17 Aug, 2022
1 commit
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[ Upstream commit 6e195b0f7c8e50927fa31946369c22a0534ec7e2 ]
Sohaib Mohamed started a serie of tiny and incomplete checkpatch fixes but
seemingly stopped halfway -- take over and do most of it.
This is still missing net/9p/trans* and net/9p/protocol.c for a later
time...Link: http://lkml.kernel.org/r/20211102134608.1588018-3-dominique.martinet@atmark-techno.com
Signed-off-by: Dominique Martinet
Signed-off-by: Sasha Levin
29 Jun, 2022
3 commits
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commit e5690f263208c5abce7451370b7786eb25b405eb upstream.
we check for protocol version later than required, after a fid has
been obtained. Just move the version check earlier.Link: https://lkml.kernel.org/r/20220612085330.1451496-3-asmadeus@codewreck.org
Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
Cc: stable@vger.kernel.org
Reviewed-by: Tyler Hicks
Reviewed-by: Christian Schoenebeck
Signed-off-by: Dominique Martinet
Signed-off-by: Greg Kroah-Hartman -
commit beca774fc51a9ba8abbc869cf0c3d965ff17cd24 upstream.
We need to release directory fid if we fail halfway through open
This fixes fid leaking with xfstests generic 531
Link: https://lkml.kernel.org/r/20220612085330.1451496-2-asmadeus@codewreck.org
Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
Cc: stable@vger.kernel.org
Reported-by: Tyler Hicks
Reviewed-by: Tyler Hicks
Reviewed-by: Christian Schoenebeck
Signed-off-by: Dominique Martinet
Signed-off-by: Greg Kroah-Hartman -
commit 2a3dcbccd64ba35c045fac92272ff981c4cbef44 upstream.
Decrement the refcount of the parent dentry's fid after walking
each path component during a full path walk for a lookup. Failure to do
so can lead to fids that are not clunked until the filesystem is
unmounted, as indicated by this warning:9pnet: found fid 3 not clunked
The improper refcounting after walking resulted in open(2) returning
-EIO on any directories underneath the mount point when using the virtio
transport. When using the fd transport, there's no apparent issue until
the filesytem is unmounted and the warning above is emitted to the logs.In some cases, the user may not yet be attached to the filesystem and a
new root fid, associated with the user, is created and attached to the
root dentry before the full path walk is performed. Increment the new
root fid's refcount to two in that situation so that it can be safely
decremented to one after it is used for the walk operation. The new fid
will still be attached to the root dentry when
v9fs_fid_lookup_with_uid() returns so a final refcount of one is
correct/expected.Link: https://lkml.kernel.org/r/20220527000003.355812-2-tyhicks@linux.microsoft.com
Link: https://lkml.kernel.org/r/20220612085330.1451496-4-asmadeus@codewreck.org
Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
Cc: stable@vger.kernel.org
Signed-off-by: Tyler Hicks
Reviewed-by: Christian Schoenebeck
[Dominique: fix clunking fid multiple times discussed in second link]
Signed-off-by: Dominique Martinet
Signed-off-by: Greg Kroah-Hartman
09 Feb, 2022
1 commit
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commit 22e424feb6658c5d6789e45121830357809c59cb upstream.
This reverts commit 478ba09edc1f2f2ee27180a06150cb2d1a686f9c.
That commit was meant as a fix for setattrs with by fd (e.g. ftruncate)
to use an open fid instead of the first fid it found on lookup.
The proper fix for that is to use the fid associated with the open file
struct, available in iattr->ia_file for such operations, and was
actually done just before in 66246641609b ("9p: retrieve fid from file
when file instance exist.")
As such, this commit is no longer required.Furthermore, changing lookup to return open fids first had unwanted side
effects, as it turns out the protocol forbids the use of open fids for
further walks (e.g. clone_fid) and we broke mounts for some servers
enforcing this rule.Note this only reverts to the old working behaviour, but it's still
possible for lookup to return open fids if dentry->d_fsdata is not set,
so more work is needed to make sure we respect this rule in the future,
for example by adding a flag to the lookup functions to only match
certain fid open modes depending on caller requirements.Link: https://lkml.kernel.org/r/20220130130651.712293-1-asmadeus@codewreck.org
Fixes: 478ba09edc1f ("fs/9p: search open fids first")
Cc: stable@vger.kernel.org # v5.11+
Reported-by: ron minnich
Reported-by: ng@0x80.stream
Signed-off-by: Dominique Martinet
Signed-off-by: Greg Kroah-Hartman
20 Jan, 2022
1 commit
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commit 3cb6ee991496b67ee284c6895a0ba007e2d7bac3 upstream.
