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Merge tag 'idmapped-mounts-v5.12' of 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.pdfhttps://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:
1d7b902e28
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
...
- vDSO build improvements including support for building with BSD.
- Cleanup to the AMU support code and initialisation rework to support
cpufreq drivers built as modules.
- Removal of synthetic frame record from exception stack when entering
the kernel from EL0.
- Add support for the TRNG firmware call introduced by Arm spec
DEN0098.
- Cleanup and refactoring across the board.
- Avoid calling arch_get_random_seed_long() from
add_interrupt_randomness()
- Perf and PMU updates including support for Cortex-A78 and the v8.3
SPE extensions.
- Significant steps along the road to leaving the MMU enabled during
kexec relocation.
- Faultaround changes to initialise prefaulted PTEs as 'old' when
hardware access-flag updates are supported, which drastically
improves vmscan performance.
- CPU errata updates for Cortex-A76 (#1463225) and Cortex-A55
(#1024718)
- Preparatory work for yielding the vector unit at a finer granularity
in the crypto code, which in turn will one day allow us to defer
softirq processing when it is in use.
- Support for overriding CPU ID register fields on the command-line.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
- vDSO build improvements including support for building with BSD.
- Cleanup to the AMU support code and initialisation rework to support
cpufreq drivers built as modules.
- Removal of synthetic frame record from exception stack when entering
the kernel from EL0.
- Add support for the TRNG firmware call introduced by Arm spec
DEN0098.
- Cleanup and refactoring across the board.
- Avoid calling arch_get_random_seed_long() from
add_interrupt_randomness()
- Perf and PMU updates including support for Cortex-A78 and the v8.3
SPE extensions.
- Significant steps along the road to leaving the MMU enabled during
kexec relocation.
- Faultaround changes to initialise prefaulted PTEs as 'old' when
hardware access-flag updates are supported, which drastically
improves vmscan performance.
- CPU errata updates for Cortex-A76 (#1463225) and Cortex-A55
(#1024718)
- Preparatory work for yielding the vector unit at a finer granularity
in the crypto code, which in turn will one day allow us to defer
softirq processing when it is in use.
- Support for overriding CPU ID register fields on the command-line.
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (85 commits)
drivers/perf: Replace spin_lock_irqsave to spin_lock
mm: filemap: Fix microblaze build failure with 'mmu_defconfig'
arm64: Make CPU_BIG_ENDIAN depend on ld.bfd or ld.lld 13.0.0+
arm64: cpufeatures: Allow disabling of Pointer Auth from the command-line
arm64: Defer enabling pointer authentication on boot core
arm64: cpufeatures: Allow disabling of BTI from the command-line
arm64: Move "nokaslr" over to the early cpufeature infrastructure
KVM: arm64: Document HVC_VHE_RESTART stub hypercall
arm64: Make kvm-arm.mode={nvhe, protected} an alias of id_aa64mmfr1.vh=0
arm64: Add an aliasing facility for the idreg override
arm64: Honor VHE being disabled from the command-line
arm64: Allow ID_AA64MMFR1_EL1.VH to be overridden from the command line
arm64: cpufeature: Add an early command-line cpufeature override facility
arm64: Extract early FDT mapping from kaslr_early_init()
arm64: cpufeature: Use IDreg override in __read_sysreg_by_encoding()
arm64: cpufeature: Add global feature override facility
arm64: Move SCTLR_EL1 initialisation to EL-agnostic code
arm64: Simplify init_el2_state to be non-VHE only
arm64: Move VHE-specific SPE setup to mutate_to_vhe()
arm64: Drop early setting of MDSCR_EL2.TPMS
...
- Fix an ABBA deadlock when renaming files on overlayfs.
- Make sure that we can't overflow the inode extent counters when adding
to or removing extents from a file.
- Make directory sgid inheritance work the same way as all the other
filesystems.
- Don't drain the buffer cache on freeze and ro remount, which should
reduce the amount of time if read-only workloads are continuing
during the freeze.
- Fix a bug where symlink size isn't reported to the vfs in ecryptfs.
- Disentangle log cleaning from log covering. This refactoring sets us
up for future changes to the log, though for now it simply means that
we can use covering for freezes, and cleaning becomes something we
only do at unmount.
