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path: root/fs/xfs/libxfs/xfs_ialloc_btree.c
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2015-05-29xfs: helper to convert holemask to inode alloc. bitmapBrian Foster1-0/+51
The inobt record holemask field is a condensed data type designed to fit into the existing on-disk record and is zero based (allocated regions are set to 0, sparse regions are set to 1) to provide backwards compatibility. This makes the type somewhat complex for use in higher level inode manipulations such as individual inode allocation, etc. Rather than foist the complexity of dealing with this field to every bit of logic that requires inode granular information, create a helper to convert the holemask to an inode allocation bitmap. The inode allocation bitmap is inode granularity similar to the inobt record free mask and indicates which inodes of the chunk are physically allocated on disk, irrespective of whether the inode is considered allocated or free by the filesystem. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2015-05-29xfs: introduce inode record hole mask for sparse inode chunksBrian Foster1-1/+10
The inode btrees track 64 inodes per record regardless of inode size. Thus, inode chunks on disk vary in size depending on the size of the inodes. This creates a contiguous allocation requirement for new inode chunks that can be difficult to satisfy on an aged and fragmented (free space) filesystems. The inode record freecount currently uses 4 bytes on disk to track the free inode count. With a maximum freecount value of 64, only one byte is required. Convert the freecount field to a single byte and use two of the remaining 3 higher order bytes left for the hole mask field. Use the final leftover byte for the total count field. The hole mask field tracks holes in the chunks of physical space that the inode record refers to. This facilitates the sparse allocation of inode chunks when contiguous chunks are not available and allows the inode btrees to identify what portions of the chunk contain valid inodes. The total count field contains the total number of valid inodes referred to by the record. This can also be deduced from the hole mask. The count field provides clarity and redundancy for internal record verification. Note that neither of the new fields can be written to disk on fs' without sparse inode support. Doing so writes to the high-order bytes of freecount and causes corruption from the perspective of older kernels. The on-disk inobt record data structure is updated with a union to distinguish between the original, "full" format and the new, "sparse" format. The conversion routines to get, insert and update records are updated to translate to and from the on-disk record accordingly such that freecount remains a 4-byte value on non-supported fs, yet the new fields of the in-core record are always valid with respect to the record. This means that higher level code can refer to the current in-core record format unconditionally and lower level code ensures that records are translated to/from disk according to the capabilities of the fs. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: move most of xfs_sb.h to xfs_format.hChristoph Hellwig1-1/+0
More on-disk format consolidation. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-11-28xfs: merge xfs_ag.h into xfs_format.hChristoph Hellwig1-1/+0
More on-disk format consolidation. A few declarations that weren't on-disk format related move into better suitable spots. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-25xfs: global error sign conversionDave Chinner1-3/+3
Convert all the errors the core XFs code to negative error signs like the rest of the kernel and remove all the sign conversion we do in the interface layers. Errors for conversion (and comparison) found via searches like: $ git grep " E" fs/xfs $ git grep "return E" fs/xfs $ git grep " E[A-Z].*;$" fs/xfs Negation points found via searches like: $ git grep "= -[a-z,A-Z]" fs/xfs $ git grep "return -[a-z,A-D,F-Z]" fs/xfs $ git grep " -[a-z].*;" fs/xfs [ with some bits I missed from Brian Foster ] Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2014-06-25libxfs: move source filesDave Chinner1-0/+422
Move all the source files that are shared with userspace into libxfs/. This is done as one big chunk simpy to get it done quickly Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>