With the nrext64 feature enabled, it's possible for a data fork to have
2^48 extent mappings. Even with a 64k fsblock size, that maps out to
a bmbt containing more than 2^32 blocks. Therefore, this predicate must
return a u64 count to avoid an integer wraparound that will cause scrub
to do the wrong thing.
It's unlikely that any such filesystem currently exists, because the
incore bmbt would consume more than 64GB of kernel memory on its own,
and so far nobody except me has driven a filesystem that far, judging
from the lack of complaints.
Cc: <stable@vger.kernel.org> # v5.19
Fixes: df9ad5cc7a ("xfs: Introduce macros to represent new maximum extent counts for data/attr forks")
Signed-off-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Right now, the realtime section uses a single pair of metadata inodes to
store the free space information. This presents a scalability problem
since every thread trying to allocate or free rt extents have to lock
these files. Solve this problem by sharding the realtime section into
separate realtime allocation groups.
While we're at it, define a superblock to be stamped into the start of
the rt section. This enables utilities such as blkid to identify block
devices containing realtime sections, and avoids the situation where
anything written into block 0 of the realtime extent can be
misinterpreted as file data.
The best advantage for rtgroups will become evident later when we get to
adding rmap and reflink to the realtime volume, since the geometry
constraints are the same for rt groups and AGs. Hence we can reuse all
that code directly.
This is a very large patchset, but it catches us up with 20 years of
technical debt that have accumulated.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'realtime-groups-6.13_2024-11-05' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into staging-merge
xfs: shard the realtime section [v5.5 06/10]
Right now, the realtime section uses a single pair of metadata inodes to
store the free space information. This presents a scalability problem
since every thread trying to allocate or free rt extents have to lock
these files. Solve this problem by sharding the realtime section into
separate realtime allocation groups.
While we're at it, define a superblock to be stamped into the start of
the rt section. This enables utilities such as blkid to identify block
devices containing realtime sections, and avoids the situation where
anything written into block 0 of the realtime extent can be
misinterpreted as file data.
The best advantage for rtgroups will become evident later when we get to
adding rmap and reflink to the realtime volume, since the geometry
constraints are the same for rt groups and AGs. Hence we can reuse all
that code directly.
This is a very large patchset, but it catches us up with 20 years of
technical debt that have accumulated.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Add in-memory data structures for sharding the realtime volume into
independent allocation groups. For existing filesystems, the entire rt
volume is modelled as having a single large group, with (potentially) a
number of rt extents exceeding 2^32 blocks, though these are not likely
to exist because the codebase has been a bit broken for decades. The
next series fills in the ondisk format and other supporting structures.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'incore-rtgroups-6.13_2024-11-05' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into staging-merge
xfs: create incore rt allocation groups [v5.5 04/10]
Add in-memory data structures for sharding the realtime volume into
independent allocation groups. For existing filesystems, the entire rt
volume is modelled as having a single large group, with (potentially) a
number of rt extents exceeding 2^32 blocks, though these are not likely
to exist because the codebase has been a bit broken for decades. The
next series fills in the ondisk format and other supporting structures.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Convert the xfs_mount perag tree to use an xarray instead of a radix
tree. There should be no functional changes here.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'perag-xarray-6.13_2024-11-05' of https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into staging-merge
xfs: convert perag to use xarrays [v5.5 01/10]
Convert the xfs_mount perag tree to use an xarray instead of a radix
tree. There should be no functional changes here.
With a bit of luck, this should all go splendidly.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
We're about to segment xfs_rtblock_t addresses, so we must create
type-specific helpers to do rt extent rounding of file block offsets
because the rtb helpers soon will not do the right thing there.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_swap_extent_rmap does not use log items to track the overall
progress of an attempt to swap the extent mappings between two files.
If the system crashes in the middle of swapping a partially written
realtime extent, the mapping will be left in an inconsistent state
wherein a file can point to multiple extents on the rt volume.
