kernel/linux.git/fs/xfs/libxfs, branch linux-4.4.y

xfs: fix attr leaf header freemap.size underflow

2020-10-01T09:11:51+00:00

[ Upstream commit 2a2b5932db67586bacc560cc065d62faece5b996 ] The leaf format xattr addition helper xfs_attr3_leaf_add_work() adjusts the block freemap in a couple places. The first update drops the size of the freemap that the caller had already selected to place the xattr name/value data. Before the function returns, it also checks whether the entries array has encroached on a freemap range by virtue of the new entry addition. This is necessary because the entries array grows from the start of the block (but end of the block header) towards the end of the block while the name/value data grows from the end of the block in the opposite direction. If the associated freemap is already empty, however, size is zero and the subtraction underflows the field and causes corruption. This is reproduced rarely by generic/070. The observed behavior is that a smaller sized freemap is aligned to the end of the entries list, several subsequent xattr additions land in larger freemaps and the entries list expands into the smaller freemap until it is fully consumed and then underflows. Note that it is not otherwise a corruption for the entries array to consume an empty freemap because the nameval list (i.e. the firstused pointer in the xattr header) starts beyond the end of the corrupted freemap. Update the freemap size modification to account for the fact that the freemap entry can be empty and thus stale. Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin

xfs: initialize the shortform attr header padding entry

2020-09-23T06:44:23+00:00

[ Upstream commit 125eac243806e021f33a1fdea3687eccbb9f7636 ] Don't leak kernel memory contents into the shortform attr fork. Signed-off-by: Darrick J. Wong Reviewed-by: Eric Sandeen Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Sasha Levin

xfs: don't call xfs_da_shrink_inode with NULL bp

2020-08-21T08:52:52+00:00

[ Upstream commit bb3d48dcf86a97dc25fe9fc2c11938e19cb4399a ] xfs_attr3_leaf_create may have errored out before instantiating a buffer, for example if the blkno is out of range. In that case there is no work to do to remove it, and in fact xfs_da_shrink_inode will lead to an oops if we try. This also seems to fix a flaw where the original error from xfs_attr3_leaf_create gets overwritten in the cleanup case, and it removes a pointless assignment to bp which isn't used after this. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199969 Reported-by: Xu, Wen Tested-by: Xu, Wen Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin

xfs: set format back to extents if xfs_bmap_extents_to_btree

2020-07-31T14:43:16+00:00

commit 2c4306f719b083d17df2963bc761777576b8ad1b upstream. If xfs_bmap_extents_to_btree fails in a mode where we call xfs_iroot_realloc(-1) to de-allocate the root, set the format back to extents. Otherwise we can assume we can dereference ifp->if_broot based on the XFS_DINODE_FMT_BTREE format, and crash. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199423 Signed-off-by: Eric Sandeen Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong [iwamatsu: backported to 4.4.y] Signed-off-by: Nobuhiro Iwamatsu (CIP) Signed-off-by: Greg Kroah-Hartman

xfs: don't fail when converting shortform attr to long form during ATTR_REPLACE

2019-01-26T08:42:52+00:00

commit 7b38460dc8e4eafba06c78f8e37099d3b34d473c upstream. Kanda Motohiro reported that expanding a tiny xattr into a large xattr fails on XFS because we remove the tiny xattr from a shortform fork and then try to re-add it after converting the fork to extents format having not removed the ATTR_REPLACE flag. This fails because the attr is no longer present, causing a fs shutdown. This is derived from the patch in his bug report, but we really shouldn't ignore a nonzero retval from the remove call. Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=199119 Reported-by: kanda.motohiro@gmail.com Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Darrick J. Wong Cc: Ben Hutchings Signed-off-by: Greg Kroah-Hartman