- Speed up file fsyncs by reducing iolock cycling.
- Fix delalloc blocks leaking when changing the project id fails because
of input validation errors in FSSETXATTR.
- Fix oversized quota reservation when converting unwritten extents
during a DAX write.
- Create a transaction allocation helper function to standardize the
idiom of allocating a transaction, reserving blocks, locking inodes,
and reserving quota. Replace all the open-coded logic for file
creation, file ownership changes, and file modifications to use them.
- Actually shut down the fs if the incore quota reservations get
corrupted.
- Fix background block garbage collection scans to not block and to
actually clean out CoW staging extents properly.
- Run block gc scans when we run low on project quota.
- Use the standardized transaction allocation helpers to make it so that
ENOSPC and EDQUOT errors during reservation will back out, invoke the
block gc scanner, and try again. This is preparation for introducing
background inode garbage collection in the next cycle.
- Combine speculative post-EOF block garbage collection with speculative
copy on write block garbage collection.
- Enable multithreaded quotacheck.
- Allow sysadmins to tweak the CPU affinities and maximum concurrency
levels of quotacheck and background blockgc worker pools.
- Expose the inode btree counter feature in the fs geometry ioctl.
- Cleanups of the growfs code in preparation for starting work on
filesystem shrinking.
- Fix all the bloody gcc warnings that the maintainer knows about. :P
- Fix a RST syntax error.
- Don't trigger bmbt corruption assertions after the fs shuts down.
- Restore behavior of forcing SIGBUS on a shut down filesystem when
someone triggers a mmap write fault (or really, any buffered write).
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Merge tag 'xfs-5.12-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Darrick Wong:
"There's a lot going on this time, which seems about right for this
drama-filled year.
Community developers added some code to speed up freezing when
read-only workloads are still running, refactored the logging code,
added checks to prevent file extent counter overflow, reduced iolock
cycling to speed up fsync and gc scans, and started the slow march
towards supporting filesystem shrinking.
There's a huge refactoring of the internal speculative preallocation
garbage collection code which fixes a bunch of bugs, makes the gc
scheduling per-AG and hence multithreaded, and standardizes the retry
logic when we try to reserve space or quota, can't, and want to
trigger a gc scan. We also enable multithreaded quotacheck to reduce
mount times further. This is also preparation for background file gc,
which may or may not land for 5.13.
We also fixed some deadlocks in the rename code, fixed a quota
accounting leak when FSSETXATTR fails, restored the behavior that
write faults to an mmap'd region actually cause a SIGBUS, fixed a bug
where sgid directory inheritance wasn't quite working properly, and
fixed a bug where symlinks weren't working properly in ecryptfs. We
also now advertise the inode btree counters feature that was
introduced two cycles ago.
Summary:
- Fix an ABBA deadlock when renaming files on overlayfs.
- Make sure that we can't overflow the inode extent counters when
adding to or removing extents from a file.
- Make directory sgid inheritance work the same way as all the other
filesystems.
- Don't drain the buffer cache on freeze and ro remount, which should
reduce the amount of time if read-only workloads are continuing
during the freeze.
- Fix a bug where symlink size isn't reported to the vfs in ecryptfs.
- Disentangle log cleaning from log covering. This refactoring sets
us up for future changes to the log, though for now it simply means
that we can use covering for freezes, and cleaning becomes
something we only do at unmount.
- Speed up file fsyncs by reducing iolock cycling.
- Fix delalloc blocks leaking when changing the project id fails
because of input validation errors in FSSETXATTR.
- Fix oversized quota reservation when converting unwritten extents
during a DAX write.
- Create a transaction allocation helper function to standardize the
idiom of allocating a transaction, reserving blocks, locking
inodes, and reserving quota. Replace all the open-coded logic for
file creation, file ownership changes, and file modifications to
use them.
- Actually shut down the fs if the incore quota reservations get
corrupted.
- Fix background block garbage collection scans to not block and to
actually clean out CoW staging extents properly.
- Run block gc scans when we run low on project quota.
- Use the standardized transaction allocation helpers to make it so
that ENOSPC and EDQUOT errors during reservation will back out,
invoke the block gc scanner, and try again. This is preparation for
introducing background inode garbage collection in the next cycle.