The new file range exchange functionality handles this correctly, so all
callers must upgrade to that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create an incore object that will contain information about a realtime
allocation group. This will eventually enable us to shard the realtime
section in a similar manner to how we shard the data section, but for
now just a single object for the entire RT subvolume is created.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
In commit 11f4c3a53a, we tried to simplify the extent lookup in
xfs_can_free_eofblocks so that it doesn't incur the overhead of all the
extra stuff that xfs_bmapi_read does around the iext lookup.
Unfortunately, this causes regressions on generic/603, xfs/108,
generic/219, xfs/173, generic/694, xfs/052, generic/230, and xfs/441
when always_cow is turned on. In all cases, the regressions take the
form of alwayscow files consuming rather more space than the golden
output is expecting. I observed that in all these cases, the cause of
the excess space usage was due to CoW fork delalloc reservations that go
beyond EOF.
For alwayscow files we allow posteof delalloc CoW reservations because
all writes go through the CoW fork. Recall that all extents in the CoW
fork are accounted for via i_delayed_blks, which means that prior to
this patch, we'd invoke xfs_free_eofblocks on first close if anything
was in the CoW fork. Now we don't do that.
Fix the problem by reverting the removal of the i_delayed_blks check.
Cc: <stable@vger.kernel.org> # v6.12-rc1
Fixes: 11f4c3a53a ("xfs: simplify extent lookup in xfs_can_free_eofblocks")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
xfs_zero_extent does some really odd gymnstics to calculate the block
layer sectors numbers passed to blkdev_issue_zeroout. This is because it
used to call sb_issue_zeroout and the calculations in that helper got
open coded here in the rather misleadingly named commit 3dc2916107
("dax: use sb_issue_zerout instead of calling dax_clear_sectors").
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
xfs_buffered_write_iomap_begin can also create delallocate reservations
that need cleaning up, prepare for that by adding support for the COW
fork in xfs_bmap_punch_delalloc_range.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
* Introduce new ioctls to exchange contents of two files.
The first ioctl does the preparation work to exchange the contents of two
files while the second ioctl performs the actual exchange if the target
file has not been changed since a given sampling point.
* Fixes
- Fix bugs associated with calculating the maximum range of realtime
extents to scan for free space.
- Copy keys instead of records when resizing the incore BMBT root block.
- Do not report FITRIMming more bytes than possibly exist in the
filesystem.
- Modify xfs_fs.h to prevent C++ compilation errors.
- Do not over eagerly free post-EOF speculative preallocation.
- Ensure st_blocks never goes to zero during COW writes
* Cleanups/refactors
- Use Xarray to hold per-AG data instead of a Radix tree.
- Cleanup the following functionality,
- Realtime bitmap.
- Inode allocator.
- Quota.
- Inode rooted btree code.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.12-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
"New code:
- Introduce new ioctls to exchange contents of two files.
The first ioctl does the preparation work to exchange the contents
of two files while the second ioctl performs the actual exchange if
the target file has not been changed since a given sampling point.
Fixes:
- Fix bugs associated with calculating the maximum range of realtime
extents to scan for free space.
- Copy keys instead of records when resizing the incore BMBT root
block.
- Do not report FITRIMming more bytes than possibly exist in the
filesystem.
- Modify xfs_fs.h to prevent C++ compilation errors.
- Do not over eagerly free post-EOF speculative preallocation.
- Ensure st_blocks never goes to zero during COW writes
Cleanups/refactors:
- Use Xarray to hold per-AG data instead of a Radix tree.
