linux-2.6-block.git
5 months agoxfs: unlock new repair tempfiles after creation
Darrick J. Wong [Mon, 15 Apr 2024 21:55:16 +0000 (14:55 -0700)]
xfs: unlock new repair tempfiles after creation

After creation, drop the ILOCK on temporary files that have been created
to stage a repair.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: don't pick up IOLOCK during rmapbt repair scan
Darrick J. Wong [Mon, 15 Apr 2024 21:55:15 +0000 (14:55 -0700)]
xfs: don't pick up IOLOCK during rmapbt repair scan

Now that we've fixed the directory operations to hold the ILOCK until
they're finished with rmapbt updates for directory shape changes, we no
longer need to take this lock when scanning directories for rmapbt
records.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: Hold inode locks in xfs_rename
Allison Henderson [Mon, 15 Apr 2024 21:55:14 +0000 (14:55 -0700)]
xfs: Hold inode locks in xfs_rename

Modify xfs_rename to hold all inode locks across a rename operation
We will need this later when we add parent pointers

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: Hold inode locks in xfs_trans_alloc_dir
Allison Henderson [Mon, 15 Apr 2024 21:55:13 +0000 (14:55 -0700)]
xfs: Hold inode locks in xfs_trans_alloc_dir

Modify xfs_trans_alloc_dir to hold locks after return.  Caller will be
responsible for manual unlock.  We will need this later to hold locks
across parent pointer operations

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: Hold inode locks in xfs_ialloc
Allison Henderson [Mon, 15 Apr 2024 21:55:12 +0000 (14:55 -0700)]
xfs: Hold inode locks in xfs_ialloc

Modify xfs_ialloc to hold locks after return.  Caller will be
responsible for manual unlock.  We will need this later to hold locks
across parent pointer operations

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
[djwong: hold the parent ilocked across transaction rolls too]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: Increase XFS_QM_TRANS_MAXDQS to 5
Allison Henderson [Mon, 15 Apr 2024 21:55:12 +0000 (14:55 -0700)]
xfs: Increase XFS_QM_TRANS_MAXDQS to 5

With parent pointers enabled, a rename operation can update up to 5
inodes: src_dp, target_dp, src_ip, target_ip and wip.  This causes
their dquots to a be attached to the transaction chain, so we need
to increase XFS_QM_TRANS_MAXDQS.  This patch also add a helper
function xfs_dqlockn to lock an arbitrary number of dquots.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: Increase XFS_DEFER_OPS_NR_INODES to 5
Allison Henderson [Mon, 15 Apr 2024 21:55:11 +0000 (14:55 -0700)]
xfs: Increase XFS_DEFER_OPS_NR_INODES to 5

Renames that generate parent pointer updates can join up to 5
inodes locked in sorted order.  So we need to increase the
number of defer ops inodes and relock them in the same way.

Signed-off-by: Allison Henderson <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Catherine Hoang <catherine.hoang@oracle.com>
[djwong: have one sorting function]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agodocs: describe xfs directory tree online fsck
Darrick J. Wong [Mon, 15 Apr 2024 21:55:10 +0000 (14:55 -0700)]
docs: describe xfs directory tree online fsck

I've added a scrubber that checks the directory tree structure and fixes
them; describe this in the design documentation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agodocs: update offline parent pointer repair strategy
Darrick J. Wong [Mon, 15 Apr 2024 21:55:09 +0000 (14:55 -0700)]
docs: update offline parent pointer repair strategy

Now update how xfs_repair checks and repairs parent pointer info.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agodocs: update online directory and parent pointer repair sections
Darrick J. Wong [Mon, 15 Apr 2024 21:55:08 +0000 (14:55 -0700)]
docs: update online directory and parent pointer repair sections

Update the case studies of online directory and parent pointer
reconstruction to reflect what they actually do in the final version.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agodocs: update the parent pointers documentation to the final version
Darrick J. Wong [Mon, 15 Apr 2024 21:55:07 +0000 (14:55 -0700)]
docs: update the parent pointers documentation to the final version

Now that we've decided on the ondisk format of parent pointers, update
the documentation to reflect that.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: fix performance problems when fstrimming a subset of a fragmented AG
Darrick J. Wong [Mon, 15 Apr 2024 21:55:06 +0000 (14:55 -0700)]
xfs: fix performance problems when fstrimming a subset of a fragmented AG

On a 10TB filesystem where the free space in each AG is heavily
fragmented, I noticed some very high runtimes on a FITRIM call for the
entire filesystem.  xfs_scrub likes to report progress information on
each phase of the scrub, which means that a strace for the entire
filesystem:

ioctl(3, FITRIM, {start=0x0, len=10995116277760, minlen=0}) = 0 <686.209839>

shows that scrub is uncommunicative for the entire duration.  Reducing
the size of the FITRIM requests to a single AG at a time produces lower
times for each individual call, but even this isn't quite acceptable,
because the time between progress reports are still very high:

Strace for the first 4x 1TB AGs looks like (2):
ioctl(3, FITRIM, {start=0x0, len=1099511627776, minlen=0}) = 0 <68.352033>
ioctl(3, FITRIM, {start=0x10000000000, len=1099511627776, minlen=0}) = 0 <68.760323>
ioctl(3, FITRIM, {start=0x20000000000, len=1099511627776, minlen=0}) = 0 <67.235226>
ioctl(3, FITRIM, {start=0x30000000000, len=1099511627776, minlen=0}) = 0 <69.465744>

I then had the idea to limit the length parameter of each call to a
smallish amount (~11GB) so that we could report progress relatively
quickly, but much to my surprise, each FITRIM call still took ~68
seconds!

Unfortunately, the by-length fstrim implementation handles this poorly
because it walks the entire free space by length index (cntbt), which is
a very inefficient way to walk a subset of the blocks of an AG.

Therefore, create a second implementation that will walk the bnobt and
perform the trims in block number order.  This implementation avoids the
worst problems of the original code, though it lacks the desirable
attribute of freeing the biggest chunks first.

On the other hand, this second implementation will be much easier to
constrain the system call latency, and makes it much easier to report
fstrim progress to anyone who's running xfs_scrub.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com
5 months agoxfs: create subordinate scrub contexts for xchk_metadata_inode_subtype
Darrick J. Wong [Mon, 15 Apr 2024 21:55:06 +0000 (14:55 -0700)]
xfs: create subordinate scrub contexts for xchk_metadata_inode_subtype

When a file-based metadata structure is being scrubbed in
xchk_metadata_inode_subtype, we should create an entirely new scrub
context so that each scrubber doesn't trip over another's buffers.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: pin inodes that would otherwise overflow link count
Darrick J. Wong [Mon, 15 Apr 2024 21:55:05 +0000 (14:55 -0700)]
xfs: pin inodes that would otherwise overflow link count

The VFS inc_nlink function does not explicitly check for integer
overflows in the i_nlink field.  Instead, it checks the link count
against s_max_links in the vfs_{link,create,rename} functions.  XFS
sets the maximum link count to 2.1 billion, so integer overflows should
not be a problem.