- Combine speculative post-EOF block garbage collection with
speculative copy on write block garbage collection.
- Enable multithreaded quotacheck.
- Allow sysadmins to tweak the CPU affinities and maximum concurrency
levels of quotacheck and background blockgc worker pools.
- Expose the inode btree counter feature in the fs geometry ioctl.
- Cleanups of the growfs code in preparation for starting work on
filesystem shrinking.
- Fix all the bloody gcc warnings that the maintainer knows about. :P
- Fix a RST syntax error.
- Don't trigger bmbt corruption assertions after the fs shuts down.
- Restore behavior of forcing SIGBUS on a shut down filesystem when
someone triggers a mmap write fault (or really, any buffered
write)"
* tag 'xfs-5.12-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (85 commits)
xfs: consider shutdown in bmapbt cursor delete assert
xfs: fix boolreturn.cocci warnings
xfs: restore shutdown check in mapped write fault path
xfs: fix rst syntax error in admin guide
xfs: fix incorrect root dquot corruption error when switching group/project quota types
xfs: get rid of xfs_growfs_{data,log}_t
xfs: rename `new' to `delta' in xfs_growfs_data_private()
libxfs: expose inobtcount in xfs geometry
xfs: don't bounce the iolock between free_{eof,cow}blocks
xfs: expose the blockgc workqueue knobs publicly
xfs: parallelize block preallocation garbage collection
xfs: rename block gc start and stop functions
xfs: only walk the incore inode tree once per blockgc scan
xfs: consolidate the eofblocks and cowblocks workers
xfs: consolidate incore inode radix tree posteof/cowblocks tags
xfs: remove trivial eof/cowblocks functions
xfs: hide xfs_icache_free_cowblocks
xfs: hide xfs_icache_free_eofblocks
xfs: relocate the eofb/cowb workqueue functions
xfs: set WQ_SYSFS on all workqueues in debug mode
...
In anticipation of more restructuring of the eof/cowblocks gc code,
refactor calling of those two functions into a single internal helper
function, then present a new standard interface to purge speculative
block preallocations and start shifting higher level code to use that.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Change the signature of xfs_blockgc_free_quota in preparation for the
next few patches. Callers can now pass EOF_FLAGS into the function to
control scan parameters; and the function will now pass back any
corruption errors seen while scanning, though for our retry loops we'll
just try again unconditionally.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Move this function further down in the file so that later cleanups won't
have to declare static functions. Change the name because we're about
to rework all the code that performs garbage collection of speculatively
allocated file blocks. No functional changes.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
The functions to run an eof/cowblocks scan to try to reduce quota usage
are kind of a mess -- the logic repeatedly initializes an eofb structure
and there are logic bugs in the code that result in the cowblocks scan
never actually happening.
Replace all three functions with a single function that fills out an
eofb and runs both eof and cowblocks scans.
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Attempt shared locking for unaligned DIO, but only if the the
underlying extent is already allocated and in written state. On
failure, retry with the existing exclusive locking.
Test case is fio randrw of 512 byte IOs using AIO and an iodepth of
32 IOs.
Vanilla:
READ: bw=4560KiB/s (4670kB/s), 4560KiB/s-4560KiB/s (4670kB/s-4670kB/s), io=134MiB (140MB), run=30001-30001msec
WRITE: bw=4567KiB/s (4676kB/s), 4567KiB/s-4567KiB/s (4676kB/s-4676kB/s), io=134MiB (140MB), run=30001-30001msec
Patched:
READ: bw=37.6MiB/s (39.4MB/s), 37.6MiB/s-37.6MiB/s (39.4MB/s-39.4MB/s), io=1127MiB (1182MB), run=30002-30002msec
WRITE: bw=37.6MiB/s (39.4MB/s), 37.6MiB/s-37.6MiB/s (39.4MB/s-39.4MB/s), io=1128MiB (1183MB), run=30002-30002msec
That's an improvement from ~18k IOPS to a ~150k IOPS, which is
about the IOPS limit of the VM block device setup I'm testing on.