- Cleanups to:
- realtime bitmap
- inode allocator
- quota
- inode rooted btree code"
* tag 'xfs-6.12-merge-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (61 commits)
xfs: ensure st_blocks never goes to zero during COW writes
xfs: use xas_for_each_marked in xfs_reclaim_inodes_count
xfs: convert perag lookup to xarray
xfs: simplify tagged perag iteration
xfs: move the tagged perag lookup helpers to xfs_icache.c
xfs: use kfree_rcu_mightsleep to free the perag structures
xfs: use LIST_HEAD() to simplify code
xfs: Remove duplicate xfs_trans_priv.h header
xfs: remove unnecessary check
xfs: Use xfs set and clear mp state helpers
xfs: reclaim speculative preallocations for append only files
xfs: simplify extent lookup in xfs_can_free_eofblocks
xfs: check XFS_EOFBLOCKS_RELEASED earlier in xfs_release_eofblocks
xfs: only free posteof blocks on first close
xfs: don't free post-EOF blocks on read close
xfs: skip all of xfs_file_release when shut down
xfs: don't bother returning errors from xfs_file_release
xfs: refactor f_op->release handling
xfs: remove the i_mode check in xfs_release
xfs: standardize the btree maxrecs function parameters
...
The XFS XFS_DIFLAG_APPEND maps to the VFS S_APPEND flag, which forbids
writes that don't append at the current EOF.
But the commit originally adding XFS_DIFLAG_APPEND support (commit
a23321e766d in xfs xfs-import repository) also checked it to skip
releasing speculative preallocations, which doesn't make any sense.
Another commit (dd9f438e32 in the xfs-import repository) later extended
that flag to also report these speculation preallocations which should
not exist in getbmap.
Remove these checks as nothing XFS_DIFLAG_APPEND implies that
preallocations beyond EOF should exist, but explicitly check for
XFS_DIFLAG_APPEND in xfs_file_release to bypass the algorithm that
discard preallocations on the first close as append only files aren't
expected to be written to only once.
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>
xfs_can_free_eofblocks just cares if there is an extent beyond EOF.
Replace the call to xfs_bmapi_read with a xfs_iext_lookup_extent
as we've already checked that extents are read in earlier.
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>
Move the xfs_is_always_cow_inode check from the caller into
xfs_alloc_file_space to prepare for refactoring of xfs_file_fallocate.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240827065123.1762168-6-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Call xfs_flush_unmap_range from xfs_free_file_space so that
xfs_file_fallocate doesn't have to predict which mode will call it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20240827065123.1762168-5-hch@lst.de
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The RT extent range must be considered in the xfs_flush_unmap_range() call
to stabilize the boundary.
This code change is originally from Dave Chinner.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Currently xfs_flush_unmap_range() does unmap for a full RT extent range,
which we also want to ensure is clean and idle.
This code change is originally from Dave Chinner.
Reviewed-by: Christoph Hellwig <hch@lst.de>4
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
xfs_can_free_eofblocks returns false for files that have persistent
preallocations unless the force flag is passed and there are delayed
blocks. This means it won't free delalloc reservations for files
with persistent preallocations unless the force flag is set, and it
will also free the persistent preallocations if the force flag is
set and the file happens to have delayed allocations.
Both of these are bad, so do away with the force flag and always free
only post-EOF delayed allocations for files with the XFS_DIFLAG_PREALLOC
or APPEND flags set.
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>
Currently the calls to xfs_iext_count_may_overflow and
xfs_iext_count_upgrade are always paired. Merge them into a single
function to simplify the callers and the actual check and upgrade
logic itself.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Unreserving quotas can't fail due to quota limits, and we'll notice a
shut down file system a bit later in all the callers anyway. Return
void and remove the error checking and propagation in the callers.
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>
xfs_bmapi_write can return 0 without actually returning a mapping in
mval in two different cases:
1) when there is absolutely no space available to do an allocation
2) when converting delalloc space, and the allocation is so small
that it only covers parts of the delalloc extent before the
range requested by the caller
Callers at best can handle one of these cases, but in many cases can't
cope with either one. Switch xfs_bmapi_write to always return a
mapping or return an error code instead. For case 1) above ENOSPC is
the obvious choice which is very much what the callers expect anyway.
