Under certain situations, an incremental send operation can contain
a rmdir operation that will make the receiving end fail when attempting
to execute it, because the target directory is not yet empty.
Consider the following example:
Parent snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- c/ (ino 260)
|
|--- del/ (ino 259)
|--- tmp/ (ino 258)
|--- x/ (ino 261)
Send snapshot:
. (ino 256)
|--- a/ (ino 257)
| |--- x/ (ino 261)
|
|--- c/ (ino 260)
|--- tmp/ (ino 258)
1) When processing inode 258, we delay its rename operation because inode
260 is its new parent in the send snapshot and it was not yet renamed
(since 260 > 258, that is, beyond the current progress);
2) When processing inode 259, we realize we can not yet send an rmdir
operation (against inode 259) because inode 258 was still not yet
renamed/moved away from inode 259. Therefore we update data structures
so that after inode 258 is renamed, we try again to see if we can
finally send an rmdir operation for inode 259;
3) When we process inode 260, we send a rename operation for it followed
by a rename operation for inode 258. Once we send the rename operation
for inode 258 we then check if we can finally issue an rmdir for its
previous parent, inode 259, by calling the can_rmdir() function with
a value of sctx->cur_ino + 1 (260 + 1 = 261) for its "progress"
argument. This makes can_rmdir() return true (value 1) because even
though there's still a child inode of inode 259 that was not yet
renamed/moved, which is inode 261, the given value of progress (261)
is not lower then 261 (that is, not lower than the inode number of
some child of inode 259). So we end up sending a rmdir operation for
inode 259 before its child inode 261 is processed and renamed.
So fix this by passing the correct progress value to the call to
can_rmdir() from within apply_dir_move() (where we issue delayed rename
operations), which should match stcx->cur_ino (the number of the inode
currently being processed) and not sctx->cur_ino + 1.
A test case for fstests follows soon.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Rewrote change log to be more detailed, clear and well formatted]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Example scenario:
Parent snapshot:
. (ino 277)
|---- tmp/ (ino 278)
|---- pre/ (ino 280)
| |---- wait_dir/ (ino 281)
|
|---- desc/ (ino 282)
|---- ance/ (ino 283)
| |---- below_ance/ (ino 279)
|
|---- other_dir/ (ino 284)
Send snapshot:
. (ino 277)
|---- tmp/ (ino 278)
|---- other_dir/ (ino 284)
|---- below_ance/ (ino 279)
| |---- pre/ (ino 280)
|
|---- wait_dir/ (ino 281)
|---- desc/ (ino 282)
|---- ance/ (ino 283)
While computing the send stream the following steps happen:
1) While processing inode 279 we end up delaying its rename operation
because its new parent in the send snapshot, inode 284, was not
yet processed and therefore not yet renamed;
2) Later when processing inode 280 we end up renaming it immediately to
"ance/below_once/pre" and not delay its rename operation because its
new parent (inode 279 in the send snapshot) has its rename operation
delayed and inode 280 is not an encestor of inode 279 (its parent in
the send snapshot) in the parent snapshot;
3) When processing inode 281 we end up delaying its rename operation
because its new parent in the send snapshot, inode 284, was not yet
processed and therefore not yet renamed;
4) When processing inode 282 we do not delay its rename operation because
its parent in the send snapshot, inode 281, already has its own rename
operation delayed and our current inode (282) is not an ancestor of
inode 281 in the parent snapshot. Therefore inode 282 is renamed to
"ance/below_ance/pre/wait_dir";
5) When processing inode 283 we realize that we can rename it because one
of its ancestors in the send snapshot, inode 281, has its rename
operation delayed and inode 283 is not an ancestor of inode 281 in the
parent snapshot. So a rename operation to rename inode 283 to
"ance/below_ance/pre/wait_dir/desc/ance" is issued. This path is
invalid due to a missing path building loop that was undetected by
the incremental send implementation, as inode 283 ends up getting
included twice in the path (once with its path in the parent snapshot).
Therefore its rename operation must wait before the ancestor inode 284
is renamed.
