-----BEGIN PGP SIGNATURE-----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=M+mV
-----END PGP SIGNATURE-----
Merge tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random
Pull more random number generator updates from Jason Donenfeld:
"This time with some large scale treewide cleanups.
The intent of this pull is to clean up the way callers fetch random
integers. The current rules for doing this right are:
- If you want a secure or an insecure random u64, use get_random_u64()
- If you want a secure or an insecure random u32, use get_random_u32()
The old function prandom_u32() has been deprecated for a while
now and is just a wrapper around get_random_u32(). Same for
get_random_int().
- If you want a secure or an insecure random u16, use get_random_u16()
- If you want a secure or an insecure random u8, use get_random_u8()
- If you want secure or insecure random bytes, use get_random_bytes().
The old function prandom_bytes() has been deprecated for a while
now and has long been a wrapper around get_random_bytes()
- If you want a non-uniform random u32, u16, or u8 bounded by a
certain open interval maximum, use prandom_u32_max()
I say "non-uniform", because it doesn't do any rejection sampling
or divisions. Hence, it stays within the prandom_*() namespace, not
the get_random_*() namespace.
I'm currently investigating a "uniform" function for 6.2. We'll see
what comes of that.
By applying these rules uniformly, we get several benefits:
- By using prandom_u32_max() with an upper-bound that the compiler
can prove at compile-time is ≤65536 or ≤256, internally
get_random_u16() or get_random_u8() is used, which wastes fewer
batched random bytes, and hence has higher throughput.
- By using prandom_u32_max() instead of %, when the upper-bound is
not a constant, division is still avoided, because
prandom_u32_max() uses a faster multiplication-based trick instead.
- By using get_random_u16() or get_random_u8() in cases where the
return value is intended to indeed be a u16 or a u8, we waste fewer
batched random bytes, and hence have higher throughput.
This series was originally done by hand while I was on an airplane
without Internet. Later, Kees and I worked on retroactively figuring
out what could be done with Coccinelle and what had to be done
manually, and then we split things up based on that.
So while this touches a lot of files, the actual amount of code that's
hand fiddled is comfortably small"
* tag 'random-6.1-rc1-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/crng/random:
prandom: remove unused functions
treewide: use get_random_bytes() when possible
treewide: use get_random_u32() when possible
treewide: use get_random_{u8,u16}() when possible, part 2
treewide: use get_random_{u8,u16}() when possible, part 1
treewide: use prandom_u32_max() when possible, part 2
treewide: use prandom_u32_max() when possible, part 1
Rather than incurring a division or requesting too many random bytes for
the given range, use the prandom_u32_max() function, which only takes
the minimum required bytes from the RNG and avoids divisions. This was
done mechanically with this coccinelle script:
@basic@
expression E;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
typedef u64;
@@
(
- ((T)get_random_u32() % (E))
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ((E) - 1))
+ prandom_u32_max(E * XXX_MAKE_SURE_E_IS_POW2)
|
- ((u64)(E) * get_random_u32() >> 32)
+ prandom_u32_max(E)
|
- ((T)get_random_u32() & ~PAGE_MASK)
+ prandom_u32_max(PAGE_SIZE)
)
@multi_line@
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
identifier RAND;
expression E;
@@
- RAND = get_random_u32();
... when != RAND
- RAND %= (E);
+ RAND = prandom_u32_max(E);
// Find a potential literal
@literal_mask@
expression LITERAL;
type T;
identifier get_random_u32 =~ "get_random_int|prandom_u32|get_random_u32";
position p;
@@
((T)get_random_u32()@p & (LITERAL))
// Add one to the literal.
@script:python add_one@
literal << literal_mask.LITERAL;
RESULT;
@@
value = None
if literal.startswith('0x'):
value = int(literal, 16)
elif literal[0] in '123456789':
value = int(literal, 10)
if value is None:
print("I don't know how to handle %s" % (literal))
cocci.include_match(False)
elif value == 2**32 - 1 or value == 2**31 - 1 or value == 2**24 - 1 or value == 2**16 - 1 or value == 2**8 - 1:
print("Skipping 0x%x for cleanup elsewhere" % (value))
cocci.include_match(False)
elif value & (value + 1) != 0:
print("Skipping 0x%x because it's not a power of two minus one" % (value))
cocci.include_match(False)
elif literal.startswith('0x'):
coccinelle.RESULT = cocci.make_expr("0x%x" % (value + 1))
else:
coccinelle.RESULT = cocci.make_expr("%d" % (value + 1))
// Replace the literal mask with the calculated result.
