Commit Graph

406 Commits

Author SHA1 Message Date
Christoph Hellwig
9c4f29d391 xfs: factor out a xfs_bmap_is_real_extent helper
This checks for all the non-normal extent types, including handling both
encodings of delayed allocations.

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>
2017-04-03 15:18:16 -07:00
Darrick J. Wong
005c5db8fd xfs: rework the inline directory verifiers
The inline directory verifiers should be called on the inode fork data,
which means after iformat_local on the read side, and prior to
ifork_flush on the write side.  This makes the fork verifier more
consistent with the way buffer verifiers work -- i.e. they will operate
on the memory buffer that the code will be reading and writing directly.

Furthermore, revise the verifier function to return -EFSCORRUPTED so
that we don't flood the logs with corruption messages and assert
notices.  This has been a particular problem with xfs/348, which
triggers the XFS_WANT_CORRUPTED_RETURN assertions, which halts the
kernel when CONFIG_XFS_DEBUG=y.  Disk corruption isn't supposed to do
that, at least not in a verifier.

Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
v2: get the inode d_ops the proper way
v3: describe the bug that this patch fixes; no code changes
2017-03-28 14:51:10 -07:00
Darrick J. Wong
630a04e79d xfs: verify inline directory data forks
When we're reading or writing the data fork of an inline directory,
check the contents to make sure we're not overflowing buffers or eating
garbage data.  xfs/348 corrupts an inline symlink into an inline
directory, triggering a buffer overflow bug.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
---
v2: add more checks consistent with _dir2_sf_check and make the verifier
usable from anywhere.
2017-03-15 00:24:25 -07:00
Christoph Hellwig
2fcc319d24 xfs: try any AG when allocating the first btree block when reflinking
When a reflink operation causes the bmap code to allocate a btree block
we're currently doing single-AG allocations due to having ->firstblock
set and then try any higher AG due a little reflink quirk we've put in
when adding the reflink code.  But given that we do not have a minleft
reservation of any kind in this AG we can still not have any space in
the same or higher AG even if the file system has enough free space.
To fix this use a XFS_ALLOCTYPE_FIRST_AG allocation in this fall back
path instead.

[And yes, we need to redo this properly instead of piling hacks over
 hacks.  I'm working on that, but it's not going to be a small series.
 In the meantime this fixes the customer reported issue]

Also add a warning for failing allocations to make it easier to debug.

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>
2017-03-08 10:38:53 -08:00
Brian Foster
f65e6fad29 xfs: use iomap new flag for newly allocated delalloc blocks
Commit fa7f138 ("xfs: clear delalloc and cache on buffered write
failure") fixed one regression in the iomap error handling code and
exposed another. The fundamental problem is that if a buffered write
is a rewrite of preexisting delalloc blocks and the write fails, the
failure handling code can punch out preexisting blocks with valid
file data.

This was reproduced directly by sub-block writes in the LTP
kernel/syscalls/write/write03 test. A first 100 byte write allocates
a single block in a file. A subsequent 100 byte write fails and
punches out the block, including the data successfully written by
the previous write.

To address this problem, update the ->iomap_begin() handler to
distinguish newly allocated delalloc blocks from preexisting
delalloc blocks via the IOMAP_F_NEW flag. Use this flag in the
->iomap_end() handler to decide when a failed or short write should
punch out delalloc blocks.

This introduces the subtle requirement that ->iomap_begin() should
never combine newly allocated delalloc blocks with existing blocks
in the resulting iomap descriptor. This can occur when a new
delalloc reservation merges with a neighboring extent that is part
of the current write, for example. Therefore, drop the
post-allocation extent lookup from xfs_bmapi_reserve_delalloc() and
just return the record inserted into the fork. This ensures only new
blocks are returned and thus that preexisting delalloc blocks are
always handled as "found" blocks and not punched out on a failed
rewrite.