Fix this by not terminating the rename dependency checks when we find an
ancestor, in the send snapshot, that has its rename operation delayed. So
that we continue doing the same checks if the current inode is not an
ancestor, in the parent snapshot, of an ancestor in the send snapshot we
are processing in the loop.
The problem and reproducer were reported by Robbie Ko, as part of a patch
titled "Btrfs: incremental send, avoid ancestor rename to descendant".
However the fix was unnecessarily complicated and can be addressed with
much less code and effort.
Reported-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
The function path_loop() can return a negative integer, signaling an
error, 0 if there's no path loop and 1 if there's a path loop. We were
treating any non zero values as meaning that a path loop exists. Fix
this by explicitly checking for errors and gracefully return them to
user space.
Signed-off-by: Filipe Manana <fdmanana@suse.com>
When doing an incremental send we can end up not moving directories that
have the same name. This happens when the same parent directory has
different child directories with the same name in the parent and send
snapshots.
For example, consider the following scenario:
Parent snapshot:
. (ino 256)
|---- d/ (ino 257)
| |--- p1/ (ino 258)
|
|---- p1/ (ino 259)
Send snapshot:
. (ino 256)
|--- d/ (ino 257)
|--- p1/ (ino 259)
|--- p1/ (ino 258)
The directory named "d" (inode 257) has in both snapshots an entry with
the name "p1" but it refers to different inodes in both snapshots (inode
258 in the parent snapshot and inode 259 in the send snapshot). When
attempting to move inode 258, the operation is delayed because its new
parent, inode 259, was not yet moved/renamed (as the stream is currently
processing inode 258). Then when processing inode 259, we also end up
delaying its move/rename operation so that it happens after inode 258 is
moved/renamed. This decision to delay the move/rename rename operation
of inode 259 is due to the fact that the new parent inode (257) still
has inode 258 as its child, which has the same name has inode 259. So
we end up with inode 258 move/rename operation waiting for inode's 259
move/rename operation, which in turn it waiting for inode's 258
move/rename. This results in ending the send stream without issuing
move/rename operations for inodes 258 and 259 and generating the
following warnings in syslog/dmesg:
[148402.979747] ------------[ cut here ]------------
[148402.980588] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6177 btrfs_ioctl_send+0xe03/0xe51 [btrfs]
[148402.981928] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs]
[148402.986999] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1
[148402.988136] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[148402.988136] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000
[148402.988136] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018212139fac8
[148402.988136] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000
[148402.988136] Call Trace:
[148402.988136] [<ffffffff8126b42c>] dump_stack+0x67/0x90
[148402.988136] [<ffffffff81052b14>] __warn+0xc2/0xdd
[148402.988136] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f
[148402.988136] [<ffffffffa04bc831>] btrfs_ioctl_send+0xe03/0xe51 [btrfs]
[148402.988136] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs]
[148402.988136] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc
[148402.988136] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57
[148402.988136] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34
[148402.988136] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be
[148402.988136] [<ffffffff81196f0c>] ? __fget+0x6b/0x77
[148402.988136] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71
[148402.988136] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79
[148402.988136] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8
[148402.988136] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa
[148403.011373] ---[ end trace a4539270c8056f8b ]---
[148403.012296] ------------[ cut here ]------------
[148403.013071] WARNING: CPU: 14 PID: 4117 at fs/btrfs/send.c:6194 btrfs_ioctl_send+0xe19/0xe51 [btrfs]
[148403.014447] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq tpm_tis ppdev tpm parport_pc psmouse parport sg pcspkr i2c_piix4 i2c_core evdev processor serio_raw button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy [last unloaded: btrfs]