The 9P2000.L setattr method v9fs_vfs_setattr_dotl() copies struct iattr
values without checking whether they are valid causing unitialized
values to be copied. The 9P2000 setattr method v9fs_vfs_setattr() method
gets this right. Check whether struct iattr fields are valid first
before copying in v9fs_vfs_setattr_dotl() too and make sure that all
other fields are set to 0 apart from {g,u}id which should be set to
INVALID_{G,U}ID. This ensure that they can be safely sent over the wire
or printed for debugging later on.Link: https://lkml.kernel.org/r/20211129114434.3637938-1-brauner@kernel.org
Link: https://lkml.kernel.org/r/000000000000a0d53f05d1c72a4c%40google.com
Cc: Eric Van Hensbergen
Cc: Latchesar Ionkov
Cc: Dominique Martinet
Cc: stable@kernel.org
Cc: v9fs-developer@lists.sourceforge.net
Reported-by: syzbot+dfac92a50024b54acaa4@syzkaller.appspotmail.com
Signed-off-by: Christian Brauner
[Dominique: do not set a/mtime with just ATTR_A/MTIME as discussed]
Signed-off-by: Dominique Martinet
Signed-off-by: Greg Kroah-Hartman
05 Oct, 2021
1 commit
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Fix a bunch of kerneldoc warnings shown up by W=1 in the 9p filesystem:
(1) Add/remove/fix kerneldoc parameters descriptions.
(2) Move __add_fid() from between v9fs_fid_add() and its comment.
(3) 9p's caches_show() doesn't really make sense as an API function, so
remove the kerneldoc annotation. It's also not prefixed with 'v9fs_'.
Also remove the kerneldoc markers from the 9p fscache wrappers.Signed-off-by: David Howells
Reviewed-by: Dominique Martinet
Reviewed-by: Jeff Layton
cc: Mauro Carvalho Chehab
cc: v9fs-developer@lists.sourceforge.net
cc: linux-fsdevel@vger.kernel.org
cc: linux-doc@vger.kernel.org
Link: https://lore.kernel.org/r/163214005516.2945267.7000234432243167892.stgit@warthog.procyon.org.uk/ # rfc v1
Link: https://lore.kernel.org/r/163281899704.2790286.9177774252843775348.stgit@warthog.procyon.org.uk/ # rfc v2
03 Sep, 2021
1 commit
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Pull overlayfs update from Miklos Szeredi:
- Copy up immutable/append/sync/noatime attributes (Amir Goldstein)
- Improve performance by enabling RCU lookup.
