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path: root/fs/xfs/libxfs/xfs_refcount.c
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2020-03-13xfs: make the btree ag cursor private union anonymousDave Chinner
This is much less widely used than the bc_private union was, so this is done as a single patch. The named union xfs_btree_cur_private goes away and is embedded into the struct xfs_btree_cur_ag as an anonymous union, and the code is modified via this script: $ sed -i 's/priv\.\([abt|refc]\)/\1/g' fs/xfs/*[ch] fs/xfs/*/*[ch] Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2020-03-13xfs: convert btree cursor ag-private member nameDave Chinner
bc_private.a -> bc_ag conversion via script: `sed -i 's/bc_private\.a/bc_ag/g' fs/xfs/*[ch] fs/xfs/*/*[ch]` And then revert the change to the bc_ag #define in fs/xfs/libxfs/xfs_btree.h manually. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2020-01-26xfs: remove unnecessary null pointer checks from _read_agf callersDarrick J. Wong
Drop the null buffer pointer checks in all code that calls xfs_alloc_read_agf and doesn't pass XFS_ALLOC_FLAG_TRYLOCK because they're no longer necessary. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-11-13xfs: convert open coded corruption check to use XFS_IS_CORRUPTDarrick J. Wong
Convert the last of the open coded corruption check and report idioms to use the XFS_IS_CORRUPT macro. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-11-12xfs: kill the XFS_WANT_CORRUPT_* macrosDarrick J. Wong
The XFS_WANT_CORRUPT_* macros conceal subtle side effects such as the creation of local variables and redirections of the code flow. This is pretty ugly, so replace them with explicit XFS_IS_CORRUPT tests that remove both of those ugly points. The change was performed with the following coccinelle script: @@ expression mp, test; identifier label; @@ - XFS_WANT_CORRUPTED_GOTO(mp, test, label); + if (XFS_IS_CORRUPT(mp, !test)) { error = -EFSCORRUPTED; goto label; } @@ expression mp, test; @@ - XFS_WANT_CORRUPTED_RETURN(mp, test); + if (XFS_IS_CORRUPT(mp, !test)) return -EFSCORRUPTED; @@ expression mp, lval, rval; @@ - XFS_IS_CORRUPT(mp, !(lval == rval)) + XFS_IS_CORRUPT(mp, lval != rval) @@ expression mp, e1, e2; @@ - XFS_IS_CORRUPT(mp, !(e1 && e2)) + XFS_IS_CORRUPT(mp, !e1 || !e2) @@ expression e1, e2; @@ - !(e1 == e2) + e1 != e2 @@ expression e1, e2, e3, e4, e5, e6; @@ - !(e1 == e2 && e3 == e4) || e5 != e6 + e1 != e2 || e3 != e4 || e5 != e6 @@ expression e1, e2, e3, e4, e5, e6; @@ - !(e1 == e2 || (e3 <= e4 && e5 <= e6)) + e1 != e2 && (e3 > e4 || e5 > e6) @@ expression mp, e1, e2; @@ - XFS_IS_CORRUPT(mp, !(e1 <= e2)) + XFS_IS_CORRUPT(mp, e1 > e2) @@ expression mp, e1, e2; @@ - XFS_IS_CORRUPT(mp, !(e1 < e2)) + XFS_IS_CORRUPT(mp, e1 >= e2) @@ expression mp, e1; @@ - XFS_IS_CORRUPT(mp, !!e1) + XFS_IS_CORRUPT(mp, e1) @@ expression mp, e1, e2; @@ - XFS_IS_CORRUPT(mp, !(e1 || e2)) + XFS_IS_CORRUPT(mp, !e1 && !e2) @@ expression mp, e1, e2, e3, e4; @@ - XFS_IS_CORRUPT(mp, !(e1 == e2) && !(e3 == e4)) + XFS_IS_CORRUPT(mp, e1 != e2 && e3 != e4) @@ expression mp, e1, e2, e3, e4; @@ - XFS_IS_CORRUPT(mp, !(e1 <= e2) || !(e3 >= e4)) + XFS_IS_CORRUPT(mp, e1 > e2 || e3 < e4) @@ expression mp, e1, e2, e3, e4; @@ - XFS_IS_CORRUPT(mp, !(e1 == e2) && !(e3 <= e4)) + XFS_IS_CORRUPT(mp, e1 != e2 && e3 > e4) Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-11-04xfs: always log corruption errorsDarrick J. Wong
Make sure we log something to dmesg whenever we return -EFSCORRUPTED up the call stack. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-08-28xfs: remove unnecessary int returns from deferred refcount functionsDarrick J. Wong
Remove the return value from the functions that schedule deferred refcount operations since they never fail and do not return status. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-08-28xfs: remove unnecessary int returns from deferred rmap functionsDarrick J. Wong
Remove the return value from the functions that schedule deferred rmap operations since they never fail and do not return status. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-08-26fs: xfs: Remove KM_NOSLEEP and KM_SLEEP.Tetsuo Handa
Since no caller is using KM_NOSLEEP and no callee branches on KM_SLEEP, we can remove KM_NOSLEEP and replace KM_SLEEP with 0. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28xfs: remove unused header filesEric Sandeen