@plus_one@
expression literal_mask.LITERAL;
position literal_mask.p;
expression add_one.RESULT;
identifier FUNC;
@@
- (FUNC()@p & (LITERAL))
+ prandom_u32_max(RESULT)
@collapse_ret@
type T;
identifier VAR;
expression E;
@@
{
- T VAR;
- VAR = (E);
- return VAR;
+ return E;
}
@drop_var@
type T;
identifier VAR;
@@
{
- T VAR;
... when != VAR
}
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Yury Norov <yury.norov@gmail.com>
Reviewed-by: KP Singh <kpsingh@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz> # for ext4 and sbitmap
Reviewed-by: Christoph Böhmwalder <christoph.boehmwalder@linbit.com> # for drbd
Acked-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Heiko Carstens <hca@linux.ibm.com> # for s390
Acked-by: Ulf Hansson <ulf.hansson@linaro.org> # for mmc
Acked-by: Darrick J. Wong <djwong@kernel.org> # for xfs
Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>
We should set the 'stat->size' to the real number of snapshots for
snapdirs.
Link: https://tracker.ceph.com/issues/57342
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
When the client has enough caps to satisfy a setattr locally without
having to talk to the server, we currently do the setattr without
incrementing the change attribute.
Ensure that if the ctime changes locally, then the change attribute
does too.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Just fail the request instead sending the request out, or the peer
MDS will crash.
Link: https://tracker.ceph.com/issues/56529
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
If the 'i_inline_version' is 1, that means the file is just new
created and there shouldn't have any inline data in it, we should
skip retrieving the inline data from MDS.
This also could help reduce possiblity of dead lock issue introduce
by the inline data and Fcr caps.
Gradually we will remove the inline feature from kclient after ceph's
scrub too have support to unline the inline data, currently this
could help reduce the teuthology test failures.
This is possiblly could also fix a bug that for some old clients if
they couldn't explictly uninline the inline data when writing, the
inline version will keep as 1 always. We may always reading non-exist
data from inline data.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
And for the 'Xs' caps for getxattr we will also choose the auth MDS,
because the MDS side code is buggy due to setxattr won't notify the
replica MDSes when the values changed and the replica MDS will return
the old values. Though we will fix it in MDS code, but this still
makes sense for old ceph.
Link: https://tracker.ceph.com/issues/55331
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Change the signature of netfs helper functions to take a struct netfs_inode
pointer rather than a struct inode pointer where appropriate, thereby
relieving the need for the network filesystem to convert its internal inode
format down to the VFS inode only for netfslib to bounce it back up. For
type safety, it's better not to do that (and it's less typing too).
Give netfs_write_begin() an extra argument to pass in a pointer to the
netfs_inode struct rather than deriving it internally from the file
pointer. Note that the ->write_begin() and ->write_end() ops are intended
to be replaced in the future by netfslib code that manages this without the
need to call in twice for each page.
netfs_readpage() and similar are intended to be pointed at directly by the
address_space_operations table, so must stick to the signature dictated by
the function pointers there.
Changes
=======
- Updated the kerneldoc comments and documentation [DH].
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-cachefs@redhat.com
Link: https://lore.kernel.org/r/CAHk-=wgkwKyNmNdKpQkqZ6DnmUL-x9hp0YBnUGjaPFEAdxDTbw@mail.gmail.com/
While randstruct was satisfied with using an open-coded "void *" offset
cast for the netfs_i_context <-> inode casting, __builtin_object_size() as
used by FORTIFY_SOURCE was not as easily fooled. This was causing the
following complaint[1] from gcc v12:
In file included from include/linux/string.h:253,
from include/linux/ceph/ceph_debug.h:7,
from fs/ceph/inode.c:2:
In function 'fortify_memset_chk',
inlined from 'netfs_i_context_init' at include/linux/netfs.h:326:2,
inlined from 'ceph_alloc_inode' at fs/ceph/inode.c:463:2:
include/linux/fortify-string.h:242:25: warning: call to '__write_overflow_field' declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
242 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Fix this by embedding a struct inode into struct netfs_i_context (which
should perhaps be renamed to struct netfs_inode). The struct inode
vfs_inode fields are then removed from the 9p, afs, ceph and cifs inode
structs and vfs_inode is then simply changed to "netfs.inode" in those
filesystems.
