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Merge more updates from Andrew Morton:
"87 patches.
Subsystems affected by this patch series: mm (pagecache and hugetlb),
procfs, misc, MAINTAINERS, lib, checkpatch, binfmt, kallsyms, ramfs,
init, codafs, nilfs2, hfs, crash_dump, signals, seq_file, fork,
sysvfs, kcov, gdb, resource, selftests, and ipc"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (87 commits)
ipc/ipc_sysctl.c: remove fallback for !CONFIG_PROC_SYSCTL
ipc: check checkpoint_restore_ns_capable() to modify C/R proc files
selftests/kselftest/runner/run_one(): allow running non-executable files
virtio-mem: disallow mapping virtio-mem memory via /dev/mem
kernel/resource: disallow access to exclusive system RAM regions
kernel/resource: clean up and optimize iomem_is_exclusive()
scripts/gdb: handle split debug for vmlinux
kcov: replace local_irq_save() with a local_lock_t
kcov: avoid enable+disable interrupts if !in_task()
kcov: allocate per-CPU memory on the relevant node
Documentation/kcov: define `ip' in the example
Documentation/kcov: include types.h in the example
sysv: use BUILD_BUG_ON instead of runtime check
kernel/fork.c: unshare(): use swap() to make code cleaner
seq_file: fix passing wrong private data
seq_file: move seq_escape() to a header
signal: remove duplicate include in signal.h
crash_dump: remove duplicate include in crash_dump.h
crash_dump: fix boolreturn.cocci warning
hfs/hfsplus: use WARN_ON for sanity check
...
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Historically (pre-2.5), the inode shrinker used to reclaim only empty
inodes and skip over those that still contained page cache. This caused
problems on highmem hosts: struct inode could put fill lowmem zones
before the cache was getting reclaimed in the highmem zones.
To address this, the inode shrinker started to strip page cache to
facilitate reclaiming lowmem. However, this comes with its own set of
problems: the shrinkers may drop actively used page cache just because
the inodes are not currently open or dirty - think working with a large
git tree. It further doesn't respect cgroup memory protection settings
and can cause priority inversions between containers.
Nowadays, the page cache also holds non-resident info for evicted cache
pages in order to detect refaults. We've come to rely heavily on this
data inside reclaim for protecting the cache workingset and driving swap
behavior. We also use it to quantify and report workload health through
psi. The latter in turn is used for fleet health monitoring, as well as
driving automated memory sizing of workloads and containers, proactive
reclaim and memory offloading schemes.
The consequences of dropping page cache prematurely is that we're seeing
subtle and not-so-subtle failures in all of the above-mentioned
scenarios, with the workload generally entering unexpected thrashing
states while losing the ability to reliably detect it.
To fix this on non-highmem systems at least, going back to rotating
inodes on the LRU isn't feasible. We've tried (commit a76cf1a474d7
("mm: don't reclaim inodes with many attached pages")) and failed
(commit 69056ee6a8a3 ("Revert "mm: don't reclaim inodes with many
attached pages"")).
The issue is mostly that shrinker pools attract pressure based on their
size, and when objects get skipped the shrinkers remember this as
deferred reclaim work. This accumulates excessive pressure on the
remaining inodes, and we can quickly eat into heavily used ones, or
dirty ones that require IO to reclaim, when there potentially is plenty
of cold, clean cache around still.
Instead, this patch keeps populated inodes off the inode LRU in the
first place - just like an open file or dirty state would. An otherwise
clean and unused inode then gets queued when the last cache entry
disappears. This solves the problem without reintroducing the reclaim
issues, and generally is a bit more scalable than having to wade through
potentially hundreds of thousands of busy inodes.
