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To turn the KMSG_DUMP_* reasons into a more ordered list, collapse
the redundant KMSG_DUMP_(RESTART|HALT|POWEROFF) reasons into
KMSG_DUMP_SHUTDOWN. The current users already don't meaningfully
distinguish between them, so there's no need to, as discussed here:
https://lore.kernel.org/lkml/CA+CK2bAPv5u1ih5y9t5FUnTyximtFCtDYXJCpuyjOyHNOkRdqw@mail.gmail.com/
Link: https://lore.kernel.org/lkml/20200515184434.8470-2-keescook@chromium.org/
Reviewed-by: Pavel Tatashin <pasha.tatashin@soleen.com>
Reviewed-by: Petr Mladek <pmladek@suse.com>
Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc)
Signed-off-by: Kees Cook <keescook@chromium.org>
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Move the ftrace log merging logic out of pstore/ram into pstore/ftrace
so other backends can use it, like pstore/zone.
Link: https://lore.kernel.org/lkml/20200510202436.63222-7-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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This changes the ftrace record merging code to be agnostic of
pstore/ram, as the first step to making it available as a generic
routine for other backends to use, such as pstore/zone.
Link: https://lore.kernel.org/lkml/20200510202436.63222-6-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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Refactor device tree size parsing routines to be able to pass a non-zero
default value for providing a configurable default for the coming
"max_reason" field. Also rename the helpers, since we're not always
parsing a size -- we're parsing a u32 and making sure it's not greater
than INT_MAX.
Link: https://lore.kernel.org/lkml/20200506211523.15077-4-keescook@chromium.org/
Link: https://lore.kernel.org/lkml/20200521205223.175957-1-tyhicks@linux.microsoft.com
Signed-off-by: Kees Cook <keescook@chromium.org>
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A couple module parameters had 0600 permissions, but changing them would
have no impact on ramoops, so switch these to 0400 to reflect reality.
Link: https://lore.kernel.org/lkml/20200506211523.15077-7-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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It is easier to see how module params are used if they're near the
variables they use.
Link: https://lore.kernel.org/lkml/20200510202436.63222-4-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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If the pstore backend changes, there's no indication in the logs what
the console is (it always says "pstore"). Instead, pass through the
active backend's name. (Also adjust the selftest to match.)
Link: https://lore.kernel.org/lkml/20200510202436.63222-5-keescook@chromium.org/
Link: https://lore.kernel.org/lkml/20200526135429.GQ12456@shao2-debian
Signed-off-by: Kees Cook <keescook@chromium.org>
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In order to more cleanly pass around backend names, make the "name" member
const. This means the module param needs to be dynamic (technically, it
was before, so this actually cleans up a minor memory leak if a backend
was specified and then gets unloaded.)
Link: https://lore.kernel.org/lkml/20200510202436.63222-3-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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The CON_ENABLED flag gets cleared during unregister_console(), so make
sure we already reset the console flags before calling register_console(),
otherwise unloading and reloading a pstore backend will not restart
console logging.
Signed-off-by: Kees Cook <keescook@chromium.org>
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If a backend was unloaded without having first removed all its
associated records in pstorefs, subsequent removals would crash while
attempting to call into the now missing backend. Add automatic removal
from the tree in pstore_unregister(), so that no references to the
backend remain.
Reported-by: Luis Henriques <lhenriques@suse.com>
Link: https://lore.kernel.org/lkml/87o8yrmv69.fsf@suse.com
Link: https://lore.kernel.org/lkml/20200506152114.50375-11-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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The pstore.update_ms value was being disabled during pstore_unregister(),
which would cause any prior value to go unnoticed on the next
pstore_register(). Instead, just let del_timer() stop the timer, which
was always sufficient. This additionally refactors the timer reset code
and allows the timer to be enabled if the module parameter is changed
away from the default.
Link: https://lore.kernel.org/lkml/20200506152114.50375-10-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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Nothing was protecting changes to the pstorefs superblock. Add locking
and refactor away is_pstore_mounted(), instead using a helper to add a
way to safely lock the pstorefs root inode during filesystem changes.
