If two threads write-fault on the same hole at the same time, the winner
of the race will return to userspace and complete their store, only to
have the loser overwrite their store with zeroes. Fix this for now by
taking the i_mmap_sem for write instead of read, and do so outside the
call to get_block(). Now the loser of the race will see the block has
already been zeroed, and will not zero it again.
This severely limits our scalability. I have ideas for improving it, but
those can wait for a later patch.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara pointed out that in the case where we are writing to a hole, we
can end up with a lock inversion between the page lock and the journal
lock. We can avoid this by starting the transaction in ext4 before
calling into DAX. The journal lock nests inside the superblock
pagefault lock, so we have to duplicate that code from dax_fault, like
XFS does.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAX wants different semantics from any currently-existing ext4 get_block
callback. Unlike ext4_get_block_write(), it needs to honour the
'create' flag, and unlike ext4_get_block(), it needs to be able to
return unwritten extents. So introduce a new ext4_get_block_dax() which
has those semantics.
We could also change ext4_get_block_write() to honour the 'create' flag,
but that might have consequences on other users that I do not currently
understand.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kara pointed out I should be more explicit here about the perils of
racing against truncate. The comment is mostly the same as for the PTE
case.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
DAX relies on the get_block function either zeroing newly allocated
blocks before they're findable by subsequent calls to get_block, or
marking newly allocated blocks as unwritten. ext4_get_block() cannot
create unwritten extents, but ext4_get_block_write() can.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Reported-by: Andy Rudoff <andy.rudoff@intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use DAX to provide support for huge pages.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use DAX to provide support for huge pages.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use DAX to provide support for huge pages.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the support code for DAX-enabled filesystems to allow them to
provide huge pages in response to faults.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In order to handle the !CONFIG_TRANSPARENT_HUGEPAGES case, we need to
return VM_FAULT_FALLBACK from the inlined dax_pmd_fault(), which is
defined in linux/mm.h. Given that we don't want to include <linux/mm.h>
in <linux/fs.h>, the easiest solution is to move the DAX-related
functions to a new header, <linux/dax.h>. We could also have moved
VM_FAULT_* definitions to a new header, or a different header that isn't
quite such a boil-the-ocean header as <linux/mm.h>, but this felt like
the best option.
Signed-off-by: Matthew Wilcox <willy@linux.intel.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Highlights include:
Stable patches:
- Fix atomicity of pNFS commit list updates
- Fix NFSv4 handling of open(O_CREAT|O_EXCL|O_RDONLY)
- nfs_set_pgio_error sometimes misses errors
- Fix a thinko in xs_connect()
- Fix borkage in _same_data_server_addrs_locked()
- Fix a NULL pointer dereference of migration recovery ops for v4.2 client
- Don't let the ctime override attribute barriers.
- Revert "NFSv4: Remove incorrect check in can_open_delegated()"
- Ensure flexfiles pNFS driver updates the inode after write finishes
- flexfiles must not pollute the attribute cache with attrbutes from the DS
- Fix a protocol error in layoutreturn
- Fix a protocol issue with NFSv4.1 CLOSE stateids
Bugfixes + cleanups
- pNFS blocks bugfixes from Christoph
- Various cleanups from Anna
- More fixes for delegation corner cases
- Don't fsync twice for O_SYNC/IS_SYNC files
- Fix pNFS and flexfiles layoutstats bugs
- pnfs/flexfiles: avoid duplicate tracking of mirror data
- pnfs: Fix layoutget/layoutreturn/return-on-close serialisation issues.
- pnfs/flexfiles: error handling retries a layoutget before fallback to MDS
Features:
- Full support for the OPEN NFS4_CREATE_EXCLUSIVE4_1 mode from Kinglong
- More RDMA client transport improvements from Chuck
- Removal of the deprecated ib_reg_phys_mr() and ib_rereg_phys_mr() verbs
from the SUNRPC, Lustre and core infiniband tree.
- Optimise away the close-to-open getattr if there is no cached data
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Merge tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Stable patches:
- Fix atomicity of pNFS commit list updates
- Fix NFSv4 handling of open(O_CREAT|O_EXCL|O_RDONLY)
- nfs_set_pgio_error sometimes misses errors
- Fix a thinko in xs_connect()
- Fix borkage in _same_data_server_addrs_locked()
- Fix a NULL pointer dereference of migration recovery ops for v4.2
client
- Don't let the ctime override attribute barriers.
