BMC/Intel-BMC/linux.git/fs/xfs/libxfs/xfs_ialloc.c, branch dev

Merge branch 'xfs-misc-fixes-for-4.2-2' into for-next

2015-06-04T03:31:13+00:00

xfs: check min blks for random debug mode sparse allocations

2015-06-04T03:03:34+00:00

The inode allocator enables random sparse inode chunk allocations in DEBUG mode to facilitate testing. Sparse inode allocations are not always possible, however, depending on the fs geometry. For example, there is no possibility for a sparse inode allocation on filesystems where the block size is large enough to fit one or more inode chunks within a single block. Fix up the DEBUG mode sparse inode allocation logic to trigger random sparse allocations only when the geometry of the fs allows it. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

Merge branch 'xfs-sparse-inode' into for-next

2015-06-01T00:51:38+00:00

xfs: skip unallocated regions of inode chunks in xfs_ifree_cluster()

2015-05-28T23:26:03+00:00

xfs_ifree_cluster() is called to mark all in-memory inodes and inode buffers as stale. This occurs after we've removed the inobt records and dropped any references of inobt data. xfs_ifree_cluster() uses the starting inode number to walk the namespace of inodes expected for a single chunk a cluster buffer at a time. The cluster buffer disk addresses are calculated by decoding the sequential inode numbers expected from the chunk. The problem with this approach is that if the inode chunk being removed is a sparse chunk, not all of the buffer addresses that are calculated as part of this sequence may be inode clusters. Attempting to acquire the buffer based on expected inode characterstics (i.e., cluster length) can lead to errors and is generally incorrect. We already use a couple variables to carry requisite state from xfs_difree() to xfs_ifree_cluster(). Rather than add a third, define a new internal structure to carry the existing parameters through these functions. Add an alloc field that represents the physical allocation bitmap of inodes in the chunk being removed. Modify xfs_ifree_cluster() to check each inode against the bitmap and skip the clusters that were never allocated as real inodes on disk. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: only free allocated regions of inode chunks

2015-05-28T23:22:52+00:00

An inode chunk is currently added to the transaction free list based on a simple fsb conversion and hardcoded chunk length. The nature of sparse chunks is such that the physical chunk of inodes on disk may consist of one or more discontiguous parts. Blocks that reside in the holes of the inode chunk are not inodes and could be allocated to any other use or not allocated at all. Refactor the existing xfs_bmap_add_free() call into the xfs_difree_inode_chunk() helper. The new helper uses the existing calculation if a chunk is not sparse. Otherwise, use the inobt record holemask to free the contiguous regions of the chunk. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: filter out sparse regions from individual inode allocation

2015-05-28T23:20:10+00:00

Inode allocation from an existing record with free inodes traditionally selects the first inode available according to the ir_free mask. With sparse inode chunks, the ir_free mask could refer to an unallocated region. We must mask the unallocated regions out of ir_free before using it to select a free inode in the chunk. Update the xfs_inobt_first_free_inode() helper to find the first free inode available of the allocated regions of the inode chunk. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: randomly do sparse inode allocations in DEBUG mode

2015-05-28T23:19:29+00:00

Sparse inode allocations generally only occur when full inode chunk allocation fails. This requires some level of filesystem space usage and fragmentation. For filesystems formatted with sparse inode chunks enabled, do random sparse inode chunk allocs when compiled in DEBUG mode to increase test coverage. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: allocate sparse inode chunks on full chunk allocation failure

2015-05-28T23:18:32+00:00

xfs_ialloc_ag_alloc() makes several attempts to allocate a full inode chunk. If all else fails, reduce the allocation to the sparse length and alignment and attempt to allocate a sparse inode chunk. If sparse chunk allocation succeeds, check whether an inobt record already exists that can track the chunk. If so, inherit and update the existing record. Otherwise, insert a new record for the sparse chunk. Create helpers to align sparse chunk inode records and insert or update existing records in the inode btrees. The xfs_inobt_insert_sprec() helper implements the merge or update semantics required for sparse inode records with respect to both the inobt and finobt. To update the inobt, either insert a new record or merge with an existing record. To update the finobt, use the updated inobt record to either insert or replace an existing record. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: pass inode count through ordered icreate log item

2015-05-28T23:05:49+00:00

v5 superblocks use an ordered log item for logging the initialization of inode chunks. The icreate log item is currently hardcoded to an inode count of 64 inodes. The agbno and extent length are used to initialize the inode chunk from log recovery. While an incorrect inode count does not lead to bad inode chunk initialization, we should pass the correct inode count such that log recovery has enough data to perform meaningful validity checks on the chunk. Signed-off-by: Brian Foster Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner

xfs: introduce inode record hole mask for sparse inode chunks

2015-05-28T23:03:04+00:00

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 Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner