kernel/fs/xfs/xfs_rtalloc.h, branch linux-rolling-stable

xfs: make metabtree reservations global

2025-03-03T15:16:43Z

Currently each metabtree inode has it's own space reservation to ensure it can be expanded to the maximum size, mirroring what is done for the AG-based btrees. But unlike the AG-based btrees the metabtree inodes aren't restricted to allocate from a single AG but can use free space form the entire file system. And unlike AG-based btrees where the required reservation shrinks with the available free space due to this, the metabtree reservations for the rtrmap and rtfreflink trees are not bound in any way by the data device free space as they track RT extent allocations. This is not very efficient as it requires a large number of blocks to be set aside that can't be used at all by other btrees. Switch to a model that uses a global pool instead in preparation for reducing the amount of reserved space, which now also removes the overloading of the i_nblocks field for metabtree inodes, which would create problems if metabtree inodes ever had a big enough xattr fork to require xattr blocks outside the inode. Signed-off-by: Christoph Hellwig Reviewed-by: "Darrick J. Wong"

xfs: fix CoW forks for realtime files

2024-12-23T21:06:17Z

Port the copy on write fork repair to realtime files. Signed-off-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig

xfs: check that the rtrmapbt maxlevels doesn't increase when growing fs

2024-12-23T21:06:06Z

The size of filesystem transaction reservations depends on the maximum height (maxlevels) of the realtime btrees. Since we don't want a grow operation to increase the reservation size enough that we'll fail the minimum log size checks on the next mount, constrain growfs operations if they would cause an increase in those maxlevels. Signed-off-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig

xfs: allow inode-based btrees to reserve space in the data device

2024-12-23T21:06:03Z

Create a new space reservation scheme so that btree metadata for the realtime volume can reserve space in the data device to avoid space underruns. Back when we were testing the rmap and refcount btrees for the data device, people observed occasional shutdowns when xfs_btree_split was called for either of those two btrees. This happened when certain operations (mostly writeback ioends) created new rmap or refcount records, which would expand the size of the btree. If there were no free blocks available the allocation would fail and the split would shut down the filesystem. I considered pre-reserving blocks for btree expansion at the time of a write() call, but there wasn't any good way to attach the reservations to an inode and keep them there all the way to ioend processing. Unlike delalloc reservations which have that indlen mechanism, there's no way to do that for mapped extents; and indlen blocks are given back during the delalloc -> unwritten transition. The solution was to reserve sufficient blocks for rmap/refcount btree expansion at mount time. This is what the XFS_AG_RESV_* flags provide; any expansion of those two btrees can come from the pre-reserved space. This patch brings that pre-reservation ability to inode-rooted btrees so that the rt rmap and refcount btrees can also save room for future expansion. Signed-off-by: "Darrick J. Wong" Reviewed-by: Christoph Hellwig

xfs: check the realtime superblock at mount time

2024-11-05T21:38:39Z

Check the realtime superblock at mount time, to ensure that the label and uuids actually match the primary superblock on the data device. If the rt superblock is good, attach it to the xfs_mount so that the log can use ordered buffers to keep this primary in sync with the primary super on the data device. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

xfs: move xfs_bmap_rtalloc to xfs_rtalloc.c

2023-12-22T05:48:11Z

xfs_bmap_rtalloc is currently in xfs_bmap_util.c, which is a somewhat odd spot for it, given that is only called from xfs_bmap.c and calls into xfs_rtalloc.c to do the actual work. Move xfs_bmap_rtalloc to xfs_rtalloc.c and mark xfs_rtpick_extent xfs_rtallocate_extent and xfs_rtallocate_extent static now that they aren't called from outside of xfs_rtalloc.c. Signed-off-by: Christoph Hellwig Reviewed-by: "Darrick J. Wong" Signed-off-by: Chandan Babu R

xfs: convert rt extent numbers to xfs_rtxnum_t

2023-10-17T23:24:22Z

Further disambiguate the xfs_rtblock_t uses by creating a new type, xfs_rtxnum_t, to store the position of an extent within the realtime section, in units of rtextents. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

xfs: convert xfs_extlen_t to xfs_rtxlen_t in the rt allocator

2023-10-17T23:24:22Z

In most of the filesystem, we use xfs_extlen_t to store the length of a file (or AG) space mapping in units of fs blocks. Unfortunately, the realtime allocator also uses it to store the length of a rt space mapping in units of rt extents. This is confusing, since one rt extent can consist of many fs blocks. Separate the two by introducing a new type (xfs_rtxlen_t) to store the length of a space mapping (in units of realtime extents) that would be found in a file. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

xfs: move the xfs_rtbitmap.c declarations to xfs_rtbitmap.h

2023-10-17T23:24:22Z

Move all the declarations for functionality in xfs_rtbitmap.c into a separate xfs_rtbitmap.h header file. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig

xfs: rt stubs should return negative errnos when rt disabled

2023-10-17T23:22:40Z

When realtime support is not compiled into the kernel, these functions should return negative errnos, not positive errnos. While we're at it, fix a broken macro declaration. Signed-off-by: Darrick J. Wong Reviewed-by: Christoph Hellwig