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2018-07-26xfs: bypass final dfops roll in trans commit pathBrian Foster
Once xfs_defer_finish() has completed all deferred operations, it checks the dirty state of the transaction and rolls it once more to return a clean transaction for the caller. This primarily to cover the case where repeated xfs_defer_finish() calls are made in a loop and we need to make sure that the caller starts the next iteration with a clean transaction. Otherwise we risk transaction reservation overrun. This final transaction roll is not required in the transaction commit path, however, because the transaction is immediately committed and freed after dfops completion. Refactor the final roll into a separate helper such that we can avoid it in the transaction commit path. Lift the dfops reset as well so dfops remains valid until after the last call to xfs_defer_trans_roll(). The reset is also unnecessary in the transaction commit path because the transaction is about to complete. This eliminates unnecessary regrants of transactions where the associated transaction roll can be replaced by a transaction commit. 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>
2018-07-26xfs: drop unnecessary xfs_defer_finish() dfops parameterBrian Foster
Every caller of xfs_defer_finish() now passes the transaction and its associated ->t_dfops. The xfs_defer_ops parameter is therefore no longer necessary and can be removed. Since most xfs_defer_finish() callers also have to consider xfs_defer_cancel() on error, update the latter to also receive the transaction for consistency. The log recovery code contains an outlier case that cancels a dfops directly without an available transaction. Retain an internal wrapper to support this outlier case for the time being. 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>
2018-07-26xfs: remove unnecessary dfops init calls in xattr codeBrian Foster
Each xfs_defer_init() call in the xattr code uses the internal dfops reference. In addition, a successful xfs_defer_finish() always returns with a reset xfs_defer_ops structure. Given that along with the fact that every xfs_defer_init() call in the xattr code is followed up by an xfs_defer_finish(), the former calls are no longer necessary and can be removed. Note that the xfs_defer_init() call in the remote value copy loop of xfs_attr_rmtval_set() is not followed by a finish, but the dfops is unused in this instance. 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>
2018-07-26xfs: 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>
2018-07-26xfs: use internal dfops during [b|c]ui recoveryBrian Foster
bmap and refcount intent processing associates a dfops from the caller with a local transaction to collect all deferred items for post-processing. Use the internal dfops in both of these functions and move the deferred items to the parent dfops before the transaction commits. 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>
2018-07-26xfs: use internal dfops in attr codeBrian Foster
Remove the unnecessary on-stack dfops structure and use the internal transaction dfops instead. The lower level xattr code already appropriately accesses ->t_dfops throughout. 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>
2018-07-26xfs: use internal dfops in cow blocks cancelBrian Foster
All callers either explicitly initialize a dfops or pass a transaction with an internal dfops. Drop the hacky old dfops replacement logic and use the one associated with the transaction. 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>
2018-07-26xfs: support embedded dfops in transactionBrian Foster
The dfops structure used by multi-transaction operations is typically stored on the stack and carried around by the associated transaction. The lifecycle of dfops does not quite match that of the transaction, but they are tightly related in that the former depends on the latter. The relationship of these objects is tight enough that we can avoid the cumbersome boilerplate code required in most cases to manage them separately by just embedding an xfs_defer_ops in the transaction itself. This means that a transaction allocation returns with an initialized dfops, a transaction commit finishes pending deferred items before the tx commit, a transaction cancel cancels the dfops before the transaction and a transaction dup operation transfers the current dfops state to the new transaction. The dup operation is slightly complicated by the fact that we can no longer just copy a dfops pointer from the old transaction to the new transaction. This is solved through a dfops move helper that