Link: https://lore.kernel.org/lkml/20200506152114.50375-9-keescook@chromium.org/
Signed-off-by: Kees Cook <keescook@chromium.org>
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Overflowed requests in io_uring_cancel_files() should be shed only of
inflight and overflowed refs. All other left references are owned by
someone else.
If refcount_sub_and_test() fails, it will go further and put put extra
ref, don't do that. Also, don't need to do io_wq_cancel_work()
for overflowed reqs, they will be let go shortly anyway.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Offset timeouts wait not for sqe->off non-timeout CQEs, but rather
sqe->off + number of prior inflight requests. Wait exactly for
sqe->off non-timeout completions
Reported-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Separate flushing offset timeouts io_commit_cqring() by moving it into a
helper. Just a preparation, makes following patches clearer.
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Move the computation of creds from prepare_binfmt into begin_new_exec
so that the creds need only be computed once. This is just code
reorganization no semantic changes of any kind are made.
Moving the computation is safe. I have looked through the kernel and
verified none of the binfmts look at bprm->cred directly, and that
there are no helpers that look at bprm->cred indirectly. Which means
that it is not a problem to compute the bprm->cred later in the
execution flow as it is not used until it becomes current->cred.
A new function bprm_creds_from_file is added to contain the work that
needs to be done. bprm_creds_from_file first computes which file
bprm->executable or most likely bprm->file that the bprm->creds
will be computed from.
The funciton bprm_fill_uid is updated to receive the file instead of
accessing bprm->file. The now unnecessary work needed to reset the
bprm->cred->euid, and bprm->cred->egid is removed from brpm_fill_uid.
A small comment to document that bprm_fill_uid now only deals with the
work to handle suid and sgid files. The default case is already
heandled by prepare_exec_creds.
The function security_bprm_repopulate_creds is renamed
security_bprm_creds_from_file and now is explicitly passed the file
from which to compute the creds. The documentation of the
bprm_creds_from_file security hook is updated to explain when the hook
is called and what it needs to do. The file is passed from
cap_bprm_creds_from_file into get_file_caps so that the caps are
computed for the appropriate file. The now unnecessary work in
cap_bprm_creds_from_file to reset the ambient capabilites has been
removed. A small comment to document that the work of
cap_bprm_creds_from_file is to read capabilities from the files
secureity attribute and derive capabilities from the fact the
user had uid 0 has been added.
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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There is a small bug in the code that recomputes parts of bprm->cred
for every bprm->file. The code never recomputes the part of
clear_dangerous_personality_flags it is responsible for.
Which means that in practice if someone creates a sgid script
the interpreter will not be able to use any of:
READ_IMPLIES_EXEC
ADDR_NO_RANDOMIZE
ADDR_COMPAT_LAYOUT
MMAP_PAGE_ZERO.
This accentially clearing of personality flags probably does
not matter in practice because no one has complained
but it does make the code more difficult to understand.
Further remaining bug compatible prevents the recomputation from being
removed and replaced by simply computing bprm->cred once from the
final bprm->file.
Making this change removes the last behavior difference between
computing bprm->creds from the final file and recomputing
bprm->cred several times. Which allows this behavior change
to be justified for it's own reasons, and for any but hunts
looking into why the behavior changed to wind up here instead
of in the code that will follow that computes bprm->cred
from the final bprm->file.
This small logic bug appears to have existed since the code
started clearing dangerous personality bits.
History Tree: git://git.kernel.org/pub/scm/linux/kernel/git/tglx/history.git
Fixes: 1bb0fa189c6a ("[PATCH] NX: clean up legacy binary support")
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
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Pull ceph fixes from Ilya Dryomov:
"Cache tiering and cap handling fixups, both marked for stable"
* tag 'ceph-for-5.7-rc8' of git://github.com/ceph/ceph-client:
ceph: flush release queue when handling caps for unknown inode
libceph: ignore pool overlay and cache logic on redirects
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git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2
Pull gfs2 fix from Andreas Gruenbacher:
"Fix the previous, flawed gfs2_find_jhead commit"
* tag 'gfs2-v5.7-rc7.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2:
gfs2: Even more gfs2_find_jhead fixes
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This code was using get_user_pages*(), in a "Case 1" scenario
(Direct IO), using the categorization from [1]. That means that it's
time to convert the get_user_pages*() + put_page() calls to
pin_user_pages*() + unpin_user_pages() calls.