However.  It's possible that online repair could find that a file has
more than four billion links, particularly if the link count got
corrupted while creating hardlinks to the file.  The di_nlinkv2 field is
not large enough to store a value larger than 2^32, so we ought to
define a magic pin value of ~0U which means that the inode never gets
deleted.  This will prevent a UAF error if the repair finds this
situation and users begin deleting links to the file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: try to avoid allocating from sick inode clusters
Darrick J. Wong [Mon, 15 Apr 2024 21:55:04 +0000 (14:55 -0700)]
xfs: try to avoid allocating from sick inode clusters

I noticed that xfs/413 and xfs/375 occasionally failed while fuzzing
core.mode of an inode.  The root cause of these problems is that the
field we fuzzed (core.mode or core.magic, typically) causes the entire
inode cluster buffer verification to fail, which affects several inodes
at once.  The repair process tries to create either a /lost+found or a
temporary repair file, but regrettably it picks the same inode cluster
that we just corrupted, with the result that repair triggers the demise
of the filesystem.

Try avoid this by making the inode allocation path detect when the perag
health status indicates that someone has found bad inode cluster
buffers, and try to read the inode cluster buffer.  If the cluster
buffer fails the verifiers, try another AG.  This isn't foolproof and
can result in premature ENOSPC, but that might be better than shutting
down.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: check unused nlink fields in the ondisk inode
Darrick J. Wong [Mon, 15 Apr 2024 21:55:03 +0000 (14:55 -0700)]
xfs: check unused nlink fields in the ondisk inode

v2/v3 inodes use di_nlink and not di_onlink; and v1 inodes use di_onlink
and not di_nlink.  Whichever field is not in use, make sure its contents
are zero, and teach xfs_scrub to fix that if it is.

This clears a bunch of missing scrub failure errors in xfs/385 for
core.onlink.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: repair AGI unlinked inode bucket lists
Darrick J. Wong [Mon, 15 Apr 2024 21:55:02 +0000 (14:55 -0700)]
xfs: repair AGI unlinked inode bucket lists

Teach the AGI repair code to rebuild the unlinked buckets and lists.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: hoist AGI repair context to a heap object
Darrick J. Wong [Mon, 15 Apr 2024 21:55:01 +0000 (14:55 -0700)]
xfs: hoist AGI repair context to a heap object

Save ~460 bytes of stack space by moving all the repair context to a
heap object.  We're going to add even more context data in the next
patch, which is why we really need to do this now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: check AGI unlinked inode buckets
Darrick J. Wong [Mon, 15 Apr 2024 21:55:00 +0000 (14:55 -0700)]
xfs: check AGI unlinked inode buckets

Look for corruptions in the AGI unlinked bucket chains.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: online repair of symbolic links
Darrick J. Wong [Mon, 15 Apr 2024 21:54:59 +0000 (14:54 -0700)]
xfs: online repair of symbolic links

If a symbolic link target looks bad, try to sift through the rubble to
find as much of the target buffer that we can, and stage a new target
(short or remote format as needed) in a temporary file and use the
atomic extent swapping mechanism to commit the results.  In the worst
case, we replace the target with an overly long filename that cannot
possibly resolve.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: pass the owner to xfs_symlink_write_target
Darrick J. Wong [Mon, 15 Apr 2024 21:54:59 +0000 (14:54 -0700)]
xfs: pass the owner to xfs_symlink_write_target

Require callers of xfs_symlink_write_target to pass the owner number
explicitly.  This sets us up for online repair to be able to write a
remote symlink target to sc->tempip with sc->ip's inumber in the block
heaader.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: expose xfs_bmap_local_to_extents for online repair
Darrick J. Wong [Mon, 15 Apr 2024 21:54:58 +0000 (14:54 -0700)]
xfs: expose xfs_bmap_local_to_extents for online repair

Allow online repair to call xfs_bmap_local_to_extents and add a void *
argument at the end so that online repair can pass its own context.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: ensure dentry consistency when the orphanage adopts a file
Darrick J. Wong [Mon, 15 Apr 2024 21:54:57 +0000 (14:54 -0700)]
xfs: ensure dentry consistency when the orphanage adopts a file

When the orphanage adopts a file, that file becomes a child of the
orphanage.  The dentry cache may have entries for the orphanage
directory and the name we've chosen, so (1) make sure we abort if the
dcache has a positive entry because something's not right; and (2)
invalidate and purge negative dentries if the adoption goes through.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: move files to orphanage instead of letting nlinks drop to zero
Darrick J. Wong [Mon, 15 Apr 2024 21:54:56 +0000 (14:54 -0700)]
xfs: move files to orphanage instead of letting nlinks drop to zero

If we encounter an inode with a nonzero link count but zero observed
links, move it to the orphanage.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: move orphan files to the orphanage
Darrick J. Wong [Mon, 15 Apr 2024 21:54:55 +0000 (14:54 -0700)]
xfs: move orphan files to the orphanage

When we're repairing a directory structure or fixing the dotdot entry of
a subdirectory, it's possible that we won't ever find a parent for the
subdirectory.  When this is the case, move it to the orphanage, aka
/lost+found.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: ask the dentry cache if it knows the parent of a directory
Darrick J. Wong [Mon, 15 Apr 2024 21:54:54 +0000 (14:54 -0700)]
xfs: ask the dentry cache if it knows the parent of a directory

It's possible that the dentry cache can tell us the parent of a
directory.  Therefore, when repairing directory dot dot entries, query
the dcache as a last resort before scanning the entire filesystem.

A reviewer asks:

"How high is the chance that we actually have a valid dcache entry for a
file in a corrupted directory?"

There's a decent chance of this actually working.  Say you have a
1000-block directory foo, and block 980 gets corrupted.  Let's further
suppose that block 0 has a correct entry for ".." and "bar".  If someone
accesses /mnt/foo/bar, that will cause the dcache to create a dentry
from /mnt to /mnt/foo whose d_parent points back to /mnt.  If you then
want to rebuild the directory, XFS can obtain the parent from the dcache
without needing to wander into parent pointers or scan the filesystem to
find /mnt's connection to foo.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: online repair of parent pointers
Darrick J. Wong [Mon, 15 Apr 2024 21:54:53 +0000 (14:54 -0700)]
xfs: online repair of parent pointers

Teach the online repair code to fix parent pointers for directories.
For now, this means correcting the dotdot entry of an existing directory
that is otherwise consistent.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: scan the filesystem to repair a directory dotdot entry
Darrick J. Wong [Mon, 15 Apr 2024 21:54:52 +0000 (14:54 -0700)]
xfs: scan the filesystem to repair a directory dotdot entry

Teach the online directory repair code to scan the filesystem so that we
can set the dotdot entry when we're rebuilding a directory.  This
involves dropping ILOCK on the directory that we're repairing, which
means that the VFS can sneak in and tell us to update dotdot at any
time.  Deal with these races by using a dirent hook to absorb dotdot
updates, and be careful not to check the scan results until after we've
retaken the ILOCK.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: online repair of directories
Darrick J. Wong [Mon, 15 Apr 2024 21:54:51 +0000 (14:54 -0700)]
xfs: online repair of directories

If a directory looks like it's in bad shape, try to sift through the
rubble to find whatever directory entries we can, scan the directory
tree for the parent (if needed), stage the new directory contents in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: inactivate directory data blocks
Darrick J. Wong [Mon, 15 Apr 2024 21:54:50 +0000 (14:54 -0700)]
xfs: inactivate directory data blocks

Teach inode inactivation to delete all the incore buffers backing a
directory.  In normal runtime this should never happen because the VFS
forbids rmdir on a non-empty directory.