- Misc fixes and improvements
The reason this touches so many files is that the ->get_acl() method now
gets a "bool rcu" argument. The ->get_acl() API was updated based on
comments from Al and Linus:Link: https://lore.kernel.org/linux-fsdevel/CAJfpeguQxpd6Wgc0Jd3ks77zcsAv_bn0q17L3VNnnmPKu11t8A@mail.gmail.com/
* tag 'ovl-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: enable RCU'd ->get_acl()
vfs: add rcu argument to ->get_acl() callback
ovl: fix BUG_ON() in may_delete() when called from ovl_cleanup()
ovl: use kvalloc in xattr copy-up
ovl: update ctime when changing fileattr
ovl: skip checking lower file's i_writecount on truncate
ovl: relax lookup error on mismatch origin ftype
ovl: do not set overlay.opaque for new directories
ovl: add ovl_allow_offline_changes() helper
ovl: disable decoding null uuid with redirect_dir
ovl: consistent behavior for immutable/append-only inodes
ovl: copy up sync/noatime fileattr flags
ovl: pass ovl_fs to ovl_check_setxattr()
fs: add generic helper for filling statx attribute flags
01 Sep, 2021
1 commit
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Pull btrfs updates from David Sterba:
"The highlights of this round are integrations with fs-verity and
idmapped mounts, the rest is usual mix of minor improvements, speedups
and cleanups.There are some patches outside of btrfs, namely updating some VFS
interfaces, all straightforward and acked.Features:
- fs-verity support, using standard ioctls, backward compatible with
read-only limitation on inodes with previously enabled fs-verity- idmapped mount support
- make mount with rescue=ibadroots more tolerant to partially damaged
trees- allow raid0 on a single device and raid10 on two devices,
degenerate cases but might be useful as an intermediate step during
conversion to other profiles- zoned mode block group auto reclaim can be disabled via sysfs knob
Performance improvements:
- continue readahead of node siblings even if target node is in
memory, could speed up full send (on sample test +11%)- batching of delayed items can speed up creating many files
- fsync/tree-log speedups
- avoid unnecessary work (gains +2% throughput, -2% run time on
sample load)
- reduced lock contention on renames (on dbench +4% throughput,
up to -30% latency)Fixes:
- various zoned mode fixes
- preemptive flushing threshold tuning, avoid excessive work on
almost full filesystemsCore:
- continued subpage support, preparation for implementing remaining
features like compression and defragmentation; with some
limitations, write is now enabled on 64K page systems with 4K
sectors, still considered experimental
- no readahead on compressed reads
- inline extents disabled
- disabled raid56 profile conversion and mount- improved flushing logic, fixing early ENOSPC on some workloads
- inode flags have been internally split to read-only and read-write
incompat bit parts, used by fs-verity- new tree items for fs-verity
- descriptor item
- Merkle tree item- inode operations extended to be namespace-aware
- cleanups and refactoring
Generic code changes:
- fs: new export filemap_fdatawrite_wbc
- fs: removed sync_inode
- block: bio_trim argument type fixups
- vfs: add namespace-aware lookup"
* tag 'for-5.15-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (114 commits)
btrfs: reset replace target device to allocation state on close
btrfs: zoned: fix ordered extent boundary calculation
btrfs: do not do preemptive flushing if the majority is global rsv
btrfs: reduce the preemptive flushing threshold to 90%
btrfs: tree-log: check btrfs_lookup_data_extent return value
btrfs: avoid unnecessarily logging directories that had no changes
btrfs: allow idmapped mount
btrfs: handle ACLs on idmapped mounts
btrfs: allow idmapped INO_LOOKUP_USER ioctl
btrfs: allow idmapped SUBVOL_SETFLAGS ioctl
btrfs: allow idmapped SET_RECEIVED_SUBVOL ioctls
btrfs: relax restrictions for SNAP_DESTROY_V2 with subvolids
btrfs: allow idmapped SNAP_DESTROY ioctls
btrfs: allow idmapped SNAP_CREATE/SUBVOL_CREATE ioctls
btrfs: check whether fsgid/fsuid are mapped during subvolume creation
btrfs: allow idmapped permission inode op
btrfs: allow idmapped setattr inode op
btrfs: allow idmapped tmpfile inode op
btrfs: allow idmapped symlink inode op
btrfs: allow idmapped mkdir inode op
...
