Commit Graph

234 Commits

Author SHA1 Message Date
Darrick J. Wong
72f76f7364 xfs: fix uninitialized return values in scrub code
Fix smatch complaints about uninitialized return codes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Darrick J. Wong
0a1e1567b3 xfs: pass inode number to xfs_scrub_ino_set_{preen,warning}
There are two ways to scrub an inode -- calling xfs_iget and checking
the raw inode core, or by loading the inode cluster buffer and checking
the on-disk contents directly.  The second method is only useful if
_iget fails the verifiers; when this is the case, sc->ip is NULL and
calling the tracepoint will cause a system crash.

Therefore, pass the raw inode number directly into the _preen and
_warning functions.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Darrick J. Wong
35ce852334 xfs: refactor the directory data block bestfree checks
In a directory data block, the zeroth bestfree item must point to the
longest free space.  Therefore, when we check the bestfree block's
records against the data blocks, we only need to compare with bf[0] and
don't need the loop.

The weird loop was most probably the result of an earlier refactoring
gone bad.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-09 09:10:45 -08:00
Christoph Hellwig
88aa5de46b xfs: trivial sparse fixes for the new scrub code
[darrick: fix broken initializer in xfs_scrub_xattr]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-06 11:53:58 -08:00
Christoph Hellwig
6bdcf26ade xfs: use a b+tree for the in-core extent list
Replace the current linear list and the indirection array for the in-core
extent list with a b+tree to avoid the need for larger memory allocations
for the indirection array when lots of extents are present.  The current
extent list implementations leads to heavy pressure on the memory
allocator when modifying files with a high extent count, and can lead
to high latencies because of that.

The replacement is a b+tree with a few quirks.  The leaf nodes directly
store the extent record in two u64 values.  The encoding is a little bit
different from the existing in-core extent records so that the start
offset and length which are required for lookups can be retreived with
simple mask operations.  The inner nodes store a 64-bit key containing
the start offset in the first half of the node, and the pointers to the
next lower level in the second half.  In either case we walk the node
from the beginninig to the end and do a linear search, as that is more
efficient for the low number of cache lines touched during a search
(2 for the inner nodes, 4 for the leaf nodes) than a binary search.
We store termination markers (zero length for the leaf nodes, an
otherwise impossible high bit for the inner nodes) to terminate the key
list / records instead of storing a count to use the available cache
lines as efficiently as possible.

One quirk of the algorithm is that while we normally split a node half and
half like usual btree implementations we just spill over entries added at
the very end of the list to a new node on its own.  This means we get a
100% fill grade for the common cases of bulk insertion when reading an
inode into memory, and when only sequentially appending to a file.  The
downside is a slightly higher chance of splits on the first random
insertions.

Both insert and removal manually recurse into the lower levels, but
the bulk deletion of the whole tree is still implemented as a recursive
function call, although one limited by the overall depth and with very
little stack usage in every iteration.

For the first few extents we dynamically grow the list from a single
extent to the next powers of two until we have a first full leaf block
and that building the actual tree.

The code started out based on the generic lib/btree.c code from Joern
Engel based on earlier work from Peter Zijlstra, but has since been
rewritten beyond recognition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-06 11:53:41 -08:00
Christoph Hellwig
b2b1712a64 xfs: introduce the xfs_iext_cursor abstraction
Add a new xfs_iext_cursor structure to hide the direct extent map
index manipulations. In addition to the existing lookup/get/insert/
remove and update routines new primitives to get the first and last
extent cursor, as well as moving up and down by one extent are
provided.  Also new are convenience to increment/decrement the
cursor and retreive the new extent, as well as to peek into the
previous/next extent without updating the cursor and last but not
least a macro to iterate over all extents in a fork.

[darrick: rename for_each_iext to for_each_xfs_iext]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-11-06 11:53:40 -08:00
Darrick J. Wong
0dca060c2a xfs: scrub: avoid uninitialized return code
The newly added xfs_scrub_da_btree_block() function has one code path
that returns the 'error' variable without initializing it first, as
shown by this compiler warning:

fs/xfs/scrub/dabtree.c: In function 'xfs_scrub_da_btree_block':
fs/xfs/scrub/dabtree.c:462:9: error: 'error' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Return zero since the caller will exit the scrub code if we don't produce a
buffer pointer.

