The dm_early_create() function (which deals with "dm-mod.create=" kernel
command line option) calls dm_hash_insert() who gets an extra reference
to the md object.
In case of failure, this reference wasn't being released, causing
dm_destroy() to hang, thus hanging the whole boot process.
Fix this by calling __hash_remove() in the error path.
Fixes: 6bbc923dfc ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Just some things that stood out like a sore thumb.
Also, converted some printk(KERN_CRIT, ...) to DMCRIT(...)
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Unfortunatelly, there may be bios coming even after the reboot notifier
was called. We don't want these bios to make the bitmap dirty again.
To address this, implement a synchronous mode - when a bio is about to
be terminated, we clean the bitmap and terminate the bio after the clean
operation succeeds. This obviously slows down bio processing, but it
makes sure that when all bios are finished, the bitmap will be clean.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When in bitmap mode the bitmap must be cleared when rebooting. This
commit adds the reboot hook.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce an alternate mode of operation where dm-integrity uses a
bitmap instead of a journal. If a bit in the bitmap is 1, the
corresponding region's data and integrity tags are not synchronized - if
the machine crashes, the unsynchronized regions will be recalculated.
The bitmap mode is faster than the journal mode, because we don't have
to write the data twice, but it is also less reliable, because if data
corruption happens when the machine crashes, it may not be detected.
Benchmark results for an SSD connected to a SATA300 port, when doing
large linear writes with dd:
buffered I/O:
raw device throughput - 245MB/s
dm-integrity with journaling - 120MB/s
dm-integrity with bitmap - 238MB/s
direct I/O with 1MB block size:
raw device throughput - 248MB/s
dm-integrity with journaling - 123MB/s
dm-integrity with bitmap - 223MB/s
For more info see dm-integrity in Documentation/device-mapper/
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce a function add_new_range_and_wait() in order to avoid
repetitive code. It will be used in the following commit.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Change n_sectors data type from unsigned to sector_t. Following commits
will need to lock large ranges.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Pass size to dm_integrity_alloc_page_list(). This is needed so
following commits can pass a size that is different from
ic->journal_pages.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Introduce a function rw_journal_sectors() that takes sector and length
as its arguments instead of a section and the number of sections.
This functions will be used in further patches.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Update documentation with the "meta_device" parameter and flags.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
If we are not journaling, don't report journaling options in the table
status.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The functions kfree, vfree and kvfree do nothing if we pass a NULL
pointer to them. So we don't need to test the pointer for NULL.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When we use separate devices for data and metadata, dm-integrity would
incorrectly calculate the size of the metadata device as if it had
512-byte block size - and it would refuse activation with larger block
size and smaller metadata device.
Fix this so that it takes actual block size into account, which fixes
the following reported issue:
https://gitlab.com/cryptsetup/cryptsetup/issues/450
Fixes: 356d9d52e1 ("dm integrity: allow separate metadata device")
Cc: stable@vger.kernel.org # v4.19+
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Fix sparse warnings:
drivers/md/dm-dust.c:495:12: warning: symbol 'dm_dust_init' was not declared. Should it be static?
drivers/md/dm-dust.c:505:13: warning: symbol 'dm_dust_exit' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Variable block is an unsigned long long hence the less than zero
comparison is always false, hence it is redundant and can be removed.
Addresses-Coverity: ("Unsigned compared against 0")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Bryan Gurney <bgurney@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit b592211c33 ("dm mpath: fix attached_handler_name leak and
dangling hw_handler_name pointer") fixed a memory leak for the case
where setup_scsi_dh() returns failure. But setup_scsi_dh may return
success and not "use" attached_handler_name if the
retain_attached_hwhandler flag is not set on the map. As setup_scsi_sh
properly "steals" the pointer by nullifying it, freeing it
unconditionally in parse_path() is safe.
Fixes: b592211c33 ("dm mpath: fix attached_handler_name leak and dangling hw_handler_name pointer")
Cc: stable@vger.kernel.org
Reported-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Martin Wilck <mwilck@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm-init should allow up to DM_MAX_{DEVICES,TARGETS} for devices/targets,
and not DM_MAX_{DEVICES,TARGETS} - 1.
Fix the checks and also fix the error message when the number of devices
is surpassed.