23 Aug, 2021
2 commits
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We're going to remove sync_inode, so migrate to filemap_fdatawrite_wbc
instead.Reviewed-by: Christoph Hellwig
Reviewed-by: Nikolay Borisov
Signed-off-by: Josef Bacik
Reviewed-by: David Sterba
Signed-off-by: David Sterba -
We added CONFIG_MANDATORY_FILE_LOCKING in 2015, and soon after turned it
off in Fedora and RHEL8. Several other distros have followed suit.I've heard of one problem in all that time: Someone migrated from an
older distro that supported "-o mand" to one that didn't, and the host
had a fstab entry with "mand" in it which broke on reboot. They didn't
actually _use_ mandatory locking so they just removed the mount option
and moved on.This patch rips out mandatory locking support wholesale from the kernel,
along with the Kconfig option and the Documentation file. It also
changes the mount code to ignore the "mand" mount option instead of
erroring out, and to throw a big, ugly warning.Signed-off-by: Jeff Layton
19 Aug, 2021
1 commit
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Add a rcu argument to the ->get_acl() callback to allow
get_cached_acl_rcu() to call the ->get_acl() method in the next patch.Signed-off-by: Miklos Szeredi
08 May, 2021
1 commit
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Pull 9p updates from Dominique Martinet:
"An error handling fix and constification"* tag '9p-for-5.13-rc1' of git://github.com/martinetd/linux:
fs: 9p: fix v9fs_file_open writeback fid error check
9p: Constify static struct v9fs_attr_group
31 Mar, 2021
2 commits
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IS_ERR() and PTR_ERR() use wrong pointer, it should be
writeback_fid, fix it.Link: http://lkml.kernel.org/r/20210330130632.1054357-1-yangyingliang@huawei.com
Fixes: 5bfe97d7382b ("9p: Fix writeback fid incorrectly being attached to dentry")
Reported-by: Hulk Robot
Signed-off-by: Yang Yingliang
[Dominique: adjusted commit summary]
Signed-off-by: Dominique Martinet -
The only usage of v9fs_attr_group is to pass its address to
sysfs_create_group() and sysfs_create_group(), both which takes pointers
to const struct attribute_group. Make it const to allow the compiler to
put it in read-only memory.Link: http://lkml.kernel.org/r/20210108224650.25872-1-rikard.falkeborn@gmail.com
Signed-off-by: Rikard Falkeborn
Signed-off-by: Dominique Martinet
13 Mar, 2021
1 commit
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In commit 45089142b149 Aneesh had missed one (admittedly, very unlikely
to hit) case in v9fs_stat2inode_dotl(). However, the same considerations
apply there as well - we have no business whatsoever to change ->i_rdev
or the file type.Signed-off-by: Al Viro
08 Mar, 2021
1 commit
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inode_wrong_type(inode, mode) returns true if setting inode->i_mode
to given value would've changed the inode type. We have enough of
those checks open-coded to make a helper worthwhile.Signed-off-by: Al Viro
28 Feb, 2021
1 commit
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Pull misc vfs updates from Al Viro:
"Assorted stuff pile - no common topic here"* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
whack-a-mole: don't open-code iminor/imajor
9p: fix misuse of sscanf() in v9fs_stat2inode()
audit_alloc_mark(): don't open-code ERR_CAST()
fs/inode.c: make inode_init_always() initialize i_ino to 0
vfs: don't unnecessarily clone write access for writable fds
23 Feb, 2021
1 commit
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1) sscanf() return value needs to be checked, damnit
2) sscanf() is perfectly capable of checking for fixed prefix,
no need for that %13s + strncmp with constant string.
3) st->extension is a valid string; no need for voodoo with
str*cpy() there.Signed-off-by: Al Viro
24 Jan, 2021
5 commits
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Extend some inode methods with an additional user namespace argument. A
filesystem that is aware of idmapped mounts will receive the user
namespace the mount has been marked with. This can be used for
additional permission checking and also to enable filesystems to
translate between uids and gids if they need to. We have implemented all
relevant helpers in earlier patches.As requested we simply extend the exisiting inode method instead of
introducing new ones. This is a little more code churn but it's mostly
mechanical and doesnt't leave us with additional inode methods.Link: https://lore.kernel.org/r/20210121131959.646623-25-christian.brauner@ubuntu.com
Cc: Christoph Hellwig
Cc: David Howells
Cc: Al Viro
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig
Signed-off-by: Christian Brauner -
The generic_fillattr() helper fills in the basic attributes associated
with an inode. Enable it to handle idmapped mounts. If the inode is
accessed through an idmapped mount map it into the mount's user
namespace before we store the uid and gid. 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/20210121131959.646623-12-christian.brauner@ubuntu.com
Cc: Christoph Hellwig
Cc: David Howells
Cc: Al Viro
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig
Reviewed-by: James Morris
Signed-off-by: Christian Brauner -
The posix acl permission checking helpers determine whether a caller is
privileged over an inode according to the acls associated with the
inode. Add helpers that make it possible to handle acls on idmapped
mounts.The vfs and the filesystems targeted by this first iteration make use of
posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to
translate basic posix access and default permissions such as the
ACL_USER and ACL_GROUP type according to the initial user namespace (or
the superblock's user namespace) to and from the caller's current user
namespace. Adapt these two helpers to handle idmapped mounts whereby we
either map from or into the mount's user namespace depending on in which
direction we're translating.