[148403.019708] CPU: 14 PID: 4117 Comm: btrfs Tainted: G W 4.6.0-rc7-btrfs-next-31+ #1
[148403.020104] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014
[148403.020104] 0000000000000000 ffff88022139fca8 ffffffff8126b42c 0000000000000000
[148403.020104] 0000000000000000 ffff88022139fce8 ffffffff81052b14 000018322139fac8
[148403.020104] ffff88022b0db400 0000000000000000 0000000000000001 0000000000000000
[148403.020104] Call Trace:
[148403.020104] [<ffffffff8126b42c>] dump_stack+0x67/0x90
[148403.020104] [<ffffffff81052b14>] __warn+0xc2/0xdd
[148403.020104] [<ffffffff81052beb>] warn_slowpath_null+0x1d/0x1f
[148403.020104] [<ffffffffa04bc847>] btrfs_ioctl_send+0xe19/0xe51 [btrfs]
[148403.020104] [<ffffffffa048b358>] btrfs_ioctl+0x14f/0x1f81 [btrfs]
[148403.020104] [<ffffffff8108e456>] ? arch_local_irq_save+0x9/0xc
[148403.020104] [<ffffffff8108eb51>] ? __lock_is_held+0x3c/0x57
[148403.020104] [<ffffffff8118da05>] vfs_ioctl+0x18/0x34
[148403.020104] [<ffffffff8118e00c>] do_vfs_ioctl+0x550/0x5be
[148403.020104] [<ffffffff81196f0c>] ? __fget+0x6b/0x77
[148403.020104] [<ffffffff81196fa1>] ? __fget_light+0x62/0x71
[148403.020104] [<ffffffff8118e0d1>] SyS_ioctl+0x57/0x79
[148403.020104] [<ffffffff8149e025>] entry_SYSCALL_64_fastpath+0x18/0xa8
[148403.020104] [<ffffffff8108e89d>] ? trace_hardirqs_off_caller+0x3f/0xaa
[148403.038981] ---[ end trace a4539270c8056f8c ]---
There's another issue caused by similar (but more complex) changes in the
directory hierarchy that makes move/rename operations fail, described with
the following example:
Parent snapshot:
.
|---- a/ (ino 262)
| |---- c/ (ino 268)
|
|---- d/ (ino 263)
|---- ance/ (ino 267)
|---- e/ (ino 264)
|---- f/ (ino 265)
|---- ance/ (ino 266)
Send snapshot:
.
|---- a/ (ino 262)
|---- c/ (ino 268)
| |---- ance/ (ino 267)
|
|---- d/ (ino 263)
| |---- ance/ (ino 266)
|
|---- f/ (ino 265)
|---- e/ (ino 264)
When the inode 265 is processed, the path for inode 267 is computed, which
at that time corresponds to "d/ance", and it's stored in the names cache.
Later on when processing inode 266, we end up orphanizing (renaming to a
name matching the pattern o<ino>-<gen>-<seq>) inode 267 because it has
the same name as inode 266 and it's currently a child of the new parent
directory (inode 263) for inode 266. After the orphanization and while we
are still processing inode 266, a rename operation for inode 266 is
generated. However the source path for that rename operation is incorrect
because it ends up using the old, pre-orphanization, name of inode 267.
The no longer valid name for inode 267 was previously cached when
processing inode 265 and it remains usable and considered valid until
the inode currently being processed has a number greater than 267.
This resulted in the receiving side failing with the following error:
ERROR: rename d/ance/ance -> d/ance failed: No such file or directory
So fix these issues by detecting such circular dependencies for rename
operations and by clearing the cached name of an inode once the inode
is orphanized.
A test case for fstests will follow soon.
Signed-off-by: Robbie Ko <robbieko@synology.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
[Rewrote change log to be more detailed and organized, and improved
comments]
Signed-off-by: Filipe Manana <fdmanana@suse.com>
When we start an fsync we start ordered extents for all delalloc ranges.
However before attempting to log the inode, we only wait for those ordered
extents if we are not doing a full sync (bit BTRFS_INODE_NEEDS_FULL_SYNC
is set in the inode's flags). This means that if an ordered extent
completes with an IO error before we check if we can skip logging the
inode, we will not catch and report the IO error to user space. This is
because on an IO error, when the ordered extent completes we do not
update the inode, so if the inode was not previously updated by the
current transaction we end up not logging it through calls to fsync and
therefore not check its mapping flags for the presence of IO errors.
Fix this by checking for errors in the flags of the inode's mapping when
we notice we can skip logging the inode.
This caused sporadic failures in the test generic/331 (which explicitly
tests for IO errors during an fsync call).
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Pull btrfs updates from Chris Mason:
"This pull is dedicated to Josef's enospc rework, which we've been
testing for a few releases now. It fixes some early enospc problems
and is dramatically faster.