In the next patch, online directory repair stands up a new directory,
exchanges it with the broken directory, and then drops the private
temporary directory.  If we cancel the repair just prior to exchanging
the directory contents, the new directory will need to be torn down.
Note: If we commit the repair, reaping will take care of all the ondisk
space allocations and incore buffers for the old corrupt directory.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: update the unlinked list when repairing link counts
Darrick J. Wong [Mon, 15 Apr 2024 21:54:49 +0000 (14:54 -0700)]
xfs: update the unlinked list when repairing link counts

When we're repairing the link counts of a file, we must ensure either
that the file has zero link count and is on the unlinked list; or that
it has nonzero link count and is not on the unlinked list.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: ensure unlinked list state is consistent with nlink during scrub
Darrick J. Wong [Mon, 15 Apr 2024 21:54:49 +0000 (14:54 -0700)]
xfs: ensure unlinked list state is consistent with nlink during scrub

Now that we have the means to tell if an inode is on an unlinked inode
list or not, we can check that an inode with zero link count is on the
unlinked list; and an inode that has nonzero link count is not on that
list.  Make repair clean things up too.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: create an xattr iteration function for scrub
Darrick J. Wong [Mon, 15 Apr 2024 21:54:48 +0000 (14:54 -0700)]
xfs: create an xattr iteration function for scrub

Create a streamlined function to walk a file's xattrs, without all the
cursor management stuff in the regular listxattr.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: flag empty xattr leaf blocks for optimization
Darrick J. Wong [Mon, 15 Apr 2024 21:54:47 +0000 (14:54 -0700)]
xfs: flag empty xattr leaf blocks for optimization

Empty xattr leaf blocks at offset zero are a waste of space but
otherwise harmless.  If we encounter one, flag it as an opportunity for
optimization.

If we encounter empty attr leaf blocks anywhere else in the attr fork,
that's corruption.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: scrub should set preen if attr leaf has holes
Darrick J. Wong [Mon, 15 Apr 2024 21:54:46 +0000 (14:54 -0700)]
xfs: scrub should set preen if attr leaf has holes

If an attr block indicates that it could use compaction, set the preen
flag to have the attr fork rebuilt, since the attr fork rebuilder can
take care of that for us.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: repair extended attributes
Darrick J. Wong [Mon, 15 Apr 2024 21:54:45 +0000 (14:54 -0700)]
xfs: repair extended attributes

If the extended attributes look bad, try to sift through the rubble to
find whatever keys/values we can, stage a new attribute structure in a
temporary file and use the atomic extent swapping mechanism to commit
the results in bulk.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: use atomic extent swapping to fix user file fork data
Darrick J. Wong [Mon, 15 Apr 2024 21:54:44 +0000 (14:54 -0700)]
xfs: use atomic extent swapping to fix user file fork data

Build on the code that was recently added to the temporary repair file
code so that we can atomically switch the contents of any file fork,
even if the fork is in local format.  The upcoming functions to repair
xattrs, directories, and symlinks will need that capability.

Repair can lock out access to these user files by holding IOLOCK_EXCL on
these user files.  Therefore, it is safe to drop the ILOCK of both the
file being repaired and the tempfile being used for staging, and cancel
the scrub transaction.  We do this so that we can reuse the resource
estimation and transaction allocation functions used by a regular file
exchange operation.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: create a blob array data structure
Darrick J. Wong [Mon, 15 Apr 2024 21:54:43 +0000 (14:54 -0700)]
xfs: create a blob array data structure

Create a simple 'blob array' data structure for storage of arbitrarily
sized metadata objects that will be used to reconstruct metadata.  For
the intended usage (temporarily storing extended attribute names and
values) we only have to support storing objects and retrieving them.
Use the xfile abstraction to store the attribute information in memory
that can be swapped out.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: enable discarding of folios backing an xfile
Darrick J. Wong [Mon, 15 Apr 2024 21:54:42 +0000 (14:54 -0700)]
xfs: enable discarding of folios backing an xfile

Create a new xfile function to discard the page cache that's backing
part of an xfile.  The next patch wil use this to drop parts of an xfile
that aren't needed anymore.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate explicit directory free block owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:41 +0000 (14:54 -0700)]
xfs: validate explicit directory free block owners

Port the existing directory freespace block header checking function to
accept an owner number instead of an xfs_inode, then update the
callsites to use xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate explicit directory block buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:41 +0000 (14:54 -0700)]
xfs: validate explicit directory block buffer owners

Port the existing directory block header checking function to accept an
owner number instead of an xfs_inode, then update the callsites to use
xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate explicit directory data buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:40 +0000 (14:54 -0700)]
xfs: validate explicit directory data buffer owners

Port the existing directory data header checking function to accept an
owner number instead of an xfs_inode, then update the callsites to use
xfs_da_args.owner when possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate directory leaf buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:39 +0000 (14:54 -0700)]
xfs: validate directory leaf buffer owners

Check the owner field of directory leaf blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate dabtree node buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:38 +0000 (14:54 -0700)]
xfs: validate dabtree node buffer owners

Check the owner field of dabtree node blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate attr remote value buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:37 +0000 (14:54 -0700)]
xfs: validate attr remote value buffer owners

Check the owner field of xattr remote value blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: validate attr leaf buffer owners
Darrick J. Wong [Mon, 15 Apr 2024 21:54:36 +0000 (14:54 -0700)]
xfs: validate attr leaf buffer owners

Create a leaf block header checking function to validate the owner field
of xattr leaf blocks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: reduce indenting in xfs_attr_node_list
Darrick J. Wong [Mon, 15 Apr 2024 21:54:35 +0000 (14:54 -0700)]
xfs: reduce indenting in xfs_attr_node_list

Reduce the indentation here so that we can add some things in the next
patch without going over the column limits.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: use the xfs_da_args owner field to set new dir/attr block owner
Darrick J. Wong [Mon, 15 Apr 2024 21:54:34 +0000 (14:54 -0700)]
xfs: use the xfs_da_args owner field to set new dir/attr block owner

When we're creating leaf, data, freespace, or dabtree blocks for
directories and xattrs, use the explicit owner field (instead of the
xfs_inode) to set the owner field.  This will enable online repair to
construct replacement data structures in a temporary file without having
to change the owner fields prior to swapping the new and old structures.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: add an explicit owner field to xfs_da_args
Darrick J. Wong [Mon, 15 Apr 2024 21:54:34 +0000 (14:54 -0700)]
xfs: add an explicit owner field to xfs_da_args

Add an explicit owner field to xfs_da_args, which will make it easier
for online fsck to set the owner field of the temporary directory and
xattr structures that it builds to repair damaged metadata.