For case 2) there is no really good error code, so pick a funky one
from the SysV streams portfolio.
This fixes the reproducer here:
https://lore.kernel.org/linux-xfs/CAEJPjCvT3Uag-pMTYuigEjWZHn1sGMZ0GCjVVCv29tNHK76Cgg@mail.gmail.com0/
which uses reserved blocks to create file systems that are gravely
out of space and thus cause at least xfs_file_alloc_space to hang
and trigger the lack of ENOSPC handling in xfs_dquot_disk_alloc.
Note that this patch does not actually make any caller but
xfs_alloc_file_space deal intelligently with case 2) above.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: 刘通 <lyutoon@gmail.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
Replace the open-coded logic to decide if a file has a multi-fsb
allocation unit to a helper to make the code easier to read.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
The deferred bmap update log item has always supported the attr fork, so
plumb this in so that higher layers can access this.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
To use the new rwsem_assert_held()/rwsem_assert_held_write(), we can't
use the existing ASSERT macro. Add a new xfs_assert_ilocked() and
convert all the callers.
Fix an apparent bug in xfs_isilocked(): If the caller specifies
XFS_IOLOCK_EXCL | XFS_ILOCK_EXCL, xfs_assert_ilocked() will check both
the IOLOCK and the ILOCK are held for write. xfs_isilocked() only
checked that the ILOCK was held for write.
xfs_assert_ilocked() is always on, even if DEBUG or XFS_WARN aren't
defined. It's a cheap check, so I don't think it's worth defining
it away.
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
When running in a transaction context, memory allocations are scoped
to GFP_NOFS. Hence we don't need to use GFP_NOFS contexts in pure
transaction context allocations - GFP_KERNEL will automatically get
converted to GFP_NOFS as appropriate.
Go through the code and convert all the obvious GFP_NOFS allocations
in transaction context to use GFP_KERNEL. This further reduces the
explicit use of GFP_NOFS in XFS.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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>
Make xfs_bmap_btalloc_accounting more generic by handling the RT quota
reservations and then also use it from xfs_bmap_rtalloc instead of
open coding the accounting logic there.
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>
* Realtime device subsystem
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types.
- Replace open coded conversions between rt blocks and rt extents with
calls to static inline helpers.
- Replace open coded realtime geometry compuation and macros with helper
functions.
- CPU usage optimizations for realtime allocator.
- Misc. Bug fixes associated with Realtime device.
* Allow read operations to execute while an FICLONE ioctl is being serviced.
* Misc. bug fixes
- Alert user when xfs_droplink() encounters an inode with a link count of zero.
- Handle the case where the allocator could return zero extents when
servicing an fallocate request.
Signed-off-by: Chandan Babu R <chandanbabu@kernel.org>
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Merge tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Chandan Babu:
- Realtime device subsystem:
- Cleanup usage of xfs_rtblock_t and xfs_fsblock_t data types
- Replace open coded conversions between rt blocks and rt extents
with calls to static inline helpers
- Replace open coded realtime geometry compuation and macros with
helper functions
- CPU usage optimizations for realtime allocator
- Misc bug fixes associated with Realtime device
- Allow read operations to execute while an FICLONE ioctl is being
serviced
- Misc bug fixes:
- Alert user when xfs_droplink() encounters an inode with a link
count of zero
- Handle the case where the allocator could return zero extents when
servicing an fallocate request
* tag 'xfs-6.7-merge-2' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (40 commits)
xfs: allow read IO and FICLONE to run concurrently
xfs: handle nimaps=0 from xfs_bmapi_write in xfs_alloc_file_space
xfs: introduce protection for drop nlink
xfs: don't look for end of extent further than necessary in xfs_rtallocate_extent_near()
xfs: don't try redundant allocations in xfs_rtallocate_extent_near()
xfs: limit maxlen based on available space in xfs_rtallocate_extent_near()
xfs: return maximum free size from xfs_rtany_summary()
xfs: invert the realtime summary cache
xfs: simplify rt bitmap/summary block accessor functions
xfs: simplify xfs_rtbuf_get calling conventions
xfs: cache last bitmap block in realtime allocator
xfs: use accessor functions for summary info words
xfs: consolidate realtime allocation arguments
xfs: create helpers for rtsummary block/wordcount computations
xfs: use accessor functions for bitmap words
xfs: create helpers for rtbitmap block/wordcount computations
xfs: create a helper to handle logging parts of rt bitmap/summary blocks
xfs: convert rt summary macros to helpers
xfs: convert open-coded xfs_rtword_t pointer accesses to helper
xfs: remove XFS_BLOCKWSIZE and XFS_BLOCKWMASK macros
...