- Revert "NFSv4: Remove incorrect check in can_open_delegated()"
- Ensure flexfiles pNFS driver updates the inode after write finishes
- flexfiles must not pollute the attribute cache with attrbutes from
the DS
- Fix a protocol error in layoutreturn
- Fix a protocol issue with NFSv4.1 CLOSE stateids
Bugfixes + cleanups
- pNFS blocks bugfixes from Christoph
- Various cleanups from Anna
- More fixes for delegation corner cases
- Don't fsync twice for O_SYNC/IS_SYNC files
- Fix pNFS and flexfiles layoutstats bugs
- pnfs/flexfiles: avoid duplicate tracking of mirror data
- pnfs: Fix layoutget/layoutreturn/return-on-close serialisation
issues
- pnfs/flexfiles: error handling retries a layoutget before fallback
to MDS
Features:
- Full support for the OPEN NFS4_CREATE_EXCLUSIVE4_1 mode from
Kinglong
- More RDMA client transport improvements from Chuck
- Removal of the deprecated ib_reg_phys_mr() and ib_rereg_phys_mr()
verbs from the SUNRPC, Lustre and core infiniband tree.
- Optimise away the close-to-open getattr if there is no cached data"
* tag 'nfs-for-4.3-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (108 commits)
NFSv4: Respect the server imposed limit on how many changes we may cache
NFSv4: Express delegation limit in units of pages
Revert "NFS: Make close(2) asynchronous when closing NFS O_DIRECT files"
NFS: Optimise away the close-to-open getattr if there is no cached data
NFSv4.1/flexfiles: Clean up ff_layout_write_done_cb/ff_layout_commit_done_cb
NFSv4.1/flexfiles: Mark the layout for return in ff_layout_io_track_ds_error()
nfs: Remove unneeded checking of the return value from scnprintf
nfs: Fix truncated client owner id without proto type
NFSv4.1/flexfiles: Mark layout for return if the mirrors are invalid
NFSv4.1/flexfiles: RW layouts are valid only if all mirrors are valid
NFSv4.1/flexfiles: Fix incorrect usage of pnfs_generic_mark_devid_invalid()
NFSv4.1/flexfiles: Fix freeing of mirrors
NFSv4.1/pNFS: Don't request a minimal read layout beyond the end of file
NFSv4.1/pnfs: Handle LAYOUTGET return values correctly
NFSv4.1/pnfs: Don't ask for a read layout for an empty file.
NFSv4.1: Fix a protocol issue with CLOSE stateids
NFSv4.1/flexfiles: Don't mark the entire deviceid as bad for file errors
SUNRPC: Prevent SYN+SYNACK+RST storms
SUNRPC: xs_reset_transport must mark the connection as disconnected
NFSv4.1/pnfs: Ensure layoutreturn reserves space for the opaque payload
...
This update contains:
o large rework of EFI/EFD lifecycle handling to fix log recovery corruption
issues, crashes and unmount hangs
o separate metadata UUID on disk to enable changing boot label UUID for v5
filesystems
o fixes for gcc miscompilation on certain platforms and optimisation levels
o remote attribute allocation and recovery corruption fixes
o inode lockdep annotation rework to fix bugs with too many subclasses
o directory inode locking changes to prevent lockdep false positives
o a handful of minor corruption fixes
o various other small cleanups and bug fixes
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Merge tag 'xfs-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs
Pull xfs updates from Dave Chinner:
"There isn't a whole lot to this update - it's mostly bug fixes and
they are spread pretty much all over XFS. There are some corruption
fixes, some fixes for log recovery, some fixes that prevent unount
from hanging, a lockdep annotation rework for inode locking to prevent
false positives and the usual random bunch of cleanups and minor
improvements.
Deatils:
- large rework of EFI/EFD lifecycle handling to fix log recovery
corruption issues, crashes and unmount hangs
- separate metadata UUID on disk to enable changing boot label UUID
for v5 filesystems
- fixes for gcc miscompilation on certain platforms and optimisation
levels
- remote attribute allocation and recovery corruption fixes
- inode lockdep annotation rework to fix bugs with too many
subclasses
- directory inode locking changes to prevent lockdep false positives
- a handful of minor corruption fixes
- various other small cleanups and bug fixes"
* tag 'xfs-for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: (42 commits)
xfs: fix error gotos in xfs_setattr_nonsize
xfs: add mssing inode cache attempts counter increment
xfs: return errors from partial I/O failures to files
libxfs: bad magic number should set da block buffer error
xfs: fix non-debug build warnings
xfs: collapse allocsize and biosize mount option handling
xfs: Fix file type directory corruption for btree directories
xfs: lockdep annotations throw warnings on non-debug builds
xfs: Fix uninitialized return value in xfs_alloc_fix_freelist()
xfs: inode lockdep annotations broke non-lockdep build
xfs: flush entire file on dio read/write to cached file
xfs: Fix xfs_attr_leafblock definition
libxfs: readahead of dir3 data blocks should use the read verifier
xfs: stop holding ILOCK over filldir callbacks
xfs: clean up inode lockdep annotations
xfs: swap leaf buffer into path struct atomically during path shift
xfs: relocate sparse inode mount warning
xfs: dquots should be stamped with sb_meta_uuid
xfs: log recovery needs to validate against sb_meta_uuid
xfs: growfs not aware of sb_meta_uuid
...