Note: I hopefully found all the xfs_da_args definitions by looking for
automatic stack variable declarations and xfs_da_args.dp assignments:

git grep -E '(args.*dp =|struct xfs_da_args[[:space:]]*[a-z0-9][a-z0-9]*)'

Note that callers of xfs_attr_{get,set,change} can set the owner to zero
(or leave it unset) to have the default set to args->dp.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: online repair of realtime summaries
Darrick J. Wong [Mon, 15 Apr 2024 21:54:33 +0000 (14:54 -0700)]
xfs: online repair of realtime summaries

Repair the realtime summary data by constructing a new rtsummary file in
the scrub temporary file, then atomically swapping the contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: teach the tempfile to set up atomic file content exchanges
Darrick J. Wong [Mon, 15 Apr 2024 21:54:32 +0000 (14:54 -0700)]
xfs: teach the tempfile to set up atomic file content exchanges

Create some new routines to exchange the contents of a temporary file
created to stage a repair with another ondisk file.  This will be used
by the realtime summary repair function to commit atomically the new
rtsummary data, which will be staged in the tempfile.

The rest of XFS coordinates access to the realtime metadata inodes
solely through the ILOCK.  For repair to hold its exclusive access to
the realtime summary file, it has to allocate a single large transaction
and roll it repeatedly throughout the repair while holding the ILOCK.
In turn, this means that for now there's only a partial file mapping
exchange implementation for the temporary file because we can only work
within an existing transaction.

For now, the only tempswap functions needed here are to estimate the
resource requirements of the exchange, reserve more space/quota to an
existing transaction, and kick off the actual exchange.  The rest will
be added in a later patch in preparation for repairing xattrs and
directories.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: support preallocating and copying content into temporary files
Darrick J. Wong [Mon, 15 Apr 2024 21:54:31 +0000 (14:54 -0700)]
xfs: support preallocating and copying content into temporary files

Create the routines we need to preallocate space in a temporary ondisk
file and then copy the contents of an xfile into the tempfile.  The
upcoming rtsummary repair feature will construct the contents of a
realtime summary file in memory, after which it will want to copy all
that into the ondisk temporary file before atomically committing the new
rtsummary contents.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: add the ability to reap entire inode forks
Darrick J. Wong [Mon, 15 Apr 2024 21:54:30 +0000 (14:54 -0700)]
xfs: add the ability to reap entire inode forks

In preparation for supporting repair of indexed file-based metadata
(such as realtime bitmaps, directories, and extended attribute data),
add a function to reap the old blocks after a metadata repair finishes.
IOWs, this is an elaborate bunmapi call that deals with crosslinked
blocks by unmapping them without freeing them, and also scans for incore
buffers to invalidate.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: refactor live buffer invalidation for repairs
Darrick J. Wong [Mon, 15 Apr 2024 21:54:29 +0000 (14:54 -0700)]
xfs: refactor live buffer invalidation for repairs

In an upcoming patch, we will need to be able to look for xfs_buf
objects caching file-based metadata blocks without needing to walk the
(possibly corrupt) structures to find all the buffers.  Repair already
has most of the code needed to scan the buffer cache, so hoist these
utility functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: create temporary files and directories for online repair
Darrick J. Wong [Mon, 15 Apr 2024 21:54:28 +0000 (14:54 -0700)]
xfs: create temporary files and directories for online repair

Teach the online repair code how to create temporary files or
directories.  These temporary files can be used to stage reconstructed
information until we're ready to perform an atomic extent swap to commit
the new metadata.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: hide private inodes from bulkstat and handle functions
Darrick J. Wong [Mon, 15 Apr 2024 21:54:27 +0000 (14:54 -0700)]
xfs: hide private inodes from bulkstat and handle functions

We're about to start adding functionality that uses internal inodes that
are private to XFS.  What this means is that userspace should never be
able to access any information about these files, and should not be able
to open these files by handle.

To prevent users from ever finding the file or mis-interactions with the
security apparatus, set S_PRIVATE on the inode.  Don't allow bulkstat,
open-by-handle, or linking of S_PRIVATE files into the directory tree.
This should keep private inodes actually private.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: enable logged file mapping exchange feature
Darrick J. Wong [Mon, 15 Apr 2024 21:54:26 +0000 (14:54 -0700)]
xfs: enable logged file mapping exchange feature

Add the XFS_SB_FEAT_INCOMPAT_EXCHRANGE feature to the set of features
that we will permit when mounting a filesystem.  This turns on support
for the file range exchange feature.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agodocs: update swapext -> exchmaps language
Darrick J. Wong [Mon, 15 Apr 2024 21:54:25 +0000 (14:54 -0700)]
docs: update swapext -> exchmaps language

Start reworking the atomic swapext design documentation to refer to its
new file contents/mapping exchange name.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: capture inode generation numbers in the ondisk exchmaps log item
Darrick J. Wong [Mon, 15 Apr 2024 21:54:24 +0000 (14:54 -0700)]
xfs: capture inode generation numbers in the ondisk exchmaps log item

Per some very late review comments, capture the generation numbers of
both inodes involved in a file content exchange operation so that we
don't accidentally target files with have been reallocated.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: support non-power-of-two rtextsize with exchange-range
Darrick J. Wong [Mon, 15 Apr 2024 21:54:23 +0000 (14:54 -0700)]
xfs: support non-power-of-two rtextsize with exchange-range

The generic exchange-range alignment checks use (fast) bitmasking
operations to perform block alignment checks on the exchange parameters.
Unfortunately, bitmasks require that the alignment size be a power of
two.  This isn't true for realtime devices with a non-power-of-two
extent size, so we have to copy-pasta the generic checks using long
division for this to work properly.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: make file range exchange support realtime files
Darrick J. Wong [Mon, 15 Apr 2024 21:54:22 +0000 (14:54 -0700)]
xfs: make file range exchange support realtime files

Now that bmap items support the realtime device, we can add the
necessary pieces to the file range exchange code to support exchanging
mappings.  All we really need to do here is adjust the blockcount
upwards to the end of the rt extent and remove the inode checks.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: condense symbolic links after a mapping exchange operation
Darrick J. Wong [Mon, 15 Apr 2024 21:54:21 +0000 (14:54 -0700)]
xfs: condense symbolic links after a mapping exchange operation

The previous commit added a new file mapping exchange flag that enables
us to perform post-exchange processing on file2 once we're done
exchanging the extent mappings.  Now add this ability for symlinks.

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online symlink repair feature can
salvage the remote target in a temporary link and exchange the data fork
mappings when ready.  If one file is in extents format and the other is
inline, we will have to promote both to extents format to perform the
exchange.  After the exchange, we can try to condense the fixed symlink
down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: condense directories after a mapping exchange operation
Darrick J. Wong [Mon, 15 Apr 2024 21:54:20 +0000 (14:54 -0700)]
xfs: condense directories after a mapping exchange operation

The previous commit added a new file mapping exchange flag that enables
us to perform post-swap processing on file2 once we're done exchanging
extent mappings.  Now add this ability for directories.

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online directory repair feature can
create salvaged dirents in a temporary directory and exchange the data
fork mappings when ready.  If one file is in extents format and the
other is inline, we will have to promote both to extents format to
perform the exchange.  After the exchange, we can try to condense the
fixed directory down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: condense extended attributes after a mapping exchange operation
Darrick J. Wong [Mon, 15 Apr 2024 21:54:20 +0000 (14:54 -0700)]
xfs: condense extended attributes after a mapping exchange operation

Add a new file mapping exchange flag that enables us to perform
post-exchange processing on file2 once we're done exchanging the extent
mappings.  If we were swapping mappings between extended attribute
forks, we want to be able to convert file2's attr fork from block to
inline format.