Fixes: 6bbc923dfc ("dm: add support to directly boot to a mapped device")
Cc: stable@vger.kernel.org
Signed-off-by: Helen Koike <helen.koike@collabora.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add the dm-dust target, which simulates the behavior of bad sectors
at arbitrary locations, and the ability to enable the emulation of
the read failures at an arbitrary time.
This target behaves similarly to a linear target. At a given time,
the user can send a message to the target to start failing read
requests on specific blocks. When the failure behavior is enabled,
reads of blocks configured "bad" will fail with EIO.
Writes of blocks configured "bad" will result in the following:
1. Remove the block from the "bad block list".
2. Successfully complete the write.
After this point, the block will successfully contain the written
data, and will service reads and writes normally. This emulates the
behavior of a "remapped sector" on a hard disk drive.
dm-dust provides logging of which blocks have been added or removed
to the "bad block list", as well as logging when a block has been
removed from the bad block list. These messages can be used
alongside the messages from the driver using a dm-dust device to
analyze the driver's behavior when a read fails at a given time.
(This logging can be reduced via a "quiet" mode, if desired.)
NOTE: If the block size is larger than 512 bytes, only the first sector
of each "dust block" is detected. Placing a limiting layer above a dust
target, to limit the minimum I/O size to the dust block size, will
ensure proper emulation of the given large block size.
Signed-off-by: Bryan Gurney <bgurney@redhat.com>
Co-developed-by: Joe Shimkus <jshimkus@redhat.com>
Co-developed-by: John Dorminy <jdorminy@redhat.com>
Co-developed-by: John Pittman <jpittman@redhat.com>
Co-developed-by: Thomas Jaskiewicz <tjaskiew@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
This is a small optimization in writecache_find_entry().
If we go past the condition "if (unlikely(!node))", we can be certain that
there is no entry in the tree that has the block equal to the "block"
variable.
Consequently, we can return the next entry directly, we don't need to go
to the second part of the function that finds the entry with lowest or
highest seq number that matches the "block" variable.
Also, add some whitespace and cleanup needless braces.
Suggested-by: Huaisheng Ye <yehs1@lenovo.com>
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The stucture member page_offset in writeback_struct never has been
used actually. Remove it.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When the target line contains an invalid device, delay_ctr() will call
delay_dtr() with NULL workqueue. Attempting to destroy the NULL
workqueue causes a crash.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
md->dax_dev defaults to NULL and there is no need to initialize it
if CONFIG_DAX_DRIVER is disabled.
Signed-off-by: Peng Wang <rocking@whu.edu.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
After commit 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via
blk_insert_cloned_request feedback"), map_request() will requeue the tio
when issued clone request return BLK_STS_RESOURCE or BLK_STS_DEV_RESOURCE.
Thus, if device driver status is error, a tio may be requeued multiple
times until the return value is not DM_MAPIO_REQUEUE. That means
type->start_io may be called multiple times, while type->end_io is only
called when IO complete.
In fact, even without commit 396eaf21ee, setup_clone() failure can
also cause tio requeue and associated missed call to type->end_io.
The service-time path selector selects path based on in_flight_size,
which is increased by st_start_io() and decreased by st_end_io().
Missed calls to st_end_io() can lead to in_flight_size count error and
will cause the selector to make the wrong choice. In addition,
queue-length path selector will also be affected.
To fix the problem, call type->end_io in ->release_clone_rq before tio
requeue. map_info is passed to ->release_clone_rq() for map_request()
error path that result in requeue.
Fixes: 396eaf21ee ("blk-mq: improve DM's blk-mq IO merging via blk_insert_cloned_request feedback")
Cc: stable@vger.kernl.org
Signed-off-by: Yufen Yu <yuyufen@huawei.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise, just activating a thin-pool and thin device and then
deactivating them will cause the thin-pool metadata to be changed
(e.g. superblock written) -- even without any metadata being changed.
Add 'in_service' flag to struct dm_pool_metadata and set it in
pmd_write_lock() because all on-disk metadata changes must take a write
lock of pmd->root_lock. Once 'in_service' is set it is never cleared.
__commit_transaction() will return 0 if 'in_service' is not set.
dm_pool_commit_metadata() is updated to use __pmd_write_lock() so that
it isn't the sole reason for putting a thin-pool in service.
Also fix dm_pool_commit_metadata() to open the next transaction if the
return from __commit_transaction() is 0. Not seeing why the early
return ever made since for a return of 0 given that dm-io's async_io(),
as used by bufio, always returns 0.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
No functional change, but this prepares to hook off of pmd_write_lock()
with additional functionality (as provided in next commit).
