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 <hch@lst.de> Reviewed-by: "Darrick J. Wong" <djwong@kernel.org> Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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 <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
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 <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
Move all the declarations for functionality in xfs_rtbitmap.c into a separate xfs_rtbitmap.h header file. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
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 <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
Currently, xfs_bmap_del_extent_real contains a bunch of code to convert the physical extent of a data fork mapping for a realtime file into rt extents and pass that to the rt extent freeing function. Since the details of this aren't needed when CONFIG_XFS_REALTIME=n, move it to xfs_rtbitmap.c to reduce code size when realtime isn't enabled. This will (one day) enable realtime EFIs to reuse the same unit-converting call with less code duplication. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
I've been observing periodic corruption reports from xfs_scrub involving the free rt extent counter (frextents) while running xfs/141. That test uses an error injection knob to induce a torn write to the log, and an arbitrary number of recovery mounts, frextents will count fewer free rt extents than can be found the rtbitmap. The root cause of the problem is a combination of the misuse of sb_frextents in the incore mount to reflect both incore reservations made by running transactions as well as the actual count of free rt extents on disk. The following sequence can reproduce the undercount: Thread 1 Thread 2 xfs_trans_alloc(rtextents=3) xfs_mod_frextents(-3) <blocks> xfs_attr_set() xfs_bmap_attr_addfork() xfs_add_attr2() xfs_log_sb() xfs_sb_to_disk() xfs_trans_commit() <log flushed to disk> <log goes down> Note that thread 1 subtracts 3 from sb_frextents even though it never commits to using that space. Thread 2 writes the undercounted value to the ondisk superblock and logs it to the xattr transaction, which is then flushed to disk. At next mount, log recovery will find the logged superblock and write that back into the filesystem. At the end of log recovery, we reread the superblock and install the recovered undercounted frextents value into the incore superblock. From that point on, we've effectively leaked thread 1's transaction reservation. The correct fix for this is to separate the incore reservation from the ondisk usage, but that's a matter for the next patch. Because the kernel has been logging superblocks with undercounted frextents for a very long time and we don't demand that sysadmins run xfs_repair after a crash, fix the undercount by recomputing frextents after log recovery. Gating this on log recovery is a reasonable balance (I think) between correcting the problem and slowing down every mount attempt. Note that xfs_repair will fix undercounted frextents. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
Pass an explicit xfs_mount pointer to the rtalloc query functions so that they can support transactionless queries. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
The query_range functions are supposed to call a caller-supplied function on each record found in the dataset. These functions don't own the memory storing the record, so don't let them change the record. Signed-off-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Christoph Hellwig <hch@lst.de>
In commit 8ad560d2565e, we changed xfs_rtalloc_query_range to constrain
the range of bits in the realtime bitmap file that would actually be
searched. In commit a3a374bf1889, we changed the range again
(incorrectly), leading to the fix in commit d88850bd5516, which finally
corrected the range check code. Unfortunately, the author never noticed
that the function modifies its input parameters, which is a totaly no-no
since none of the other range query functions change their input
parameters.
So, fix this function yet again to stash the upper end of the query
range (i.e. the high key) in a local variable and hope this is the last
time I have to fix my own function. While we're at it, mark the key
inputs const so nobody makes this mistake again. :(
Fixes: 8ad560d2565e ("xfs: strengthen rtalloc query range checks")
Not-fixed-by: a3a374bf1889 ("xfs: fix off-by-one error in xfs_rtalloc_query_range")
Not-fixed-by: d88850bd5516 ("xfs: fix high key handling in the rt allocator's query_range function")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>