(This implies that all fork contents are exchanged.)

This isn't used anywhere right now, but we need to have the basic ondisk
flags in place so that a future online xattr repair feature can create
salvaged attrs in a temporary file and exchange the attr fork mappings
when ready.  If one file is in extents format and the other is inline,
we will have to promote both to extents format to perform the exchange.
After the exchange, we can try to condense the fixed file's attr fork
back down to inline format if possible.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: add error injection to test file mapping exchange recovery
Darrick J. Wong [Mon, 15 Apr 2024 21:54:19 +0000 (14:54 -0700)]
xfs: add error injection to test file mapping exchange recovery

Add an errortag so that we can test recovery of exchmaps log items.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: bind together the front and back ends of the file range exchange code
Darrick J. Wong [Mon, 15 Apr 2024 21:54:18 +0000 (14:54 -0700)]
xfs: bind together the front and back ends of the file range exchange code

So far, we've constructed the front end of the file range exchange code
that does all the checking; and the back end of the file mapping
exchange code that actually does the work.  Glue these two pieces
together so that we can turn on the functionality.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: create deferred log items for file mapping exchanges
Darrick J. Wong [Mon, 15 Apr 2024 21:54:17 +0000 (14:54 -0700)]
xfs: create deferred log items for file mapping exchanges

Now that we've created the skeleton of a log intent item to track and
restart file mapping exchange operations, add the upper level logic to
commit intent items and turn them into concrete work recorded in the
log.  This builds on the existing bmap update intent items that have
been around for a while now.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: introduce a file mapping exchange log intent item
Darrick J. Wong [Mon, 15 Apr 2024 21:54:16 +0000 (14:54 -0700)]
xfs: introduce a file mapping exchange log intent item

Introduce a new intent log item to handle exchanging mappings between
the forks of two files.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: create a incompat flag for atomic file mapping exchanges
Darrick J. Wong [Mon, 15 Apr 2024 21:54:15 +0000 (14:54 -0700)]
xfs: create a incompat flag for atomic file mapping exchanges

Create a incompat flag so that we only attempt to process file mapping
exchange log items if the filesystem supports it, and a geometry flag to
advertise support if it's present.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: introduce new file range exchange ioctl
Darrick J. Wong [Mon, 15 Apr 2024 21:54:14 +0000 (14:54 -0700)]
xfs: introduce new file range exchange ioctl

Introduce a new ioctl to handle exchanging ranges of bytes
between files.  The goal here is to perform the exchange atomically with
respect to applications -- either they see the file contents before the
exchange or they see that A-B is now B-A, even if the kernel crashes.

My original goal with all this code was to make it so that online repair
can build a replacement directory or xattr structure in a temporary file
and commit the repair by atomically exchanging all the data blocks
between the two files.  However, I needed a way to test this mechanism
thoroughly, so I've been evolving an ioctl interface since then.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agovfs: export remap and write check helpers
Darrick J. Wong [Mon, 15 Apr 2024 21:54:13 +0000 (14:54 -0700)]
vfs: export remap and write check helpers

Export these functions so that the next patch can use them to check the
file ranges being passed to the XFS_IOC_EXCHANGE_RANGE operation.

Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: constify xfs_bmap_is_written_extent
Darrick J. Wong [Mon, 15 Apr 2024 21:54:12 +0000 (14:54 -0700)]
xfs: constify xfs_bmap_is_written_extent

This predicate doesn't modify the structure that's being passed in, so
we can mark it const.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: refactor non-power-of-two alignment checks
Darrick J. Wong [Mon, 15 Apr 2024 21:54:12 +0000 (14:54 -0700)]
xfs: refactor non-power-of-two alignment checks

Create a helper function that can compute if a 64-bit number is an
integer multiple of a 32-bit number, where the 32-bit number is not
required to be an even power of two.  This is needed for some new code
for the realtime device, where we can set 37k allocation units and then
have to remap them.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: hoist multi-fsb allocation unit detection to a helper
Darrick J. Wong [Mon, 15 Apr 2024 21:54:11 +0000 (14:54 -0700)]
xfs: hoist multi-fsb allocation unit detection to a helper

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>
5 months agoxfs: create a new helper to return a file's allocation unit
Darrick J. Wong [Mon, 15 Apr 2024 21:54:10 +0000 (14:54 -0700)]
xfs: create a new helper to return a file's allocation unit

Create a new helper function to calculate the fundamental allocation
unit (i.e. the smallest unit of space we can allocate) of a file.
Things are going to get hairy with range-exchange on the realtime
device, so prepare for this now.

Remove the static attribute from xfs_is_falloc_aligned since the next
patch will need it.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: declare xfs_file.c symbols in xfs_file.h
Darrick J. Wong [Mon, 15 Apr 2024 21:54:09 +0000 (14:54 -0700)]
xfs: declare xfs_file.c symbols in xfs_file.h

Move the two public symbols in xfs_file.c to xfs_file.h.  We're about to
add more public symbols in that source file, so let's finally create the
header file.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: move xfs_iops.c declarations out of xfs_inode.h
Darrick J. Wong [Mon, 15 Apr 2024 21:54:08 +0000 (14:54 -0700)]
xfs: move xfs_iops.c declarations out of xfs_inode.h

Similarly, move declarations of public symbols of xfs_iops.c from
xfs_inode.h to xfs_iops.h.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: move inode lease breaking functions to xfs_inode.c
Darrick J. Wong [Mon, 15 Apr 2024 21:54:07 +0000 (14:54 -0700)]
xfs: move inode lease breaking functions to xfs_inode.c

The lease breaking functions operate at the scope of the entire VFS
inode, not subranges of a file.  Move them to xfs_inode.c since they're
already declared in xfs_inode.h.  This cleanup moves us closer to
having xfs_FOO.h declare only the symbols in xfs_FOO.c.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: only clear log incompat flags at clean unmount
Darrick J. Wong [Mon, 15 Apr 2024 21:54:06 +0000 (14:54 -0700)]
xfs: only clear log incompat flags at clean unmount

While reviewing the online fsck patchset, someone spied the
xfs_swapext_can_use_without_log_assistance function and wondered why we
go through this inverted-bitmask dance to avoid setting the
XFS_SB_FEAT_INCOMPAT_LOG_SWAPEXT feature.

(The same principles apply to the logged extended attribute update
feature bit in the since-merged LARP series.)

The reason for this dance is that xfs_add_incompat_log_feature is an
expensive operation -- it forces the log, pushes the AIL, and then if
nobody's beaten us to it, sets the feature bit and issues a synchronous
write of the primary superblock.  That could be a one-time cost
amortized over the life of the filesystem, but the log quiesce and cover
operations call xfs_clear_incompat_log_features to remove feature bits
opportunistically.  On a moderately loaded filesystem this leads to us
cycling those bits on and off over and over, which hurts performance.

Why do we clear the log incompat bits?  Back in ~2020 I think Dave and I
had a conversation on IRC[2] about what the log incompat bits represent.
IIRC in that conversation we decided that the log incompat bits protect
unrecovered log items so that old kernels won't try to recover them and
barf.  Since a clean log has no protected log items, we could clear the
bits at cover/quiesce time.