Further, rename netfs_i_context to netfs_inode, get rid of the
netfs_inode() function that converted a netfs_i_context pointer to an
inode pointer (that can now be done with &ctx->inode) and rename the
netfs_i_context() function to netfs_inode() (which is now a wrapper
around container_of()).
Most of the changes were done with:
perl -p -i -e 's/vfs_inode/netfs.inode/'g \
`git grep -l 'vfs_inode' -- fs/{9p,afs,ceph,cifs}/*.[ch]`
Kees suggested doing it with a pair structure[2] and a special
declarator to insert that into the network filesystem's inode
wrapper[3], but I think it's cleaner to embed it - and then it doesn't
matter if struct randomisation reorders things.
Dave Chinner suggested using a filesystem-specific VFS_I() function in
each filesystem to convert that filesystem's own inode wrapper struct
into the VFS inode struct[4].
Version #2:
- Fix a couple of missed name changes due to a disabled cifs option.
- Rename nfs_i_context to nfs_inode
- Use "netfs" instead of "nic" as the member name in per-fs inode wrapper
structs.
[ This also undoes commit 507160f46c ("netfs: gcc-12: temporarily
disable '-Wattribute-warning' for now") that is no longer needed ]
Fixes: bc899ee1c8 ("netfs: Add a netfs inode context")
Reported-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
cc: Jonathan Corbet <corbet@lwn.net>
cc: Eric Van Hensbergen <ericvh@gmail.com>
cc: Latchesar Ionkov <lucho@ionkov.net>
cc: Dominique Martinet <asmadeus@codewreck.org>
cc: Christian Schoenebeck <linux_oss@crudebyte.com>
cc: Marc Dionne <marc.dionne@auristor.com>
cc: Ilya Dryomov <idryomov@gmail.com>
cc: Steve French <smfrench@gmail.com>
cc: William Kucharski <william.kucharski@oracle.com>
cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
cc: Dave Chinner <david@fromorbit.com>
cc: linux-doc@vger.kernel.org
cc: v9fs-developer@lists.sourceforge.net
cc: linux-afs@lists.infradead.org
cc: ceph-devel@vger.kernel.org
cc: linux-cifs@vger.kernel.org
cc: samba-technical@lists.samba.org
cc: linux-fsdevel@vger.kernel.org
cc: linux-hardening@vger.kernel.org
Link: https://lore.kernel.org/r/d2ad3a3d7bdd794c6efb562d2f2b655fb67756b9.camel@kernel.org/ [1]
Link: https://lore.kernel.org/r/20220517210230.864239-1-keescook@chromium.org/ [2]
Link: https://lore.kernel.org/r/20220518202212.2322058-1-keescook@chromium.org/ [3]
Link: https://lore.kernel.org/r/20220524101205.GI2306852@dread.disaster.area/ [4]
Link: https://lore.kernel.org/r/165296786831.3591209.12111293034669289733.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165305805651.4094995.7763502506786714216.stgit@warthog.procyon.org.uk # v2
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This is a pure band-aid so that I can continue merging stuff from people
while some of the gcc-12 fallout gets sorted out.
In particular, gcc-12 is very unhappy about the kinds of pointer
arithmetic tricks that netfs does, and that makes the fortify checks
trigger in afs and ceph:
In function ‘fortify_memset_chk’,
inlined from ‘netfs_i_context_init’ at include/linux/netfs.h:327:2,
inlined from ‘afs_set_netfs_context’ at fs/afs/inode.c:61:2,
inlined from ‘afs_root_iget’ at fs/afs/inode.c:543:2:
include/linux/fortify-string.h:258:25: warning: call to ‘__write_overflow_field’ declared with attribute warning: detected write beyond size of field (1st parameter); maybe use struct_group()? [-Wattribute-warning]
258 | __write_overflow_field(p_size_field, size);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
and the reason is that netfs_i_context_init() is passed a 'struct inode'
pointer, and then it does
struct netfs_i_context *ctx = netfs_i_context(inode);
memset(ctx, 0, sizeof(*ctx));
where that netfs_i_context() function just does pointer arithmetic on
the inode pointer, knowing that the netfs_i_context is laid out
immediately after it in memory.