Locking is a bit tricky because the locks protecting the inode state
(i_lock) and the inode LRU (lru_list.lock) don't nest inside the
irq-safe page cache lock (i_pages.xa_lock). Page cache deletions are
serialized through i_lock, taken before the i_pages lock, to make sure
depopulated inodes are queued reliably. Additions may race with
deletions, but we'll check again in the shrinker. If additions race
with the shrinker itself, we're protected by the i_lock: if find_inode()
or iput() win, the shrinker will bail on the elevated i_count or
I_REFERENCED; if the shrinker wins and goes ahead with the inode, it
will set I_FREEING and inhibit further igets(), which will cause the
other side to create a new instance of the inode instead.
Link: https://lkml.kernel.org/r/20210614211904.14420-4-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <guro@fb.com>
Cc: Tejun Heo <tj@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Get rid of the indirections and just provide a sync_bdevs
helper for the generic sync code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211019062530.2174626-8-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Instead offer a new sync_blockdev_nowait helper for the !wait case.
This new helper is exported as it will grow modular callers in a bit.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20211019062530.2174626-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Move it together with the rest of the block layer.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20210907141303.1371844-3-hch@lst.de
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pull iomap updates from Darrick Wong:
"The most notable externally visible change for this cycle is the
addition of support for reads to inline tail fragments of files, which
was requested by the erofs developers; and a correction for a kernel
memory corruption bug if the sysadmin tries to activate a swapfile
with more pages than the swapfile header suggests.
We also now report writeback completion errors to the file mapping
correctly, instead of munging all errors into EIO.
Internally, the bulk of the changes are Christoph's patchset to reduce
the indirect function call count by a third to a half by converting
iomap iteration from a loop pattern to a generator/consumer pattern.
As an added bonus, fsdax no longer open-codes iomap apply loops.
Summary:
- Simplify the bio_end_page usage in the buffered IO code.
- Support reading inline data at nonzero offsets for erofs.
- Fix some typos and bad grammar.
- Convert kmap_atomic usage in the inline data read path.
- Add some extra inline data input checking.
- Fix a memory corruption bug stemming from iomap_swapfile_activate
trying to activate more pages than mm was expecting.
- Pass errnos through the page writeback code so that writeback
errors are reported correctly instead of being munged to EIO.
- Replace iomap_apply with a open-coded iterator loops to reduce the
number of indirect calls by a third to a half.
- Refactor the fsdax code to use iomap iterators instead of the
open-coded iomap_apply code that it had before.
- Format file range iomap tracepoint data in hexadecimal and
standardize the names used in the pretty-print string"
* tag 'iomap-5.15-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (41 commits)
iomap: standardize tracepoint formatting and storage
mm/swap: consider max pages in iomap_swapfile_add_extent
iomap: move loop control code to iter.c
iomap: constify iomap_iter_srcmap
fsdax: switch the fault handlers to use iomap_iter
fsdax: factor out a dax_fault_actor() helper
fsdax: factor out helpers to simplify the dax fault code
iomap: rework unshare flag
iomap: pass an iomap_iter to various buffered I/O helpers
iomap: remove iomap_apply
fsdax: switch dax_iomap_rw to use iomap_iter
iomap: switch iomap_swapfile_activate to use iomap_iter
iomap: switch iomap_seek_data to use iomap_iter
iomap: switch iomap_seek_hole to use iomap_iter
iomap: switch iomap_bmap to use iomap_iter
iomap: switch iomap_fiemap to use iomap_iter
iomap: switch __iomap_dio_rw to use iomap_iter
iomap: switch iomap_page_mkwrite to use iomap_iter
iomap: switch iomap_zero_range to use iomap_iter
iomap: switch iomap_file_unshare to use iomap_iter
...
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IORING_OP_LINKAT behaves like linkat(2) and takes the same flags and
arguments.
In some internal places 'hardlink' is used instead of 'link' to avoid
confusion with the SQE links. Name 'link' conflicts with the existing
'link' member of io_kiocb.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/io-uring/20210514145259.wtl4xcsp52woi6ab@wittgenstein/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20210708063447.3556403-12-dkadashev@gmail.com
[axboe: add splice_fd_in check]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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IORING_OP_SYMLINKAT behaves like symlinkat(2) and takes the same flags
and arguments.