transfers the pending items and other dfops state across the transactions. This also requires that transaction rolling code always refer to the transaction for the current dfops reference. Finally, to facilitate incremental conversion to the internal dfops and continue to support the current external dfops mode of operation, create the new ->t_dfops_internal field with a layer of indirection. On allocation, ->t_dfops points to the internal dfops. This state is overridden by callers who re-init a local dfops on the transaction. Once ->t_dfops is overridden, the external dfops reference is maintained as the transaction rolls. This patch adds the fundamental ability to support an internal dfops. All codepaths that perform deferred processing continue to override the internal dfops until they are converted over in subsequent patches. 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>
2018-07-26xfs: pack holes in xfs_defer_ops and xfs_transBrian Foster
Both structures have holes due to member alignment. Move dop_low to the end of xfs_defer ops to sanitize the cache line alignment and move t_flags to save 8 bytes in xfs_trans. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: reset dfops to initial state after finishBrian Foster
xfs_defer_init() is currently used in two particular situations. The first and most obvious case is raw initialization of an xfs_defer_ops struct. The other case is partial reinit of xfs_defer_ops on reuse due to iteration. Most instances of the first case will be replaced by a single init of a dfops embedded in the transaction. Init calls are still technically required for the second case because the dfops may have low space mode enabled or have joined items that need to be reset before the dfops should be reused. Since the current dfops usage expects either a final transaction commit after xfs_defer_finish() or xfs_defer_init() if dfops is to be reused, we can shift some of the init logic into xfs_defer_finish() such that the latter returns with a reinitialized dfops. This eliminates the second dependency noted above such that a dfops is immediately ready for reuse after an xfs_defer_finish() without the need to change any calling code. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: remove unused deferred ops committed fieldBrian Foster
dop_committed is set when deferred item processing rolls the transaction at least once, but is only ever accessed in tracepoints. The transaction roll/commit events are already available via independent tracepoints, so remove the otherwise unused field. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: make deferred processing safe for embedded dfopsBrian Foster
xfs_defer_finish() has a couple quirks that are not safe with respect to the upcoming internal dfops functionality. First, xfs_defer_finish() attaches the passed in dfops structure to ->t_dfops and caches and restores the original value. Second, it continues to use the initial dfops reference before and after the transaction roll. These behaviors assume that dop is an independent memory allocation from the transaction itself, which may not always be true once transactions begin to use an embedded dfops structure. In the latter model, dfops processing creates a new xfs_defer_ops structure with each transaction and the associated state is migrated across to the new transaction. Fix up xfs_defer_finish() to handle the possibility of the current dfops changing after a transaction roll. Since ->t_dfops is used unconditionally in this path, it is no longer necessary to attach/restore ->t_dfops and pass it explicitly down to xfs_defer_trans_roll(). Update dop in the latter function and the caller to ensure that it always refers to the current dfops structure. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: fix transaction leak on remote attr set/remove failureBrian Foster
The xattr remote value set/remove handlers both clear args.trans in the error path without having cancelled the transaction. This leaks the transaction, causes warnings around returning to userspace with locks held and leads to system lockups or other general problems. The higher level xfs_attr_[set|remove]() functions already detect and cancel args.trans when set in the error path. Drop the NULL assignments from the rmtval handlers and allow the callers to clean up the transaction correctly. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: use ->t_dfops in log recovery intent processingBrian Foster