Reported-by: Xiong Zhou <xzhou@redhat.com>
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-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>
2017-03-08 09:58:08 -08:00
Christoph Hellwig
8d242e932f xfs: remove XFS_ALLOCTYPE_ANY_AG and XFS_ALLOCTYPE_START_AG
XFS_ALLOCTYPE_ANY_AG  was only used for the RT allocator and is unused
now, and XFS_ALLOCTYPE_START_AG has been unused for a while.

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>
2017-02-17 20:32:10 -08:00
Christoph Hellwig
410d17f67e xfs: tune down agno asserts in the bmap code
In various places we currently assert that xfs_bmap_btalloc allocates
from the same as the firstblock value passed in, unless it's either
NULLAGNO or the dop_low flag is set.  But the reflink code does not
fully follow this convention as it passes in firstblock purely as
a hint for the allocator without actually having previous allocations
in the transaction, and without having a minleft check on the current
AG, leading to the assert firing on a very full and heavily used
file system.  As even the reflink code only allocates from equal or
higher AGs for now we can simply the check to always allow for equal
or higher AGs.

Note that we need to eventually split the two meanings of the firstblock
value.  At that point we can also allow the reflink code to allocate
from any AG instead of limiting it in any way.

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>
2017-02-16 17:20:39 -08:00
Chandan Rajendra
8ee9fdbebc xfs: Use xfs_icluster_size_fsb() to calculate inode chunk alignment
On a ppc64 system, executing generic/256 test with 32k block size gives the following call trace,

XFS: Assertion failed: args->maxlen > 0, file: /root/repos/linux/fs/xfs/libxfs/xfs_alloc.c, line: 2026

kernel BUG at /root/repos/linux/fs/xfs/xfs_message.c:113!
Oops: Exception in kernel mode, sig: 5 [#1]
SMP NR_CPUS=2048
DEBUG_PAGEALLOC
NUMA
pSeries
Modules linked in:
CPU: 2 PID: 19361 Comm: mkdir Not tainted 4.10.0-rc5 #58
task: c000000102606d80 task.stack: c0000001026b8000
NIP: c0000000004ef798 LR: c0000000004ef798 CTR: c00000000082b290
REGS: c0000001026bb090 TRAP: 0700   Not tainted  (4.10.0-rc5)
MSR: 8000000000029032 <SF,EE,ME,IR,DR,RI>
CR: 28004428  XER: 00000000
CFAR: c0000000004ef180 SOFTE: 1
GPR00: c0000000004ef798 c0000001026bb310 c000000001157300 ffffffffffffffea
GPR04: 000000000000000a c0000001026bb130 0000000000000000 ffffffffffffffc0
GPR08: 00000000000000d1 0000000000000021 00000000ffffffd1 c000000000dd4990
GPR12: 0000000022004444 c00000000fe00800 0000000020000000 0000000000000000
GPR16: 0000000000000000 0000000043a606fc 0000000043a76c08 0000000043a1b3d0
GPR20: 000001002a35cd60 c0000001026bbb80 0000000000000000 0000000000000001
GPR24: 0000000000000240 0000000000000004 c00000062dc55000 0000000000000000
GPR28: 0000000000000004 c00000062ecd9200 0000000000000000 c0000001026bb6c0
NIP [c0000000004ef798] .assfail+0x28/0x30
LR [c0000000004ef798] .assfail+0x28/0x30
Call Trace:
[c0000001026bb310] [c0000000004ef798] .assfail+0x28/0x30 (unreliable)
[c0000001026bb380] [c000000000455d74] .xfs_alloc_space_available+0x194/0x1b0
[c0000001026bb410] [c00000000045b914] .xfs_alloc_fix_freelist+0x144/0x480
[c0000001026bb580] [c00000000045c368] .xfs_alloc_vextent+0x698/0xa90
[c0000001026bb650] [c0000000004a6200] .xfs_ialloc_ag_alloc+0x170/0x820
[c0000001026bb7c0] [c0000000004a9098] .xfs_dialloc+0x158/0x320
[c0000001026bb8a0] [c0000000004e628c] .xfs_ialloc+0x7c/0x610
[c0000001026bb990] [c0000000004e8138] .xfs_dir_ialloc+0xa8/0x2f0
[c0000001026bbaa0] [c0000000004e8814] .xfs_create+0x494/0x790
[c0000001026bbbf0] [c0000000004e5ebc] .xfs_generic_create+0x2bc/0x410
[c0000001026bbce0] [c0000000002b4a34] .vfs_mkdir+0x154/0x230
[c0000001026bbd70] [c0000000002bc444] .SyS_mkdirat+0x94/0x120
[c0000001026bbe30] [c00000000000b760] system_call+0x38/0xfc
Instruction dump:
4e800020 60000000 7c0802a6 7c862378 3c82ffca 7ca72b78 38841c18 7c651b78
38600000 f8010010 f821ff91 4bfff94d <0fe00000> 60000000 7c0802a6 7c892378