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Suggested-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/io-uring/20210514145259.wtl4xcsp52woi6ab@wittgenstein/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20210708063447.3556403-11-dkadashev@gmail.com
[axboe: add splice_fd_in check]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Update the following to return int rather than long, for uniformity with
the rest of the do_* helpers in namei.c:
* do_rmdir()
* do_unlinkat()
* do_mkdirat()
* do_mknodat()
* do_symlinkat()
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <christian.brauner@ubuntu.com>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/io-uring/20210514143202.dmzfcgz5hnauy7ze@wittgenstein/
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20210708063447.3556403-9-dkadashev@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Pass in the struct filename pointers instead of the user string, and
update the three callers to do the same. This is heavily based on
commit dbea8d345177 ("fs: make do_renameat2() take struct filename").
This behaves like do_unlinkat() and do_renameat2().
Cc: Al Viro <viro@zeniv.linux.org.uk>
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Dmitry Kadashev <dkadashev@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Link: https://lore.kernel.org/r/20210708063447.3556403-4-dkadashev@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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__block_write_begin_int never modifies the passed in iomap, so mark it
const.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Richard reported sporadic (roughly one in 10 or so) null dereferences and
other strange behaviour for a set of automated LTP tests. Things like:
BUG: kernel NULL pointer dereference, address: 0000000000000008
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 0 P4D 0
Oops: 0000 [#1] PREEMPT SMP PTI
CPU: 0 PID: 1516 Comm: umount Not tainted 5.10.0-yocto-standard #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.13.0-48-gd9c812dda519-prebuilt.qemu.org 04/01/2014
RIP: 0010:kernfs_sop_show_path+0x1b/0x60
...or these others:
RIP: 0010:do_mkdirat+0x6a/0xf0
RIP: 0010:d_alloc_parallel+0x98/0x510
RIP: 0010:do_readlinkat+0x86/0x120
There were other less common instances of some kind of a general scribble
but the common theme was mount and cgroup and a dubious dentry triggering
the NULL dereference. I was only able to reproduce it under qemu by
replicating Richard's setup as closely as possible - I never did get it
to happen on bare metal, even while keeping everything else the same.
In commit 71d883c37e8d ("cgroup_do_mount(): massage calling conventions")
we see this as a part of the overall change:
--------------
struct cgroup_subsys *ss;
- struct dentry *dentry;
[...]
- dentry = cgroup_do_mount(&cgroup_fs_type, fc->sb_flags, root,
- CGROUP_SUPER_MAGIC, ns);
[...]
- if (percpu_ref_is_dying(&root->cgrp.self.refcnt)) {
- struct super_block *sb = dentry->d_sb;
- dput(dentry);
+ ret = cgroup_do_mount(fc, CGROUP_SUPER_MAGIC, ns);
+ if (!ret && percpu_ref_is_dying(&root->cgrp.self.refcnt)) {
+ struct super_block *sb = fc->root->d_sb;
+ dput(fc->root);
deactivate_locked_super(sb);
msleep(10);
return restart_syscall();
}
--------------
In changing from the local "*dentry" variable to using fc->root, we now
export/leave that dentry pointer in the file context after doing the dput()
in the unlikely "is_dying" case. With LTP doing a crazy amount of back to
back mount/unmount [testcases/bin/cgroup_regression_5_1.sh] the unlikely
becomes slightly likely and then bad things happen.
A fix would be to not leave the stale reference in fc->root as follows:
--------------
dput(fc->root);
+ fc->root = NULL;
deactivate_locked_super(sb);
--------------
...but then we are just open-coding a duplicate of fc_drop_locked() so we
simply use that instead.
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Tejun Heo <tj@kernel.org>
Cc: Zefan Li <lizefan.x@bytedance.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: stable@vger.kernel.org # v5.1+
Reported-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Fixes: 71d883c37e8d ("cgroup_do_mount(): massage calling conventions")
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
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... and provide file_open_root_mnt(), using the root of given mount.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdf
https://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: handle idmapped mounts
...