There is some helpful background in [2]: basically, this is a small
part of fixing a long-standing disconnect between pinning pages, and
file systems' use of those pages.
[1] Documentation/core-api/pin_user_pages.rst
[2] "Explicit pinning of user-space pages":
https://lwn.net/Articles/807108/
Cc: Mike Marshall <hubcap@omnibond.com>
Cc: Martin Brandenburg <martin@omnibond.com>
Cc: devel@lists.orangefs.org
Cc: linux-fsdevel@vger.kernel.org
Signed-off-by: John Hubbard <jhubbard@nvidia.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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The variable ret is being initialized with a value that is
never read and it is being updated later with a new value. The
initialization is redundant and can be removed.
Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
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The SCTP protocol allows to bind multiple address to a socket. That
feature is currently only exposed as a socket option. Add a bind_add
method struct proto that allows to bind additional addresses, and
switch the dlm code to use the method instead of going through the
socket option from kernel space.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the SCTP_NODELAY sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Fix several issues in the previous gfs2_find_jhead fix:
* When updating @blocks_submitted, @block refers to the first block block not
submitted yet, not the last block submitted, so fix an off-by-one error.
* We want to ensure that @blocks_submitted is far enough ahead of @blocks_read
to guarantee that there is in-flight I/O. Otherwise, we'll eventually end up
waiting for pages that haven't been submitted, yet.
* It's much easier to compare the number of blocks added with the number of
blocks submitted to limit the maximum bio size.
* Even with bio chaining, we can keep adding blocks until we reach the maximum
bio size, as long as we stop at a page boundary. This simplifies the logic.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Reviewed-by: Bob Peterson <rpeterso@redhat.com>
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As Andrew mentioned, some rare specific gcc versions could report
last_block uninitialized warning. Actually last_block doesn't need
to be uninitialized first from its implementation due to bio == NULL
condition. After a bio is allocated, last_block will be assigned
then.
The detailed analysis is in this thread [1]. So let's silence those
confusing gccs simply.
[1] https://lore.kernel.org/r/20200421072839.GA13867@hsiangkao-HP-ZHAN-66-Pro-G1
Cc: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200528084844.23359-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
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Convert the erofs to use new internal mount API as the old one will
be obsoleted and removed. This allows greater flexibility in
communication of mount parameters between userspace, the VFS and the
filesystem.
See Documentation/filesystems/mount_api.txt for more information.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Link: https://lore.kernel.org/r/20200529104836.17843-1-hsiangkao@redhat.com
Signed-off-by: Gao Xiang <hsiangkao@redhat.com>
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Use kcalloc instead of kmalloc in the comment according to
the previous kcalloc() call.
Link: https://lore.kernel.org/r/1590714150-15895-1-git-send-email-wang.yi59@zte.com.cn
Signed-off-by: Liao Pingfang <liao.pingfang@zte.com.cn>
Signed-off-by: Jan Kara <jack@suse.cz>
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Merge misc fixes from Andrew Morton:
"5 fixes"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
include/asm-generic/topology.h: guard cpumask_of_node() macro argument
fs/binfmt_elf.c: allocate initialized memory in fill_thread_core_info()
mm: remove VM_BUG_ON(PageSlab()) from page_mapcount()
mm,thp: stop leaking unreleased file pages
mm/z3fold: silence kmemleak false positives of slots
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KMSAN reported uninitialized data being written to disk when dumping
core. As a result, several kilobytes of kmalloc memory may be written
to the core file and then read by a non-privileged user.