4kB block IO comparison:
READ: bw=296MiB/s (310MB/s), 296MiB/s-296MiB/s (310MB/s-310MB/s), io=8868MiB (9299MB), run=30002-30002msec
WRITE: bw=296MiB/s (310MB/s), 296MiB/s-296MiB/s (310MB/s-310MB/s), io=8878MiB (9309MB), run=30002-30002msec
Which is ~150k IOPS, same as what the test gets for sub-block
AIO+DIO writes with this patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: rebased, split unaligned from nowait]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The unaligned DIO write path is more convolted than the normal path,
and we are about to make it more complex. Keep the block aligned
fast path dio write code trim and simple by splitting out the
unaligned DIO code from it.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: rebased, fixed a few minor nits]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Use a more suitable event class.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Pass the iocb and iov_iter to the tracepoints and leave decoding of
actual arguments to the code only run when tracing is enabled.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
The iomap code has been designed from the start not to do magic fallback,
so remove the assert in preparation for further code cleanups.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Drop a few pointless aio_ prefixes.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Ensure we don't block on the iolock, or waiting for I/O in
xfs_file_aio_write_checks if the caller asked to avoid that.
Fixes: 29a5d29ec1 ("xfs: nowait aio support")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Add a helper to factor out the nowait locking logical for the read/write
helpers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Enable idmapped mounts for xfs. This basically just means passing down
the user_namespace argument from the VFS methods down to where it is
passed to the relevant helpers.
Note that full-filesystem bulkstat is not supported from inside idmapped
mounts as it is an administrative operation that acts on the whole file
system. The limitation is not applied to the bulkstat single operation
that just operates on a single inode.
Link: https://lore.kernel.org/r/20210121131959.646623-40-christian.brauner@ubuntu.com
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Pass a set of flags to iomap_dio_rw instead of the boolean
wait_for_completion argument. The IOMAP_DIO_FORCE_WAIT flag
replaces the wait_for_completion, but only needs to be passed
when the iocb isn't synchronous to start with to simplify the
callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
[djwong: rework xfs_file.c so that we can push iomap changes separately]
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
If the inode is not pinned by the time fsync is called we don't need the
ilock to protect against concurrent clearing of ili_fsync_fields as the
inode won't need a log flush or clearing of these fields. Not taking
the iolock allows for full concurrency of fsync and thus O_DSYNC
completions with io_uring/aio write submissions.
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>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Factor out the log syncing logic into two helpers to make the code easier
to read and more maintainable.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
The comment in xfs_file_aio_write_checks() about calling file_modified()
after dropping the ilock doesn't make sense, because the code that
unconditionally acquires and drops the ilock was removed by
commit 467f78992a ("xfs: reduce ilock hold times in
xfs_file_aio_write_checks").
Remove this outdated comment.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
alloc_set_pte() has two users with different requirements: in the
faultaround code, it called from an atomic context and PTE page table
has to be preallocated. finish_fault() can sleep and allocate page table
as needed.
PTL locking rules are also strange, hard to follow and overkill for
finish_fault().
Let's untangle the mess. alloc_set_pte() has gone now. All locking is
explicit.
The price is some code duplication to handle huge pages in faultaround
path, but it should be fine, having overall improvement in readability.
Link: https://lore.kernel.org/r/20201229132819.najtavneutnf7ajp@box
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
[will: s/from from/from/ in comment; spotted by willy]
Signed-off-by: Will Deacon <will@kernel.org>
In commit fe341eb151, I forgot that xfs_free_file_space isn't strictly
a "remove mapped blocks" function. It is actually a function to zero
file space by punching out the middle and writing zeroes to the
unaligned ends of the specified range. Therefore, putting a rtextsize
alignment check in that function is wrong because that breaks unaligned
ZERO_RANGE on the realtime volume.
Furthermore, xfs_file_fallocate already has alignment checks for the
functions require the file range to be aligned to the size of a
fundamental allocation unit (which is 1 FSB on the data volume and 1 rt
extent on the realtime volume). Create a new helper to check fallocate
arguments against the realtiem allocation unit size, fix the fallocate
frontend to use it, fix free_file_space to delete the correct range, and
remove a now redundant check from insert_file_space.
NOTE: The realtime extent size is not required to be a power of two!