When block size is larger than inode cluster size, the call to
XFS_B_TO_FSBT(mp, mp->m_inode_cluster_size) returns 0. Also, mkfs.xfs
would have set xfs_sb->sb_inoalignmt to 0. This causes
xfs_ialloc_cluster_alignment() to return 0.  Due to this
args.minalignslop (in xfs_ialloc_ag_alloc()) gets the unsigned
equivalent of -1 assigned to it. This later causes alloc_len in
xfs_alloc_space_available() to have a value of 0. In such a scenario
when args.total is also 0, the assert statement "ASSERT(args->maxlen >
0);" fails.

This commit fixes the bug by replacing the call to XFS_B_TO_FSBT() in
xfs_ialloc_cluster_alignment() with a call to xfs_icluster_size_fsb().

Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-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>
2017-02-16 17:20:38 -08:00
Brian Foster
75d65361cf xfs: split indlen reservations fairly when under reserved
Certain workoads that punch holes into speculative preallocation can
cause delalloc indirect reservation splits when the delalloc extent is
split in two. If further splits occur, an already short-handed extent
can be split into two in a manner that leaves zero indirect blocks for
one of the two new extents. This occurs because the shortage is large
enough that the xfs_bmap_split_indlen() algorithm completely drains the
requested indlen of one of the extents before it honors the existing
reservation.

This ultimately results in a warning from xfs_bmap_del_extent(). This
has been observed during file copies of large, sparse files using 'cp
--sparse=always.'

To avoid this problem, update xfs_bmap_split_indlen() to explicitly
apply the reservation shortage fairly between both extents. This smooths
out the overall indlen shortage and defers the situation where we end up
with a delalloc extent with zero indlen reservation to extreme
circumstances.

Reported-by: Patrick Dung <mpatdung@gmail.com>
Signed-off-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>
2017-02-16 17:20:12 -08:00
Brian Foster
0e339ef855 xfs: handle indlen shortage on delalloc extent merge
When a delalloc extent is created, it can be merged with pre-existing,
contiguous, delalloc extents. When this occurs,
xfs_bmap_add_extent_hole_delay() merges the extents along with the
associated indirect block reservations. The expectation here is that the
combined worst case indlen reservation is always less than or equal to
the indlen reservation for the individual extents.

This is not always the case, however, as existing extents can less than
the expected indlen reservation if the extent was previously split due
to a hole punch. If a new extent merges with such an extent, the total
indlen requirement may be larger than the sum of the indlen reservations
held by both extents.

xfs_bmap_add_extent_hole_delay() assumes that the worst case indlen
reservation is always available and assigns it to the merged extent
without consideration for the indlen held by the pre-existing extent. As
a result, the subsequent xfs_mod_fdblocks() call can attempt an
unintentional allocation rather than a free (indicated by an ASSERT()
failure). Further, if the allocation happens to fail in this context,
the failure goes unhandled and creates a filesystem wide block
accounting inconsistency.

Fix xfs_bmap_add_extent_hole_delay() to function as designed. Cap the
indlen reservation assigned to the merged extent to the sum of the
indlen reservations held by each of the individual extents.