This also includes an updated fix for the delalloc accounting that
happens after a fault in copy_from_user. My patch in v4.7 was almost
but not quite enough"
* 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
Btrfs: fix delalloc accounting after copy_from_user faults
Btrfs: avoid deadlocks during reservations in btrfs_truncate_block
Btrfs: use FLUSH_LIMIT for relocation in reserve_metadata_bytes
Btrfs: fill relocation block rsv after allocation
Btrfs: always use trans->block_rsv for orphans
Btrfs: change how we calculate the global block rsv
Btrfs: use root when checking need_async_flush
Btrfs: don't bother kicking async if there's nothing to reclaim
Btrfs: fix release reserved extents trace points
Btrfs: add fsid to some tracepoints
Btrfs: add tracepoints for flush events
Btrfs: fix delalloc reservation amount tracepoint
Btrfs: trace pinned extents
Btrfs: introduce ticketed enospc infrastructure
Btrfs: add tracepoint for adding block groups
Btrfs: warn_on for unaccounted spaces
Btrfs: change delayed reservation fallback behavior
Btrfs: always reserve metadata for delalloc extents
Btrfs: fix callers of btrfs_block_rsv_migrate
Btrfs: add bytes_readonly to the spaceinfo at once
Pull NFS client updates from Trond Myklebust:
"Highlights include:
Stable bugfixes:
- nfs: don't create zero-length requests
- several LAYOUTGET bugfixes
Features:
- several performance related features
- more aggressive caching when we can rely on close-to-open
cache consistency
- remove serialisation of O_DIRECT reads and writes
- optimise several code paths to not flush to disk unnecessarily.
However allow for the idiosyncracies of pNFS for those layout
types that need to issue a LAYOUTCOMMIT before the metadata can
be updated on the server.
- SUNRPC updates to the client data receive path
- pNFS/SCSI support RH/Fedora dm-mpath device nodes
- pNFS files/flexfiles can now use unprivileged ports when
the generic NFS mount options allow it.
Bugfixes:
- Don't use RDMA direct data placement together with data
integrity or privacy security flavours
- Remove the RDMA ALLPHYSICAL memory registration mode as
it has potential security holes.
- Several layout recall fixes to improve NFSv4.1 protocol
compliance.
- Fix an Oops in the pNFS files and flexfiles connection
setup to the DS
- Allow retry of operations that used a returned delegation
stateid
- Don't mark the inode as revalidated if a LAYOUTCOMMIT is
outstanding
- Fix writeback races in nfs4_copy_range() and
nfs42_proc_deallocate()"
* tag 'nfs-for-4.8-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (104 commits)
pNFS: Actively set attributes as invalid if LAYOUTCOMMIT is outstanding
NFSv4: Clean up lookup of SECINFO_NO_NAME
NFSv4.2: Fix warning "variable ‘stateids’ set but not used"
NFSv4: Fix warning "no previous prototype for ‘nfs4_listxattr’"
SUNRPC: Fix a compiler warning in fs/nfs/clnt.c
pNFS: Remove redundant smp_mb() from pnfs_init_lseg()
pNFS: Cleanup - do layout segment initialisation in one place
pNFS: Remove redundant stateid invalidation
pNFS: Remove redundant pnfs_mark_layout_returned_if_empty()
pNFS: Clear the layout metadata if the server changed the layout stateid
pNFS: Cleanup - don't open code pnfs_mark_layout_stateid_invalid()
NFS: pnfs_mark_matching_lsegs_return() should match the layout sequence id
pNFS: Do not set plh_return_seq for non-callback related layoutreturns
pNFS: Ensure layoutreturn acts as a completion for layout callbacks
pNFS: Fix CB_LAYOUTRECALL stateid verification
pNFS: Always update the layout barrier seqid on LAYOUTGET
pNFS: Always update the layout stateid if NFS_LAYOUT_INVALID_STID is set
pNFS: Clear the layout return tracking on layout reinitialisation
pNFS: LAYOUTRETURN should only update the stateid if the layout is valid
nfs: don't create zero-length requests
...