If xfs_bmapi_write finds a delalloc extent at the requested range, it
tries to convert the entire delalloc extent to a real allocation.
But if the allocator cannot find a single free extent large enough to
cover the start block of the requested range, xfs_bmapi_write will
return 0 but leave *nimaps set to 0.
In that case we simply need to keep looping with the same startoffset_fsb
so that one of the following allocations will eventually reach the
requested range.
Note that this could affect any caller of xfs_bmapi_write that covers
an existing delayed allocation. As far as I can tell we do not have
any other such caller, though - the regular writeback path uses
xfs_bmapi_convert_delalloc to convert delayed allocations to real ones,
and direct I/O invalidates the page cache first.
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>
Create a pair of functions to round rtblock numbers up or down to the
nearest rt extent.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Convert these calls to use the helpers, and clean up all these places
where the same variable can have different units depending on where it
is in the function.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a helper to compute the realtime extent (xfs_rtxlen_t) from an
extent length (xfs_extlen_t) value.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a helper to compute the misalignment between a file extent
(xfs_extlen_t) and a realtime extent.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Create a helper to convert a realtime extent to a realtime block. Later
on we'll change the helper to use bit shifts when possible.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
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>
In later patches, we're going to change how the inode's ctime field is
used. Switch to using accessor functions instead of raw accesses of
inode->i_ctime.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230705190309.579783-80-jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
In commit 8ee81ed581, Ye Bin complained about an ASSERT in the bmapx
code that trips if we encounter a delalloc extent after flushing the
pagecache to disk. The ioctl code does not hold MMAPLOCK so it's
entirely possible that a racing write page fault can create a delalloc
extent after the file has been flushed. The proposed solution was to
replace the assertion with an early return that avoids filling out the
bmap recordset with a delalloc entry if the caller didn't ask for it.
At the time, I recall thinking that the forward logic sounded ok, but
felt hesitant because I suspected that changing this code would cause
something /else/ to burst loose due to some other subtlety.
syzbot of course found that subtlety. If all the extent mappings found
after the flush are delalloc mappings, we'll reach the end of the data
fork without ever incrementing bmv->bmv_entries. This is new, since
before we'd have emitted the delalloc mappings even though the caller
didn't ask for them. Once we reach the end, we'll try to set
BMV_OF_LAST on the -1st entry (because bmv_entries is zero) and go
corrupt something else in memory. Yay.
I really dislike all these stupid patches that fiddle around with debug
code and break things that otherwise worked well enough. Nobody was
complaining that calling XFS_IOC_BMAPX without BMV_IF_DELALLOC would
return BMV_OF_DELALLOC records, and now we've gone from "weird behavior
that nobody cared about" to "bad behavior that must be addressed
immediately".
Maybe I'll just ignore anything from Huawei from now on for my own sake.