Fixes: fe341eb151 ("xfs: ensure that fpunch, fcollapse, and finsert operations are aligned to rt extent size")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Commit 5833112df7 tried to make it so that a remap operation would
force the log out to disk if the filesystem is mounted with mandatory
synchronous writes. Unfortunately, that commit failed to handle the
case where the inode or the file descriptor require mandatory
synchronous writes.
Refactor the check into into a helper that will look for all three
conditions, and now we can treat reflink just like any other synchronous
write.
Fixes: 5833112df7 ("xfs: reflink should force the log out if mounted with wsync")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
When running in a dax mode, if the user maps a page with MAP_PRIVATE and
PROT_WRITE, the xfs filesystem would incorrectly update ctime and mtime
when the user hits a COW fault.
This breaks building of the Linux kernel. How to reproduce:
1. extract the Linux kernel tree on dax-mounted xfs filesystem
2. run make clean
3. run make -j12
4. run make -j12
at step 4, make would incorrectly rebuild the whole kernel (although it
was already built in step 3).
The reason for the breakage is that almost all object files depend on
objtool. When we run objtool, it takes COW page fault on its .data
section, and these faults will incorrectly update the timestamp of the
objtool binary. The updated timestamp causes make to rebuild the whole
tree.
Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- Fix some btree block pingponging problems when swapping extents
- Redesign the reflink copy loop so that we only run one remapping
operation per transaction. This helps us avoid running out of block
reservation on highly deduped filesystems.
- Take the MMAPLOCK around filemap_map_pages.
- Make inode reclaim fully async so that we avoid stalling processes on
flushing inodes to disk.
- Reduce inode cluster buffer RMW cycles by attaching the buffer to
dirty inodes so we won't let go of the cluster buffer when we know
we're going to need it soon.
- Add some more checks to the realtime bitmap file scrubber.
- Don't trip false lockdep warnings in fs freeze.
- Remove various redundant lines of code.
- Remove unnecessary calls to xfs_perag_{get,put}.
- Preserve I_VERSION state across remounts.
- Fix an unmount hang due to AIL going to sleep with a non-empty delwri
buffer list.
- Fix an error in the inode allocation space reservation macro that
caused regressions in generic/531.
- Fix a potential livelock when dquot flush fails because the dquot
buffer is locked.
- Fix a miscalculation when reserving inode quota that could cause users
to exceed a hardlimit.
- Refactor struct xfs_dquot to use native types for incore fields
instead of abusing the ondisk struct for this purpose. This will
eventually enable proper y2038+ support, but for now it merely cleans
up the quota function declarations.
- Actually increment the quota softlimit warning counter so that soft
failures turn into hard(er) failures when they exceed the softlimit
warning counter limits set by the administrator.
- Split incore dquot state flags into their own field and namespace, to
avoid mixing them with quota type flags.
- Create a new quota type flags namespace so that we can make it obvious
when a quota function takes a quota type (user, group, project) as an
argument.
- Rename the ondisk dquot flags field to type, as that more accurately
represents what we store in it.
- Drop our bespoke memory allocation flags in favor of GFP_*.
- Rearrange the xattr functions so that we no longer mix metadata
updates and transaction management (e.g. rolling complex transactions)
in the same functions. This work will prepare us for atomic xattr
operations (itself a prerequisite for directory backrefs) in future
release cycles.
- Support FS_DAX_FL (aka FS_XFLAG_DAX) via GETFLAGS/SETFLAGS.
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Merge tag 'xfs-5.9-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull xfs updates from Darrick Wong:
"There are quite a few changes in this release, the most notable of
which is that we've made inode flushing fully asynchronous, and we no
longer block memory reclaim on this.
Furthermore, we have fixed a long-standing bug in the quota code where
soft limit warnings and inode limits were never tracked properly.
Moving further down the line, the reflink control loops have been
redesigned to behave more efficiently; and numerous small bugs have
been fixed (see below). The xattr and quota code have been extensively
refactored in preparation for more new features coming down the line.
Finally, the behavior of DAX between ext4 and xfs has been stabilized,
which gets us a step closer to removing the experimental tag from that
feature.
We have a few new contributors this time around. Welcome, all!
I anticipate a second pull request next week for a few small bugfixes
that have been trickling in, but this is it for big changes.