There are many, many xfs header files which are included but unneeded (or included twice) in the xfs code, so remove them. nb: xfs_linux.h includes about 9 headers for everyone, so those explicit includes get removed by this. I'm not sure what the preference is, but if we wanted explicit includes everywhere, a followup patch could remove those xfs_*.h includes from xfs_linux.h and move them into the files that need them. Or it could be left as-is. Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02xfs: pass transaction to xfs_defer_add()Brian Foster
The majority of remaining references to struct xfs_defer_ops in XFS are associated with xfs_defer_add(). At this point, there are no more external xfs_defer_ops users left. All instances of xfs_defer_ops are embedded in the transaction, which means we can safely pass the transaction down to the dfops add interface. Update xfs_defer_add() to receive the transaction as a parameter. Various subsystems implement wrappers to allocate and construct the context specific data structures for the associated deferred operation type. Update these to also carry the transaction down as needed and clean up unused dfops parameters along the way. This removes most of the remaining references to struct xfs_defer_ops throughout the code and facilitates removal of the structure. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> [darrick: fix unused variable warnings with ftrace disabled] Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02xfs: drop dop param from xfs_defer_op_type ->finish_item() callbackBrian Foster
The dfops infrastructure ->finish_item() callback passes the transaction and dfops as separate parameters. Since dfops is always part of a transaction, the latter parameter is no longer necessary. Remove it from the various callbacks. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: remove all boilerplate defer init/finish codeBrian Foster
At this point, the transaction subsystem completely manages deferred items internally such that the common and boilerplate xfs_trans_alloc() -> xfs_defer_init() -> xfs_defer_finish() -> xfs_trans_commit() sequence can be replaced with a simple transaction allocation and commit. Remove all such boilerplate deferred ops code. In doing so, we change each case over to use the dfops in the transaction and specifically eliminate: - The on-stack dfops and associated xfs_defer_init() call, as the internal dfops is initialized on transaction allocation. - xfs_bmap_finish() calls that precede a final xfs_trans_commit() of a transaction. - xfs_defer_cancel() calls in error handlers that precede a transaction cancel. The only deferred ops calls that remain are those that are non-deterministic with respect to the final commit of the associated transaction or are open-coded due to special handling. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Bill O'Donnell <billodo@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>
2018-07-23xfs: clean up xfs_btree_del_cursor callersDarrick J. Wong
Less trivial cleanups of the error argument to xfs_btree_del_cursor; these require some minor code refactoring. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-07-23xfs: trivial xfs_btree_del_cursor cleanupsDarrick J. Wong
The error argument to xfs_btree_del_cursor already understands the "nonzero for error" semantics, so remove pointless error testing in the callers and pass it directly. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-07-11xfs: remove xfs_defer_init() firstblock paramBrian Foster
All but one caller of xfs_defer_init() passes in the ->t_firstblock of the associated transaction. The one outlier is xlog_recover_process_intents(), which simply passes a dummy value because a valid pointer is required. This firstblock variable can simply be removed. At this point we could remove the xfs_defer_init() firstblock parameter and initialize ->t_firstblock directly. Even that is not necessary, however, because ->t_firstblock is automatically reinitialized in the new transaction on a transaction roll. Since xfs_defer_init() should never occur more than once on a particular transaction (since the corresponding finish will roll it), replace the reinit from xfs_defer_init() with an assert that verifies the transaction has a NULLFSBLOCK firstblock. 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>
2018-07-11xfs: replace no-op firstblock init with ->t_firstblockBrian Foster