Reported-by: syzbot+c103d3808a0de5faaf80@syzkaller.appspotmail.com
Link: https://lore.kernel.org/linux-xfs/20230412024907.GP360889@frogsfrogsfrogs/
Fixes: 8ee81ed581 ("xfs: fix BUG_ON in xfs_getbmap()")
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 tp->t_firstblock field is now raelly tracking the highest AG we
have locked, not the block number of the highest allocation we've
made. It's purpose is to prevent AGF locking deadlocks, so rename it
to "highest AG" and simplify the implementation to just track the
agno rather than a fsbno.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
All the callers of xfs_bmap_punch_delalloc_range() jump through
hoops to convert a byte range to filesystem blocks before calling
xfs_bmap_punch_delalloc_range(). Instead, pass the byte range to
xfs_bmap_punch_delalloc_range() and have it do the conversion to
filesystem blocks internally.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Replace the shouty macros here with typechecked helper functions.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Replace this shouty macro with a real C function that has a more
descriptive name.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Syzkaller reported a UAF bug a while back:
==================================================================
BUG: KASAN: use-after-free in xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
Read of size 4 at addr ffff88802cec919c by task syz-executor262/2958
CPU: 2 PID: 2958 Comm: syz-executor262 Not tainted
5.15.0-0.30.3-20220406_1406 #3
Hardware name: Red Hat KVM, BIOS 1.13.0-2.module+el8.3.0+7860+a7792d29
04/01/2014
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x82/0xa9 lib/dump_stack.c:106
print_address_description.constprop.9+0x21/0x2d5 mm/kasan/report.c:256
__kasan_report mm/kasan/report.c:442 [inline]
kasan_report.cold.14+0x7f/0x11b mm/kasan/report.c:459
xfs_ilock_attr_map_shared+0xe3/0xf6 fs/xfs/xfs_inode.c:127
xfs_attr_get+0x378/0x4c2 fs/xfs/libxfs/xfs_attr.c:159
xfs_xattr_get+0xe3/0x150 fs/xfs/xfs_xattr.c:36
__vfs_getxattr+0xdf/0x13d fs/xattr.c:399
cap_inode_need_killpriv+0x41/0x5d security/commoncap.c:300
security_inode_need_killpriv+0x4c/0x97 security/security.c:1408
dentry_needs_remove_privs.part.28+0x21/0x63 fs/inode.c:1912
dentry_needs_remove_privs+0x80/0x9e fs/inode.c:1908
do_truncate+0xc3/0x1e0 fs/open.c:56
handle_truncate fs/namei.c:3084 [inline]
do_open fs/namei.c:3432 [inline]
path_openat+0x30ab/0x396d fs/namei.c:3561
do_filp_open+0x1c4/0x290 fs/namei.c:3588
do_sys_openat2+0x60d/0x98c fs/open.c:1212
do_sys_open+0xcf/0x13c fs/open.c:1228
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
RIP: 0033:0x7f7ef4bb753d
Code: 00 c3 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 48 89 f8 48 89 f7 48
89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73
01 c3 48 8b 0d 1b 79 2c 00 f7 d8 64 89 01 48
RSP: 002b:00007f7ef52c2ed8 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
RAX: ffffffffffffffda RBX: 0000000000404148 RCX: 00007f7ef4bb753d
RDX: 00007f7ef4bb753d RSI: 0000000000000000 RDI: 0000000020004fc0
RBP: 0000000000404140 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0030656c69662f2e
R13: 00007ffd794db37f R14: 00007ffd794db470 R15: 00007f7ef52c2fc0
</TASK>
Allocated by task 2953:
kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
kasan_set_track mm/kasan/common.c:46 [inline]
set_alloc_info mm/kasan/common.c:434 [inline]
__kasan_slab_alloc+0x68/0x7c mm/kasan/common.c:467
kasan_slab_alloc include/linux/kasan.h:254 [inline]