Summary:
- Fix some btree block pingponging problems when swapping extents
- Redesign the reflink copy loop so that we only run one remapping
operation per transaction. This helps us avoid running out of block
reservation on highly deduped filesystems.
- Take the MMAPLOCK around filemap_map_pages.
- Make inode reclaim fully async so that we avoid stalling processes
on flushing inodes to disk.
- Reduce inode cluster buffer RMW cycles by attaching the buffer to
dirty inodes so we won't let go of the cluster buffer when we know
we're going to need it soon.
- Add some more checks to the realtime bitmap file scrubber.
- Don't trip false lockdep warnings in fs freeze.
- Remove various redundant lines of code.
- Remove unnecessary calls to xfs_perag_{get,put}.
- Preserve I_VERSION state across remounts.
- Fix an unmount hang due to AIL going to sleep with a non-empty
delwri buffer list.
- Fix an error in the inode allocation space reservation macro that
caused regressions in generic/531.
- Fix a potential livelock when dquot flush fails because the dquot
buffer is locked.
- Fix a miscalculation when reserving inode quota that could cause
users to exceed a hardlimit.
- Refactor struct xfs_dquot to use native types for incore fields
instead of abusing the ondisk struct for this purpose. This will
eventually enable proper y2038+ support, but for now it merely
cleans up the quota function declarations.
- Actually increment the quota softlimit warning counter so that soft
failures turn into hard(er) failures when they exceed the softlimit
warning counter limits set by the administrator.
- Split incore dquot state flags into their own field and namespace,
to avoid mixing them with quota type flags.
- Create a new quota type flags namespace so that we can make it
obvious when a quota function takes a quota type (user, group,
project) as an argument.
- Rename the ondisk dquot flags field to type, as that more
accurately represents what we store in it.
- Drop our bespoke memory allocation flags in favor of GFP_*.
- Rearrange the xattr functions so that we no longer mix metadata
updates and transaction management (e.g. rolling complex
transactions) in the same functions. This work will prepare us for
atomic xattr operations (itself a prerequisite for directory
backrefs) in future release cycles.
- Support FS_DAX_FL (aka FS_XFLAG_DAX) via GETFLAGS/SETFLAGS"
* tag 'xfs-5.9-merge-7' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (117 commits)
fs/xfs: Support that ioctl(SETXFLAGS/GETXFLAGS) can set/get inode DAX on XFS.
xfs: Lift -ENOSPC handler from xfs_attr_leaf_addname
xfs: Simplify xfs_attr_node_addname
xfs: Simplify xfs_attr_leaf_addname
xfs: Add helper function xfs_attr_node_removename_rmt
xfs: Add helper function xfs_attr_node_removename_setup
xfs: Add remote block helper functions
xfs: Add helper function xfs_attr_leaf_mark_incomplete
xfs: Add helpers xfs_attr_is_shortform and xfs_attr_set_shortform
xfs: Remove xfs_trans_roll in xfs_attr_node_removename
xfs: Remove unneeded xfs_trans_roll_inode calls
xfs: Add helper function xfs_attr_node_shrink
xfs: Pull up xfs_attr_rmtval_invalidate
xfs: Refactor xfs_attr_rmtval_remove
xfs: Pull up trans roll in xfs_attr3_leaf_clearflag
xfs: Factor out xfs_attr_rmtval_invalidate
xfs: Pull up trans roll from xfs_attr3_leaf_setflag
xfs: Refactor xfs_attr_try_sf_addname
xfs: Split apart xfs_attr_leaf_addname
xfs: Pull up trans handling in xfs_attr3_leaf_flipflags
...
- Make sure we call ->iomap_end with a failure code if ->iomap_begin
failed in any way; some filesystems need to try to undo things.
- Don't invalidate the page cache during direct reads since we already
sync'd the cache with disk.
- Make direct writes fall back to the page cache if the pre-write
cache invalidation fails. This avoids a cache coherency problem.
- Fix some idiotic virus scanner warning bs in the previous tag.
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Merge tag 'iomap-5.9-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap updates from Darrick Wong:
"The most notable changes are:
- iomap no longer invalidates the page cache when performing a direct
read, since doing so is unnecessary and the old directio code
doesn't do that either.