xlog_finish_defer_ops() processes the deferred operations collected over the entire intent recovery sequence. We can't xfs_defer_init() here because the dfops is already populated. Attach it manually and eliminate the last caller of xfs_defer_finish() that doesn't pass ->t_dfops. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26xfs: pull up dfops from xfs_itruncate_extents()Brian Foster
xfs_itruncate_extents[_flags]() uses a local dfops with a transaction provided by the caller. It uses hacky ->t_dfops replacement logic to avoid stomping over an already populated ->t_dfops. The latter never occurs for current callers and the logic itself is not really appropriate. Clean this up by updating all callers to initialize a dfops and to use that down in xfs_itruncate_extents(). This more closely resembles the upcoming logic where dfops will be embedded within the transaction. We can also replace the xfs_defer_init() in the xfs_itruncate_extents_flags() loop with an assert. Both dfops and firstblock should be in a valid state after xfs_defer_finish() and the inode joined to the dfops is fixed throughout the loop. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Bill O'Donnell <billodo@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26fuse: reduce allocation size for splice_writeAndrey Ryabinin
The 'bufs' array contains 'pipe->buffers' elements, but the fuse_dev_splice_write() uses only 'pipe->nrbufs' elements. So reduce the allocation size to 'pipe->nrbufs' elements. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: use kvmalloc to allocate array of pipe_buffer structs.Andrey Ryabinin
The amount of pipe->buffers is basically controlled by userspace by fcntl(... F_SETPIPE_SZ ...) so it could be large. High order allocations could be slow (if memory is heavily fragmented) or may fail if the order is larger than PAGE_ALLOC_COSTLY_ORDER. Since the 'bufs' doesn't need to be physically contiguous, use the kvmalloc_array() to allocate memory. If high order page isn't available, the kvamalloc*() will fallback to 0-order. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: convert last timespec use to timespec64Arnd Bergmann
All of fuse uses 64-bit timestamps with the exception of the fuse_change_attributes(), so let's convert this one as well. Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fs: fuse: Adding new return type vm_fault_tSouptick Joarder
Use new return type vm_fault_t for fault handler in struct vm_operations_struct. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. commit 1c8f422059ae ("mm: change return type to vm_fault_t") Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: simplify fuse_abort_conn()Miklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: Add missed unlock_page() to fuse_readpages_fill()Kirill Tkhai
The above error path returns with page unlocked, so this place seems also to behave the same. Fixes: f8dbdf81821b ("fuse: rework fuse_readpages()") Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: Don't access pipe->buffers without pipe_lock()Andrey Ryabinin
fuse_dev_splice_write() reads pipe->buffers to determine the size of 'bufs' array before taking the pipe_lock(). This is not safe as another thread might change the 'pipe->buffers' between the allocation and taking the pipe_lock(). So we end up with too small 'bufs' array. Move the bufs allocations inside pipe_lock()/pipe_unlock() to fix this. Fixes: dd3bb14f44a6 ("fuse: support splice() writing to fuse device") Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: <stable@vger.kernel.org> # v2.6.35 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: fix initial parallel diropsMiklos Szeredi
If parallel dirops are enabled in FUSE_INIT reply, then first operation may leave fi->mutex held. Reported-by: syzbot <syzbot+3f7b29af1baa9d0a55be@syzkaller.appspotmail.com> Fixes: 5c672ab3f0ee ("fuse: serialize dirops by default") Cc: <stable@vger.kernel.org> # v4.7 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: Fix oops at process_init_reply()Miklos Szeredi
syzbot is hitting NULL pointer dereference at process_init_reply(). This is because deactivate_locked_super() is called before response for initial request is processed. Fix this by aborting and waiting for all requests (including FUSE_INIT) before resetting fc->sb. Original patch by Tetsuo Handa <penguin-kernel@I-love.SKAURA.ne.jp>. Reported-by: syzbot <syzbot+b62f08f4d5857755e3bc@syzkaller.appspotmail.com> Fixes: e27c9d3877a0 ("fuse: fuse: add time_gran to INIT_OUT") Cc: <stable@vger.kernel.org> # v3.19 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: umount should wait for all requestsMiklos Szeredi
fuse_abort_conn() does not guarantee that all async requests have actually finished aborting (i.e. their ->end() function is called). This could actually result in still used inodes after umount. Add a helper to wait until all requests are fully done. This is done by looking at the "num_waiting" counter. When this counter drops to zero, we can be sure that no more requests are outstanding. Fixes: 0d8e84b0432b ("fuse: simplify request abort") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: fix unlocked access to processing queueMiklos Szeredi
fuse_dev_release() assumes that it's the only one referencing the fpq->processing list, but that's not true, since fuse_abort_conn() can be doing the same without any serialization between the two. Fixes: c3696046beb3 ("fuse: separate pqueue for clones") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-26fuse: fix double request_end()Miklos Szeredi
Refcounting of request is broken when fuse_abort_conn() is called and request is on the fpq->io list: - ref is taken too late - then it is not dropped Fixes: 0d8e84b0432b ("fuse: simplify request abort") Cc: <stable@vger.kernel.org> # v4.2 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-07-25gfs2: Special-case rindex for gfs2_growAndreas Gruenbacher
To speed up the common case of appending to a file, gfs2_write_alloc_required presumes that writing beyond the end of a file will always require additional blocks to be allocated. This assumption is incorrect for preallocates files, but there are no negative consequences as long as *some* space is still left on the filesystem. One special file that always has some space preallocated beyond the end of the file is the rindex: when growing a filesystem, gfs2_grow adds one or more new resource groups and appends records describing those resource groups to the rindex; the preallocated space ensures that this is always possible. However, when a filesystem is completely full, gfs2_write_alloc_required will indicate that an additional allocation is required, and appending the next record to the rindex will fail even though space for that record has already been preallocated. To fix that, skip the incorrect optimization in gfs2_write_alloc_required, but for the rindex only. Other writes to preallocated space beyond the end of the file are still allowed to fail on completely full filesystems. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Bob Peterson <rpeterso@redhat.com>
2018-07-25Merge tag 'fscache-fixes-20180725' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull fscache/cachefiles fixes from David Howells: - Allow cancelled operations to be queued so they can be cleaned up. - Fix a refcounting bug in the monitoring of reads on backend files whereby a race can occur between monitor objects being listed for work, the work processing being queued and the work processor running and destroying the monitor objects. - Fix a ref overput in object attachment, whereby a tentatively considered object is put in error handling without first being 'got'. - Fix a missing clear of the CACHEFILES_OBJECT_ACTIVE flag whereby an assertion occurs when we retry because it seems the object is now active. - Wait rather BUG'ing on an object collision in the depths of cachefiles as the active object should be being cleaned up - also depends on the one above. * tag 'fscache-fixes-20180725' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: cachefiles: Wait rather than BUG'ing on "Unexpected object collision" cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flag fscache: Fix reference overput in fscache_attach_object() error handling cachefiles: Fix refcounting bug in backing-file read monitoring fscache: Allow cancelled operations to be enqueued
2018-07-25cachefiles: Wait rather than BUG'ing on "Unexpected object collision"Kiran Kumar Modukuri
If we meet a conflicting object that is marked FSCACHE_OBJECT_IS_LIVE in the active object tree, we have been emitting a BUG after logging information about it and the new object. Instead, we should wait for the CACHEFILES_OBJECT_ACTIVE flag to be cleared on the old object (or return an error). The ACTIVE flag should be cleared after it has been removed from the active object tree. A timeout of 60s is used in the wait, so we shouldn't be able to get stuck there. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25cachefiles: Fix missing clear of the CACHEFILES_OBJECT_ACTIVE flagKiran Kumar Modukuri
In cachefiles_mark_object_active(), the new object is marked active and then we try to add it to the active object tree. If a conflicting object is already present, we want to wait for that to go away. After the wait, we go round again and try to re-mark the object as being active - but it's already marked active from the first time we went through and a BUG is issued. Fix this by clearing the CACHEFILES_OBJECT_ACTIVE flag before we try again. Analysis from Kiran Kumar Modukuri: [Impact] Oops during heavy NFS + FSCache + Cachefiles CacheFiles: Error: Overlong wait for old active object to go away. BUG: unable to handle kernel NULL pointer dereference at 0000000000000002 CacheFiles: Error: Object already active kernel BUG at fs/cachefiles/namei.c:163! [Cause] In a heavily loaded system with big files being read and truncated, an fscache object for a cookie is being dropped and a new object being looked. The new object being looked for has to wait for the old object to go away before the new object is moved to active state. [Fix] Clear the flag 'CACHEFILES_OBJECT_ACTIVE' for the new object when retrying the object lookup. [Testcase] Have run ~100 hours of NFS stress tests and have not seen this bug recur. [Regression Potential] - Limited to fscache/cachefiles. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25fscache: Fix reference overput in fscache_attach_object() error handlingKiran Kumar Modukuri
When a cookie is allocated that causes fscache_object structs to be allocated, those objects are initialised with the cookie pointer, but aren't blessed with a ref on that cookie unless the attachment is successfully completed in fscache_attach_object(). If attachment fails because the parent object was dying or there was a collision, fscache_attach_object() returns without incrementing the cookie counter - but upon failure of this function, the object is released which then puts the cookie, whether or not a ref was taken on the cookie. Fix this by taking a ref on the cookie when it is assigned in fscache_object_init(), even when we're creating a root object. Analysis from Kiran Kumar: This bug has been seen in 4.4.0-124-generic #148-Ubuntu kernel BugLink: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1776277 fscache cookie ref count updated incorrectly during fscache object allocation resulting in following Oops. kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/internal.h:321! kernel BUG at /build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639! [Cause] Two threads are trying to do operate on a cookie and two objects. (1) One thread tries to unmount the filesystem and in process goes over a huge list of objects marking them dead and deleting the objects. cookie->usage is also decremented in following path: nfs_fscache_release_super_cookie -> __fscache_relinquish_cookie ->__fscache_cookie_put ->BUG_ON(atomic_read(&cookie->usage) <= 0); (2) A second thread tries to lookup an object for reading data in following path: fscache_alloc_object 1) cachefiles_alloc_object -> fscache_object_init -> assign cookie, but usage not bumped. 2) fscache_attach_object -> fails in cant_attach_object because the cookie's backing object or cookie's->parent object are going away 3) fscache_put_object -> cachefiles_put_object ->fscache_object_destroy ->fscache_cookie_put ->BUG_ON(atomic_read(&cookie->usage) <= 0); [NOTE from dhowells] It's unclear as to the circumstances in which (2) can take place, given that thread (1) is in nfs_kill_super(), however a conflicting NFS mount with slightly different parameters that creates a different superblock would do it. A backtrace from Kiran seems to show that this is a possibility: kernel BUG at/build/linux-Y09MKI/linux-4.4.0/fs/fscache/cookie.c:639! ... RIP: __fscache_cookie_put+0x3a/0x40 [fscache] Call Trace: __fscache_relinquish_cookie+0x87/0x120 [fscache] nfs_fscache_release_super_cookie+0x2d/0xb0 [nfs] nfs_kill_super+0x29/0x40 [nfs] deactivate_locked_super+0x48/0x80 deactivate_super+0x5c/0x60 cleanup_mnt+0x3f/0x90 __cleanup_mnt+0x12/0x20 task_work_run+0x86/0xb0 exit_to_usermode_loop+0xc2/0xd0 syscall_return_slowpath+0x4e/0x60 int_ret_from_sys_call+0x25/0x9f [Fix] Bump up the cookie usage in fscache_object_init, when it is first being assigned a cookie atomically such that the cookie is added and bumped up if its refcount is not zero. Remove the assignment in fscache_attach_object(). [Testcase] I have run ~100 hours of NFS stress tests and not seen this bug recur. [Regression Potential] - Limited to fscache/cachefiles. Fixes: ccc4fc3d11e9 ("FS-Cache: Implement the cookie management part of the netfs API") Signed-off-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-25cachefiles: Fix refcounting bug in backing-file read monitoringKiran Kumar Modukuri
cachefiles_read_waiter() has the right to access a 'monitor' object by virtue of being called under the waitqueue lock for one of the pages in its purview. However, it has no ref on that monitor object or on the associated operation. What it is allowed to do is to move the monitor object to the operation's to_do list, but once it drops the work_lock, it's actually no longer permitted to access that object. However, it is trying to enqueue the retrieval operation for processing - but it can only do this via a pointer in the monitor object, something it shouldn't be doing. If it doesn't enqueue the operation, the operation may not get processed. If the order is flipped so that the enqueue is first, then it's possible for the work processor to look at the to_do list before the monitor is enqueued upon it. Fix this by getting a ref on the operation so that we can trust that it will still be there once we've added the monitor to the to_do list and dropped the work_lock. The op can then be enqueued after the lock is dropped. The bug can manifest in one of a couple of ways. The first manifestation looks like: FS-Cache: FS-Cache: Assertion failed FS-Cache: 6 == 5 is false ------------[ cut here ]------------ kernel BUG at fs/fscache/operation.c:494! RIP: 0010:fscache_put_operation+0x1e3/0x1f0 ... fscache_op_work_func+0x26/0x50 process_one_work+0x131/0x290 worker_thread+0x45/0x360 kthread+0xf8/0x130 ? create_worker+0x190/0x190 ? kthread_cancel_work_sync+0x10/0x10 ret_from_fork+0x1f/0x30 This is due to the operation being in the DEAD state (6) rather than INITIALISED, COMPLETE or CANCELLED (5) because it's already passed through fscache_put_operation(). The bug can also manifest like the following: kernel BUG at fs/fscache/operation.c:69! ... [exception RIP: fscache_enqueue_operation+246] ... #7 [ffff883fff083c10] fscache_enqueue_operation at ffffffffa0b793c6 #8 [ffff883fff083c28] cachefiles_read_waiter at ffffffffa0b15a48 #9 [ffff883fff083c48] __wake_up_common at ffffffff810af028 I'm not entirely certain as to which is line 69 in Lei's kernel, so I'm not entirely clear which assertion failed. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") Reported-by: Lei Xue <carmark.dlut@gmail.com> Reported-by: Vegard Nossum <vegard.nossum@gmail.com> Reported-by: Anthony DeRobertis <aderobertis@metrics.net> Reported-by: NeilBrown <neilb@suse.com> Reported-by: Daniel Axtens <dja@axtens.net> Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Daniel Axtens <dja@axtens.net>
2018-07-25fscache: Allow cancelled operations to be enqueuedKiran Kumar Modukuri
Alter the state-check assertion in fscache_enqueue_operation() to allow cancelled operations to be given processing time so they can be cleaned up. Also fix a debugging statement that was requiring such operations to have an object assigned. Fixes: 9ae326a69004 ("CacheFiles: A cache that backs onto a mounted filesystem") Reported-by: Kiran Kumar Modukuri <kiran.modukuri@gmail.com> Signed-off-by: David Howells <dhowells@redhat.com>
2018-07-24Merge ra.kernel.org:/pub/scm/linux/kernel/git/davem/netDavid S. Miller
2018-07-25GFS2: rgrp free blocks used incorrectlyBob Peterson
Before this patch, several functions in rgrp.c checked the value of rgd->rd_free_clone. That does not take into account blocks that were reserved by a multi-block reservation. This causes a problem when space gets tight in the file system. For example, when function gfs2_inplace_reserve checks to see if a rgrp has enough blocks to satisfy the request, it can accept a rgrp that it should reject because, although there are enough blocks to satisfy the request _now_, those blocks may be reserved for another running process. A second problem with this occurs when we've reserved the remaining blocks in an rgrp: function rg_mblk_search() can reject an rgrp improperly because it calculates: u32 free_blocks = rgd->rd_free_clone - rgd->rd_reserved; But rd_reserved includes blocks that the current process just reserved in its own call to inplace_reserve. For example, it can reserve the last 128 blocks of an rgrp, then reject that same rgrp because the above calculates out to free_blocks = 0; Consequences include, but are not limited to, (1) leaving holes, and thus increasing file system fragmentation, and (2) reporting file system is full long before it actually is. This patch introduces a new function, rgd_free, which returns the number of clone-free blocks (blocks that are truly free as opposed to blocks that are still being used because an unlinked file is still open) minus the number of blocks reserved by processes, but not counting the blocks we ourselves reserved (because obviously we need to allocate them). Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-25gfs2: remove redundant variable 'moved'Colin Ian King