Suggested-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Otherwise, memory that is allocated (and potentially not previously
zeroed) will get written to disk as part of the space maps.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
In functions writecache_discard() and writecache_find_entry() there is a
high probablity that the pointer of structure rb_node won't equal NULL.
Add unlikely for the pointer node NULL.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
bio is already available so there is no need to access it in terms of
the wb pointer.
Signed-off-by: Huaisheng Ye <yehs1@lenovo.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Substitute the global locking scheme with a fine grained one, employing
the read-write semaphore and the scalable exception tables with
per-bucket locks introduced by the previous two commits.
Summarizing, we now use a read-write semaphore to protect the mostly
read fields of the snapshot structure, e.g., valid, active, etc., and
per-bucket bit spinlocks to protect accesses to the complete and pending
exception tables.
Finally, we use an extra spinlock (pe_allocation_lock) to serialize the
allocation of new exceptions by the exception store. This allocation is
really fast, so the extra spinlock doesn't hurt the performance.
This scheme allows dm-snapshot to scale better, resulting in increased
IOPS and reduced latency.
Following are some benchmark results using the null_blk device:
modprobe null_blk gb=1024 bs=512 submit_queues=8 hw_queue_depth=4096 \
queue_mode=2 irqmode=1 completion_nsec=1 nr_devices=1
* Benchmark fio_origin_randwrite_throughput_N, from the device mapper
test suite [1] (direct IO, random 4K writes to origin device, IO
engine libaio):
+--------------+-------------+------------+
| # of workers | IOPS Before | IOPS After |
+--------------+-------------+------------+
| 1 | 57708 | 66421 |
| 2 | 63415 | 77589 |
| 4 | 67276 | 98839 |
| 8 | 60564 | 109258 |
+--------------+-------------+------------+
* Benchmark fio_origin_randwrite_latency_N, from the device mapper test
suite [1] (direct IO, random 4K writes to origin device, IO engine
psync):
+--------------+-----------------------+----------------------+
| # of workers | Latency (usec) Before | Latency (usec) After |
+--------------+-----------------------+----------------------+
| 1 | 16.25 | 13.27 |
| 2 | 31.65 | 25.08 |
| 4 | 55.28 | 41.08 |
| 8 | 121.47 | 74.44 |
+--------------+-----------------------+----------------------+
* Benchmark fio_snapshot_randwrite_throughput_N, from the device mapper
test suite [1] (direct IO, random 4K writes to snapshot device, IO
engine libaio):
+--------------+-------------+------------+
| # of workers | IOPS Before | IOPS After |
+--------------+-------------+------------+
| 1 | 72593 | 84938 |
| 2 | 97379 | 134973 |
| 4 | 90610 | 143077 |
| 8 | 90537 | 180085 |
+--------------+-------------+------------+
* Benchmark fio_snapshot_randwrite_latency_N, from the device mapper
test suite [1] (direct IO, random 4K writes to snapshot device, IO
engine psync):
+--------------+-----------------------+----------------------+
| # of workers | Latency (usec) Before | Latency (usec) After |
+--------------+-----------------------+----------------------+
| 1 | 12.53 | 10.6 |
| 2 | 19.78 | 14.89 |
| 4 | 40.37 | 23.47 |
| 8 | 89.32 | 48.48 |
+--------------+-----------------------+----------------------+
[1] https://github.com/jthornber/device-mapper-test-suite
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Use list_bl to implement the exception hash tables' buckets. This change
permits concurrent access, to distinct buckets, by multiple threads.
Also, implement helper functions to lock and unlock the exception tables
based on the chunk number of the exception at hand.
We retain the global locking, by means of down_write(), which is
replaced by the next commit.
Still, we must acquire the per-bucket spinlocks when accessing the hash
tables, since list_bl does not allow modification on unlocked lists.
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
dm-snapshot uses a single mutex to serialize every access to the
snapshot state. This includes all accesses to the complete and pending
exception tables, which occur at every origin write, every snapshot
read/write and every exception completion.
The lock statistics indicate that this mutex is a bottleneck (average
wait time ~480 usecs for 8 processes doing random 4K writes to the
origin device) preventing dm-snapshot to scale as the number of threads
doing IO increases.
The major contention points are __origin_write()/snapshot_map() and
pending_complete(), i.e., the submission and completion of pending
exceptions.