As Dave Chinner pointed out in the thread, clearing log incompat bits at
unmount time has positive effects for golden root disk image generator
setups, since the generator could be running a newer kernel than what
gets written to the golden image -- if there are log incompat fields set
in the golden image that was generated by a newer kernel/OS image
builder then the provisioning host cannot mount the filesystem even
though the log is clean and recovery is unnecessary to mount the
filesystem.

Given that it's expensive to set log incompat bits, we really only want
to do that once per bit per mount.  Therefore, I propose that we only
clear log incompat bits as part of writing a clean unmount record.  Do
this by adding an operational state flag to the xfs mount that guards
whether or not the feature bit clearing can actually take place.

This eliminates the l_incompat_users rwsem that we use to protect a log
cleaning operation from clearing a feature bit that a frontend thread is
trying to set -- this lock adds another way to fail w.r.t. locking.  For
the swapext series, I shard that into multiple locks just to work around
the lockdep complaints, and that's fugly.

Link: https://lore.kernel.org/linux-xfs/20240131230043.GA6180@frogsfrogsfrogs/
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
5 months agoxfs: fix error bailout in xrep_abt_build_new_trees
Darrick J. Wong [Mon, 15 Apr 2024 21:54:06 +0000 (14:54 -0700)]
xfs: fix error bailout in xrep_abt_build_new_trees

Dan Carpenter reports:

"Commit 4bdfd7d15747 ("xfs: repair free space btrees") from Dec 15,
2023 (linux-next), leads to the following Smatch static checker
warning:

        fs/xfs/scrub/alloc_repair.c:781 xrep_abt_build_new_trees()
        warn: missing unwind goto?"

That's a bug, so let's fix it.

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 4bdfd7d15747 ("xfs: repair free space btrees")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: fix potential AGI <-> ILOCK ABBA deadlock in xrep_dinode_findmode_walk_directory
Darrick J. Wong [Mon, 15 Apr 2024 21:54:05 +0000 (14:54 -0700)]
xfs: fix potential AGI <-> ILOCK ABBA deadlock in xrep_dinode_findmode_walk_directory

xfs/399 found the following deadlock when fuzzing core.mode = ones:

/proc/20506/task/20558/stack :
[<0>] xfs_ilock+0xa0/0x240 [xfs]
[<0>] xfs_ilock_data_map_shared+0x1b/0x20 [xfs]
[<0>] xrep_dinode_findmode_walk_directory+0x69/0xe0 [xfs]
[<0>] xrep_dinode_find_mode+0x103/0x2a0 [xfs]
[<0>] xrep_dinode_mode+0x7c/0x120 [xfs]
[<0>] xrep_dinode_core+0xed/0x2b0 [xfs]
[<0>] xrep_dinode_problems+0x10/0x80 [xfs]
[<0>] xrep_inode+0x6c/0xc0 [xfs]
[<0>] xrep_attempt+0x64/0x1d0 [xfs]
[<0>] xfs_scrub_metadata+0x365/0x840 [xfs]
[<0>] xfs_scrubv_metadata+0x282/0x430 [xfs]
[<0>] xfs_ioc_scrubv_metadata+0x149/0x1a0 [xfs]
[<0>] xfs_file_ioctl+0xc68/0x1780 [xfs]
/proc/20506/task/20559/stack :
[<0>] xfs_buf_lock+0x3b/0x110 [xfs]
[<0>] xfs_buf_find_lock+0x66/0x1c0 [xfs]
[<0>] xfs_buf_get_map+0x208/0xc00 [xfs]
[<0>] xfs_buf_read_map+0x5d/0x2c0 [xfs]
[<0>] xfs_trans_read_buf_map+0x1b0/0x4c0 [xfs]
[<0>] xfs_read_agi+0xbd/0x190 [xfs]
[<0>] xfs_ialloc_read_agi+0x47/0x160 [xfs]
[<0>] xfs_imap_lookup+0x69/0x1f0 [xfs]
[<0>] xfs_imap+0x1fc/0x3d0 [xfs]
[<0>] xfs_iget+0x357/0xd50 [xfs]
[<0>] xchk_dir_actor+0x16e/0x330 [xfs]
[<0>] xchk_dir_walk_block+0x164/0x1e0 [xfs]
[<0>] xchk_dir_walk+0x13a/0x190 [xfs]
[<0>] xchk_directory+0x1a2/0x2b0 [xfs]
[<0>] xfs_scrub_metadata+0x2f4/0x840 [xfs]
[<0>] xfs_scrubv_metadata+0x282/0x430 [xfs]
[<0>] xfs_ioc_scrubv_metadata+0x149/0x1a0 [xfs]
[<0>] xfs_file_ioctl+0xc68/0x1780 [xfs]

Thread 20558 holds an AGI buffer and is trying to grab the ILOCK of the
root directory.  Thread 20559 holds the root directory ILOCK and is
trying to grab the AGI of an inode that is one of the root directory's
children.  The AGI held by 20558 is the same buffer that 20559 is trying
to acquire.  In other words, this is an ABBA deadlock.

In general, the lock order is ILOCK and then AGI -- rename does this
while preparing for an operation involving whiteouts or renaming files
out of existence; and unlink does this when moving an inode to the
unlinked list.  The only place where we do it in the opposite order is
on the child during an icreate, but at that point the child is marked
INEW and is not visible to other threads.

Work around this deadlock by replacing the blocking ilock attempt with a
nonblocking loop that aborts after 30 seconds.  Relax for a jiffy after
a failed lock attempt.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: fix an AGI lock acquisition ordering problem in xrep_dinode_findmode
Darrick J. Wong [Mon, 15 Apr 2024 21:54:04 +0000 (14:54 -0700)]
xfs: fix an AGI lock acquisition ordering problem in xrep_dinode_findmode

While reviewing the next patch which fixes an ABBA deadlock between the
AGI and a directory ILOCK, someone asked a question about why we're
holding the AGI in the first place.  The reason for that is to quiesce
the inode structures for that AG while we do a repair.

I then realized that the xrep_dinode_findmode invokes xchk_iscan_iter,
which walks the inobts (and hence the AGIs) to find all the inodes.
This itself is also an ABBA vector, since the damaged inode could be in
AG 5, which we hold while we scan AG 0 for directories.  5 -> 0 is not
allowed.

To address this, modify the iscan to allow trylock of the AGI buffer
using the flags argument to xfs_ialloc_read_agi that the previous patch
added.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoxfs: pass xfs_buf lookup flags to xfs_*read_agi
Darrick J. Wong [Mon, 15 Apr 2024 21:54:03 +0000 (14:54 -0700)]
xfs: pass xfs_buf lookup flags to xfs_*read_agi

Allow callers to pass buffer lookup flags to xfs_read_agi and
xfs_ialloc_read_agi.  This will be used in the next patch to fix a
deadlock in the online fsck inode scanner.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
5 months agoLinux 6.9-rc4 v6.9-rc4
Linus Torvalds [Sun, 14 Apr 2024 20:38:39 +0000 (13:38 -0700)]
Linux 6.9-rc4

5 months agoMerge tag 'pull-sysfs-annotation-fix' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sun, 14 Apr 2024 18:41:51 +0000 (11:41 -0700)]
Merge tag 'pull-sysfs-annotation-fix' of git://git./linux/kernel/git/viro/vfs

Pull sysfs fix from Al Viro:
 "Get rid of lockdep false positives around sysfs/overlayfs

  syzbot has uncovered a class of lockdep false positives for setups
  with sysfs being one of the backing layers in overlayfs. The root
  cause is that of->mutex allocated when opening a sysfs file read-only
  (which overlayfs might do) is confused with of->mutex of a file opened
  writable (held in write to sysfs file, which overlayfs won't do).