Reported-by: sam <sunhaoyl@outlook.com>
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kees Cook <keescook@chromium.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: <stable@vger.kernel.org>
Link: http://lkml.kernel.org/r/20200419100848.63472-1-glider@google.com
Link: https://github.com/google/kmsan/issues/76
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Add a helper to directly set the RXRPC_MIN_SECURITY_LEVEL sockopt from
kernel space without going through a fake uaccess.
Thanks to David Howells for the documentation updates.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Howells <dhowells@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the TCP_USER_TIMEOUT sockopt from kernel
space without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the TCP_NODELAY sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Acked-by: Jason Gunthorpe <jgg@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the TCP_CORK sockopt from kernel space
without going through a fake uaccess. Cleanup the callers to avoid
pointless wrappers now that this is a simple function call.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the SO_RCVBUFFORCE sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the SO_KEEPALIVE sockopt from kernel space
without going through a fake uaccess.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the SO_SNDTIMEO_NEW sockopt from kernel
space without going through a fake uaccess. The interface is
simplified to only pass the seconds value, as that is the only
thing needed at the moment.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Add a helper to directly set the SO_REUSEADDR sockopt from kernel space
without going through a fake uaccess.
For this the iscsi target now has to formally depend on inet to avoid
a mostly theoretical compile failure. For actual operation it already
did depend on having ipv4 or ipv6 support.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Sagi Grimberg <sagi@grimberg.me>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Support for Clang's Shadow Call Stack in the kernel
(Sami Tolvanen and Will Deacon)
* for-next/scs:
arm64: entry-ftrace.S: Update comment to indicate that x18 is live
scs: Move DEFINE_SCS macro into core code
scs: Remove references to asm/scs.h from core code
scs: Move scs_overflow_check() out of architecture code
arm64: scs: Use 'scs_sp' register alias for x18
scs: Move accounting into alloc/free functions
arm64: scs: Store absolute SCS stack pointer value in thread_info
efi/libstub: Disable Shadow Call Stack
arm64: scs: Add shadow stacks for SDEI
arm64: Implement Shadow Call Stack
arm64: Disable SCS for hypervisor code
arm64: vdso: Disable Shadow Call Stack
arm64: efi: Restore register x18 if it was corrupted
arm64: Preserve register x18 when CPU is suspended
arm64: Reserve register x18 from general allocation with SCS
scs: Disable when function graph tracing is enabled
scs: Add support for stack usage debugging
scs: Add page accounting for shadow call stack allocations
scs: Add support for Clang's Shadow Call Stack (SCS)
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We always preallocate a data extent for writing a free space cache, which
causes writeback to always try the nocow path first, since the free space
inode has the prealloc bit set in its flags.
However if the block group that contains the data extent for the space
cache has been turned to RO mode due to a running scrub or balance for
example, we have to fallback to the cow path. In that case once a new data
extent is allocated we end up calling btrfs_add_reserved_bytes(), which
decrements the counter named bytes_may_use from the data space_info object
with the expection that this counter was previously incremented with the
same amount (the size of the data extent).
However when we started writeout of the space cache at cache_save_setup(),
we incremented the value of the bytes_may_use counter through a call to
btrfs_check_data_free_space() and then decremented it through a call to
btrfs_prealloc_file_range_trans() immediately after. So when starting the
writeback if we fallback to cow mode we have to increment the counter
bytes_may_use of the data space_info again to compensate for the extent
allocation done by the cow path.
When this issue happens we are incorrectly decrementing the bytes_may_use
counter and when its current value is smaller then the amount we try to
subtract we end up with the following warning:
------------[ cut here ]------------
WARNING: CPU: 3 PID: 657 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
CPU: 3 PID: 657 Comm: kworker/u8:7 Tainted: G W 5.6.0-rc7-btrfs-next-58 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Workqueue: writeback wb_workfn (flush-btrfs-1591)
RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Code: ff ff 48 (...)