The NFSv4 delegation spec allows the server to tell a client to limit how
much data it cache after the file is closed. In return, the server
guarantees enough free space to avoid ENOSPC situations, etc.
Prior to this patch, we assumed we could always cache aggressively after
close. Unfortunately, this causes problems with servers that set the
limit to 0 and therefore do not offer any ENOSPC guarantees.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Since we're tracking modifications to the page cache on a per-page
basis, it makes sense to express the limit to how much we may cache
in units of pages.
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Pull vfs updates from Al Viro:
"In this one:
- d_move fixes (Eric Biederman)
- UFS fixes (me; locking is mostly sane now, a bunch of bugs in error
handling ought to be fixed)
- switch of sb_writers to percpu rwsem (Oleg Nesterov)
- superblock scalability (Josef Bacik and Dave Chinner)
- swapon(2) race fix (Hugh Dickins)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (65 commits)
vfs: Test for and handle paths that are unreachable from their mnt_root
dcache: Reduce the scope of i_lock in d_splice_alias
dcache: Handle escaped paths in prepend_path
mm: fix potential data race in SyS_swapon
inode: don't softlockup when evicting inodes
inode: rename i_wb_list to i_io_list
sync: serialise per-superblock sync operations
inode: convert inode_sb_list_lock to per-sb
inode: add hlist_fake to avoid the inode hash lock in evict
writeback: plug writeback at a high level
change sb_writers to use percpu_rw_semaphore
shift percpu_counter_destroy() into destroy_super_work()
percpu-rwsem: kill CONFIG_PERCPU_RWSEM
percpu-rwsem: introduce percpu_rwsem_release() and percpu_rwsem_acquire()
percpu-rwsem: introduce percpu_down_read_trylock()
document rwsem_release() in sb_wait_write()
fix the broken lockdep logic in __sb_start_write()
introduce __sb_writers_{acquired,release}() helpers
ufs_inode_get{frag,block}(): get rid of 'phys' argument
ufs_getfrag_block(): tidy up a bit
...
I've gotten several more over the past week, but this group has been
in for-next for at least a couple of weeks so I figured I'd push them
first while I test the rest. Most of the ones not in this set are
bug-fixes anyways so I could hold them for rc1 if you'd rather they
see more time in for-next.
-eric
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Merge tag 'for-linus-4.3-merge-window-part-1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs
Pull 9p updates from Eric Van Hensbergen:
"Just a few cleanups for 4.3 merge window for the 9p file system. I've
gotten several more over the past week, but this group has been in
for-next for at least a couple of weeks so I figured I'd push them
first while I test the rest.
Most of the ones not in this set are bug-fixes anyways so I could hold
them for rc1"
* tag 'for-linus-4.3-merge-window-part-1' of git://git.kernel.org/pub/scm/linux/kernel/git/ericvh/v9fs:
9p: fix return code of read() when count is 0
9p: remove unused option Opt_trans
- Add Jeff Layton as an nfsd co-maintainer: no change to
existing practice, just an acknowledgement of the status quo.
- Two patches ("nfsd: ensure that...") for a race overlooked by
the state locking rewrite, causing a crash noticed by multiple
users.
- Lots of smaller bugfixes all over from Kinglong Mee.
- From Jeff, some cleanup of server rpc code in preparation for
possible shift of nfsd threads to workqueues.
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Merge tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linux
Pull nfsd updates from Bruce Fields:
"Nothing major, but:
- Add Jeff Layton as an nfsd co-maintainer: no change to existing
practice, just an acknowledgement of the status quo.
- Two patches ("nfsd: ensure that...") for a race overlooked by the
state locking rewrite, causing a crash noticed by multiple users.
- Lots of smaller bugfixes all over from Kinglong Mee.
- From Jeff, some cleanup of server rpc code in preparation for
possible shift of nfsd threads to workqueues"
* tag 'nfsd-4.3' of git://linux-nfs.org/~bfields/linux: (52 commits)
nfsd: deal with DELEGRETURN racing with CB_RECALL
nfsd: return CLID_INUSE for unexpected SETCLIENTID_CONFIRM case
nfsd: ensure that delegation stateid hash references are only put once
nfsd: ensure that the ol stateid hash reference is only put once
net: sunrpc: fix tracepoint Warning: unknown op '->'
nfsd: allow more than one laundry job to run at a time
nfsd: don't WARN/backtrace for invalid container deployment.
fs: fix fs/locks.c kernel-doc warning
nfsd: Add Jeff Layton as co-maintainer
NFSD: Return word2 bitmask if setting security label in OPEN/CREATE
NFSD: Set the attributes used to store the verifier for EXCLUSIVE4_1
nfsd: SUPPATTR_EXCLCREAT must be encoded before SECURITY_LABEL.
nfsd: Fix an FS_LAYOUT_TYPES/LAYOUT_TYPES encode bug
NFSD: Store parent's stat in a separate value
nfsd: Fix two typos in comments
lockd: NLM grace period shouldn't block NFSv4 opens
nfsd: include linux/nfs4.h in export.h
sunrpc: Switch to using hash list instead single list
sunrpc/nfsd: Remove redundant code by exports seq_operations functions
sunrpc: Store cache_detail in seq_file's private directly
...