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Pull io_uring updates from Jens Axboe:
"Highlights from this cycles are things like request recycling and
task_work optimizations, which net us anywhere from 10-20% of speedups
on workloads that mostly are inline.
This work was originally done to put io_uring under memcg, which adds
considerable overhead. But it's a really nice win as well. Also worth
highlighting is the LOOKUP_CACHED work in the VFS, and using it in
io_uring. Greatly speeds up the fast path for file opens.
Summary:
- Put io_uring under memcg protection. We accounted just the rings
themselves under rlimit memlock before, now we account everything.
- Request cache recycling, persistent across invocations (Pavel, me)
- First part of a cleanup/improvement to buffer registration (Bijan)
- SQPOLL fixes (Hao)
- File registration NULL pointer fixup (Dan)
- LOOKUP_CACHED support for io_uring
- Disable /proc/thread-self/ for io_uring, like we do for /proc/self
- Add Pavel to the io_uring MAINTAINERS entry
- Tons of code cleanups and optimizations (Pavel)
- Support for skip entries in file registration (Noah)"
* tag 'for-5.12/io_uring-2021-02-17' of git://git.kernel.dk/linux-block: (103 commits)
io_uring: tctx->task_lock should be IRQ safe
proc: don't allow async path resolution of /proc/thread-self components
io_uring: kill cached requests from exiting task closing the ring
io_uring: add helper to free all request caches
io_uring: allow task match to be passed to io_req_cache_free()
io-wq: clear out worker ->fs and ->files
io_uring: optimise io_init_req() flags setting
io_uring: clean io_req_find_next() fast check
io_uring: don't check PF_EXITING from syscall
io_uring: don't split out consume out of SQE get
io_uring: save ctx put/get for task_work submit
io_uring: don't duplicate io_req_task_queue()
io_uring: optimise SQPOLL mm/files grabbing
io_uring: optimise out unlikely link queue
io_uring: take compl state from submit state
io_uring: inline io_complete_rw_common()
io_uring: move res check out of io_rw_reissue()
io_uring: simplify iopoll reissuing
io_uring: clean up io_req_free_batch_finish()
io_uring: move submit side state closer in the ring
...
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Assumes current->files->file_lock is already held on invocation. Helps
the caller check the file before removing the fd, if it needs to.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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no point going through the intermediate pipe
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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The may_follow_link(), may_linkat(), may_lookup(), may_open(),
may_o_create(), may_create_in_sticky(), may_delete(), and may_create()
helpers determine whether the caller is privileged enough to perform the
associated operations. Let them handle idmapped mounts by mapping the
inode or fsids according to the mount's user namespace. Afterwards the
checks are identical to non-idmapped inodes. The patch takes care to
retrieve the mount's user namespace right before performing permission
checks and passing it down into the fileystem so the user namespace
can't change in between by someone idmapping a mount that is currently
not idmapped. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.
Link: https://lore.kernel.org/r/20210121131959.646623-13-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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Pull block updates from Jens Axboe:
"Another series of killing more code than what is being added, again
thanks to Christoph's relentless cleanups and tech debt tackling.