xfs_refcount_recover_cow_leftovers() has no need for a firstblock variable and so passes an unrelated xfs_fsblock_t to xfs_defer_init() to avoid declaring one. Replace this no-op initialization with ->t_firstblock. This will be optimized away by the removal of the xfs_defer_init() firstblock param. 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>
2018-07-11xfs: refactor dfops init to attach to transactionBrian Foster
Most callers of xfs_defer_init() immediately attach the dfops structure to a transaction. Add a transaction parameter to eliminate much of this boilerplate code. This also helps self-document the fact that many codepaths now expect a dfops pointer implicitly via xfs_trans->t_dfops. 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>
2018-07-11xfs: use ->t_dfops in reflink cow recover pathBrian Foster
Use ->t_dfops of the leftover COW reservation cleanup transaction. 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>
2018-07-11xfs: remove unused btree cursor bc_private.a.dfops fieldBrian Foster
The xfs_btree_cur.bc_private.a.dfops field is only ever initialized by the refcountbt cursor init function. The only caller of that function with a non-NULL dfops is from deferred completion context, which already has attached to ->t_dfops. In addition to that, the only actual reference of a.dfops is the cursor duplication function, which means the field is effectively unused. Remove the dfops field from the bc_private.a union. Any future users can acquire the dfops from the transaction. This patch does not change behavior. 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>
2018-06-06xfs: convert to SPDX license tagsDave Chinner
Remove the verbose license text from XFS files and replace them with SPDX tags. This does not change the license of any of the code, merely refers to the common, up-to-date license files in LICENSES/ This change was mostly scripted. fs/xfs/Makefile and fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected and modified by the following command: for f in `git grep -l "GNU General" fs/xfs/` ; do echo $f cat $f | awk -f hdr.awk > $f.new mv -f $f.new $f done And the hdr.awk script that did the modification (including detecting the difference between GPL-2.0 and GPL-2.0+ licenses) is as follows: $ cat hdr.awk BEGIN { hdr = 1.0 tag = "GPL-2.0" str = "" } /^ \* This program is free software/ { hdr = 2.0; next } /any later version./ { tag = "GPL-2.0+" next } /^ \*\// { if (hdr > 0.0) { print "// SPDX-License-Identifier: " tag print str print $0 str="" hdr = 0.0 next } print $0 next } /^ \* / { if (hdr > 1.0) next if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 next } /^ \*/ { if (hdr > 0.0) next print $0 next } // { if (hdr > 0.0) { if (str != "") str = str "\n" str = str $0 next } print $0 } END { } $ Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-06xfs: validate btree records on retrievalDave Chinner
So we don't check the validity of records as we walk the btree. When there are corrupt records in the free space btree (e.g. zero startblock/length or beyond EOAG) we just blindly use it and things go bad from there. That leads to assert failures on debug kernels like this: XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_alloc.c, line: 450 .... Call Trace: xfs_alloc_fixup_trees+0x368/0x5c0 xfs_alloc_ag_vextent_near+0x79a/0xe20 xfs_alloc_ag_vextent+0x1d3/0x330 xfs_alloc_vextent+0x5e9/0x870 Or crashes like this: XFS (loop0): xfs_buf_find: daddr 0x7fb28 out of range, EOFS 0x8000 ..... BUG: unable to handle kernel NULL pointer dereference at 00000000000000c8 .... Call Trace: xfs_bmap_add_extent_hole_real+0x67d/0x930 xfs_bmapi_write+0x934/0xc90 xfs_da_grow_inode_int+0x27e/0x2f0 xfs_dir2_grow_inode+0x55/0x130 xfs_dir2_sf_to_block+0x94/0x5d0 xfs_dir2_sf_addname+0xd0/0x590 xfs_dir_createname+0x168/0x1a0 xfs_rename+0x658/0x9b0 By checking that free space records pulled from the trees are within the valid range, we catch many of these corruptions before they can do damage. This is a generic btree record checking deficiency. We need to validate the records we fetch from all the different btrees before we use them to catch corruptions like this. This patch results in a corrupt record emitting an error message and returning -EFSCORRUPTED, and the higher layers catch that and abort: XFS (loop0): Size Freespace BTree record corruption in AG 0 detected! XFS (loop0): start block 0x0 block count 0x0 XFS (loop0): Internal error xfs_trans_cancel at line 1012 of file fs/xfs/xfs_trans.c. Caller xfs_create+0x42a/0x670 ..... Call Trace: dump_stack+0x85/0xcb xfs_trans_cancel+0x19f/0x1c0 xfs_create+0x42a/0x670 xfs_generic_create+0x1f6/0x2c0 vfs_create+0xf9/0x180 do_mknodat+0x1f9/0x210 do_syscall_64+0x5a/0x180 entry_SYSCALL_64_after_hwframe+0x49/0xbe ..... XFS (loop0): xfs_do_force_shutdown(0x8) called from line 1013 of file fs/xfs/xfs_trans.c. Return address = ffffffff81500868 XFS (loop0): Corruption of in-memory data detected. Shutting down filesystem Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-06-01xfs: fix error handling in xfs_refcount_insert()xfs-4.18-merge-2Dave Chinner
generic/475 fired an assert failure just after the filesystem was shut down: XFS: Assertion failed: fs_is_ok, file: fs/xfs/libxfs/xfs_refcount.c, line: 182 ..... Call Trace: xfs_refcount_insert+0x151/0x190 xfs_refcount_adjust_extents.constprop.11+0x9c/0x470 xfs_refcount_adjust.constprop.10+0xb0/0x270 xfs_refcount_finish_one+0x25a/0x420 xfs_trans_log_finish_refcount_update+0x2a/0x40 xfs_refcount_update_finish_item+0x35/0xa0 xfs_defer_finish+0x15e/0x4d0 xfs_reflink_remap_extent+0x1bc/0x610 xfs_reflink_remap_blocks+0x6e/0x280 xfs_reflink_remap_range+0x311/0x530 vfs_clone_file_range+0x119/0x200 .... If xfs_btree_insert() returns an error, the corruption check fires instead of passing the error back the caller. The corruption check should be after we've checked for an error, not before, thereby avoiding assert failures if the filesystem shuts down during a refcount btree record insert. Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-05-15xfs: add repair helpers for the reference count btreeDarrick J. Wong
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> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-05-15xfs: expose various functions to repair codeDarrick J. Wong
Expose various helpers that the repair code will want to use. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2018-04-09xfs: non-scrub - remove unused function parametersxfs-4.17-merge-2Eric Sandeen
Signed-off-by: Eric Sandeen <sandeen@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-01-17xfs: add scrub cross-referencing helpers for the refcount btreesDarrick J. Wong
Add a couple of functions to the refcount btrees that will be used to cross-reference metadata against the refcountbt. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-12-21xfs: queue deferred rmap ops for cow staging extent alloc/free in the right ↵Darrick J. Wong
order Under the deferred rmap operation scheme, there's a certain order in which the rmap deferred ops have to be queued to maintain integrity during log replay. For alloc/map operations that order is cui -> rui; for free/unmap operations that order is cui -> rui -> efi. However, the initial refcount code got the ordering wrong in the free side of things because it queued refcount free op and an EFI and the refcount free op queued a rmap free op, resulting in the order cui -> efi -> rui. If we fail before the efd finishes, the efi recovery will try to do a wildcard rmap removal and the subsequent rui will fail to find the rmap and blow up. This didn't ever happen due to other screws up in handling unknown owner rmap removals, but those other screw ups broke recovery in other ways, so fix the ordering to follow the intended rules. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2017-11-01xfs: move error injection tags into their own fileDarrick J. Wong
Move the error injection tag names into a libxfs header so that we can share it between kernel and userspace. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Dave Chinner <dchinner@redhat.com>
2017-09-01xfs: remove the ip argument to xfs_defer_finishChristoph Hellwig
And instead require callers to explicitly join the inode using xfs_defer_ijoin. Also consolidate the defer error handling in a few places using a goto label. 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>
2017-07-20xfs: check _alloc_read_agf buffer pointer before usingxfs-4.13-fixes-1Darrick J. Wong
In some circumstances, _alloc_read_agf can return an error code of zero but also a null AGF buffer pointer. Check for this and jump out. Fixes-coverity-id: 1415250 Fixes-coverity-id: 1415320 Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-06-27xfs: remove unneeded parameter from XFS_TEST_ERRORDarrick J. Wong
