This makes it difficult to compare the differences between the userspac eand kernel files are the userspace files don't have the getdents code in them. Move all the kernel getdents code to a separate file to bring the shared content between userspace and kernel files closer together. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Mark Tinguely <tinguely@sgi.com> Signed-off-by: Ben Myers <bpm@sgi.com>