Pull userns vfs updates from Eric Biederman:
"This tree contains some very long awaited work on generalizing the
user namespace support for mounting filesystems to include filesystems
with a backing store. The real world target is fuse but the goal is
to update the vfs to allow any filesystem to be supported. This
patchset is based on a lot of code review and testing to approach that
goal.
While looking at what is needed to support the fuse filesystem it
became clear that there were things like xattrs for security modules
that needed special treatment. That the resolution of those concerns
would not be fuse specific. That sorting out these general issues
made most sense at the generic level, where the right people could be
drawn into the conversation, and the issues could be solved for
everyone.
At a high level what this patchset does a couple of simple things:
- Add a user namespace owner (s_user_ns) to struct super_block.
- Teach the vfs to handle filesystem uids and gids not mapping into
to kuids and kgids and being reported as INVALID_UID and
INVALID_GID in vfs data structures.
By assigning a user namespace owner filesystems that are mounted with
only user namespace privilege can be detected. This allows security
modules and the like to know which mounts may not be trusted. This
also allows the set of uids and gids that are communicated to the
filesystem to be capped at the set of kuids and kgids that are in the
owning user namespace of the filesystem.
One of the crazier corner casees this handles is the case of inodes
whose i_uid or i_gid are not mapped into the vfs. Most of the code
simply doesn't care but it is easy to confuse the inode writeback path
so no operation that could cause an inode write-back is permitted for
such inodes (aka only reads are allowed).
This set of changes starts out by cleaning up the code paths involved
in user namespace permirted mounts. Then when things are clean enough
adds code that cleanly sets s_user_ns. Then additional restrictions
are added that are possible now that the filesystem superblock
contains owner information.
These changes should not affect anyone in practice, but there are some
parts of these restrictions that are changes in behavior.
- Andy's restriction on suid executables that does not honor the
suid bit when the path is from another mount namespace (think
/proc/[pid]/fd/) or when the filesystem was mounted by a less
privileged user.
- The replacement of the user namespace implicit setting of MNT_NODEV
with implicitly setting SB_I_NODEV on the filesystem superblock
instead.
Using SB_I_NODEV is a stronger form that happens to make this state
user invisible. The user visibility can be managed but it caused
problems when it was introduced from applications reasonably
expecting mount flags to be what they were set to.
There is a little bit of work remaining before it is safe to support
mounting filesystems with backing store in user namespaces, beyond
what is in this set of changes.
- Verifying the mounter has permission to read/write the block device
during mount.
- Teaching the integrity modules IMA and EVM to handle filesystems
mounted with only user namespace root and to reduce trust in their
security xattrs accordingly.
- Capturing the mounters credentials and using that for permission
checks in d_automount and the like. (Given that overlayfs already
does this, and we need the work in d_automount it make sense to
generalize this case).
Furthermore there are a few changes that are on the wishlist:
- Get all filesystems supporting posix acls using the generic posix
acls so that posix_acl_fix_xattr_from_user and
posix_acl_fix_xattr_to_user may be removed. [Maintainability]
- Reducing the permission checks in places such as remount to allow
the superblock owner to perform them.
- Allowing the superblock owner to chown files with unmapped uids and
gids to something that is mapped so the files may be treated
normally.
I am not considering even obvious relaxations of permission checks
until it is clear there are no more corner cases that need to be
locked down and handled generically.
Many thanks to Seth Forshee who kept this code alive, and putting up
with me rewriting substantial portions of what he did to handle more
corner cases, and for his diligent testing and reviewing of my
changes"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (30 commits)
fs: Call d_automount with the filesystems creds
fs: Update i_[ug]id_(read|write) to translate relative to s_user_ns
evm: Translate user/group ids relative to s_user_ns when computing HMAC
dquot: For now explicitly don't support filesystems outside of init_user_ns
quota: Handle quota data stored in s_user_ns in quota_setxquota
quota: Ensure qids map to the filesystem
vfs: Don't create inodes with a uid or gid unknown to the vfs
vfs: Don't modify inodes with a uid or gid unknown to the vfs
cred: Reject inodes with invalid ids in set_create_file_as()
fs: Check for invalid i_uid in may_follow_link()
vfs: Verify acls are valid within superblock's s_user_ns.
userns: Handle -1 in k[ug]id_has_mapping when !CONFIG_USER_NS
fs: Refuse uid/gid changes which don't map into s_user_ns
selinux: Add support for unprivileged mounts from user namespaces
Smack: Handle labels consistently in untrusted mounts
Smack: Add support for unprivileged mounts from user namespaces
fs: Treat foreign mounts as nosuid
fs: Limit file caps to the user namespace of the super block
userns: Remove the now unnecessary FS_USERNS_DEV_MOUNT flag
userns: Remove implicit MNT_NODEV fragility.