slab_post_alloc_hook mm/slab.h:519 [inline]
slab_alloc_node mm/slub.c:3213 [inline]
slab_alloc mm/slub.c:3221 [inline]
kmem_cache_alloc+0x11b/0x3eb mm/slub.c:3226
kmem_cache_zalloc include/linux/slab.h:711 [inline]
xfs_ifork_alloc+0x25/0xa2 fs/xfs/libxfs/xfs_inode_fork.c:287
xfs_bmap_add_attrfork+0x3f2/0x9b1 fs/xfs/libxfs/xfs_bmap.c:1098
xfs_attr_set+0xe38/0x12a7 fs/xfs/libxfs/xfs_attr.c:746
xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
__vfs_setxattr+0x11b/0x177 fs/xattr.c:180
__vfs_setxattr_noperm+0x128/0x5e0 fs/xattr.c:214
__vfs_setxattr_locked+0x1d4/0x258 fs/xattr.c:275
vfs_setxattr+0x154/0x33d fs/xattr.c:301
setxattr+0x216/0x29f fs/xattr.c:575
__do_sys_fsetxattr fs/xattr.c:632 [inline]
__se_sys_fsetxattr fs/xattr.c:621 [inline]
__x64_sys_fsetxattr+0x243/0x2fe fs/xattr.c:621
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
Freed by task 2949:
kasan_save_stack+0x19/0x38 mm/kasan/common.c:38
kasan_set_track+0x1c/0x21 mm/kasan/common.c:46
kasan_set_free_info+0x20/0x30 mm/kasan/generic.c:360
____kasan_slab_free mm/kasan/common.c:366 [inline]
____kasan_slab_free mm/kasan/common.c:328 [inline]
__kasan_slab_free+0xe2/0x10e mm/kasan/common.c:374
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1700 [inline]
slab_free_freelist_hook mm/slub.c:1726 [inline]
slab_free mm/slub.c:3492 [inline]
kmem_cache_free+0xdc/0x3ce mm/slub.c:3508
xfs_attr_fork_remove+0x8d/0x132 fs/xfs/libxfs/xfs_attr_leaf.c:773
xfs_attr_sf_removename+0x5dd/0x6cb fs/xfs/libxfs/xfs_attr_leaf.c:822
xfs_attr_remove_iter+0x68c/0x805 fs/xfs/libxfs/xfs_attr.c:1413
xfs_attr_remove_args+0xb1/0x10d fs/xfs/libxfs/xfs_attr.c:684
xfs_attr_set+0xf1e/0x12a7 fs/xfs/libxfs/xfs_attr.c:802
xfs_xattr_set+0xeb/0x1a9 fs/xfs/xfs_xattr.c:59
__vfs_removexattr+0x106/0x16a fs/xattr.c:468
cap_inode_killpriv+0x24/0x47 security/commoncap.c:324
security_inode_killpriv+0x54/0xa1 security/security.c:1414
setattr_prepare+0x1a6/0x897 fs/attr.c:146
xfs_vn_change_ok+0x111/0x15e fs/xfs/xfs_iops.c:682
xfs_vn_setattr_size+0x5f/0x15a fs/xfs/xfs_iops.c:1065
xfs_vn_setattr+0x125/0x2ad fs/xfs/xfs_iops.c:1093
notify_change+0xae5/0x10a1 fs/attr.c:410
do_truncate+0x134/0x1e0 fs/open.c:64
handle_truncate fs/namei.c:3084 [inline]
do_open fs/namei.c:3432 [inline]
path_openat+0x30ab/0x396d fs/namei.c:3561
do_filp_open+0x1c4/0x290 fs/namei.c:3588
do_sys_openat2+0x60d/0x98c fs/open.c:1212
do_sys_open+0xcf/0x13c fs/open.c:1228
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x3a/0x7e arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0x0
The buggy address belongs to the object at ffff88802cec9188
which belongs to the cache xfs_ifork of size 40
The buggy address is located 20 bytes inside of
40-byte region [ffff88802cec9188, ffff88802cec91b0)
The buggy address belongs to the page:
page:00000000c3af36a1 refcount:1 mapcount:0 mapping:0000000000000000
index:0x0 pfn:0x2cec9
flags: 0xfffffc0000200(slab|node=0|zone=1|lastcpupid=0x1fffff)
raw: 000fffffc0000200 ffffea00009d2580 0000000600000006 ffff88801a9ffc80
raw: 0000000000000000 0000000080490049 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff88802cec9080: fb fb fb fc fc fa fb fb fb fb fc fc fb fb fb fb
ffff88802cec9100: fb fc fc fb fb fb fb fb fc fc fb fb fb fb fb fc
>ffff88802cec9180: fc fa fb fb fb fb fc fc fa fb fb fb fb fc fc fb
^
ffff88802cec9200: fb fb fb fb fc fc fb fb fb fb fb fc fc fb fb fb
ffff88802cec9280: fb fb fc fc fa fb fb fb fb fc fc fa fb fb fb fb
==================================================================