xfs: detect agfl count corruption and reset agfl

2018-06-06T14:46:20+00:00

commit a27ba2607e60312554cbcd43fc660b2c7f29dc9c upstream. The struct xfs_agfl v5 header was originally introduced with unexpected padding that caused the AGFL to operate with one less slot than intended. The header has since been packed, but the fix left an incompatibility for users who upgrade from an old kernel with the unpacked header to a newer kernel with the packed header while the AGFL happens to wrap around the end. The newer kernel recognizes one extra slot at the physical end of the AGFL that the previous kernel did not. The new kernel will eventually attempt to allocate a block from that slot, which contains invalid data, and cause a crash. This condition can be detected by comparing the active range of the AGFL to the count. While this detects a padding mismatch, it can also trigger false positives for unrelated flcount corruption. Since we cannot distinguish a size mismatch due to padding from unrelated corruption, we can't trust the AGFL enough to simply repopulate the empty slot. Instead, avoid unnecessarily complex detection logic and and use a solution that can handle any form of flcount corruption that slips through read verifiers: distrust the entire AGFL and reset it to an empty state. Any valid blocks within the AGFL are intentionally leaked. This requires xfs_repair to rectify (which was already necessary based on the state the AGFL was found in). The reset mitigates the side effect of the padding mismatch problem from a filesystem crash to a free space accounting inconsistency. The generic approach also means that this patch can be safely backported to kernels with or without a packed struct xfs_agfl. Check the AGF for an invalid freelist count on initial read from disk. If detected, set a flag on the xfs_perag to indicate that a reset is required before the AGFL can be used. In the first transaction that attempts to use a flagged AGFL, reset it to empty, warn the user about the inconsistency and allow the freelist fixup code to repopulate the AGFL with new blocks. The xfs_perag flag is cleared to eliminate the need for repeated checks on each block allocation operation. This allows kernels that include the packing fix commit 96f859d52bcb ("libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct") to handle older unpacked AGFL formats without a filesystem crash. Suggested-by: Dave Chinner Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Reviewed-by Dave Chiluk Signed-off-by: Darrick J. Wong Signed-off-by: Dave Chiluk Signed-off-by: Greg Kroah-Hartman

xfs: remove racy hasattr check from attr ops

2018-05-30T05:48:52+00:00

commit 5a93790d4e2df73e30c965ec6e49be82fc3ccfce upstream. 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 Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Cc: Daniel Sangorrin Signed-off-by: Greg Kroah-Hartman

xfs: fix incorrect extent state in xfs_bmap_add_extent_unwritten_real

2017-12-20T09:05:00+00:00

[ Upstream commit 5e422f5e4fd71d18bc6b851eeb3864477b3d842e ] There was one spot in xfs_bmap_add_extent_unwritten_real that didn't use the passed in new extent state but always converted to normal, leading to wrong behavior when converting from normal to unwritten. Only found by code inspection, it seems like this code path to move partial extent from written to unwritten while merging it with the next extent is rarely exercised. Signed-off-by: Christoph Hellwig Reviewed-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

xfs: fix unaligned access in xfs_btree_visit_blocks

2017-06-07T10:06:03+00:00

commit a4d768e702de224cc85e0c8eac9311763403b368 upstream. This structure copy was throwing unaligned access warnings on sparc64: Kernel unaligned access at TPC[1043c088] xfs_btree_visit_blocks+0x88/0xe0 [xfs] xfs_btree_copy_ptrs does a memcpy, which avoids it. Signed-off-by: Eric Sandeen Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman

xfs: fix indlen accounting error on partial delalloc conversion

2017-06-07T10:06:02+00:00

commit 0daaecacb83bc6b656a56393ab77a31c28139bc7 upstream. The delalloc -> real block conversion path uses an incorrect calculation in the case where the middle part of a delalloc extent is being converted. This is documented as a rare situation because XFS generally attempts to maximize contiguity by converting as much of a delalloc extent as possible. If this situation does occur, the indlen reservation for the two new delalloc extents left behind by the conversion of the middle range is calculated and compared with the original reservation. If more blocks are required, the delta is allocated from the global block pool. This delta value can be characterized as the difference between the new total requirement (temp + temp2) and the currently available reservation minus those blocks that have already been allocated (startblockval(PREV.br_startblock) - allocated). The problem is that the current code does not account for previously allocated blocks correctly. It subtracts the current allocation count from the (new - old) delta rather than the old indlen reservation. This means that more indlen blocks than have been allocated end up stashed in the remaining extents and free space accounting is broken as a result. Fix up the calculation to subtract the allocated block count from the original extent indlen and thus correctly allocate the reservation delta based on the difference between the new total requirement and the unused blocks from the original reservation. Also remove a bogus assert that contradicts the fact that the new indlen reservation can be larger than the original indlen reservation. Signed-off-by: Brian Foster Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong Signed-off-by: Greg Kroah-Hartman