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path: root/fs/xfs/xfs_dir2_readdir.c
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2013-10-04xfs: dirent dtype presence is dependent on directory magic numbersDave Chinner
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> (cherry picked from commit 367993e7c6428cb7617ab7653d61dca54e2fdede)
2013-08-22xfs: Add read-only support for dirent filetype fieldDave Chinner
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>
2013-08-12xfs: reshuffle dir2 definitions around for userspaceDave Chinner
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>
2013-08-12xfs: move getdents code into it's own fileDave Chinner
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>