Variable 'moved' s being assigned but is never used hence it is redundant and can be removed. This has been the case ever since commit c752666c. Cleans up clang warning: warning: variable 'moved' set but not used [-Wunused-but-set-variable] Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-25gfs2: use iomap_readpage for blocksize == PAGE_SIZEAndreas Gruenbacher
We only use iomap_readpage for pages that don't have buffer heads attached yet: iomap_readpage would otherwise read pages from disk that are marked buffer_uptodate() but not PageUptodate(). Those pages may actually contain data more recent than what's on disk. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Bob Peterson <rpeterso@redhat.com>
2018-07-25gfs2: Use iomap for stuffed direct I/O readsAndreas Gruenbacher
Remove the fallback code from direct to buffered I/O for stuffed reads. For stuffed writes, we must keep the fallback code: the deferred glock we are holding under direct I/O doesn't allow to write to the inode or change the file size. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Bob Peterson <rpeterso@redhat.com>
2018-07-25Merge branch 'iomap-4.19-merge' into linux-gfs2/for-nextAndreas Gruenbacher
Merge xfs branch 'iomap-4.19-merge' into linux-gfs2/for-next. This brings in readpage and direct I/O support for inline data. The IOMAP_F_BUFFER_HEAD flag introduced in commit "iomap: add initial support for writes without buffer heads" needs to be set for gfs2 as well, so do that in the merge. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-25gfs2: fallocate_chunk: Always initialize struct iomapAndreas Gruenbacher
In fallocate_chunk, always initialize the iomap before calling gfs2_iomap_get_alloc: future changes could otherwise cause things like iomap.flags to leak across calls. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Reviewed-by: Bob Peterson <rpeterso@redhat.com>
2018-07-24fs/cifs: Simplify ib_post_(send|recv|srq_recv)() callsBart Van Assche
Instead of declaring and passing a dummy 'bad_wr' pointer, pass NULL as third argument to ib_post_(send|recv|srq_recv)(). Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>
2018-07-25GFS2: Fix recovery issues for spectatorsBob Peterson
This patch fixes a couple problems dealing with spectators who remain with gfs2 mounts after the last non-spectator node fails. Before this patch, spectator mounts would try to acquire the dlm's mounted lock EX as part of its normal recovery sequence. The mounted lock is only used to determine whether the node is the first mounter, the first node to mount the file system, for the purposes of file system recovery and journal replay. It's not necessary for spectators: they should never do journal recovery. If they acquire the lock it will prevent another "real" first-mounter from acquiring the lock in EX mode, which means it also cannot do journal recovery because it doesn't think it's the first node to mount the file system. This patch checks if the mounter is a spectator, and if so, avoids grabbing the mounted lock. This allows a secondary mounter who is really the first non-spectator mounter, to do journal recovery: since the spectator doesn't acquire the lock, it can grab it in EX mode, and therefore consider itself to be the first mounter both as a "real" first mount, and as a first-real-after-spectator. Note that the control lock still needs to be taken in PR mode in order to fetch the lvb value so it has the current status of all journal's recovery. This is used as it is today by a first mounter to replay the journals. For spectators, it's merely used to fetch the status bits. All recovery is bypassed and the node waits until recovery is completed by a non-spectator node. I also improved the cryptic message given by control_mount when a spectator is waiting for a non-spectator to perform recovery. It also fixes a problem in gfs2_recover_set whereby spectators were never queueing recovery work for their own journal. They cannot do recovery themselves, but they still need to queue the work so they can check the recovery bits and clear the DFL_BLOCK_LOCKS bit once the recovery happens on another node. When the work queue runs on a spectator, it bypasses most of the work so it won't print a bunch of annoying messages. All it will print is a bunch of messages that look like this until recovery completes on the non-spectator node: GFS2: fsid=mycluster:scratch.s: recover generation 3 jid 0 GFS2: fsid=mycluster:scratch.s: recover jid 0 result busy These continue every 1.5 seconds until the recovery is done by the non-spectator, at which time it says: GFS2: fsid=mycluster:scratch.s: recover generation 4 done Then it proceeds with its mount. If the file system is mounted in spectator node and the last remaining non-spectator is fenced, any IO to the file system is blocked by dlm and the spectator waits until recovery is performed by a non-spectator. If a spectator tries to mount the file system before any non-spectators, it blocks and repeatedly gives this kernel message: GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount. GFS2: fsid=mycluster:scratch: Recovery is required. Waiting for a non-spectator to mount. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-24exofs: use bio_clone_fast in _write_mirrorChristoph Hellwig