Since we moved the injected error frequency controls to the mountpoint, we can get rid of the last argument to XFS_TEST_ERROR. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-06-19xfs: try to avoid blowing out the transaction reservation when bunmaping a ↵Darrick J. Wong
shared extent In a pathological scenario where we are trying to bunmapi a single extent in which every other block is shared, it's possible that trying to unmap the entire large extent in a single transaction can generate so many EFIs that we overflow the transaction reservation. Therefore, use a heuristic to guess at the number of blocks we can safely unmap from a reflink file's data fork in an single transaction. This should prevent problems such as the log head slamming into the tail and ASSERTs that trigger because we've exceeded the transaction reservation. Note that since bunmapi can fail to unmap the entire range, we must also teach the deferred unmap code to roll into a new transaction whenever we get low on reservation. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: random edits, all bugs are my fault] Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-19xfs: avoid mount-time deadlock in CoW extent recoveryxfs-4.12-fixes-1Darrick J. Wong
If a malicious user corrupts the refcount btree to cause a cycle between different levels of the tree, the next mount attempt will deadlock in the CoW recovery routine while grabbing buffer locks. We can use the ability to re-grab a buffer that was previous locked to a transaction to avoid deadlocks, so do that here. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2016-10-10xfs: rework refcount cow recovery error handlingDarrick J. Wong
The error handling in xfs_refcount_recover_cow_leftovers is confused and can potentially leak memory, so rework it to release resources correctly on error. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-10-05xfs: store in-progress CoW allocations in the refcount btreeDarrick J. Wong
Due to the way the CoW algorithm in XFS works, there's an interval during which blocks allocated to handle a CoW can be lost -- if the FS goes down after the blocks are allocated but before the block remapping takes place. This is exacerbated by the cowextsz hint -- allocated reservations can sit around for a while, waiting to get used. Since the refcount btree doesn't normally store records with refcount of 1, we can use it to record these in-progress extents. In-progress blocks cannot be shared because they're not user-visible, so there shouldn't be any conflicts with other programs. This is a better solution than holding EFIs during writeback because (a) EFIs can't be relogged currently, (b) even if they could, EFIs are bound by available log space, which puts an unnecessary upper bound on how much CoW we can have in flight, and (c) we already have a mechanism to track blocks. At mount time, read the refcount records and free anything we find with a refcount of 1 because those were in-progress when the FS went down. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: introduce reflink utility functionsDarrick J. Wong
These functions will be used by the other reflink functions to find the maximum length of a range of shared blocks. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.coM> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: connect refcount adjust functions to upper layersDarrick J. Wong
Plumb in the upper level interface to schedule and finish deferred refcount operations via the deferred ops mechanism. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: adjust refcount of an extent of blocks in refcount btreeDarrick J. Wong
Provide functions to adjust the reference counts for an extent of physical blocks stored in the refcount btree. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Christoph Hellwig <hch@lst.de>
2016-10-03xfs: add refcount btree operationsDarrick J. Wong
Implement the generic btree operations required to manipulate refcount btree blocks. The implementation is similar to the bmapbt, though it will only allocate and free blocks from the AG. Since the refcount root and level fields are separate from the existing roots and levels array, they need a separate logging flag. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> [hch: fix logging of AGF refcount btree fields] Signed-off-by: Christoph Hellwig <hch@lst.de>