  Assigning them separate lockdep classes fixes that bunch and it's
  obviously safe"

* tag 'pull-sysfs-annotation-fix' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  kernfs: annotate different lockdep class for of->mutex of writable files

5 months agoMerge tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 14 Apr 2024 17:48:51 +0000 (10:48 -0700)]
Merge tag 'x86-urgent-2024-04-14' of git://git./linux/kernel/git/tip/tip

Pull misc x86 fixes from Ingo Molnar:

 - Follow up fixes for the BHI mitigations code

 - Fix !SPECULATION_MITIGATIONS bug not turning off mitigations as
   expected

 - Work around an APIC emulation bug when the kernel is built with Clang
   and run as a SEV guest

 - Follow up x86 topology fixes

* tag 'x86-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu/amd: Move TOPOEXT enablement into the topology parser
  x86/cpu/amd: Make the NODEID_MSR union actually work
  x86/cpu/amd: Make the CPUID 0x80000008 parser correct
  x86/bugs: Replace CONFIG_SPECTRE_BHI_{ON,OFF} with CONFIG_MITIGATION_SPECTRE_BHI
  x86/bugs: Remove CONFIG_BHI_MITIGATION_AUTO and spectre_bhi=auto
  x86/bugs: Clarify that syscall hardening isn't a BHI mitigation
  x86/bugs: Fix BHI handling of RRSBA
  x86/bugs: Rename various 'ia32_cap' variables to 'x86_arch_cap_msr'
  x86/bugs: Cache the value of MSR_IA32_ARCH_CAPABILITIES
  x86/bugs: Fix BHI documentation
  x86/cpu: Actually turn off mitigations by default for SPECULATION_MITIGATIONS=n
  x86/topology: Don't update cpu_possible_map in topo_set_cpuids()
  x86/bugs: Fix return type of spectre_bhi_state()
  x86/apic: Force native_apic_mem_read() to use the MOV instruction

5 months agoMerge tag 'timers-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sun, 14 Apr 2024 17:32:22 +0000 (10:32 -0700)]
Merge tag 'timers-urgent-2024-04-14' of git://git./linux/kernel/git/tip/tip

Pull timer fixes from Ingo Molnar:

 - Address a (valid) W=1 build warning

 - Fix timer self-tests

 - Annotate a KCSAN warning wrt. accesses to the tick_do_timer_cpu
   global variable

 - Address a !CONFIG_BUG build warning

* tag 'timers-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  selftests: kselftest: Fix build failure with NOLIBC
  selftests: timers: Fix abs() warning in posix_timers test
  selftests: kselftest: Mark functions that unconditionally call exit() as __noreturn
  selftests: timers: Fix posix_timers ksft_print_msg() warning
  selftests: timers: Fix valid-adjtimex signed left-shift undefined behavior
  bug: Fix no-return-statement warning with !CONFIG_BUG
  timekeeping: Use READ/WRITE_ONCE() for tick_do_timer_cpu
  selftests/timers/posix_timers: Reimplement check_timer_distribution()
  irqflags: Explicitly ignore lockdep_hrtimer_exit() argument

5 months agoMerge tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 14 Apr 2024 17:26:27 +0000 (10:26 -0700)]
Merge tag 'perf-urgent-2024-04-14' of git://git./linux/kernel/git/tip/tip

Pull perf event fix from Ingo Molnar:
 "Fix the x86 PMU multi-counter code returning invalid data in certain
  circumstances"

* tag 'perf-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  perf/x86: Fix out of range data

5 months agoMerge tag 'locking-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel...
Linus Torvalds [Sun, 14 Apr 2024 17:13:56 +0000 (10:13 -0700)]
Merge tag 'locking-urgent-2024-04-14' of git://git./linux/kernel/git/tip/tip

Pull locking fix from Ingo Molnar:
 "Fix a PREEMPT_RT build bug"

* tag 'locking-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking: Make rwsem_assert_held_write_nolockdep() build with PREEMPT_RT=y

5 months agoMerge tag 'irq-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git...
Linus Torvalds [Sun, 14 Apr 2024 17:12:34 +0000 (10:12 -0700)]
Merge tag 'irq-urgent-2024-04-14' of git://git./linux/kernel/git/tip/tip

Pull irq fix from Ingo Molnar:
 "Fix a bug in the GIC irqchip driver"

* tag 'irq-urgent-2024-04-14' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  irqchip/gic-v3-its: Fix VSYNC referencing an unmapped VPE on GIC v4.1

5 months agoMerge tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost
Linus Torvalds [Sun, 14 Apr 2024 17:05:59 +0000 (10:05 -0700)]
Merge tag 'for_linus' of git://git./linux/kernel/git/mst/vhost

Pull virtio bugfixes from Michael Tsirkin:
 "Some small, obvious (in hindsight) bugfixes:

   - new ioctl in vhost-vdpa has a wrong # - not too late to fix

   - vhost has apparently been lacking an smp_rmb() - due to code
     duplication :( The duplication will be fixed in the next merge
     cycle, this is a minimal fix

   - an error message in vhost talks about guest moving used index -
     which of course never happens, guest only ever moves the available
     index

   - i2c-virtio didn't set the driver owner so it did not get refcounted
     correctly"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  vhost: correct misleading printing information
  vhost-vdpa: change ioctl # for VDPA_GET_VRING_SIZE
  virtio: store owner from modules with register_virtio_driver()
  vhost: Add smp_rmb() in vhost_enable_notify()
  vhost: Add smp_rmb() in vhost_vq_avail_empty()

5 months agoMerge tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping
Linus Torvalds [Sun, 14 Apr 2024 17:02:40 +0000 (10:02 -0700)]
Merge tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping

Pull dma-mapping fixes from Christoph Hellwig:

 - fix up swiotlb buffer padding even more (Petr Tesarik)

 - fix for partial dma_sync on swiotlb (Michael Kelley)

 - swiotlb debugfs fix (Dexuan Cui)

* tag 'dma-maping-6.9-2024-04-14' of git://git.infradead.org/users/hch/dma-mapping:
  swiotlb: do not set total_used to 0 in swiotlb_create_debugfs_files()
  swiotlb: fix swiotlb_bounce() to do partial sync's correctly
  swiotlb: extend buffer pre-padding to alloc_align_mask if necessary

5 months agokernfs: annotate different lockdep class for of->mutex of writable files
Amir Goldstein [Fri, 5 Apr 2024 14:56:35 +0000 (17:56 +0300)]
kernfs: annotate different lockdep class for of->mutex of writable files

The writable file /sys/power/resume may call vfs lookup helpers for
arbitrary paths and readonly files can be read by overlayfs from vfs
helpers when sysfs is a lower layer of overalyfs.

To avoid a lockdep warning of circular dependency between overlayfs
inode lock and kernfs of->mutex, use a different lockdep class for
writable and readonly kernfs files.