Signed-off-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>
2017-02-16 17:20:12 -08:00
Christoph Hellwig
ebf5587261 xfs: improve handling of busy extents in the low-level allocator
Currently we force the log and simply try again if we hit a busy extent,
but especially with online discard enabled it might take a while after
the log force for the busy extents to disappear, and we might have
already completed our second pass.

So instead we add a new waitqueue and a generation counter to the pag
structure so that we can do wakeups once we've removed busy extents,
and we replace the single retry with an unconditional one - after
all we hold the AGF buffer lock, so no other allocations or frees
can be racing with us in this AG.

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>
2017-02-09 10:50:25 -08:00
Christoph Hellwig
a14234c72b xfs: go straight to real allocations for direct I/O COW writes
When we allocate COW fork blocks for direct I/O writes we currently first
create a delayed allocation, and then convert it to a real allocation
once we've got the delayed one.

As there is no good reason for that this patch instead makes use call
xfs_bmapi_write from the COW allocation path.  The only interesting bits
are a few tweaks the low-level allocator to allow for this, most notably
the need to remove the call to xfs_bmap_extsize_align for the cowextsize
in xfs_bmap_btalloc - for the existing convert case it's a no-op, but
for the direct allocation case it would blow up our block reservation
way beyond what we reserved for the transaction.

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>
2017-02-06 17:47:47 -08:00
Darrick J. Wong
05a630d76b xfs: allow unwritten extents in the CoW fork
In the data fork, we only allow extents to perform the following state
transitions:

delay -> real <-> unwritten

There's no way to move directly from a delalloc reservation to an
/unwritten/ allocated extent.  However, for the CoW fork we want to be
able to do the following to each extent:

delalloc -> unwritten -> written -> remapped to data fork

This will help us to avoid a race in the speculative CoW preallocation
code between a first thread that is allocating a CoW extent and a second
thread that is remapping part of a file after a write.  In order to do
this, however, we need two things: first, we have to be able to
transition from da to unwritten, and second the function that converts
between real and unwritten has to be made aware of the cow fork.  Do
both of those things.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:14:01 -08:00
Darrick J. Wong
de14c5f541 xfs: verify free block header fields
Perform basic sanity checking of the directory free block header
fields so that we avoid hanging the system on invalid data.

(Granted that just means that now we shutdown on directory write,
but that seems better than hanging...)

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:14:00 -08:00
Darrick J. Wong
b3bf607d58 xfs: check for obviously bad level values in the bmbt root
We can't handle a bmbt that's taller than BTREE_MAXLEVELS, and there's
no such thing as a zero-level bmbt (for that we have extents format),
so if we see this, send back an error code.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:59 -08:00
Darrick J. Wong
d5a91baeb6 xfs: filter out obviously bad btree pointers
Don't let anybody load an obviously bad btree pointer.  Since the values
come from disk, we must return an error, not just ASSERT.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
2017-02-02 15:13:58 -08:00
Darrick J. Wong
7a652bbe36 xfs: fail _dir_open when readahead fails
When we open a directory, we try to readahead block 0 of the directory
on the assumption that we're going to need it soon.  If the bmbt is
corrupt, the directory will never be usable and the readahead fails
immediately, so we might as well prevent the directory from being opened
at all.  This prevents a subsequent read or modify operation from
hitting it and taking the fs offline.

NOTE: We're only checking for early failures in the block mapping, not
the readahead directory block itself.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:58 -08:00
Darrick J. Wong
4b5bd5bf3f xfs: fix toctou race when locking an inode to access the data map
We use di_format and if_flags to decide whether we're grabbing the ilock
in btree mode (btree extents not loaded) or shared mode (anything else),
but the state of those fields can be changed by other threads that are
also trying to load the btree extents -- IFEXTENTS gets set before the
_bmap_read_extents call and cleared if it fails.

We don't actually need to have IFEXTENTS set until after the bmbt
records are successfully loaded and validated, which will fix the race
between multiple threads trying to read the same directory.  The next
patch strengthens directory bmbt validation by refusing to open the
directory if reading the bmbt to start directory readahead fails.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-02-02 15:13:57 -08:00
Eric Sandeen
64f61ab604 xfs: remove unused struct declarations
After scratching my head looking for "xfs_busy_extent" I realized
it's not used; it's xfs_extent_busy, and the declaration for the
other name is bogus.  Remove that and a few others as well.