RSP: 0000:ffffa41608f13660 EFLAGS: 00010287
RAX: 0000000000001000 RBX: ffff9615b93ae400 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9615b96ab410
RBP: fffffffffffee000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff961585e62a40 R11: 0000000000000000 R12: ffff9615b96ab400
R13: ffff9615a1a2a000 R14: 0000000000012000 R15: ffff9615b93ae400
FS: 0000000000000000(0000) GS:ffff9615bb200000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055cbbc2ae178 CR3: 0000000115794006 CR4: 00000000003606e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
find_free_extent+0x4a0/0x16c0 [btrfs]
btrfs_reserve_extent+0x91/0x180 [btrfs]
cow_file_range+0x12d/0x490 [btrfs]
btrfs_run_delalloc_range+0x9f/0x6d0 [btrfs]
? find_lock_delalloc_range+0x221/0x250 [btrfs]
writepage_delalloc+0xe8/0x150 [btrfs]
__extent_writepage+0xe8/0x4c0 [btrfs]
extent_write_cache_pages+0x237/0x530 [btrfs]
extent_writepages+0x44/0xa0 [btrfs]
do_writepages+0x23/0x80
__writeback_single_inode+0x59/0x700
writeback_sb_inodes+0x267/0x5f0
__writeback_inodes_wb+0x87/0xe0
wb_writeback+0x382/0x590
? wb_workfn+0x4a2/0x6c0
wb_workfn+0x4a2/0x6c0
process_one_work+0x26d/0x6a0
worker_thread+0x4f/0x3e0
? process_one_work+0x6a0/0x6a0
kthread+0x103/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffffb2abdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace bd7c03622e0b0a52 ]---
------------[ cut here ]------------
So fix this by incrementing the bytes_may_use counter of the data
space_info when we fallback to the cow path. If the cow path is successful
the counter is decremented after extent allocation (by
btrfs_add_reserved_bytes()), if it fails it ends up being decremented as
well when clearing the delalloc range (extent_clear_unlock_delalloc()).
This could be triggered sporadically by the test case btrfs/061 from
fstests.
Fixes: 82d5902d9c681b ("Btrfs: Support reading/writing on disk free ino cache")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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When doing a buffered write we always try to reserve data space for it,
even when the file has the NOCOW bit set or the write falls into a file
range covered by a prealloc extent. This is done both because it is
expensive to check if we can do a nocow write (checking if an extent is
shared through reflinks or if there's a hole in the range for example),
and because when writeback starts we might actually need to fallback to
COW mode (for example the block group containing the target extents was
turned into RO mode due to a scrub or balance).
When we are unable to reserve data space we check if we can do a nocow
write, and if we can, we proceed with dirtying the pages and setting up
the range for delalloc. In this case the bytes_may_use counter of the
data space_info object is not incremented, unlike in the case where we
are able to reserve data space (done through btrfs_check_data_free_space()
which calls btrfs_alloc_data_chunk_ondemand()).
Later when running delalloc we attempt to start writeback in nocow mode
but we might revert back to cow mode, for example because in the meanwhile
a block group was turned into RO mode by a scrub or relocation. The cow
path after successfully allocating an extent ends up calling
btrfs_add_reserved_bytes(), which expects the bytes_may_use counter of
the data space_info object to have been incremented before - but we did
not do it when the buffered write started, since there was not enough
available data space. So btrfs_add_reserved_bytes() ends up decrementing
the bytes_may_use counter anyway, and when the counter's current value
is smaller then the size of the allocated extent we get a stack trace
like the following:
------------[ cut here ]------------
WARNING: CPU: 0 PID: 20138 at fs/btrfs/space-info.h:115 btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Modules linked in: btrfs blake2b_generic xor raid6_pq libcrc32c (...)
CPU: 0 PID: 20138 Comm: kworker/u8:15 Not tainted 5.6.0-rc7-btrfs-next-58 #5
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014
Workqueue: writeback wb_workfn (flush-btrfs-1754)
RIP: 0010:btrfs_add_reserved_bytes+0x3d6/0x4e0 [btrfs]
Code: ff ff 48 (...)