The mirroring code never changes the bio data or biovecs. This means we can reuse the biovec allocation easily instead of duplicating it. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by Boaz Harrosh <ooo@electrozaur.com> Reviewed-by: Ming Lei <ming.lei@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2018-07-24xfs: properly handle free inodes in extent hint validatorsEric Sandeen
When inodes are freed in xfs_ifree(), di_flags is cleared (so extent size hints are removed) but the actual extent size fields are left intact. This causes the extent hint validators to fail on freed inodes which once had extent size hints. This can be observed (for example) by running xfs/229 twice on a non-crc xfs filesystem, or presumably on V5 with ikeep. Fixes: 7d71a67 ("xfs: verify extent size hint is valid in inode verifier") Fixes: 02a0fda ("xfs: verify COW extent size hint is valid in inode verifier") 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>
2018-07-24Merge branch 'iomap-write' into linux-gfs2/for-nextAndreas Gruenbacher
Pull in the gfs2 iomap-write changes: Tweak the existing code to properly support iomap write and eliminate an unnecessary special case in gfs2_block_map. Implement iomap write support for buffered and direct I/O. Simplify some of the existing code and eliminate code that is no longer used: gfs2: Remove gfs2_write_{begin,end} gfs2: iomap direct I/O support gfs2: gfs2_extent_length cleanup gfs2: iomap buffered write support gfs2: Further iomap cleanups This is based on the following changes on the xfs 'iomap-4.19-merge' branch: iomap: add private pointer to struct iomap iomap: add a page_done callback iomap: generic inline data handling iomap: complete partial direct I/O writes synchronously iomap: mark newly allocated buffer heads as new fs: factor out a __generic_write_end helper Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-24fs: gfs2: Adding new return type vm_fault_tSouptick Joarder
Use new return type vm_fault_t for gfs2_page_mkwrite handler. see commit 1c8f422059ae ("mm: change return type to vm_fault_t") for reference. Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-24gfs2: using posix_acl_xattr_size instead of posix_acl_to_xattrChengguang Xu
It seems better to get size by calling posix_acl_xattr_size() instead of calling posix_acl_to_xattr() with NULL buffer argument. posix_acl_xattr_size() never returns 0, so remove the unnecessary check. Signed-off-by: Chengguang Xu <cgxu519@gmx.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-24gfs2: Don't reject a supposedly full bitmap if we have blocks reservedBob Peterson
Before this patch, you could get into situations like this: 1. Process 1 searches for X free blocks, finds them, makes a reservation 2. Process 2 searches for free blocks in the same rgrp, but now the bitmap is full because process 1's reservation is skipped over. So it marks the bitmap as GBF_FULL. 3. Process 1 tries to allocate blocks from its own reservation, but since the GBF_FULL bit is set, it skips over the rgrp and searches elsewhere, thus not using its own reservation. This patch adds an additional check to allow processes to use their own reservations. Signed-off-by: Bob Peterson <rpeterso@redhat.com> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2018-07-23filesystem-dax: Introduce dax_lock_mapping_entry()Dan Williams
In preparation for implementing support for memory poison (media error) handling via dax mappings, implement a lock_page() equivalent. Poison error handling requires rmap and needs guarantees that the page->mapping association is maintained / valid (inode not freed) for the duration of the lookup. In the device-dax case it is sufficient to simply hold a dev_pagemap reference. In the filesystem-dax case we need to use the entry lock. Export the entry lock via dax_lock_mapping_entry() that uses rcu_read_lock() to protect against the inode being freed, and revalidates the page->mapping association under xa_lock(). Cc: Christoph Hellwig <hch@lst.de> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Dave Jiang <dave.jiang@intel.com>