Pull btrfs updates from Chris Mason:
"This has Jeff Mahoney's long standing trim patch that fixes corners
where trims were missing. Omar has some raid5/6 fixes, especially for
using scrub and device replace when devices are missing.
Zhao Lie continues cleaning and fixing things, this series fixes some
really hard to hit corners in xfstests. I had to pull it last merge
window due to some deadlocks, but those are now resolved.
I added support for Tejun's new blkio controllers. It seems to work
well for single devices, we'll expand to multi-device as well"
* 'for-linus-4.3' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (47 commits)
btrfs: fix compile when block cgroups are not enabled
Btrfs: fix file read corruption after extent cloning and fsync
Btrfs: check if previous transaction aborted to avoid fs corruption
btrfs: use __GFP_NOFAIL in alloc_btrfs_bio
btrfs: Prevent from early transaction abort
btrfs: Remove unused arguments in tree-log.c
btrfs: Remove useless condition in start_log_trans()
Btrfs: add support for blkio controllers
Btrfs: remove unused mutex from struct 'btrfs_fs_info'
Btrfs: fix parity scrub of RAID 5/6 with missing device
Btrfs: fix device replace of a missing RAID 5/6 device
Btrfs: add RAID 5/6 BTRFS_RBIO_REBUILD_MISSING operation
Btrfs: count devices correctly in readahead during RAID 5/6 replace
Btrfs: remove misleading handling of missing device scrub
btrfs: fix clone / extent-same deadlocks
Btrfs: fix defrag to merge tail file extent
Btrfs: fix warning in backref walking
btrfs: Add WARN_ON() for double lock in btrfs_tree_lock()
btrfs: Remove root argument in extent_data_ref_count()
btrfs: Fix wrong comment of btrfs_alloc_tree_block()
...
vma->vm_ops->mremap() looks more natural and clean in move_vma(), and this
way ->mremap() can have more users. Say, vdso.
While at it, s/aio_ring_remap/aio_ring_mremap/.
Note: this is the minimal change before ->mremap() finds another user in
file_operations; this method should have more arguments, and it can be
used to kill arch_remap().
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Laurent Dufour <ldufour@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
During the refile in userfaultfd_read both waitqueues could look empty to
the lockless wake_userfault(). Use a seqcount to prevent this false
negative that could leave an userfault blocked.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is only simple to achieve if the userfault is going to return to
userland (not to the kernel) because we can avoid returning VM_FAULT_RETRY
despite we temporarily released the mmap_sem. The fault would just be
retried by userland then. This is safe at least on x86 and powerpc (the
two archs with the syscall implemented so far).
Hint to verify for which archs this is safe: after handle_mm_fault
returns, no access to data structures protected by the mmap_sem must be
done by the fault code in arch/*/mm/fault.c until up_read(&mm->mmap_sem)
is called.
This has two main benefits: signals can run with lower latency in
production (signals aren't blocked by userfaults and userfaults are
immediately repeated after signal processing) and gdb can then trivially
debug the threads blocked in this kind of userfaults coming directly from
userland.
On a side note: while gdb has a need to get signal processed, coredumps
always worked perfectly with userfaults, no matter if the userfault is
triggered by GUP a kernel copy_user or directly from userland.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
UFFDIO_API was already forced before read/poll could work. This makes the
code more strict to force it also for all other ioctls.
All users would already have been required to call UFFDIO_API before
invoking other ioctls but this makes it more explicit.
This will ensure we can change all ioctls (all but UFFDIO_API/struct
uffdio_api) with a bump of uffdio_api.api.
There's no actual plan or need to change the API or the ioctl, the current
API already should cover fine even the non cooperative usage, but this is
just for the longer term future just in case.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These two ioctl allows to either atomically copy or to map zeropages
into the virtual address space. This is used by the thread that opened
the userfaultfd to resolve the userfaults.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This allows to select the userfaultfd during configuration to build it.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Solve in-kernel the race between UFFDIO_COPY|ZEROPAGE and
userfaultfd_read if they are run on different threads simultaneously.
Until now qemu solved the race in userland: the race was explicitly
and intentionally left for userland to solve. However we can also
solve it in kernel.
Requiring all users to solve this race if they use two threads (one
for the background transfer and one for the userfault reads) isn't
very attractive from an API prospective, furthermore this allows to
remove a whole bunch of mutex and bitmap code from qemu, making it
faster. The cost of __get_user_pages_fast should be insignificant
considering it scales perfectly and the pagetables are already hot in
the CPU cache, compared to the overhead in userland to maintain those
structures.