(struct xfs_log_callback is used, but the 2nd declaration is
unnecessary).

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-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>
2017-01-30 16:32:25 -08:00
Eric Sandeen
b6f41e4482 xfs: remove boilerplate around xfs_btree_init_block
Now that xfs_btree_init_block_int is able to determine crc
status from the passed-in mp, we can determine the proper
magic as well if we are given a btree number, rather than
an explicit magic value.

Change xfs_btree_init_block[_int] callers to pass in the
btree number, and let xfs_btree_init_block_int use the
xfs_magics array via the xfs_btree_magic macro to determine
which magic value is needed.  This makes all of the
if (crc) / else stanzas identical, and the if/else can be
removed, leading to a single, common init_block call.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
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>
2017-01-30 16:32:24 -08:00
Eric Sandeen
af7d20fd83 xfs: make xfs_btree_magic more generic
Right now the xfs_btree_magic() define takes only a cursor;
change this to take crc and btnum args to make it more generically
useful, and move to a function.

This will allow xfs_btree_init_block_int callers which don't
have a cursor to make use of the xfs_magics array, which will
happen in the next patch.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
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>
2017-01-30 16:32:24 -08:00
Eric Sandeen
f88ae46b09 xfs: glean crc status from mp not flags in xfs_btree_init_block_int
xfs_btree_init_block_int() can determine whether crcs are
in effect without the passed-in XFS_BTREE_CRC_BLOCKS flag;
the mp argument allows us to determine this from the
superblock.  Remove the flag from callers, and use
xfs_sb_version_hascrc(&mp->m_sb) internally instead.

This removes one difference between the if & else cases
in the callers.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
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>
2017-01-30 16:32:24 -08:00
Christoph Hellwig
493611ebd6 xfs: extsize hints are not unlikely in xfs_bmap_btalloc
With COW files they are the hotpath, just like for files with the
extent size hint attribute.  We really shouldn't micro-manage anything
but failure cases with unlikely.

Additionally Arnd Bergmann recently reported that one of these two
unlikely annotations causes link failures together with an upcoming
kernel instrumentation patch, so let's get rid of it ASAP.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-25 08:59:43 -08:00
Brian Foster
5a93790d4e xfs: remove racy hasattr check from attr ops
xfs_attr_[get|remove]() have unlocked attribute fork checks to optimize
away a lock cycle in cases where the fork does not exist or is otherwise
empty. This check is not safe, however, because an attribute fork short
form to extent format conversion includes a transient state that causes
the xfs_inode_hasattr() check to fail. Specifically,
xfs_attr_shortform_to_leaf() creates an empty extent format attribute
fork and then adds the existing shortform attributes to it.

This means that lookup of an existing xattr can spuriously return
-ENOATTR when racing against a setxattr that causes the associated
format conversion. This was originally reproduced by an untar on a
particularly configured glusterfs volume, but can also be reproduced on
demand with properly crafted xattr requests.

The format conversion occurs under the exclusive ilock. xfs_attr_get()
and xfs_attr_remove() already have the proper locking and checks further
down in the functions to handle this situation correctly. Drop the
unlocked checks to avoid the spurious failure and rely on the existing
logic.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-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>
2017-01-25 07:53:43 -08:00
Christoph Hellwig
76d771b4cb xfs: use per-AG reservations for the finobt
Currently we try to rely on the global reserved block pool for block
allocations for the free inode btree, but I have customer reports
(fairly complex workload, need to find an easier reproducer) where that
is not enough as the AG where we free an inode that requires a new
finobt block is entirely full.  This causes us to cancel a dirty
transaction and thus a file system shutdown.

I think the right way to guard against this is to treat the finot the same
way as the refcount btree and have a per-AG reservations for the possible
worst case size of it, and the patch below implements that.