- iomap embraced the use of returning ENOTBLK from a direct write to
trigger falling back to a buffered write since ext4 already did
this and btrfs wants it for their port.
- iomap falls back to buffered writes if we're doing a direct write
and the page cache invalidation after the flush fails; this was
necessary to handle a corner case in the btrfs port.
- Remove email virus scanner detritus that was accidentally included
in yesterday's pull request. Clearly I need(ed) to update my git
branch checker scripts. :("
* tag 'iomap-5.9-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
iomap: fall back to buffered writes for invalidation failures
xfs: use ENOTBLK for direct I/O to buffered I/O fallback
iomap: Only invalidate page cache pages on direct IO writes
iomap: Make sure iomap_end is called after iomap_begin
Failing to invalid the page cache means data in incoherent, which is
a very bad state for the system. Always fall back to buffered I/O
through the page cache if we can't invalidate mappings.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Acked-by: Bob Peterson <rpeterso@redhat.com>
Acked-by: Damien Le Moal <damien.lemoal@wdc.com>
Reviewed-by: Theodore Ts'o <tytso@mit.edu> # for ext4
Reviewed-by: Andreas Gruenbacher <agruenba@redhat.com> # for gfs2
Reviewed-by: Ritesh Harjani <riteshh@linux.ibm.com>
This is what the classic fs/direct-io.c implementation and thuse other
file systems use.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The inode log item is kind of special in that it can be aggregating
new changes in memory at the same time time existing changes are
being written back to disk. This means there are fields in the log
item that are accessed concurrently from contexts that don't share
any locking at all.
e.g. updating ili_last_fields occurs at flush time under the
ILOCK_EXCL and flush lock at flush time, under the flush lock at IO
completion time, and is read under the ILOCK_EXCL when the inode is
logged. Hence there is no actual serialisation between reading the
field during logging of the inode in transactions vs clearing the
field in IO completion.
We currently get away with this by the fact that we are only
clearing fields in IO completion, and nothing bad happens if we
accidentally log more of the inode than we actually modify. Worst
case is we consume a tiny bit more memory and log bandwidth.
However, if we want to do more complex state manipulations on the
log item that requires updates at all three of these potential
locations, we need to have some mechanism of serialising those
operations. To do this, introduce a spinlock into the log item to
serialise internal state.
This could be done via the xfs_inode i_flags_lock, but this then
leads to potential lock inversion issues where inode flag updates
need to occur inside locks that best nest inside the inode log item
locks (e.g. marking inodes stale during inode cluster freeing).
Using a separate spinlock avoids these sorts of problems and
simplifies future code.
This does not touch the use of ili_fields in the item formatting
code - that is entirely protected by the ILOCK_EXCL at this point in
time, so it remains untouched.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
The page faultround path ->map_pages is implemented in XFS via
filemap_map_pages(). This function checks that pages found in page
cache lookups have not raced with truncate based invalidation by
checking page->mapping is correct and page->index is within EOF.
However, we've known for a long time that this is not sufficient to
protect against races with invalidations done by operations that do
not change EOF. e.g. hole punching and other fallocate() based
direct extent manipulations. The way we protect against these
races is we wrap the page fault operations in a XFS_MMAPLOCK_SHARED
lock so they serialise against fallocate and truncate before calling
into the filemap function that processes the fault.
Do the same for XFS's ->map_pages implementation to close this
potential data corruption issue.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Move the double-inode locking helpers to xfs_inode.c since they're not
specific to reflink.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Refactor the two functions that we use to lock and unlock two inodes to
block userspace from initiating IO against a file, whether via system
calls or mmap activity.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Fix the return value of xfs_reflink_remap_prep so that its return value
conventions match the rest of xfs.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
There are there are three extents counters per inode, one for each of
the forks. Two are in the legacy icdinode and one is directly in
struct xfs_inode. Switch to a single counter in the xfs_ifork structure
where it uses up padding at the end of the structure. This simplifies
various bits of code that just wants the number of extents counter and
can now directly dereference it.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Chandan Babu R <chandanrlinux@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reflink should force the log out to disk if the filesystem was mounted
with wsync, the same as most other operations in xfs.