...
The only place where we feed to __d_rehash() something other than
d_hash(dentry->d_name.hash) is __d_move(), where we give it d_hash
of another dentry. Postpone rehashing until we'd switched the
names and we are rid of that exception, along with the need to
keep _d_rehash() and __d_rehash() separate.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Probe-mounting a volume too small for UBIFS results in kernel log
polution which might irritate users.
Address this by silencing errors which may happen during boot if the
rootfs is e.g. squashfs (and thus rather small) stored on a UBI volume.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
Pull fuse updates from Miklos Szeredi:
"This fixes error propagation from writeback to fsync/close for
writeback cache mode as well as adding a missing capability flag to
the INIT message. The rest are cleanups.
(The commits are recent but all the code actually sat in -next for a
while now. The recommits are due to conflict avoidance and the
addition of Cc: stable@...)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
fuse: use filemap_check_errors()
mm: export filemap_check_errors() to modules
fuse: fix wrong assignment of ->flags in fuse_send_init()
fuse: fuse_flush must check mapping->flags for errors
fuse: fsync() did not return IO errors
fuse: don't mess with blocking signals
new helper: wait_event_killable_exclusive()
fuse: improve aio directIO write performance for size extending writes
This reverts commit 3c9fe8cdff.
As Miklos points out in commit c1b2cc1a76, the "lookup_hash()" helper
is now unused, and in fact, with the hash salting changes, since the
hash of a dentry name now depends on the directory dentry it is in, the
helper function isn't even really likely to be useful.
So rather than keep it around in case somebody else might end up finding
a use for it, let's just remove the helper and not trick people into
thinking it might be a useful thing.
For example, I had obviously completely missed how the helper didn't
follow the normal dentry hashing patterns, and how the hash salting
patch broke overlayfs. Things would quietly build and look sane, but
not work.
Suggested-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull overlayfs update from Miklos Szeredi:
"First of all, this fixes a regression in overlayfs introduced by the
dentry hash salting. I've moved the patch fixing this to the front of
the queue, so if (god forbid) something needs to be bisected in
overlayfs this regression won't interfere with that.
The biggest part is preparation for selinux support, done by Vivek
Goyal. Essentially this makes all operations on underlying
filesystems be done with credentials of mounter. This makes
everything nicely consistent.
There are also fixes for a number of known and recently discovered
non-standard behavior (thanks to Eryu Guan for testing and improving
the test suites)"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (23 commits)
ovl: simplify empty checking
qstr: constify instances in overlayfs
ovl: clear nlink on rmdir
ovl: disallow overlayfs as upperdir
ovl: fix warning
ovl: remove duplicated include from super.c
ovl: append MAY_READ when diluting write checks
ovl: dilute permission checks on lower only if not special file
ovl: fix POSIX ACL setting
ovl: share inode for hard link
ovl: store real inode pointer in ->i_private
ovl: permission: return ECHILD instead of ENOENT
ovl: update atime on upper
ovl: fix sgid on directory
ovl: simplify permission checking
ovl: do not require mounter to have MAY_WRITE on lower
ovl: do operations on underlying file system in mounter's context
ovl: modify ovl_permission() to do checks on two inodes
ovl: define ->get_acl() for overlay inodes
ovl: move some common code in a function
...