RSP: 0018:ffffbda18a4b3568 EFLAGS: 00010287
RAX: 0000000000000000 RBX: ffff9ca076f5d800 RCX: 0000000000000000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: ffff9ca068470410
RBP: fffffffffffff000 R08: 0000000000000001 R09: 0000000000000000
R10: ffff9ca079d58040 R11: 0000000000000000 R12: ffff9ca068470400
R13: ffff9ca0408b2000 R14: 0000000000001000 R15: ffff9ca076f5d800
FS: 0000000000000000(0000) GS:ffff9ca07a600000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005605dbfe7048 CR3: 0000000138570006 CR4: 00000000003606f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
find_free_extent+0x4a0/0x16c0 [btrfs]
btrfs_reserve_extent+0x91/0x180 [btrfs]
cow_file_range+0x12d/0x490 [btrfs]
run_delalloc_nocow+0x341/0xa40 [btrfs]
btrfs_run_delalloc_range+0x1ea/0x6d0 [btrfs]
? find_lock_delalloc_range+0x221/0x250 [btrfs]
writepage_delalloc+0xe8/0x150 [btrfs]
__extent_writepage+0xe8/0x4c0 [btrfs]
extent_write_cache_pages+0x237/0x530 [btrfs]
? btrfs_wq_submit_bio+0x9f/0xc0 [btrfs]
extent_writepages+0x44/0xa0 [btrfs]
do_writepages+0x23/0x80
__writeback_single_inode+0x59/0x700
writeback_sb_inodes+0x267/0x5f0
__writeback_inodes_wb+0x87/0xe0
wb_writeback+0x382/0x590
? wb_workfn+0x4a2/0x6c0
wb_workfn+0x4a2/0x6c0
process_one_work+0x26d/0x6a0
worker_thread+0x4f/0x3e0
? process_one_work+0x6a0/0x6a0
kthread+0x103/0x140
? kthread_create_worker_on_cpu+0x70/0x70
ret_from_fork+0x3a/0x50
irq event stamp: 0
hardirqs last enabled at (0): [<0000000000000000>] 0x0
hardirqs last disabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
softirqs last enabled at (0): [<ffffffff94ebdedf>] copy_process+0x74f/0x2020
softirqs last disabled at (0): [<0000000000000000>] 0x0
---[ end trace f9f6ef8ec4cd8ec9 ]---
So to fix this, when falling back into cow mode check if space was not
reserved, by testing for the bit EXTENT_NORESERVE in the respective file
range, and if not, increment the bytes_may_use counter for the data
space_info object. Also clear the EXTENT_NORESERVE bit from the range, so
that if the cow path fails it decrements the bytes_may_use counter when
clearing the delalloc range (through the btrfs_clear_delalloc_extent()
callback).
Fixes: 7ee9e4405f264e ("Btrfs: check if we can nocow if we don't have data space")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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If an error happens while running dellaloc in COW mode for a range, we can
end up calling extent_clear_unlock_delalloc() for a range that goes beyond
our range's end offset by 1 byte, which affects 1 extra page. This results
in clearing bits and doing page operations (such as a page unlock) outside
our target range.
Fix that by calling extent_clear_unlock_delalloc() with an inclusive end
offset, instead of an exclusive end offset, at cow_file_range().
Fixes: a315e68f6e8b30 ("Btrfs: fix invalid attempt to free reserved space on failure to cow range")
CC: stable@vger.kernel.org # 4.14+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The local 'b' variable is only used to directly read values from passed
extent buffer. So eliminate it and directly use the input parameter.
Furthermore this shrinks the size of the following functions:
./scripts/bloat-o-meter ctree.orig fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-73 (-73)
Function old new delta
read_block_for_search.isra 876 871 -5
push_node_left 1112 1044 -68
Total: Before=50348, After=50275, chg -0.14%
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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This function wraps the optimisation implemented by d7396f07358a
("Btrfs: optimize key searches in btrfs_search_slot") however this
optimisation is really used in only one place - btrfs_search_slot.
Just open code the optimisation and also add a comment explaining how it
works since it's not clear just by looking at the code - the key point
here is it depends on an internal invariant that BTRFS' btree provides,
namely intermediate pointers always contain the key at slot0 at the
child node. So in the case of exact match we can safely assume that the
given key will always be in slot 0 on lower levels.