Applying this patch is backwards compatible with respect to the
userfaultfd userland API, however reverting this change wouldn't be
backwards compatible anymore.
Without this patch qemu in the background transfer thread, has to read
the old state, and do UFFDIO_WAKE if old_state is missing but it
become REQUESTED by the time it tries to set it to RECEIVED (signaling
the other side received an userfault).
vcpu background_thr userfault_thr
----- ----- -----
vcpu0 handle_mm_fault()
postcopy_place_page
read old_state -> MISSING
UFFDIO_COPY 0x7fb76a139000 (no wakeup, still pending)
vcpu0 fault at 0x7fb76a139000 enters handle_userfault
poll() is kicked
poll() -> POLLIN
read() -> 0x7fb76a139000
postcopy_pmi_change_state(MISSING, REQUESTED) -> REQUESTED
tmp_state = postcopy_pmi_change_state(old_state, RECEIVED) -> REQUESTED
/* check that no userfault raced with UFFDIO_COPY */
if (old_state == MISSING && tmp_state == REQUESTED)
UFFDIO_WAKE from background thread
And a second case where a UFFDIO_WAKE would be needed is in the userfault thread:
vcpu background_thr userfault_thr
----- ----- -----
vcpu0 handle_mm_fault()
postcopy_place_page
read old_state -> MISSING
UFFDIO_COPY 0x7fb76a139000 (no wakeup, still pending)
tmp_state = postcopy_pmi_change_state(old_state, RECEIVED) -> RECEIVED
vcpu0 fault at 0x7fb76a139000 enters handle_userfault
poll() is kicked
poll() -> POLLIN
read() -> 0x7fb76a139000
if (postcopy_pmi_change_state(MISSING, REQUESTED) == RECEIVED)
UFFDIO_WAKE from userfault thread
This patch removes the need of both UFFDIO_WAKE and of the associated
per-page tristate as well.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This makes read O(1) and poll that was already O(1) becomes lockless.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is an optimization but it's a userland visible one and it affects
the API.
The downside of this optimization is that if you call poll() and you
get POLLIN, read(ufd) may still return -EAGAIN. The blocked userfault
may be waken by a different thread, before read(ufd) comes
around. This in short means that poll() isn't really usable if the
userfaultfd is opened in blocking mode.
userfaults won't wait in "pending" state to be read anymore and any
UFFDIO_WAKE or similar operations that has the objective of waking
userfaults after their resolution, will wake all blocked userfaults
for the resolved range, including those that haven't been read() by
userland yet.
The behavior of poll() becomes not standard, but this obviates the
need of "spurious" UFFDIO_WAKE and it lets the userland threads to
restart immediately without requiring an UFFDIO_WAKE. This is even
more significant in case of repeated faults on the same address from
multiple threads.
This optimization is justified by the measurement that the number of
spurious UFFDIO_WAKE accounts for 5% and 10% of the total
userfaults for heavy workloads, so it's worth optimizing those away.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I had requests to return the full address (not the page aligned one) to
userland.
It's not entirely clear how the page offset could be relevant because
userfaults aren't like SIGBUS that can sigjump to a different place and it
actually skip resolving the fault depending on a page offset. There's
currently no real way to skip the fault especially because after a
UFFDIO_COPY|ZEROPAGE, the fault is optimized to be retried within the
kernel without having to return to userland first (not even self modifying
code replacing the .text that touched the faulting address would prevent
the fault to be repeated). Userland cannot skip repeating the fault even
more so if the fault was triggered by a KVM secondary page fault or any
get_user_pages or any copy-user inside some syscall which will return to
kernel code. The second time FAULT_FLAG_RETRY_NOWAIT won't be set leading
to a SIGBUS being raised because the userfault can't wait if it cannot
release the mmap_map first (and FAULT_FLAG_RETRY_NOWAIT is required for
that).
Still returning userland a proper structure during the read() on the uffd,
can allow to use the current UFFD_API for the future non-cooperative
extensions too and it looks cleaner as well. Once we get additional
fields there's no point to return the fault address page aligned anymore
to reuse the bits below PAGE_SHIFT.
The only downside is that the read() syscall will read 32bytes instead of
8bytes but that's not going to be measurable overhead.
The total number of new events that can be extended or of new future bits
for already shipped events, is limited to 64 by the features field of the
uffdio_api structure. If more will be needed a bump of UFFD_API will be
required.
[akpm@linux-foundation.org: use __packed]
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is (seems to be) the minimal thing that is required to unblock
standard uffd usage from the non-cooperative one. Now more bits can be
added to the features field indicating e.g. UFFD_FEATURE_FORK and others
needed for the latter use-case.
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Once an userfaultfd has been created and certain region of the process
virtual address space have been registered into it, the thread responsible
for doing the memory externalization can manage the page faults in
userland by talking to the kernel using the userfaultfd protocol.
poll() can be used to know when there are new pending userfaults to be
read (POLLIN).