Similarly, cap_convert_nscap() is used by the vfs to translate user
namespace and non-user namespace aware filesystem capabilities from the
superblock's user namespace to the caller's user namespace. Enable it to
handle idmapped mounts by accounting for the mount's user namespace.In addition the fileystems targeted in the first iteration of this patch
series make use of the posix_acl_chmod() and, posix_acl_update_mode()
helpers. Both helpers perform permission checks on the target inode. Let
them handle idmapped mounts. These two helpers are called when posix
acls are set by the respective filesystems to handle this case we extend
the ->set() method to take an additional user namespace argument to pass
the mount's user namespace down.Link: https://lore.kernel.org/r/20210121131959.646623-9-christian.brauner@ubuntu.com
Cc: Christoph Hellwig
Cc: David Howells
Cc: Al Viro
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig
Signed-off-by: Christian Brauner -
When file attributes are changed most filesystems rely on the
setattr_prepare(), setattr_copy(), and notify_change() helpers for
initialization and permission checking. Let them handle idmapped mounts.
If the inode is accessed through an idmapped mount map it into the
mount's user namespace. Afterwards the checks are identical to
non-idmapped mounts. If the initial user namespace is passed nothing
changes so non-idmapped mounts will see identical behavior as before.Helpers that perform checks on the ia_uid and ia_gid fields in struct
iattr assume that ia_uid and ia_gid are intended values and have already
been mapped correctly at the userspace-kernelspace boundary as we
already do today. 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/20210121131959.646623-8-christian.brauner@ubuntu.com
Cc: Christoph Hellwig
Cc: David Howells
Cc: Al Viro
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig
Signed-off-by: Christian Brauner -
The inode_owner_or_capable() helper determines whether the caller is the
owner of the inode or is capable with respect to that inode. Allow it to
handle idmapped mounts. If the inode is accessed through an idmapped
mount it according to the mount's user namespace. Afterwards the checks
are identical to non-idmapped mounts. If the initial user namespace is
passed nothing changes so non-idmapped mounts will see identical
behavior as before.Similarly, allow the inode_init_owner() helper to handle idmapped
mounts. It initializes a new inode on idmapped mounts by mapping the
fsuid and fsgid of the caller from the mount's user namespace. 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/20210121131959.646623-7-christian.brauner@ubuntu.com
Cc: Christoph Hellwig
Cc: David Howells
Cc: Al Viro
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig
Reviewed-by: James Morris
Signed-off-by: Christian Brauner
22 Dec, 2020
1 commit
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Pull 9p update from Dominique Martinet:
- fix long-standing limitation on open-unlink-fop pattern
- add refcount to p9_fid (fixes the above and will allow for more
cleanups and simplifications in the future)* tag '9p-for-5.11-rc1' of git://github.com/martinetd/linux:
9p: Remove unnecessary IS_ERR() check
9p: Uninitialized variable in v9fs_writeback_fid()
9p: Fix writeback fid incorrectly being attached to dentry
9p: apply review requests for fid refcounting
9p: add refcount to p9_fid struct
fs/9p: search open fids first
fs/9p: track open fids
fs/9p: fix create-unlink-getattr idiom
02 Dec, 2020
2 commits
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The default splice operations got removed recently, add it back to 9p
with iter_file_splice_write like many other filesystems do.Link: http://lkml.kernel.org/r/1606837496-21717-1-git-send-email-asmadeus@codewreck.org
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Dominique Martinet
Acked-by: Toke Høiland-Jørgensen
Reviewed-by: Christoph Hellwig -
The v9fs file operations were missing the splice_read operations, which
breaks sendfile() of files on such a filesystem. I discovered this while
trying to load an eBPF program using iproute2 inside a 'virtme' environment
which uses 9pfs for the virtual file system. iproute2 relies on sendfile()
with an AF_ALG socket to hash files, which was erroring out in the virtual
environment.Since generic_file_splice_read() seems to just implement splice_read in
terms of the read_iter operation, I simply added the generic implementation
to the file operations, which fixed the error I was seeing. A quick grep
indicates that this is what most other file systems do as well.Link: http://lkml.kernel.org/r/20201201135409.55510-1-toke@redhat.com
Fixes: 36e2c7421f02 ("fs: don't allow splice read/write without explicit ops")
Signed-off-by: Toke Høiland-Jørgensen
Signed-off-by: Dominique Martinet
01 Dec, 2020
2 commits
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The "fid" variable can't be an error pointer so there is no need to
check. The code is slightly cleaner if we move the increment before
the break and remove the NULL check as well.Signed-off-by: Dan Carpenter
Signed-off-by: Dominique Martinet -
If v9fs_fid_lookup_with_uid() fails then "fid" is not initialized.