Pull freevxfs updates from Christoph Hellwig:
"Support for foreign endianess and HP-UP superblocks from
Krzysztof Błaszkowski"
* tag 'freevxfs-for-4.8' of git://git.infradead.org/users/hch/freevxfs:
freevxfs: update Kconfig information
freevxfs: refactor readdir and lookup code
freevxfs: fix lack of inode initialization
freevxfs: fix memory leak in vxfs_read_fshead()
freevxfs: update documentation and cresdits for HP-UX support
freevxfs: implement ->alloc_inode and ->destroy_inode
freevxfs: avoid the need for forward declaring the super operations
freevxfs: move VFS inode allocation into vxfs_blkiget and vxfs_stiget
freevxfs: remove vxfs_put_fake_inode
freevxfs: handle big endian HP-UX file systems
Pull configfs update from Christoph Hellwig:
"A simple error handling fix from Tal Shorer"
* tag 'configfs-for-4.8' of git://git.infradead.org/users/hch/configfs:
configfs: don't set buffer_needs_fill to zero if show() returns error
Pull CIFS/SMB3 fixes from Steve French:
"Various CIFS/SMB3 fixes, most for stable"
* 'for-next' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: Fix a possible invalid memory access in smb2_query_symlink()
fs/cifs: make share unaccessible at root level mountable
cifs: fix crash due to race in hmac(md5) handling
cifs: unbreak TCP session reuse
cifs: Check for existing directory when opening file with O_CREAT
Add MF-Symlinks support for SMB 2.0
Fix sparse warnings from the use of "struct xattr_handler"
structures that are not exported by making them static. Fixes
the following sparse warnings:
/fs/ubifs/xattr.c:595:28: warning: symbol 'ubifs_user_xattr_handler' was not declared. Should it be static?
/fs/ubifs/xattr.c:601:28: warning: symbol 'ubifs_trusted_xattr_handler' was not declared. Should it be static?
/fs/ubifs/xattr.c:607:28: warning: symbol 'ubifs_security_xattr_handler' was not declared. Should it be static?
Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Signed-off-by: Richard Weinberger <richard@nod.at>
This change completes commit
90bea5a3f0 ("UBIFS: respect MS_SILENT mount flag")
which already implements support for MS_SILENT except for that one
error message which is still being displayed despite MS_SILENT being
set. Suppress that error message as well in case MS_SILENT is set.
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
[rw: massaged commit message]
Signed-off-by: Richard Weinberger <richard@nod.at>
fuse_flush() calls write_inode_now() that triggers writeback, but actual
writeback will happen later, on fuse_sync_writes(). If an error happens,
fuse_writepage_end() will set error bit in mapping->flags. So, we have to
check mapping->flags after fuse_sync_writes().
Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12 ("fuse: Turn writeback cache on")
Cc: <stable@vger.kernel.org> # v3.15+
Due to implementation of fuse writeback filemap_write_and_wait_range() does
not catch errors. We have to do this directly after fuse_sync_writes()
Signed-off-by: Alexey Kuznetsov <kuznet@virtuozzo.com>
Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 4d99ff8f12 ("fuse: Turn writeback cache on")
Cc: <stable@vger.kernel.org> # v3.15+
The empty checking logic is duplicated in ovl_check_empty_and_clear() and
ovl_remove_and_whiteout(), except the condition for clearing whiteouts is
different:
ovl_check_empty_and_clear() checked for being upper
ovl_remove_and_whiteout() checked for merge OR lower
Move the intersection of those checks (upper AND merge) into
ovl_check_empty_and_clear() and simplify ovl_remove_and_whiteout().
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
This does not work and does not make sense. So instead of fixing it
(probably not hard) just disallow.
Reported-by: Andrei Vagin <avagin@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org>
Right now we remove MAY_WRITE/MAY_APPEND bits from mask if realfile is on
lower/. This is done as files on lower will never be written and will be
copied up. But to copy up a file, mounter should have MAY_READ permission
otherwise copy up will fail. So set MAY_READ in mask when MAY_WRITE is
reset.
Dan Walsh noticed this when he did access(lowerfile, W_OK) and it returned
True (context mounts) but when he tried to actually write to file, it
failed as mounter did not have permission on lower file.
[SzM] don't set MAY_READ if only MAY_APPEND is set without MAY_WRITE; this
won't trigger a copy-up.
Reported-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from
mask as lower/ will never be written and file will be copied up. But this
is not true for special files. These files are not copied up and are opened
in place. So don't dilute the checks for these types of files.