Replace this mutex with a rw semaphore.
We essentially revert commit ae1093be5a ("dm snapshot: use mutex
instead of rw_semaphore") and together with the next two patches we
substitute the single mutex with a fine-grained locking scheme, where we
use a read-write semaphore to protect the mostly read fields of the
snapshot structure, e.g., valid, active, etc., and per-bucket bit
spinlocks to protect accesses to the complete and pending exception
tables.
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
When completing a pending exception, pending_complete() waits for all
conflicting reads to drain, before inserting the final, completed
exception. Conflicting reads are snapshot reads redirected to the
origin, because the relevant chunk is not remapped to the COW device the
moment we receive the read.
The completed exception must be inserted into the exception table after
all conflicting reads drain to ensure snapshot reads don't return
corrupted data. This is required because inserting the completed
exception into the exception table signals that the relevant chunk is
remapped and both origin writes and snapshot merging will now overwrite
the chunk in origin.
This wait is done holding the snapshot lock to ensure that
pending_complete() doesn't starve if new snapshot reads keep coming for
this chunk.
In preparation for the next commit, where we use a spinlock instead of a
mutex to protect the exception tables, we remove the need for holding
the lock while waiting for conflicting reads to drain.
We achieve this in two steps:
1. pending_complete() inserts the completed exception before waiting for
conflicting reads to drain and removes the pending exception after
all conflicting reads drain.
This ensures that new snapshot reads will be redirected to the COW
device, instead of the origin, and thus pending_complete() will not
starve. Moreover, we use the existence of both a completed and
a pending exception to signify that the COW is done but there are
conflicting reads in flight.
2. In __origin_write() we check first if there is a pending exception
and then if there is a completed exception. If there is a pending
exception any submitted BIO is delayed on the pe->origin_bios list and
DM_MAPIO_SUBMITTED is returned. This ensures that neither writes to the
origin nor snapshot merging can overwrite the origin chunk, until all
conflicting reads drain, and thus snapshot reads will not return
corrupted data.
Summarizing, we now have the following possible combinations of pending
and completed exceptions for a chunk, along with their meaning:
A. No exceptions exist: The chunk has not been remapped yet.
B. Only a pending exception exists: The chunk is currently being copied
to the COW device.
C. Both a pending and a completed exception exist: COW for this chunk
has completed but there are snapshot reads in flight which had been
redirected to the origin before the chunk was remapped.
D. Only the completed exception exists: COW has been completed and there
are no conflicting reads in flight.
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Acked-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add hlist_bl_add_before/behind helpers to add an element before/after an
existing element in a bl_list.
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Commit 1c97be677f ("list: Use WRITE_ONCE() when adding to lists and
hlists") introduced the use of WRITE_ONCE() to atomically write the list
head's ->next pointer.
hlist_add_behind() doesn't touch the hlist head's ->first pointer so
there is no reason to use WRITE_ONCE() in this case.
Co-developed-by: Ilias Tsitsimpis <iliastsi@arrikto.com>
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Reviewed-by: Paul E. McKenney <paulmck@linux.ibm.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Add missing dm_bitset_cursor_next() to properly advance the bitset
cursor.
Otherwise, the discarded state of all blocks is set according to the
discarded state of the first block.
Fixes: ae4a46a1f6 ("dm cache metadata: use bitset cursor api to load discard bitset")
Cc: stable@vger.kernel.org
Signed-off-by: Nikos Tsironis <ntsironis@arrikto.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The function blkdev_report_zones() returns success even if no zone
information is reported (empty report). Empty zone reports can only
happen if the report start sector passed exceeds the device capacity.
The conditions for this to happen are either a bug in the caller code,
or, a change in the device that forced the low level driver to change
the device capacity to a value that is lower than the report start
sector. This situation includes a failed disk revalidation resulting in
the disk capacity being changed to 0.
If this change happens while dm-zoned is in its initialization phase
executing dmz_init_zones(), this function may enter an infinite loop
and hang the system. To avoid this, add a check to disallow empty zone
reports and bail out early. Also fix the function dmz_update_zone() to
make sure that the report for the requested zone was correctly obtained.