The v9fs_fid_lookup_with_uid() can't return NULL. If it returns an
error pointer then we can still pass that to clone_fid() and it will
return the error pointer back again.Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
Signed-off-by: Dan Carpenter
Signed-off-by: Dominique Martinet
20 Nov, 2020
3 commits
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v9fs_dir_release needs fid->ilist to have been initialized for filp's
fid, not the inode's writeback fid's.With refcounting this can be improved on later but this appears to fix
null deref issues.Link: http://lkml.kernel.org/r/1605802012-31133-3-git-send-email-asmadeus@codewreck.org
Fixes: 6636b6dcc3db ("fs/9p: track open fids")
Signed-off-by: Dominique Martinet -
Fix style issues in parent commit ("apply review requests for fid
refcounting"), no functional change.Link: http://lkml.kernel.org/r/1605802012-31133-2-git-send-email-asmadeus@codewreck.org
Fixes: 6636b6dcc3db ("9p: add refcount to p9_fid struct")
Signed-off-by: Dominique Martinet -
Fix race issue in fid contention.
Eric's and Greg's patch offer a mechanism to fix open-unlink-f*syscall
bug in 9p. But there is race issue in fid parallel accesses.
As Greg's patch stores all of fids from opened files into according inode,
so all the lookup fid ops can retrieve fid from inode preferentially. But
there is no mechanism to handle the fid contention issue. For example,
there are two threads get the same fid in the same time and one of them
clunk the fid before the other thread ready to discard the fid. In this
scenario, it will lead to some fatal problems, even kernel core dump.I introduce a mechanism to fix this race issue. A counter field introduced
into p9_fid struct to store the reference counter to the fid. When a fid
is allocated from the inode or dentry, the counter will increase, and
will decrease at the end of its occupation. It is guaranteed that the
fid won't be clunked before the reference counter go down to 0, then
we can avoid the clunked fid to be used.tests:
race issue test from the old test case:
for file in {01..50}; do touch f.${file}; done
seq 1 1000 | xargs -n 1 -P 50 -I{} cat f.* > /dev/nullopen-unlink-f*syscall test:
I have tested for f*syscall include: ftruncate fstat fchown fchmod faccessat.Link: http://lkml.kernel.org/r/20200923141146.90046-5-jianyong.wu@arm.com
Fixes: 478ba09edc1f ("fs/9p: search open fids first")
Signed-off-by: Jianyong Wu
Signed-off-by: Dominique Martinet
03 Nov, 2020
3 commits
-
A previous patch fixed the "create-unlink-getattr" idiom: if getattr is
called on an unlinked file, we try to find an open fid attached to the
corresponding inode.We have a similar issue with file permissions and setattr:
open("./test.txt", O_RDWR|O_CREAT, 0666) = 4
chmod("./test.txt", 0) = 0
truncate("./test.txt", 0) = -1 EACCES (Permission denied)
ftruncate(4, 0) = -1 EACCES (Permission denied)The failure is expected with truncate() but not with ftruncate().
This happens because the lookup code does find a matching fid in the
dentry list. Unfortunately, this is not an open fid and the server
will be forced to rely on the path name, rather than on an open file
descriptor. This is the case in QEMU: the setattr operation will use
truncate() and fail because of bad write permissions.This patch changes the logic in the lookup code, so that we consider
open fids first. It gives a chance to the server to match this open
fid to an open file descriptor and use ftruncate() instead of truncate().