Note that this could increase mount times with large finobt trees.  In
an ideal world we would have added a field for the number of finobt
fields to the AGI, similar to what we did for the refcount blocks.
We should do add it next time we rev the AGI or AGF format by adding
new fields.

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>
2017-01-25 07:49:35 -08:00
Christoph Hellwig
4dfa2b8411 xfs: only update mount/resv fields on success in __xfs_ag_resv_init
Try to reserve the blocks first and only then update the fields in
or hanging off the mount structure.  This way we can call __xfs_ag_resv_init
again after a previous failure.

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>
2017-01-25 07:49:34 -08:00
Darrick J. Wong
83d230eb5c xfs: verify dirblocklog correctly
sb_dirblklog is added to sb_blocklog to compute the directory block size
in bytes.  Therefore, we must compare the sum of both those values
against XFS_MAX_BLOCKSIZE_LOG, not just dirblklog.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-01-24 12:23:33 -08:00
Christoph Hellwig
d2b3964a07 xfs: fix COW writeback race
Due to the way how xfs_iomap_write_allocate tries to convert the whole
found extents from delalloc to real space we can run into a race
condition with multiple threads doing writes to this same extent.
For the non-COW case that is harmless as the only thing that can happen
is that we call xfs_bmapi_write on an extent that has already been
converted to a real allocation.  For COW writes where we move the extent
from the COW to the data fork after I/O completion the race is, however,
not quite as harmless.  In the worst case we are now calling
xfs_bmapi_write on a region that contains hole in the COW work, which
will trip up an assert in debug builds or lead to file system corruption
in non-debug builds.  This seems to be reproducible with workloads of
small O_DSYNC write, although so far I've not managed to come up with
a with an isolated reproducer.

The fix for the issue is relatively simple:  tell xfs_bmapi_write
that we are only asked to convert delayed allocations and skip holes
in that case.

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>
2017-01-23 10:55:07 -08:00
Arnd Bergmann
fd29f7af75 xfs: fix xfs_mode_to_ftype() prototype
A harmless warning just got introduced:

fs/xfs/libxfs/xfs_dir2.h:40:8: error: type qualifiers ignored on function return type [-Werror=ignored-qualifiers]

Removing the 'const' modifier avoids the warning and has no
other effect.

Fixes: 1fc4d33fed ("xfs: replace xfs_mode_to_ftype table with switch statement")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-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>
2017-01-18 12:39:21 -08:00
Amir Goldstein
a324cbf10a xfs: sanity check inode di_mode
Check for invalid file type in xfs_dinode_verify()
and fail to load the inode structure from disk.

Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-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>
2017-01-17 11:42:22 -08:00
Amir Goldstein
1fc4d33fed xfs: replace xfs_mode_to_ftype table with switch statement
The size of the xfs_mode_to_ftype[] conversion table
was too small to handle an invalid value of mode=S_IFMT.

Instead of fixing the table size, replace the conversion table
with a conversion helper that uses a switch statement.

Suggested-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-17 11:41:43 -08:00
Amir Goldstein
b597dd5373 xfs: add missing include dependencies to xfs_dir2.h
xfs_dir2.h dereferences some data types in inline functions
and fails to include those type definitions, e.g.:
xfs_dir2_data_aoff_t, struct xfs_da_geometry.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-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>
2017-01-17 11:41:42 -08:00
Amir Goldstein
3c6f46eacd xfs: sanity check directory inode di_size
This changes fixes an assertion hit when fuzzing on-disk
i_mode values.

The easy case to fix is when changing an empty file
i_mode to S_IFDIR. In this case, xfs_dinode_verify()
detects an illegal zero size for directory and fails
to load the inode structure from disk.

For the case of non empty file whose i_mode is changed
to S_IFDIR, the ASSERT() statement in xfs_dir2_isblock()
is replaced with return -EFSCORRUPTED, to avoid interacting
with corrupted jusk also when XFS_DEBUG is disabled.