This contains:
- blk-iocost improvements (Baolin Wang)
- part0 iostat fix (Jeffle Xu)
- Disable iopoll for split bios (Jeffle Xu)
- block tracepoint cleanups (Christoph Hellwig)
- Merging of struct block_device and hd_struct (Christoph Hellwig)
- Rework/cleanup of how block device sizes are updated (Christoph
Hellwig)
- Simplification of gendisk lookup and removal of block device
aliasing (Christoph Hellwig)
- Block device ioctl cleanups (Christoph Hellwig)
- Removal of bdget()/blkdev_get() as exported API (Christoph Hellwig)
- Disk change rework, avoid ->revalidate_disk() (Christoph Hellwig)
- sbitmap improvements (Pavel Begunkov)
- Hybrid polling fix (Pavel Begunkov)
- bvec iteration improvements (Pavel Begunkov)
- Zone revalidation fixes (Damien Le Moal)
- blk-throttle limit fix (Yu Kuai)
- Various little fixes"
* tag 'for-5.11/block-2020-12-14' of git://git.kernel.dk/linux-block: (126 commits)
blk-mq: fix msec comment from micro to milli seconds
blk-mq: update arg in comment of blk_mq_map_queue
blk-mq: add helper allocating tagset->tags
Revert "block: Fix a lockdep complaint triggered by request queue flushing"
nvme-loop: use blk_mq_hctx_set_fq_lock_class to set loop's lock class
blk-mq: add new API of blk_mq_hctx_set_fq_lock_class
block: disable iopoll for split bio
block: Improve blk_revalidate_disk_zones() checks
sbitmap: simplify wrap check
sbitmap: replace CAS with atomic and
sbitmap: remove swap_lock
sbitmap: optimise sbitmap_deferred_clear()
blk-mq: skip hybrid polling if iopoll doesn't spin
blk-iocost: Factor out the base vrate change into a separate function
blk-iocost: Factor out the active iocgs' state check into a separate function
blk-iocost: Move the usage ratio calculation to the correct place
blk-iocost: Remove unnecessary advance declaration
blk-iocost: Fix some typos in comments
blktrace: fix up a kerneldoc comment
block: remove the request_queue to argument request based tracepoints
...
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Pass in the struct filename pointers instead of the user string, and
update the three callers to do the same.
This behaves like do_unlinkat(), which also takes a filename struct and
puts it when it is done. Converting callers is then trivial.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Switch the block device lookup interfaces to directly work with a dev_t
so that struct block_device references are only acquired by the
blkdev_get variants (and the blk-cgroup special case). This means that
we now don't need an extra reference in the inode and can generally
simplify handling of struct block_device to keep the lookups contained
in the core block layer code.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Acked-by: Tejun Heo <tj@kernel.org>
Acked-by: Coly Li <colyli@suse.de> [bcache]
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Just open code the wait in the only caller of both functions.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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compat_sys_mount is identical to the regular sys_mount now, so remove it
and use the native version everywhere.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull init and set_fs() cleanups from Al Viro:
"Christoph's 'getting rid of ksys_...() uses under KERNEL_DS' series"
* 'hch.init_path' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (50 commits)
init: add an init_dup helper
init: add an init_utimes helper
init: add an init_stat helper
init: add an init_mknod helper
init: add an init_mkdir helper
init: add an init_symlink helper
init: add an init_link helper
init: add an init_eaccess helper
init: add an init_chmod helper
init: add an init_chown helper
init: add an init_chroot helper
init: add an init_chdir helper
init: add an init_rmdir helper
init: add an init_unlink helper
init: add an init_umount helper
init: add an init_mount helper
init: mark create_dev as __init
init: mark console_on_rootfs as __init
init: initialize ramdisk_execute_command at compile time
devtmpfs: refactor devtmpfsd()
...
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Add a simple helper to mknod with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_mknod.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add a simple helper to mkdir with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_mkdir.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add a simple helper to symlink with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_symlink.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add a simple helper to link with a kernel space file name and switch
the early init code over to it. Remove the now unused ksys_link.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add a simple helper to chmod with a kernel space file name and switch
the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Add a simple helper to chown with a kernel space file name and switch
the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Like ksys_umount, but takes a kernel pointer for the destination path.
Switch over the umount in the init code, which just happen to work due to
the implicit set_fs(KERNEL_DS) during early init right now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Like do_mount, but takes a kernel pointer for the destination path.
Switch over the mounts in the init code and devtmpfs to it, which
just happen to work due to the implicit set_fs(KERNEL_DS) during early
init right now.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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This mirrors do_unlinkat and will make life a little easier for
the init code to reuse the whole function with a kernel filename.
Signed-off-by: Christoph Hellwig <hch@lst.de>
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Move most of the block related definition out of fs.h into more suitable
headers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"A lot of bug fixes and cleanups for ext4, including:
- Fix performance problems found in dioread_nolock now that it is the
default, caused by transaction leaks.