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These two flags gets set in vma->vm_flags to tell the VM common code
if the userfaultfd is armed and in which mode (only tracking missing
faults, only tracking wrprotect faults or both). If neither flags is
set it means the userfaultfd is not armed on the vma.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Pavel Emelyanov <xemul@parallels.com>
Cc: Sanidhya Kashyap <sanidhya.gatech@gmail.com>
Cc: zhang.zhanghailiang@huawei.com
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Hugh Dickins <hughd@google.com>
Cc: Peter Feiner <pfeiner@google.com>
Cc: "Dr. David Alan Gilbert" <dgilbert@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: "Huangpeng (Peter)" <peter.huangpeng@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g. new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else. This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.
Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use
of "sudo" is something more sneaky:
$ BASE="ovl"
$ MNT="$BASE/mnt"
$ LOW="$BASE/lower"
$ UP="$BASE/upper"
$ WORK="$BASE/work/ 0 0
none /proc fuse.pwn user_id=1000"
$ mkdir -p "$LOW" "$UP" "$WORK"
$ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
$ cat /proc/mounts
none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
none /proc fuse.pwn user_id=1000 0 0
$ fusermount -u /proc
$ cat /proc/mounts
cat: /proc/mounts: No such file or directory
This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed. Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.
[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Acked-by: Jan Kara <jack@suse.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Cc: J. R. Okajima <hooanon05g@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NULL check before kfree is redundant and so clean them up.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These uses sometimes do and sometimes don't have '\n' terminations. Make
the uses consistently use '\n' terminations and remove the newline from
the functions.
Miscellanea:
o Coalesce formats
o Realign arguments
Signed-off-by: Joe Perches <joe@perches.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
While appending an extent to a file, it will call these functions:
ocfs2_insert_extent
-> call ocfs2_grow_tree() if there's no free rec
-> ocfs2_add_branch add a new branch to extent tree,
now rec[0] in the leaf of rightmost path is empty
-> ocfs2_do_insert_extent
-> ocfs2_rotate_tree_right
-> ocfs2_extend_rotate_transaction
-> jbd2_journal_restart if jbd2_journal_extend fail
-> ocfs2_insert_path
-> ocfs2_extend_trans
-> jbd2_journal_restart if jbd2_journal_extend fail
-> ocfs2_insert_at_leaf
-> ocfs2_et_update_clusters
Function jbd2_journal_restart() may be called and it may happened that
buffers dirtied in ocfs2_add_branch() are committed
while buffers dirtied in ocfs2_insert_at_leaf() and
ocfs2_et_update_clusters() are not.
So an empty rec[0] is left in rightmost path which will cause
read-only filesystem when call ocfs2_commit_truncate()
with the error message: "Inode %lu has an empty extent record".
This is not a serious problem, so remove the rightmost path when call
ocfs2_commit_truncate().
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1: After we call ocfs2_journal_access_di() in ocfs2_write_begin(),
jbd2_journal_restart() may also be called, in this function transaction
A's t_updates-- and obtains a new transaction B. If
jbd2_journal_commit_transaction() is happened to commit transaction A,
when t_updates==0, it will continue to complete commit and unfile
buffer.
So when jbd2_journal_dirty_metadata(), the handle is pointed a new
transaction B, and the buffer head's journal head is already freed,
jh->b_transaction == NULL, jh->b_next_transaction == NULL, it returns
EINVAL, So it triggers the BUG_ON(status).
thread 1 jbd2
ocfs2_write_begin jbd2_journal_commit_transaction
ocfs2_write_begin_nolock
ocfs2_start_trans
jbd2__journal_start(t_updates+1,
transaction A)
ocfs2_journal_access_di
ocfs2_write_cluster_by_desc
ocfs2_mark_extent_written
ocfs2_change_extent_flag
ocfs2_split_extent
ocfs2_extend_rotate_transaction
jbd2_journal_restart
(t_updates-1,transaction B) t_updates==0
__jbd2_journal_refile_buffer
(jh->b_transaction = NULL)
ocfs2_write_end
ocfs2_write_end_nolock
ocfs2_journal_dirty
jbd2_journal_dirty_metadata(bug)
ocfs2_commit_trans
2. In ext4, I found that: jbd2_journal_get_write_access() called by
ext4_write_end.
ext4_write_begin
ext4_journal_start
__ext4_journal_start_sb
ext4_journal_check_start
jbd2__journal_start
ext4_write_end
ext4_mark_inode_dirty
ext4_reserve_inode_write
ext4_journal_get_write_access
jbd2_journal_get_write_access
ext4_mark_iloc_dirty
ext4_do_update_inode
ext4_handle_dirty_metadata
jbd2_journal_dirty_metadata
3. So I think we should put ocfs2_journal_access_di before
ocfs2_journal_dirty in the ocfs2_write_end. and it works well after my
modification.