Suggested-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-17 11:41:41 -08:00
Christoph Hellwig
12ef830198 xfs: don't rely on ->total in xfs_alloc_space_available
->total is a bit of an odd parameter passed down to the low-level
allocator all the way from the high-level callers.  It's supposed to
contain the maximum number of blocks to be allocated for the whole
transaction [1].

But in xfs_iomap_write_allocate we only convert existing delayed
allocations and thus only have a minimal block reservation for the
current transaction, so xfs_alloc_space_available can't use it for
the allocation decisions.  Use the maximum of args->total and the
calculated block requirement to make a decision.  We probably should
get rid of args->total eventually and instead apply ->minleft more
broadly, but that will require some extensive changes all over.

[1] which creates lots of confusion as most callers don't decrement it
once doing a first allocation.  But that's for a separate series.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-09 13:45:01 -08:00
Christoph Hellwig
54fee133ad xfs: adjust allocation length in xfs_alloc_space_available
We must decide in xfs_alloc_fix_freelist if we can perform an
allocation from a given AG is possible or not based on the available
space, and should not fail the allocation past that point on a
healthy file system.

But currently we have two additional places that second-guess
xfs_alloc_fix_freelist: xfs_alloc_ag_vextent tries to adjust the
maxlen parameter to remove the reservation before doing the
allocation (but ignores the various minium freespace requirements),
and xfs_alloc_fix_minleft tries to fix up the allocated length
after we've found an extent, but ignores the reservations and also
doesn't take the AGFL into account (and thus fails allocations
for not matching minlen in some cases).

Remove all these later fixups and just correct the maxlen argument
inside xfs_alloc_fix_freelist once we have the AGF buffer locked.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-09 13:37:44 -08:00
Christoph Hellwig
255c516278 xfs: fix bogus minleft manipulations
We can't just set minleft to 0 when we're low on space - that's exactly
what we need minleft for: to protect space in the AG for btree block
allocations when we are low on free space.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-09 13:36:36 -08:00
Christoph Hellwig
5149fd327f xfs: bump up reserved blocks in xfs_alloc_set_aside
Setting aside 4 blocks globally for bmbt splits isn't all that useful,
as different threads can allocate space in parallel.  Bump it to 4
blocks per AG to allow each thread that is currently doing an
allocation to dip into it separately.  Without that we may no have
enough reserved blocks if there are enough parallel transactions
in an almost out space file system that all run into bmap btree
splits.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-01-09 13:35:00 -08:00
Darrick J. Wong
20e73b000b xfs: use the actual AG length when reserving blocks
We need to use the actual AG length when making per-AG reservations,
since we could otherwise end up reserving more blocks out of the last
AG than there are actual blocks.

Complained-about-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-01-03 18:39:33 -08:00
Dave Chinner
9807b773da Merge branch 'xfs-4.10-misc-fixes-4' into for-next 2016-12-09 16:56:26 +11:00
Darrick J. Wong
b24a978c37 xfs: use GPF_NOFS when allocating btree cursors
Use NOFS for allocating btree cursors, since they can be called
under the ilock.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-09 16:49:54 +11:00
Eric Sandeen
2e1d23370e xfs: ignore leaf attr ichdr.count in verifier during log replay
When we create a new attribute, we first create a shortform
attribute, and try to fit the new attribute into it.
If that fails, we copy the (empty) attribute into a leaf attribute,
and do the copy again.  Thus there can be a transient state where
we have an empty leaf attribute.

If we encounter this during log replay, the verifier will fail.
So add a test to ignore this part of the leaf attr verification
during log replay.

Thanks as usual to dchinner for spotting the problem.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-09 16:49:47 +11:00
Dave Chinner
a444d72e60 Merge branch 'xfs-4.10-misc-fixes-3' into for-next 2016-12-07 17:42:30 +11:00
Dave Chinner
cae028df53 xfs: optimise CRC updates
Nick Piggin reported that the CRC overhead in an fsync heavy
workload was higher than expected on a Power8 machine. Part of this
was to do with the fact that the power8 CRC implementation is not
efficient for CRC lengths of less than 512 bytes, and so the way we
split the CRCs over the CRC field means a lot of the CRCs are
reduced to being less than than optimal size.