- Clean up fiemap handling in ext4
- Clean up and refactor multiple block allocator (mballoc) code
- Fix a problem with mballoc with a smaller file systems running out
of blocks because they couldn't properly use blocks that had been
reserved by inode preallocation.
- Fixed a race in ext4_sync_parent() versus rename()
- Simplify the error handling in the extent manipulation code
- Make sure all metadata I/O errors are felected to
ext4_ext_dirty()'s and ext4_make_inode_dirty()'s callers.
- Avoid passing an error pointer to brelse in ext4_xattr_set()
- Fix race which could result to freeing an inode on the dirty last
in data=journal mode.
- Fix refcount handling if ext4_iget() fails
- Fix a crash in generic/019 caused by a corrupted extent node"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (58 commits)
ext4: avoid unnecessary transaction starts during writeback
ext4: don't block for O_DIRECT if IOCB_NOWAIT is set
ext4: remove the access_ok() check in ext4_ioctl_get_es_cache
fs: remove the access_ok() check in ioctl_fiemap
fs: handle FIEMAP_FLAG_SYNC in fiemap_prep
fs: move fiemap range validation into the file systems instances
iomap: fix the iomap_fiemap prototype
fs: move the fiemap definitions out of fs.h
fs: mark __generic_block_fiemap static
ext4: remove the call to fiemap_check_flags in ext4_fiemap
ext4: split _ext4_fiemap
ext4: fix fiemap size checks for bitmap files
ext4: fix EXT4_MAX_LOGICAL_BLOCK macro
add comment for ext4_dir_entry_2 file_type member
jbd2: avoid leaking transaction credits when unreserving handle
ext4: drop ext4_journal_free_reserved()
ext4: mballoc: use lock for checking free blocks while retrying
ext4: mballoc: refactor ext4_mb_good_group()
ext4: mballoc: introduce pcpu seqcnt for freeing PA to improve ENOSPC handling
ext4: mballoc: refactor ext4_mb_discard_preallocations()
...
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Ext4 needs to remove inode from writeback lists after it is out of
visibility of its journalling machinery (which can still dirty the
inode). Export inode_io_list_del() for it.
Signed-off-by: Jan Kara <jack@suse.cz>
Link: https://lore.kernel.org/r/20200421085445.5731-3-jack@suse.cz
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
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Pull io_uring updates from Jens Axboe:
"A relatively quiet round, mostly just fixes and code improvements. In
particular:
- Make statx just use the generic statx handler, instead of open
coding it. We don't need that anymore, as we always call it async
safe (Bijan)
- Enable closing of the ring itself. Also fixes O_PATH closure (me)
- Properly name completion members (me)
- Batch reap of dead file registrations (me)
- Allow IORING_OP_POLL with double waitqueues (me)
- Add tee(2) support (Pavel)
- Remove double off read (Pavel)
- Fix overflow cancellations (Pavel)
- Improve CQ timeouts (Pavel)
- Async defer drain fixes (Pavel)
- Add support for enabling/disabling notifications on a registered
eventfd (Stefano)
- Remove dead state parameter (Xiaoguang)
- Disable SQPOLL submit on dying ctx (Xiaoguang)
- Various code cleanups"
* tag 'for-5.8/io_uring-2020-06-01' of git://git.kernel.dk/linux-block: (29 commits)
io_uring: fix overflowed reqs cancellation
io_uring: off timeouts based only on completions
io_uring: move timeouts flushing to a helper
statx: hide interfaces no longer used by io_uring
io_uring: call statx directly
statx: allow system call to be invoked from io_uring
io_uring: add io_statx structure
io_uring: get rid of manual punting in io_close
io_uring: separate DRAIN flushing into a cold path
io_uring: don't re-read sqe->off in timeout_prep()
io_uring: simplify io_timeout locking
io_uring: fix flush req->refs underflow
io_uring: don't submit sqes when ctx->refs is dying
io_uring: async task poll trigger cleanup
io_uring: add tee(2) support
splice: export do_tee()
io_uring: don't repeat valid flag list
io_uring: rename io_file_put()
io_uring: remove req->needs_fixed_files
io_uring: cleanup io_poll_remove_one() logic
...