Fixes: 3b1a94c88b ("dm zoned: drive-managed zoned block device target")
Cc: stable@vger.kernel.org
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Shaun Tancheff <shaun@tancheff.com>
Signed-off-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
My static checker complains about this line from dmz_get_zoned_device()
aligned_capacity = dev->capacity & ~(blk_queue_zone_sectors(q) - 1);
The problem is that "aligned_capacity" and "dev->capacity" are sector_t
type (which is a u64 under most configs) but blk_queue_zone_sectors(q)
returns a u32 so the higher 32 bits in aligned_capacity are cleared to
zero. This patch adds a cast to address the issue.
Fixes: 114e025968 ("dm zoned: ignore last smaller runt zone")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Damien Le Moal <damien.lemoal@wdc.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
The sector used here is a little endian value, so use the right
type for it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Merge page ref overflow branch.
Jann Horn reported that he can overflow the page ref count with
sufficient memory (and a filesystem that is intentionally extremely
slow).
Admittedly it's not exactly easy. To have more than four billion
references to a page requires a minimum of 32GB of kernel memory just
for the pointers to the pages, much less any metadata to keep track of
those pointers. Jann needed a total of 140GB of memory and a specially
crafted filesystem that leaves all reads pending (in order to not ever
free the page references and just keep adding more).
Still, we have a fairly straightforward way to limit the two obvious
user-controllable sources of page references: direct-IO like page
references gotten through get_user_pages(), and the splice pipe page
duplication. So let's just do that.
* branch page-refs:
fs: prevent page refcount overflow in pipe_buf_get
mm: prevent get_user_pages() from overflowing page refcount
mm: add 'try_get_page()' helper function
mm: make page ref count overflow check tighter and more explicit
Change pipe_buf_get() to return a bool indicating whether it succeeded
in raising the refcount of the page (if the thing in the pipe is a page).
This removes another mechanism for overflowing the page refcount. All
callers converted to handle a failure.
Reported-by: Jann Horn <jannh@google.com>
Signed-off-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
If the page refcount wraps around past zero, it will be freed while
there are still four billion references to it. One of the possible
avenues for an attacker to try to make this happen is by doing direct IO
on a page multiple times. This patch makes get_user_pages() refuse to
take a new page reference if there are already more than two billion
references to the page.
Reported-by: Jann Horn <jannh@google.com>
Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is the same as the traditional 'get_page()' function, but instead
of unconditionally incrementing the reference count of the page, it only
does so if the count was "safe". It returns whether the reference count
was incremented (and is marked __must_check, since the caller obviously
has to be aware of it).
Also like 'get_page()', you can't use this function unless you already
had a reference to the page. The intent is that you can use this
exactly like get_page(), but in situations where you want to limit the
maximum reference count.
The code currently does an unconditional WARN_ON_ONCE() if we ever hit
the reference count issues (either zero or negative), as a notification
that the conditional non-increment actually happened.
NOTE! The count access for the "safety" check is inherently racy, but
that doesn't matter since the buffer we use is basically half the range
of the reference count (ie we look at the sign of the count).
Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We have a VM_BUG_ON() to check that the page reference count doesn't
underflow (or get close to overflow) by checking the sign of the count.
That's all fine, but we actually want to allow people to use a "get page
ref unless it's already very high" helper function, and we want that one
to use the sign of the page ref (without triggering this VM_BUG_ON).
Change the VM_BUG_ON to only check for small underflows (or _very_ close
to overflowing), and ignore overflows which have strayed into negative
territory.
Acked-by: Matthew Wilcox <willy@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Merge tag 'for-linus-20190412' of git://git.kernel.dk/linux-block
Pull block fixes from Jens Axboe:
"Set of fixes that should go into this round. This pull is larger than
I'd like at this time, but there's really no specific reason for that.