Signed-off-by: vicky <vicky.yangwenfang@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Zhangguanghui <zhang.guanghui@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
o2hb_elapsed_msecs computes the time taken for a disk heartbeat.
'struct timeval' variables are used to store start and end times. On
32-bit systems, the 'tv_sec' component of 'struct timeval' will overflow
in year 2038 and beyond.
This patch solves the overflow with the following:
1. Replace o2hb_elapsed_msecs using 'ktime_t' values to measure start
and end time, and built-in function 'ktime_ms_delta' to compute the
elapsed time. ktime_get_real() is used since the code prints out the
wallclock time.
2. Changes format string to print time as a single 64-bit nanoseconds
value ("%lld") instead of seconds and microseconds. This simplifies
the code since converting ktime_t to that format would need expensive
computation. However, the debug log string is less readable than the
previous format.
Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com>
Suggested by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
There is a race case between crashed dio and rm, which will lead to
OCFS2_VALID_FL not set read-only.
N1 N2
------------------------------------------------------------------------
dd with direct flag
rm file
crashed with an dio entry left
in orphan dir
clear OCFS2_VALID_FL in
ocfs2_remove_inode
recover N1 and read the corrupted inode,
and set filesystem read-only
So we skip the inode deletion this time and wait for dio entry recovered
first.
Signed-off-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The following case will lead to a lockres is freed but is still in use.
cat /sys/kernel/debug/o2dlm/locking_state dlm_thread
lockres_seq_start
-> lock dlm->track_lock
-> get resA
resA->refs decrease to 0,
call dlm_lockres_release,
and wait for "cat" unlock.
Although resA->refs is already set to 0,
increase resA->refs, and then unlock
lock dlm->track_lock
-> list_del_init()
-> unlock
-> free resA
In such a race case, invalid address access may occurs. So we should
delete list res->tracking before resA->refs decrease to 0.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This bug in mainline code is pointed out by Mark Fasheh. When
ocfs2_iop_set_acl() and ocfs2_iop_get_acl() are entered from VFS layer,
inode lock is not held. This seems to be regression from older kernels.
The patch is to fix that.
Orabug: 20189959
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
PID: 614 TASK: ffff882a739da580 CPU: 3 COMMAND: "ocfs2dc"
#0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d
#1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5
#2 [ffff882ecc375af0] oops_end at ffffffff815091d8
#3 [ffff882ecc375b20] die at ffffffff8101868b
#4 [ffff882ecc375b50] do_trap at ffffffff81508bb0
#5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5
#6 [ffff882ecc375c40] invalid_op at ffffffff815116fb
[exception RIP: ocfs2_ci_checkpointed+208]
RIP: ffffffffa0a7e940 RSP: ffff882ecc375cf0 RFLAGS: 00010002
RAX: 0000000000000001 RBX: 000000000000654b RCX: ffff8812dc83f1f8
RDX: 00000000000017d9 RSI: ffff8812dc83f1f8 RDI: ffffffffa0b2c318
RBP: ffff882ecc375d20 R8: ffff882ef6ecfa60 R9: ffff88301f272200
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffff
R13: ffff8812dc83f4f0 R14: 0000000000000000 R15: ffff8812dc83f1f8
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2]
#8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2]
#9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2]
#10 [ffff882ecc375e18] ocfs2_downconvert_thread_do_work at ffffffffa0a85445 [ocfs2]
#11 [ffff882ecc375e68] ocfs2_downconvert_thread at ffffffffa0a854de [ocfs2]
#12 [ffff882ecc375ee8] kthread at ffffffff81090da7
#13 [ffff882ecc375f48] kernel_thread_helper at ffffffff81511884
assert is tripped because the tran is not checkpointed and the lock level is PR.
Some time ago, chmod command had been executed. As result, the following call
chain left the inode cluster lock in PR state, latter on causing the assert.
system_call_fastpath
-> my_chmod
-> sys_chmod
-> sys_fchmodat
-> notify_change
-> ocfs2_setattr
-> posix_acl_chmod
-> ocfs2_iop_set_acl
-> ocfs2_set_acl
-> ocfs2_acl_set_mode
Here is how.
1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr)
1120 {
1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do.
..
1258 if (!status && attr->ia_valid & ATTR_MODE) {
1259 status = posix_acl_chmod(inode, inode->i_mode);
519 posix_acl_chmod(struct inode *inode, umode_t mode)
520 {
..
539 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS);
287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ...
288 {
289 return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL);
224 int ocfs2_set_acl(handle_t *handle,
225 struct inode *inode, ...
231 {
..
252 ret = ocfs2_acl_set_mode(inode, di_bh,
253 handle, mode);
168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ...