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The io_uring interfaces have been replaced by do_statx() and are no
longer needed.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This is a prepatory patch to allow io_uring to invoke statx directly.
Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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POSIX defines faccessat() as having a fourth "flags" argument, while the
linux syscall doesn't have it. Glibc tries to emulate AT_EACCESS and
AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken.
Add a new faccessat(2) syscall with the added flags argument and implement
both flags.
The value of AT_EACCESS is defined in glibc headers to be the same as
AT_REMOVEDIR. Use this value for the kernel interface as well, together
with the explanatory comment.
Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can
be useful and is trivial to implement.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs pathwalk sanitizing from Al Viro:
"Massive pathwalk rewrite and cleanups.
Several iterations have been posted; hopefully this thing is getting
readable and understandable now. Pretty much all parts of pathname
resolutions are affected...
The branch is identical to what has sat in -next, except for commit
message in "lift all calls of step_into() out of follow_dotdot/
follow_dotdot_rcu", crediting Qian Cai for reporting the bug; only
commit message changed there."
* 'work.dotdot1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (69 commits)
lookup_open(): don't bother with fallbacks to lookup+create
atomic_open(): no need to pass struct open_flags anymore
open_last_lookups(): move complete_walk() into do_open()
open_last_lookups(): lift O_EXCL|O_CREAT handling into do_open()
open_last_lookups(): don't abuse complete_walk() when all we want is unlazy
open_last_lookups(): consolidate fsnotify_create() calls
take post-lookup part of do_last() out of loop
link_path_walk(): sample parent's i_uid and i_mode for the last component
__nd_alloc_stack(): make it return bool
reserve_stack(): switch to __nd_alloc_stack()
pick_link(): take reserving space on stack into a new helper
pick_link(): more straightforward handling of allocation failures
fold path_to_nameidata() into its only remaining caller
pick_link(): pass it struct path already with normal refcounting rules
fs/namei.c: kill follow_mount()
non-RCU analogue of the previous commit
helper for mount rootwards traversal
follow_dotdot(): be lazy about changing nd->path
follow_dotdot_rcu(): be lazy about changing nd->path
follow_dotdot{,_rcu}(): massage loops
...
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This is bio layer functionality and not related to buffer heads.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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New LOOKUP flag, telling path_lookupat() to act as path_mountpointat().
IOW, traverse mounts at the final point and skip revalidation of the
location where it ends up.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Pull io_uring updates from Jens Axboe:
- Support for various new opcodes (fallocate, openat, close, statx,
fadvise, madvise, openat2, non-vectored read/write, send/recv, and
epoll_ctl)
- Faster ring quiesce for fileset updates
- Optimizations for overflow condition checking
- Support for max-sized clamping
- Support for probing what opcodes are supported
- Support for io-wq backend sharing between "sibling" rings
- Support for registering personalities
- Lots of little fixes and improvements
* tag 'for-5.6/io_uring-vfs-2020-01-29' of git://git.kernel.dk/linux-block: (64 commits)
io_uring: add support for epoll_ctl(2)
eventpoll: support non-blocking do_epoll_ctl() calls
eventpoll: abstract out epoll_ctl() handler
io_uring: fix linked command file table usage
io_uring: support using a registered personality for commands
io_uring: allow registering credentials
io_uring: add io-wq workqueue sharing
io-wq: allow grabbing existing io-wq
io_uring/io-wq: don't use static creds/mm assignments
io-wq: make the io_wq ref counted
io_uring: fix refcounting with batched allocations at OOM
io_uring: add comment for drain_next
io_uring: don't attempt to copy iovec for READ/WRITE
io_uring: honor IOSQE_ASYNC for linked reqs
io_uring: prep req when do IOSQE_ASYNC
io_uring: use labeled array init in io_op_defs
io_uring: optimise sqe-to-req flags translation
io_uring: remove REQ_F_IO_DRAINED
io_uring: file switch work needs to get flushed on exit
io_uring: hide uring_fd in ctx
...