Some are fixes for issues that went into this merge window, others are
not. Anyway, this contains:
- Hardware queue limiting for virtio-blk/scsi (Dongli)
- Multi-page bvec fixes for lightnvm pblk
- Multi-bio dio error fix (Jason)
- Remove the cache hint from the io_uring tool side, since we didn't
move forward with that (me)
- Make io_uring SETUP_SQPOLL root restricted (me)
- Fix leak of page in error handling for pc requests (Jérôme)
- Fix BFQ regression introduced in this merge window (Paolo)
- Fix break logic for bio segment iteration (Ming)
- Fix NVMe cancel request error handling (Ming)
- NVMe pull request with two fixes (Christoph):
- fix the initial CSN for nvme-fc (James)
- handle log page offsets properly in the target (Keith)"
* tag 'for-linus-20190412' of git://git.kernel.dk/linux-block:
block: fix the return errno for direct IO
nvmet: fix discover log page when offsets are used
nvme-fc: correct csn initialization and increments on error
block: do not leak memory in bio_copy_user_iov()
lightnvm: pblk: fix crash in pblk_end_partial_read due to multipage bvecs
nvme: cancel request synchronously
blk-mq: introduce blk_mq_complete_request_sync()
scsi: virtio_scsi: limit number of hw queues by nr_cpu_ids
virtio-blk: limit number of hw queues by nr_cpu_ids
block, bfq: fix use after free in bfq_bfqq_expire
io_uring: restrict IORING_SETUP_SQPOLL to root
tools/io_uring: remove IOCQE_FLAG_CACHEHIT
block: don't use for-inside-for in bio_for_each_segment_all
Highlights include:
Stable fixes:
- Fix a deadlock in close() due to incorrect draining of RDMA queues
Bugfixes:
- Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"
as it is causing stack overflows
- Fix a regression where NFSv4 getacl and fs_locations stopped working
- Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
- Fix xfstests failures due to incorrect copy_file_range() return values
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Merge tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs
Pull NFS client bugfixes from Trond Myklebust:
"Highlights include:
Stable fix:
- Fix a deadlock in close() due to incorrect draining of RDMA queues
Bugfixes:
- Revert "SUNRPC: Micro-optimise when the task is known not to be
sleeping" as it is causing stack overflows
- Fix a regression where NFSv4 getacl and fs_locations stopped
working
- Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
- Fix xfstests failures due to incorrect copy_file_range() return
values"
* tag 'nfs-for-5.1-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
Revert "SUNRPC: Micro-optimise when the task is known not to be sleeping"
NFSv4.1 fix incorrect return value in copy_file_range
xprtrdma: Fix helper that drains the transport
NFS: Fix handling of reply page vector
NFS: Forbid setting AF_INET6 to "struct sockaddr_in"->sin_family.
One obvious fix for a ciostor data corruption on error bug.
Signed-off-by: James E.J. Bottomley <jejb@linux.ibm.com>
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fix from James Bottomley:
"One obvious fix for a ciostor data corruption on error bug"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
scsi: csiostor: fix missing data copy in csio_scsi_err_handler()
during the merge window:
- Fix the AT91 sama5d2 programmable clk prescaler formula
- A bunch of Amlogic meson clk driver fixes for the VPU clks
- A DMI quirk for Intel's Bay Trail SoC's driver to properly mark
pmc clks as critical only when really needed
- Stop overwriting CLK_SET_RATE_PARENT flag in mediatek's clk gate
implementation
- Use the right structure to test for a frequency table in i.MX's
PLL_1416x driver
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Merge tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux
Pull clk fixes from Stephen Boyd:
"Here's more than a handful of clk driver fixes for changes that came
in during the merge window:
- Fix the AT91 sama5d2 programmable clk prescaler formula
- A bunch of Amlogic meson clk driver fixes for the VPU clks
- A DMI quirk for Intel's Bay Trail SoC's driver to properly mark pmc
clks as critical only when really needed
- Stop overwriting CLK_SET_RATE_PARENT flag in mediatek's clk gate
implementation
- Use the right structure to test for a frequency table in i.MX's
PLL_1416x driver"
* tag 'clk-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/clk/linux:
clk: imx: Fix PLL_1416X not rounding rates
clk: mediatek: fix clk-gate flag setting
platform/x86: pmc_atom: Drop __initconst on dmi table
clk: x86: Add system specific quirk to mark clocks as critical
clk: meson: vid-pll-div: remove warning and return 0 on invalid config
clk: meson: pll: fix rounding and setting a rate that matches precisely
clk: meson-g12a: fix VPU clock parents
clk: meson: g12a: fix VPU clock muxes mask
clk: meson-gxbb: round the vdec dividers to closest
clk: at91: fix programmable clock for sama5d2
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Merge tag 'pci-v5.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci
Pull PCI fixes from Bjorn Helgaas:
- Add a DMA alias quirk for another Marvell SATA device (Andre
Przywara)
- Fix a pciehp regression that broke safe removal of devices (Sergey
Miroshnichenko)
* tag 'pci-v5.1-fixes-2' of git://git.kernel.org/pub/scm/linux/kernel/git/helgaas/pci:
PCI: pciehp: Ignore Link State Changes after powering off a slot
PCI: Add function 1 DMA alias quirk for Marvell 9170 SATA controller
