djwong/linux forked from torvalds/linux

Whenever we load a buffer, explicitly re-call the structure verifier to
ensure that memory isn't corrupting things.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Expose all metadata structure buffer verifier functions via buf_ops.
These will be used by the online scrub mechanism to look for problems
with buffers that are already sitting around in memory.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

If the xattr leaf block looks corrupt, return -EFSCORRUPTED to userspace
instead of ASSERTing on debug kernels or running off the end of the
buffer on regular kernels.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Replace the current haphazard dir2 shortform verifier callsites with a
centralized verifier function that can be called either with the default
verifier functions or with a custom set.  This helps us strengthen
integrity checking while providing us with flexibility for repair tools.

xfs_repair wants this to be able to supply its own verifier functions
when trying to fix possibly corrupt metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Change the short form directory structure verifier function to return
the instruction pointer of a failing check or NULL if everything's ok.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Create a function to check the structure of short form symlink targets.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Create a function to perform structure verification for short form
extended attributes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Consolidate the fork size and format verifiers to xfs_dinode_verify so
that we can reject bad inodes earlier and in a single place.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Move the v3 inode integrity information (crc, owner, metauuid) before we
look at anything else in the inode so that we don't waste time on a torn
write or a totally garbled block.  This makes xfs_dinode_verify more
consistent with the other verifiers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Refactor the callers of verifiers to print the instruction address of a
failing check.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Modify each function that checks the contents of a metadata buffer to
return the instruction address of the failing test so that we can report
more precise failure errors to the log.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Since __xfs_dir3_data_check verifies on-disk metadata, we can't have it
noisily blowing asserts and hanging the system on corrupt data coming in
off the disk.  Instead, have it return a boolean like all the other
checker functions, and only have it noisily fail if we fail in debug
mode.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Create two helper functions to verify the headers of a long format
btree block.  We'll use this later for the realtime rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Forward everything scrub whines about to dmesg.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Repair inconsistent symbolic link data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Use the reverse-mapping btree information to rebuild an inode fork.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Try to reinitialize corrupt inodes, or clear the reflink flag
if it's not needed.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Reconstruct the refcount data from the rmap btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Rebuild the reverse mapping btree from all primary metadata.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Use the rmapbt to find inode chunks, query the chunks to compute
hole and free masks, and with that information rebuild the inobt
and finobt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Rebuild the free space btrees from the gaps in the rmap btree.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Rebuild the AGI header items with some help from the rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Regenerate the AGF and AGFL from the rmap data.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

If one of the backup superblocks is found to differ seriously from
superblock 0, write out a fresh copy from the in-core sb.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Add some helper functions for repair functions that will help us to
allocate and initialize new metadata blocks for btrees that we're
rebuilding.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Plumb in the pieces necessary to make the "scrub" subfunction of
the scrub ioctl actually work.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

These tracepoints will be used to debug the online repair routines.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Rebuilding the reverse-mapping tree requires us to quiesce all inodes in
the filesystem, so we must stop background reclamation of post-EOF and
CoW prealloc blocks.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

…g rmpabt

Add a new flag, XFS_BMAPI_NORMAP, which will perform file block
remapping without updating the rmapbt.  This will be used by the repair
code to reconstruct bmbts from the rmapbt, in which case we don't want
the rmapbt update.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Add a couple of functions to the refcount btree and generic btree code
that will be used to repair the refcountbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Add a couple of functions to the reverse mapping btree that will be used
to repair the rmapbt.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Expose various helpers that the repair code will want to use.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Add a bunch of helper functions that calculate the sizes of various
btrees.  These will be used to repair btrees and btree headers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

On a filesystem with a large amount of metadata, we can run the system
nearly out of memory while we process metadata.  If the OOM killer fires
anywhere in the system, ask the running scrub processes to abort with
ENOMEM and try again later.

(This will become more of a problem with online repair where we will
have to hold all of a reconstructed data structure in memory.)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Use an inode's block mappings to cross-reference inode block counters
and (if possible) cross reference rmapbt records against the bmbt to
ensure that the bmbt isn't missing any records.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>