Fixes: 7c4a07a424 ("xfs: scrub directory/attribute btrees")
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-11-03 09:45:56 -07:00
Darrick J. Wong
13791d3b83 xfs: scrub extended attribute leaf space
As we walk the attribute btree, explicitly check the structure of the
attribute leaves to make sure the pointers make sense and the freemap is
sensible.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-11-01 15:03:16 -07:00
Darrick J. Wong
2fdbec5cbe xfs: compare btree block keys to parent block's keys during scrub
When we're done checking all the records/keys in a btree block, compute
the low and high key of the block and compare them to the associated key
in the parent btree block.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-10-27 09:20:31 -07:00
Darrick J. Wong
c2fc338c87 xfs: scrub quota information
Perform some quick sanity testing of the disk quota information.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
29b0767b8b xfs: scrub realtime bitmap/summary
Perform simple tests of the realtime bitmap and summary.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
0f28b25731 xfs: scrub directory parent pointers
Scrub parent pointers, sort of.  For directories, we can ride the
'..' entry up to the parent to confirm that there's at most one
dentry that points back to this directory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
2a721dbbc8 xfs: scrub symbolic links
Create the infrastructure to scrub symbolic link data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
eec0482e08 xfs: scrub extended attributes
Scrub the hash tree, keys, and values in an extended attribute structure.
Refactor the attribute code to use the transaction if the caller supplied
one to avoid buffer deadocks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
df481968f3 xfs: scrub directory freespace
Check the free space information in a directory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:26 -07:00
Darrick J. Wong
a5c46e5e89 xfs: scrub directory metadata
Scrub the hash tree and all the entries in a directory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
7c4a07a424 xfs: scrub directory/attribute btrees
Provide a way to check the shape and scrub the hashes and records
in a directory or extended attribute btree.  These are helper functions
for the directory & attribute scrubbers in subsequent patches.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
[fengguang: remove unneeded variable to store return value]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
99d9d8d05d xfs: scrub inode block mappings
Scrub an individual inode's block mappings to make sure they make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
80e4e12688 xfs: scrub inodes
Scrub the fields within an inode.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
edc09b5286 xfs: scrub refcount btrees
Plumb in the pieces necessary to check the refcount btree.  If rmap is
available, check the reference count by performing an interval query
against the rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
c7e693d983 xfs: scrub rmap btrees
Check the reverse mapping records to make sure that the contents
make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
3daa664191 xfs: scrub inode btrees
Check the records of the inode btrees to make sure that the values
make sense given the inode records themselves.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
efa7a99ce1 xfs: scrub free space btrees
Check the extent records free space btrees to ensure that the values
look sane.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:25 -07:00
Darrick J. Wong
a12890aebb xfs: scrub the AGI
Add a forgotten check to the AGI verifier, then wire up the scrub
infrastructure to check the AGI contents.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
ab9d5dc59f xfs: scrub AGF and AGFL
Check the block references in the AGF and AGFL headers to make sure
they make sense.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
21fb4cb198 xfs: scrub the secondary superblocks
Ensure that the geometry presented in the backup superblocks matches
the primary superblock so that repair can recover the filesystem if
that primary gets corrupted.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
b6c1beb967 xfs: create helpers to scan an allocation group
Add some helpers to enable us to lock an AG's headers, create btree
cursors for all btrees in that allocation group, and clean up
afterwards.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
37f3fa7f16 xfs: scrub btree keys and records
Add to the btree scrubber the ability to check that the keys and
records are in the right order and actually call out to our record
iterator to do actual checking of the records.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
cc3e0948d2 xfs: scrub the shape of a metadata btree
Create a function that can check the shape of a btree -- each block
passes basic inspection and all the pointers look ok.  In the next patch
we'll add the ability to check the actual keys and records stored within
the btree.  Add some helper functions so that we report detailed scrub
errors in a uniform manner in dmesg.  These are helper functions for
subsequent patches.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
537964bceb xfs: create helpers to scrub a metadata btree
Create helper functions and tracepoints to deal with errors while
scrubbing a metadata btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
4700d22980 xfs: create helpers to record and deal with scrub problems
Create helper functions to record crc and corruption problems, and
deal with any other runtime errors that arise.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:24 -07:00
Darrick J. Wong
dcb660f922 xfs: probe the scrub ioctl
Create a probe scrubber with id 0.  This will be used by xfs_scrub to
probe the kernel's abilities to scrub (and repair) the metadata.  We do
this by validating the ioctl inputs from userspace, preparing the
filesystem for a scrub (or a repair) operation, and immediately
returning to userspace.  Userspace can use the returned errno and
structure state to decide (in broad terms) if scrub/repair are
supported by the running kernel.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:23 -07:00
Darrick J. Wong
a56371865e xfs: dispatch metadata scrub subcommands
Create structures needed to hold scrubbing context and dispatch incoming
commands to the individual scrubbers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:23 -07:00
Darrick J. Wong
36fd6e863c xfs: create an ioctl to scrub AG metadata
Create an ioctl that can be used to scrub internal filesystem metadata.
The new ioctl takes the metadata type, an (optional) AG number, an
(optional) inode number and generation, and a flags argument.  This will
be used by the upcoming XFS online scrub tool.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-10-26 15:38:23 -07:00