This does not change the current behaviour for truncate() and other
path name based syscalls, since file permissions are checked earlier
in the VFS layer.With this patch, we get:
open("./test.txt", O_RDWR|O_CREAT, 0666) = 4
chmod("./test.txt", 0) = 0
truncate("./test.txt", 0) = -1 EACCES (Permission denied)
ftruncate(4, 0) = 0Link: http://lkml.kernel.org/r/20200923141146.90046-4-jianyong.wu@arm.com
Signed-off-by: Greg Kurz
Signed-off-by: Jianyong Wu
Signed-off-by: Dominique Martinet -
This patch adds accounting of open fids in a list hanging off the i_private
field of the corresponding inode. This allows faster lookups compared to
searching the full 9p client list.The lookup code is modified accordingly.
Link: http://lkml.kernel.org/r/20200923141146.90046-3-jianyong.wu@arm.com
Signed-off-by: Greg Kurz
Signed-off-by: Jianyong Wu
Signed-off-by: Dominique Martinet -
Fixes several outstanding bug reports of not being able to getattr from an
open file after an unlink. This patch cleans up transient fids on an unlink
and will search open fids on a client if it detects a dentry that appears to
have been unlinked. This search is necessary because fstat does not pass fd
information through the VFS API to the filesystem, only the dentry which for
9p has an imperfect match to fids.Inherent in this patch is also a fix for the qid handling on create/open
which apparently wasn't being set correctly and was necessary for the search
to succeed.A possible optimization over this fix is to include accounting of open fids
with the inode in the private data (in a similar fashion to the way we track
transient fids with dentries). This would allow a much quicker search for
a matching open fid.(changed v9fs_fid_find_global to v9fs_fid_find_inode in comment)
Link: http://lkml.kernel.org/r/20200923141146.90046-2-jianyong.wu@arm.com
Signed-off-by: Eric Van Hensbergen
Signed-off-by: Greg Kurz
Signed-off-by: Jianyong Wu
Signed-off-by: Dominique Martinet
25 Oct, 2020
1 commit
-
Pull misc vfs updates from Al Viro:
"Assorted stuff all over the place (the largest group here is
Christoph's stat cleanups)"* 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: remove KSTAT_QUERY_FLAGS
fs: remove vfs_stat_set_lookup_flags
fs: move vfs_fstatat out of line
fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat
fs: remove vfs_statx_fd
fs: omfs: use kmemdup() rather than kmalloc+memcpy
[PATCH] reduce boilerplate in fsid handling
fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS
selftests: mount: add nosymfollow tests
Add a "nosymfollow" mount option.
23 Oct, 2020
1 commit
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Pull 9p updates from Dominique Martinet:
"A couple of small fixes (loff_t overflow on 32bit, syzbot
uninitialized variable warning) and code cleanup (xen)"* tag '9p-for-5.10-rc1' of git://github.com/martinetd/linux:
net: 9p: initialize sun_server.sun_path to have addr's value only when addr is valid
9p/xen: Fix format argument warning
9P: Cast to loff_t before multiplying
08 Oct, 2020
1 commit
-
On 32-bit systems, this multiplication will overflow for files larger
than 4GB.Link: http://lkml.kernel.org/r/20201004180428.14494-2-willy@infradead.org
Cc: stable@vger.kernel.org
Fixes: fb89b45cdfdc ("9P: introduction of a new cache=mmap model.")
Signed-off-by: Matthew Wilcox (Oracle)
Signed-off-by: Dominique Martinet
25 Sep, 2020
2 commits
-
Replace the two negative flags that are always used together with a
single positive flag that indicates the writeback capability instead
of two related non-capabilities. Also remove the pointless wrappers
to just check the flag.Signed-off-by: Christoph Hellwig
Reviewed-by: Jan Kara
Reviewed-by: Johannes Thumshirn
Signed-off-by: Jens Axboe -
Set up a readahead size by default, as very few users have a good
reason to change it. This means code, ecryptfs, and orangefs now
set up the values while they were previously missing it, while ubifs,
mtd and vboxsf manually set it to 0 to avoid readahead.Signed-off-by: Christoph Hellwig
Reviewed-by: Jan Kara
Acked-by: David Sterba [btrfs]
Acked-by: Richard Weinberger [ubifs, mtd]
Signed-off-by: Jens Axboe