The root cause of this bug is the unlocked access to xfs_inode.i_afp
from the getxattr code paths while trying to determine which ILOCK mode
to use to stabilize the xattr data. Unfortunately, the VFS does not
acquire i_rwsem when vfs_getxattr (or listxattr) call into the
filesystem, which means that getxattr can race with a removexattr that's
tearing down the attr fork and crash:
xfs_attr_set: xfs_attr_get:
xfs_attr_fork_remove: xfs_ilock_attr_map_shared:
xfs_idestroy_fork(ip->i_afp);
kmem_cache_free(xfs_ifork_cache, ip->i_afp);
if (ip->i_afp &&
ip->i_afp = NULL;
xfs_need_iread_extents(ip->i_afp))
<KABOOM>
ip->i_forkoff = 0;
Regrettably, the VFS is much more lax about i_rwsem and getxattr than
is immediately obvious -- not only does it not guarantee that we hold
i_rwsem, it actually doesn't guarantee that we *don't* hold it either.
The getxattr system call won't acquire the lock before calling XFS, but
the file capabilities code calls getxattr with and without i_rwsem held
to determine if the "security.capabilities" xattr is set on the file.
Fixing the VFS locking requires a treewide investigation into every code
path that could touch an xattr and what i_rwsem state it expects or sets
up. That could take years or even prove impossible; fortunately, we
can fix this UAF problem inside XFS.
An earlier version of this patch used smp_wmb in xfs_attr_fork_remove to
ensure that i_forkoff is always zeroed before i_afp is set to null and
changed the read paths to use smp_rmb before accessing i_forkoff and
i_afp, which avoided these UAF problems. However, the patch author was
too busy dealing with other problems in the meantime, and by the time he
came back to this issue, the situation had changed a bit.
On a modern system with selinux, each inode will always have at least
one xattr for the selinux label, so it doesn't make much sense to keep
incurring the extra pointer dereference. Furthermore, Allison's
upcoming parent pointer patchset will also cause nearly every inode in
the filesystem to have extended attributes. Therefore, make the inode
attribute fork structure part of struct xfs_inode, at a cost of 40 more
bytes.
This patch adds a clunky if_present field where necessary to maintain
the existing logic of xattr fork null pointer testing in the existing
codebase. The next patch switches the logic over to XFS_IFORK_Q and it
all goes away.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
We're about to make this logic do a bit more, so convert the macro to a
static inline function for better typechecking and fewer shouty macros.
No functional changes here.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
On a system with a realtime volume and a 28k realtime extent,
generic/491 fails because the test opens a file on a frozen filesystem
and closing it causes xfs_release -> xfs_can_free_eofblocks to
mistakenly think that the the blocks of the realtime extent beyond EOF
are posteof blocks to be freed. Realtime extents cannot be partially
unmapped, so this is pointless. Worse yet, this triggers posteof
cleanup, which stalls on a transaction allocation, which is why the test
fails.
Teach the predicate to account for realtime extents properly.
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
This commit enables upgrading existing inodes to use large extent counters
provided that underlying filesystem's superblock has large extent counter
feature enabled.
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