Reported-by: Dan Walsh <dwalsh@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Setting POSIX ACL needs special handling:
1) Some permission checks are done by ->setxattr() which now uses mounter's
creds ("ovl: do operations on underlying file system in mounter's
context"). These permission checks need to be done with current cred as
well.
2) Setting ACL can fail for various reasons. We do not need to copy up in
these cases.
In the mean time switch to using generic_setxattr.
[Arnd Bergmann] Fix link error without POSIX ACL. posix_acl_from_xattr()
doesn't have a 'static inline' implementation when CONFIG_FS_POSIX_ACL is
disabled, and I could not come up with an obvious way to do it.
This instead avoids the link error by defining two sets of ACL operations
and letting the compiler drop one of the two at compile time depending
on CONFIG_FS_POSIX_ACL. This avoids all references to the ACL code,
also leading to smaller code.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Inode attributes are copied up to overlay inode (uid, gid, mode, atime,
mtime, ctime) so generic code using these fields works correcty. If a hard
link is created in overlayfs separate inodes are allocated for each link.
If chmod/chown/etc. is performed on one of the links then the inode
belonging to the other ones won't be updated.
This patch attempts to fix this by sharing inodes for hard links.
Use inode hash (with real inode pointer as a key) to make sure overlay
inodes are shared for hard links on upper. Hard links on lower are still
split (which is not user observable until the copy-up happens, see
Documentation/filesystems/overlayfs.txt under "Non-standard behavior").
The inode is only inserted in the hash if it is non-directoy and upper.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
To get from overlay inode to real inode we currently use 'struct
ovl_entry', which has lifetime connected to overlay dentry. This is okay,
since each overlay dentry had a new overlay inode allocated.
Following patch will break that assumption, so need to leave out ovl_entry.
This patch stores the real inode directly in i_private, with the lowest bit
used to indicate whether the inode is upper or lower.
Lifetime rules remain, using ovl_inode_real() must only be done while
caller holds ref on overlay dentry (and hence on real dentry), or within
RCU protected regions.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fix atime update logic in overlayfs.
This patch adds an i_op->update_time() handler to overlayfs inodes. This
forwards atime updates to the upper layer only. No atime updates are done
on lower layers.
Remove implicit atime updates to underlying files and directories with
O_NOATIME. Remove explicit atime update in ovl_readlink().
Clear atime related mnt flags from cloned upper mount. This means atime
updates are controlled purely by overlayfs mount options.
Reported-by: Konstantin Khlebnikov <koct9i@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
When creating directory in workdir, the group/sgid inheritance from the
parent dir was omitted completely. Fix this by calling inode_init_owner()
on overlay inode and using the resulting uid/gid/mode to create the file.
Unfortunately the sgid bit can be stripped off due to umask, so need to
reset the mode in this case in workdir before moving the directory in
place.
Reported-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The fact that we always do permission checking on the overlay inode and
clear MAY_WRITE for checking access to the lower inode allows cruft to be
removed from ovl_permission().
1) "default_permissions" option effectively did generic_permission() on the
overlay inode with i_mode, i_uid and i_gid updated from underlying
filesystem. This is what we do by default now. It did the update using
vfs_getattr() but that's only needed if the underlying filesystem can
change (which is not allowed). We may later introduce a "paranoia_mode"
that verifies that mode/uid/gid are not changed.
2) splitting out the IS_RDONLY() check from inode_permission() also becomes
unnecessary once we remove the MAY_WRITE from the lower inode check.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Now we have two levels of checks in ovl_permission(). overlay inode
is checked with the creds of task while underlying inode is checked
with the creds of mounter.
Looks like mounter does not have to have WRITE access to files on lower/.
So remove the MAY_WRITE from access mask for checks on underlying
lower inode.
This means task should still have the MAY_WRITE permission on lower
inode and mounter is not required to have MAY_WRITE.
It also solves the problem of read only NFS mounts being used as lower.
If __inode_permission(lower_inode, MAY_WRITE) is called on read only
NFS, it fails. By resetting MAY_WRITE, check succeeds and case of
read only NFS shold work with overlay without having to specify any
special mount options (default permission).
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