170 {
183 if (handle == NULL) {
>>> BUG: inode lock not held in ex at this point <<<
184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb),
185 OCFS2_INODE_UPDATE_CREDITS);
ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach
ocfs2_acl_set_mode.#181 and do trans, the inode cluster lock is not held in EX
mode (it should be). How this could have happended?
We are the lock master, were holding lock EX and have released it in
ocfs2_setattr.#1247. Note that there are no holders of this lock at
this point. Another node needs the lock in PR, and we downconvert from
EX to PR. So the inode lock is PR when do the trans in
ocfs2_acl_set_mode.#184. The trans stays in core (not flushed to disc).
Now another node want the lock in EX, downconvert thread gets kicked
(the one that tripped assert abovt), finds an unflushed trans but the
lock is not EX (it is PR). If the lock was at EX, it would have flushed
the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before
downconverting (to NULL) for the request.
ocfs2_setattr must not drop inode lock ex in this code path. If it
does, takes it again before the trans, say in ocfs2_set_acl, another
cluster node can get in between, execute another setattr, overwriting
the one in progress on this node, resulting in a mode acl size combo
that is a mix of the two.
Orabug: 20189959
Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently error handling in dlm_request_join is a little obscure, so
optimize it to promote readability.
If packet.code is invalid, reset it to JOIN_DISALLOW to keep it
meaningful. It only influences the log printing.
Signed-off-by: Norton.Zhu <norton.zhu@huawei.com>
Cc: Srinivas Eeda <srinivas.eeda@oracle.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When running dirop_fileop_racer we found a case that inode
can not removed.
Two nodes, say Node A and Node B, mount the same ocfs2 volume. Create
two dirs /race/1/ and /race/2/ in the filesystem.
Node A Node B
rm -r /race/2/
mv /race/1/ /race/2/
call ocfs2_unlink(), get
the EX mode of /race/2/
wait for B unlock /race/2/
decrease i_nlink of /race/2/ to 0,
and add inode of /race/2/ into
orphan dir, unlock /race/2/
got EX mode of /race/2/. because
/race/1/ is dir, so inc i_nlink
of /race/2/ and update into disk,
unlock /race/2/
because i_nlink of /race/2/
is not zero, this inode will
always remain in orphan dir
This patch fixes this case by test whether i_nlink of new dir is zero.
Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Joseph Qi <joseph.qi@huawei.com>
Cc: Xue jiufei <xuejiufei@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In ocfs2, ip_alloc_sem is used to protect allocation changes on the
node. In direct IO, we add ip_alloc_sem to protect date consistent
between direct-io and ocfs2_truncate_file race (buffer io use
ip_alloc_sem already). Although inode->i_mutex lock is used to avoid
concurrency of above situation, i think ip_alloc_sem is still needed
because protect allocation changes is significant.
Other filesystem like ext4 also uses rw_semaphore to protect data
consistent between get_block-vs-truncate race by other means, So
ip_alloc_sem in ocfs2 direct io is needed.
Signed-off-by: Weiwei Wang <wangww631@huawei.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
In case a validation fails, clear the rest of the buffers and return the
error to the calling function.
This also facilitates bubbling up the error originating from ocfs2_error
to calling functions.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Caveat: This may return -EROFS for a read case, which seems wrong. This
is happening even without this patch series though. Should we convert
EROFS to EIO?
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
OCFS2 is often used in high-availaibility systems. However, ocfs2
converts the filesystem to read-only at the drop of the hat. This may
not be necessary, since turning the filesystem read-only would affect
other running processes as well, decreasing availability.
This attempt is to add errors=continue, which would return the EIO to
the calling process and terminate furhter processing so that the
filesystem is not corrupted further. However, the filesystem is not
converted to read-only.
As a future plan, I intend to create a small utility or extend
fsck.ocfs2 to fix small errors such as in the inode. The input to the
utility such as the inode can come from the kernel logs so we don't have
to schedule a downtime for fixing small-enough errors.
The patch changes the ocfs2_error to return an error. The error
returned depends on the mount option set. If none is set, the default
is to turn the filesystem read-only.
Perhaps errors=continue is not the best option name. Historically it is
used for making an attempt to progress in the current process itself.
Should we call it errors=eio? or errors=killproc? Suggestions/Comments
welcome.
Sources are available at:
https://github.com/goldwynr/linux/tree/error-cont
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Disk inode deletion may be heavily delayed when one node unlink a file
after the same dentry is freed on another node(say N1) because of memory
shrink but inode is left in memory. This inode can only be freed while
N1 doing the orphan scan work.
However, N1 may skip orphan scan for several times because other nodes
may do the work earlier. In our tests, it may take 1 hour on 4 nodes
cluster and it hurts the user experience. So we think the inode should
be freed after the data flushed to disk when i_count becomes zero to
avoid such circumstances.
Signed-off-by: Joyce.xue <xuejiufei@huawei.com>
Cc: Joel Becker <jlbec@evilplan.org>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Matthew Wilcox