Furthermore this results in a reduction of btrfs_search_slot's size:
./scripts/bloat-o-meter ctree.orig fs/btrfs/ctree.o
add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-75 (-75)
Function old new delta
btrfs_search_slot 2783 2708 -75
Total: Before=50423, After=50348, chg -0.15%
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The read and write versions don't have anything in common except for the
call to iomap_dio_rw. So split this function, and merge each half into
its only caller.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Since we now perform direct reads using i_rwsem, we can remove this
inode flag used to co-ordinate unlocked reads.
The truncate call takes i_rwsem. This means it is correctly synchronized
with concurrent direct reads.
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jth@kernel.org>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Since we removed the last user of dio_end_io(), remove the helper
function dio_end_io().
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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Switch from __blockdev_direct_IO() to iomap_dio_rw().
Rename btrfs_get_blocks_direct() to btrfs_dio_iomap_begin() and use it
as iomap_begin() for iomap direct I/O functions. This function
allocates and locks all the blocks required for the I/O.
btrfs_submit_direct() is used as the submit_io() hook for direct I/O
ops.
Since we need direct I/O reads to go through iomap_dio_rw(), we change
file_operations.read_iter() to a btrfs_file_read_iter() which calls
btrfs_direct_IO() for direct reads and falls back to
generic_file_buffered_read() for incomplete reads and buffered reads.
We don't need address_space.direct_IO() anymore so set it to noop.
Similarly, we don't need flags used in __blockdev_direct_IO(). iomap is
capable of direct I/O reads from a hole, so we don't need to return
-ENOENT.
BTRFS direct I/O is now done under i_rwsem, shared in case of reads and
exclusive in case of writes. This guards against simultaneous truncates.
Use iomap->iomap_end() to check for failed or incomplete direct I/O:
- for writes, call __endio_write_update_ordered()
- for reads, unlock extents
btrfs_dio_data is now hooked in iomap->private and not
current->journal_info. It carries the reservation variable and the
amount of data submitted, so we can calculate the amount of data to call
__endio_write_update_ordered in case of an error.
This patch removes last use of struct buffer_head from btrfs.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
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The squashfs multi CPU decompressor makes use of get_cpu_ptr() to
acquire a pointer to per-CPU data. get_cpu_ptr() implicitly disables
preemption which serializes the access to the per-CPU data.
But decompression can take quite some time depending on the size. The
observed preempt disabled times in real world scenarios went up to 8ms,
causing massive wakeup latencies. This happens on all CPUs as the
decompression is fully parallelized.
Replace the implicit preemption control with an explicit local lock.
This allows RT kernels to substitute it with a real per CPU lock, which
serializes the access but keeps the code section preemptible. On non RT
kernels this maps to preempt_disable() as before, i.e. no functional
change.
[ bigeasy: Use local_lock(), patch description]
Reported-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Julia Cartwright <julia@ni.com>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Acked-by: Peter Zijlstra <peterz@infradead.org>
Link: https://lore.kernel.org/r/20200527201119.1692513-5-bigeasy@linutronix.de
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The only difference between a few missing fixes applied to the SCTP
one is that TCP uses ->getpeername to get the remote address, while
SCTP uses kernel_getsockopt(.. SCTP_PRIMARY_ADDR). But given that
getpeername is defined to return the primary address for sctp, there
doesn't seem to be any reason for the different way of quering the
peername, or all the code duplication.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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The change to bprm->have_execfd was incomplete, leading
to a build failure:
fs/binfmt_elf_fdpic.c: In function 'create_elf_fdpic_tables':
fs/binfmt_elf_fdpic.c:591:27: error: 'BINPRM_FLAGS_EXECFD' undeclared
Change the last user of BINPRM_FLAGS_EXECFD in a corresponding
way.
Reported-by: Valdis Klētnieks <valdis.kletnieks@vt.edu>
Fixes: b8a61c9e7b4a ("exec: Generic execfd support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
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