[Note: XFS_MOUNT_WSYNC is set when the admin mounts the filesystem
with either the 'wsync' or 'sync' mount options, which effectively means
that we're classifying reflink/dedupe as IO operations and making them
synchronous when required.]
Fixes: 3fc9f5e409 ("xfs: remove xfs_reflink_remap_range")
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
[darrick: add more to the changelog]
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Create a new helper to force the log up to the last LSN touching an
inode.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Direct I/O reads can also be used with RWF_NOWAIT & co. Fix the inode
locking in xfs_file_dio_aio_read to take IOCB_NOWAIT into account.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Replace the mappedbno argument with the simple flags for xfs_da_reada_buf
and xfs_dir3_data_readahead.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
AIO+DIO can extend the file size on IO completion, and it holds
no inode locks while the IO is in flight. Therefore, a race
condition exists in file size updates if we do something like this:
aio-thread fallocate-thread
lock inode
submit IO beyond inode->i_size
unlock inode
.....
lock inode
break layouts
if (off + len > inode->i_size)
new_size = off + len
.....
inode_dio_wait()
<blocks>
.....
completes
inode->i_size updated
inode_dio_done()
....
<wakes>
<does stuff no long beyond EOF>
if (new_size)
xfs_vn_setattr(inode, new_size)
Yup, that attempt to extend the file size in the fallocate code
turns into a truncate - it removes the whatever the aio write
allocated and put to disk, and reduced the inode size back down to
where the fallocate operation ends.
Fundamentally, xfs_file_fallocate() not compatible with racing
AIO+DIO completions, so we need to move the inode_dio_wait() call
up to where the lock the inode and break the layouts.
Secondly, storing the inode size and then using it unchecked without
holding the ILOCK is not safe; we can only do such a thing if we've
locked out and drained all IO and other modification operations,
which we don't do initially in xfs_file_fallocate.
It should be noted that some of the fallocate operations are
compound operations - they are made up of multiple manipulations
that may zero data, and so we may need to flush and invalidate the
file multiple times during an operation. However, we only need to
lock out IO and other space manipulation operations once, as that
lockout is maintained until the entire fallocate operation has been
completed.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Remove xfs_zero_file_space and reorganize xfs_file_fallocate so that a
single call to xfs_alloc_file_space covers all modes that preallocate
blocks.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Add a new xfs_inode_buftarg helper that gets the data I/O buftarg for a
given inode. Replace the existing xfs_find_bdev_for_inode and
xfs_find_daxdev_for_inode helpers with this new general one and cleanup
some of the callers.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Instead of lots of magic conditionals in the main write_begin
handler this make the intent very clear. Thing will become even
better once we support delayed allocations for extent size hints
and realtime allocations.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Start untangling xfs_file_iomap_begin by splitting out the read-only
case into its own set of iomap_ops with a very simply iomap_begin
helper.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Use iomap_dio_rw() to wait for unaligned direct IO instead of opencoding
the wait.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Filesystems do not support doing IO as asynchronous in some cases. For
example in case of unaligned writes or in case file size needs to be
extended (e.g. for ext4). Instead of forcing filesystem to wait for AIO
in such cases, add argument to iomap_dio_rw() which makes the function
wait for IO completion. This also results in executing
iomap_dio_complete() inline in iomap_dio_rw() providing its return value
to the caller as for ordinary sync IO.
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
- Report both io errors and short io results to the directio endio
handler.
- Allow directio callers to pass an ops structure to iomap_dio_rw.
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Merge tag 'iomap-5.4-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux
Pull iomap updates from Darrick Wong:
"After last week's failed pull request attempt, I scuttled everything
in the branch except for the directio endio api changes, which were
trivial. Everything else will simply have to wait for the next cycle.
Summary:
- Report both io errors and short io results to the directio endio
handler.
- Allow directio callers to pass an ops structure to iomap_dio_rw"
* tag 'iomap-5.4-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
iomap: move the iomap_dio_rw ->end_io callback into a structure
iomap: split size and error for iomap_dio_rw ->end_io
Add a new iomap_dio_ops structure that for now just contains the end_io
handler. This avoid storing the function pointer in a mutable structure,
which is a possible exploit vector for kernel code execution, and prepares
for adding a submit_io handler that btrfs needs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