Reported-by: syzbot+9a5b0ced8b1bfb238b56@syzkaller.appspotmail.com
Fixes: 0fedefd4c4e3 ("kernfs: sysfs: support custom llseek method for sysfs entries")
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
5 months agoMerge tag 'ata-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux
Linus Torvalds [Sat, 13 Apr 2024 17:27:58 +0000 (10:27 -0700)]
Merge tag 'ata-6.9-rc4' of git://git./linux/kernel/git/libata/linux

Pull ata fixes from Damien Le Moal:

 - Add the mask_port_map parameter to the ahci driver. This is a
   follow-up to the recent snafu with the ASMedia controller and its
   virtual port hidding port-multiplier devices. As ASMedia confirmed
   that there is no way to determine if these slow-to-probe virtual
   ports are actually representing the ports of a port-multiplier
   devices, this new parameter allow masking ports to significantly
   speed up probing during system boot, resulting in shorter boot times.

 - A fix for an incorrect handling of a port unlock in
   ata_scsi_dev_rescan().

 - Allow command duration limits to be detected for ACS-4 devices are
   there are such devices out in the field.

* tag 'ata-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/libata/linux:
  ata: libata-core: Allow command duration limits detection for ACS-4 drives
  ata: libata-scsi: Fix ata_scsi_dev_rescan() error path
  ata: ahci: Add mask_port_map module parameter

5 months agoMerge tag 'zonefs-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal...
Linus Torvalds [Sat, 13 Apr 2024 17:25:32 +0000 (10:25 -0700)]
Merge tag 'zonefs-6.9-rc4' of git://git./linux/kernel/git/dlemoal/zonefs

Pull zonefs fix from Damien Le Moal:

 - Suppress a coccicheck warning using str_plural()

* tag 'zonefs-6.9-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/dlemoal/zonefs:
  zonefs: Use str_plural() to fix Coccinelle warning

5 months agoMerge tag 'v6.9-rc3-SMB3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Linus Torvalds [Sat, 13 Apr 2024 17:10:18 +0000 (10:10 -0700)]
Merge tag 'v6.9-rc3-SMB3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull smb client fixes from Steve French:

 - fix for oops in cifs_get_fattr of deleted files

 - fix for the remote open counter going negative in some directory
   lease cases

 - fix for mkfifo to instantiate dentry to avoid possible crash

 - important fix to allow handling key rotation for mount and remount
   (ie cases that are becoming more common when password that was used
   for the mount will expire soon but will be replaced by new password)

* tag 'v6.9-rc3-SMB3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix broken reconnect when password changing on the server by allowing password rotation
  smb: client: instantiate when creating SFU files
  smb3: fix Open files on server counter going negative
  smb: client: fix NULL ptr deref in cifs_mark_open_handles_for_deleted_file()

5 months agoata: libata-core: Allow command duration limits detection for ACS-4 drives
Igor Pylypiv [Thu, 11 Apr 2024 20:12:24 +0000 (20:12 +0000)]
ata: libata-core: Allow command duration limits detection for ACS-4 drives

Even though the command duration limits (CDL) feature was first added
in ACS-5 (major version 12), there are some ACS-4 (major version 11)
drives that implement CDL as well.

IDENTIFY_DEVICE, SUPPORTED_CAPABILITIES, and CURRENT_SETTINGS log pages
are mandatory in the ACS-4 standard so it should be safe to read these
log pages on older drives implementing the ACS-4 standard.

Fixes: 62e4a60e0cdb ("scsi: ata: libata: Detect support for command duration limits")
Cc: stable@vger.kernel.org
Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
5 months agoata: libata-scsi: Fix ata_scsi_dev_rescan() error path
Damien Le Moal [Thu, 11 Apr 2024 23:41:15 +0000 (08:41 +0900)]
ata: libata-scsi: Fix ata_scsi_dev_rescan() error path

Commit 0c76106cb975 ("scsi: sd: Fix TCG OPAL unlock on system resume")
incorrectly handles failures of scsi_resume_device() in
ata_scsi_dev_rescan(), leading to a double call to
spin_unlock_irqrestore() to unlock a device port. Fix this by redefining
the goto labels used in case of errors and only unlock the port
scsi_scan_mutex when scsi_resume_device() fails.

Bug found with the Smatch static checker warning:

drivers/ata/libata-scsi.c:4774 ata_scsi_dev_rescan()
error: double unlocked 'ap->lock' (orig line 4757)

Reported-by: Dan Carpenter <dan.carpenter@linaro.org>
Fixes: 0c76106cb975 ("scsi: sd: Fix TCG OPAL unlock on system resume")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Niklas Cassel <cassel@kernel.org>
5 months agoMerge tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Linus Torvalds [Fri, 12 Apr 2024 20:08:39 +0000 (13:08 -0700)]
Merge tag 'arm64-fixes' of git://git./linux/kernel/git/arm64/linux

Pull arm64 fix from Catalin Marinas:
 "Fix the TLBI RANGE operand calculation causing live migration under
  KVM/arm64 to miss dirty pages due to stale TLB entries"

* tag 'arm64-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux:
  arm64: tlb: Fix TLBI RANGE operand

5 months agoMerge tag 'soc-fixes-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc
Linus Torvalds [Fri, 12 Apr 2024 20:02:27 +0000 (13:02 -0700)]
Merge tag 'soc-fixes-6.9-1' of git://git./linux/kernel/git/soc/soc

Pull SoC fixes from Arnd Bergmann:
 "The device tree changes this time are all for NXP i.MX platforms,
  addressing issues with clocks and regulators on i.MX7 and i.MX8.

  The old OMAP2 based Nokia N8x0 tablet get a couple of code fixes for
  regressions that came in.

  The ARM SCMI and FF-A firmware interfaces get a couple of minor bug
  fixes.

  A regression fix for RISC-V cache management addresses a problem with
  probe order on Sifive cores"

* tag 'soc-fixes-6.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (23 commits)
  MAINTAINERS: Change Krzysztof Kozlowski's email address
  arm64: dts: imx8qm-ss-dma: fix can lpcg indices
  arm64: dts: imx8-ss-dma: fix can lpcg indices
  arm64: dts: imx8-ss-dma: fix adc lpcg indices
  arm64: dts: imx8-ss-dma: fix pwm lpcg indices
  arm64: dts: imx8-ss-dma: fix spi lpcg indices
  arm64: dts: imx8-ss-conn: fix usb lpcg indices
  arm64: dts: imx8-ss-lsio: fix pwm lpcg indices
  ARM: dts: imx7s-warp: Pass OV2680 link-frequencies
  ARM: dts: imx7-mba7: Use 'no-mmc' property
  arm64: dts: imx8-ss-conn: fix usdhc wrong lpcg clock order
  arm64: dts: freescale: imx8mp-venice-gw73xx-2x: fix USB vbus regulator
  arm64: dts: freescale: imx8mp-venice-gw72xx-2x: fix USB vbus regulator
  cache: sifive_ccache: Partially convert to a platform driver
  firmware: arm_scmi: Make raw debugfs entries non-seekable
  firmware: arm_scmi: Fix wrong fastchannel initialization
  firmware: arm_ffa: Fix the partition ID check in ffa_notification_info_get()
  ARM: OMAP2+: fix USB regression on Nokia N8x0
  mmc: omap: restore original power up/down steps
  mmc: omap: fix deferred probe
  ...