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Pull SCSI updates from James Bottomley:
"This series is slightly unusual because it includes Arnd's compat
ioctl tree here:
1c46a2cf2dbd Merge tag 'block-ioctl-cleanup-5.6' into 5.6/scsi-queue
Excluding Arnd's changes, this is mostly an update of the usual
drivers: megaraid_sas, mpt3sas, qla2xxx, ufs, lpfc, hisi_sas.
There are a couple of core and base updates around error propagation
and atomicity in the attribute container base we use for the SCSI
transport classes.
The rest is minor changes and updates"
* tag 'scsi-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi: (149 commits)
scsi: hisi_sas: Rename hisi_sas_cq.pci_irq_mask
scsi: hisi_sas: Add prints for v3 hw interrupt converge and automatic affinity
scsi: hisi_sas: Modify the file permissions of trigger_dump to write only
scsi: hisi_sas: Replace magic number when handle channel interrupt
scsi: hisi_sas: replace spin_lock_irqsave/spin_unlock_restore with spin_lock/spin_unlock
scsi: hisi_sas: use threaded irq to process CQ interrupts
scsi: ufs: Use UFS device indicated maximum LU number
scsi: ufs: Add max_lu_supported in struct ufs_dev_info
scsi: ufs: Delete is_init_prefetch from struct ufs_hba
scsi: ufs: Inline two functions into their callers
scsi: ufs: Move ufshcd_get_max_pwr_mode() to ufshcd_device_params_init()
scsi: ufs: Split ufshcd_probe_hba() based on its called flow
scsi: ufs: Delete struct ufs_dev_desc
scsi: ufs: Fix ufshcd_probe_hba() reture value in case ufshcd_scsi_add_wlus() fails
scsi: ufs-mediatek: enable low-power mode for hibern8 state
scsi: ufs: export some functions for vendor usage
scsi: ufs-mediatek: add dbg_register_dump implementation
scsi: qla2xxx: Fix a NULL pointer dereference in an error path
scsi: qla1280: Make checking for 64bit support consistent
scsi: megaraid_sas: Update driver version to 07.713.01.00-rc1
...
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To implement an async stat, we need to provide the flags mapping and
the statx user copy. Make them available internally, through
fs/internal.h.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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This is a prep patch for supporting non-blocking open from io_uring.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
adds bio_truncate() for handling bio EOD. However, bio_truncate()
doesn't use the passed 'op' parameter from guard_bio_eod's callers.
So bio_trunacate() may retrieve wrong 'op', and zering pages may
not be done for READ bio.
Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs()
in submit_bh_wbc() so that bio_truncate() can always retrieve correct
op info.
Meantime remove the 'op' parameter from guard_bio_eod() because it isn't
used any more.
Cc: Carlos Maiolino <cmaiolino@redhat.com>
Cc: linux-fsdevel@vger.kernel.org
Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Fold in kerneldoc and bio_op() change.
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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Now that both native and compat ioctl syscalls are
in the same file, a couple of simplifications can
be made, bringing the implementation closer together:
- do_vfs_ioctl(), ioctl_preallocate(), and compat_ioctl_preallocate()
can become static, allowing the compiler to optimize better
- slightly update the coding style for consistency between
the functions.
- rather than listing each command in two switch statements
for the compat case, just call a single function that has
all the common commands.
As a side-effect, FS_IOC_RESVSP/FS_IOC_RESVSP64 are now available
to x86 compat tasks, along with FS_IOC_RESVSP_32/FS_IOC_RESVSP64_32.
This is harmless for i386 emulation, and can be considered a bugfix
for x32 emulation, which never supported these in the past.
Reviewed-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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no users outside of fs/dcache.c
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
|