To optimise this, change the CRC update mechanism to zero the CRC
field first, and then compute the CRC in one pass over the buffer
and write the result back into the buffer. We can do this safely
because anything writing a CRC has exclusive access to the buffer
the CRC is being calculated over.

We leave the CRC verify code the same - it still splits the CRC
calculation - because we do not want read-only operations modifying
the underlying buffer. This is because read-only operations may not
have an exclusive access to the buffer guaranteed, and so temporary
modifications could leak out to to other processes accessing the
buffer concurrently.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 14:40:32 +11:00
Dave Chinner
11ef38afe9 xfs: make xfs btree stats less huge
Embedding a switch statement in every btree stats inc/add adds a lot
of code overhead to the core btree infrastructure paths. Stats are
supposed to be small and lightweight, but the btree stats have
become big and bloated as we've added more btrees. It needs fixing
because the reflink code will just add more overhead again.

Convert the v2 btree stats to arrays instead of independent
variables, and instead use the type to index the specific btree
array via an enum. This allows us to use array based indexing
to update the stats, rather than having to derefence variables
specific to the btree type.

If we then wrap the xfsstats structure in a union and place uint32_t
array beside it, and calculate the correct btree stats array base
array index when creating a btree cursor,  we can easily access
entries in the stats structure without having to switch names based
on the btree type.

We then replace with the switch statement with a simple set of stats
wrapper macros, resulting in a significant simplification of the
btree stats code, and:

   text	   data	    bss	    dec	    hex	filename
  48905	    144	      8	  49057	   bfa1	fs/xfs/libxfs/xfs_btree.o.old
  36793	    144	      8	  36945	   9051	fs/xfs/libxfs/xfs_btree.o

it reduces the core btree infrastructure code size by close to 25%!

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 14:38:58 +11:00
Darrick J. Wong
ef388e2054 xfs: don't allow di_size with high bit set
The on-disk field di_size is used to set i_size, which is a signed
integer of loff_t.  If the high bit of di_size is set, we'll end up with
a negative i_size, which will cause all sorts of problems.  Since the
VFS won't let us create a file with such length, we should catch them
here in the verifier too.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:38:38 +11:00
Darrick J. Wong
0f352f8ee8 xfs: error out if trying to add attrs and anextents > 0
We shouldn't assert if somehow we end up trying to add an attr fork to
an inode that apparently already has attr extents because this is an
indication of on-disk corruption.  Instead, return an error code to
userspace.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:38:11 +11:00
Darrick J. Wong
96a3aefb8f xfs: don't crash if reading a directory results in an unexpected hole
In xfs_dir3_data_read, we can encounter the situation where err == 0 and
*bpp == NULL if the given bno offset happens to be a hole; this leads to
a crash if we try to set the buffer type after the _da_read_buf call.
Holes can happen due to corrupt or malicious entries in the bmbt data,
so be a little more careful when we're handling buffers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:37:47 +11:00
Darrick J. Wong
356a322522 xfs: complain if we don't get nextents bmap records
When reading into memory all extents of a btree-format inode fork,
complain if the number of extents we find is not the same as the number
of extents reported in the inode core.  This is needed to stop an IO
action from accessing the garbage areas of the in-core fork.

[dchinner: removed redundant assert]

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:36:56 +11:00
Darrick J. Wong
bb3be7e7c1 xfs: check for bogus values in btree block headers
When we're reading a btree block, make sure that what we retrieved
matches the owner and level; and has a plausible number of records.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:33:54 +11:00
Darrick J. Wong
d2a047f31e xfs: forbid AG btrees with level == 0
There is no such thing as a zero-level AG btree since even a single-node
zero-records btree has one level.  Btree cursor constructors read
cur_nlevels straight from disk and then access things like
cur_bufs[cur_nlevels - 1] which is /really/ bad if cur_nlevels is zero!
Therefore, strengthen the verifiers to prevent this possibility.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-12-05 12:32:50 +11:00