This is all truly disgusting, since the whole "netfs_i_context is laid
out immediately after it in memory" is not actually remotely true in
general, but is just made to be that way for afs and ceph.
See for example fs/cifs/cifsglob.h:
struct cifsInodeInfo {
struct {
/* These must be contiguous */
struct inode vfs_inode; /* the VFS's inode record */
struct netfs_i_context netfs_ctx; /* Netfslib context */
};
[...]
and realize that this is all entirely wrong, and the pointer arithmetic
that netfs_i_context() is doing is also very very wrong and wouldn't
give the right answer if netfs_ctx had different alignment rules from a
'struct inode', for example).
Anyway, that's just a long-winded way to say "the gcc-12 warning is
actually quite reasonable, and our code happens to work but is pretty
disgusting".
This is getting fixed properly, but for now I made the mistake of
thinking "the week right after the merge window tends to be calm for me
as people take a breather" and I did a sustem upgrade. And I got gcc-12
as a result, so to continue merging fixes from people and not have the
end result drown in warnings, I am fixing all these gcc-12 issues I hit.
Including with these kinds of temporary fixes.
Cc: Kees Cook <keescook@chromium.org>
Cc: David Howells <dhowells@redhat.com>
Link: https://lore.kernel.org/all/AEEBCF5D-8402-441D-940B-105AA718C71F@chromium.org/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When doing a mount using as base a directory that has 'max_bytes' quotas
statfs uses that value as the total; if a subdirectory is used instead,
the same 'max_bytes' too in statfs, unless there is another quota set.
Unfortunately, if this subdirectory only has the 'max_files' quota set,
then statfs uses the filesystem total. Fix this by making sure we only
lookup realms that contain the 'max_bytes' quota.
Cc: Ryan Taylor <rptaylor@uvic.ca>
URL: https://tracker.ceph.com/issues/55090
Signed-off-by: Luís Henriques <lhenriques@suse.de>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
If any 'x' caps is issued we can just choose the auth MDS instead
of the random replica MDSes. Because only when the Locker is in
LOCK_EXEC state will the loner client could get the 'x' caps. And
if we send the getattr requests to any replica MDS it must auth pin
and tries to rdlock from the auth MDS, and then the auth MDS need
to do the Locker state transition to LOCK_SYNC. And after that the
lock state will change back.
This cost much when doing the Locker state transition and usually
will need to revoke caps from clients.
URL: https://tracker.ceph.com/issues/55240
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
From the posix and the initial statx supporting commit comments,
the AT_STATX_DONT_SYNC is a lightweight stat and the
AT_STATX_FORCE_SYNC is a heaverweight one. And also checked all
the other current usage about these two flags they are all doing
the same, that is only when the AT_STATX_FORCE_SYNC is not set
and the AT_STATX_DONT_SYNC is set will they skip sync retriving
the attributes from storage.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Fixes: 400e1286c0 ("ceph: conversion to new fscache API")
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
The MDS will always refresh the dentry lease when removing the files
or directories. And if the dentry is still hashed, we can update
the dentry lease and no need to do the lookup from the MDS later.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
-----BEGIN PGP SIGNATURE-----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=j0yx
-----END PGP SIGNATURE-----
Merge tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs
Pull netfs updates from David Howells:
"Netfs prep for write helpers.
Having had a go at implementing write helpers and content encryption
support in netfslib, it seems that the netfs_read_{,sub}request
structs and the equivalent write request structs were almost the same
and so should be merged, thereby requiring only one set of
alloc/get/put functions and a common set of tracepoints.
Merging the structs also has the advantage that if a bounce buffer is
added to the request struct, a read operation can be performed to fill
the bounce buffer, the contents of the buffer can be modified and then
a write operation can be performed on it to send the data wherever it
needs to go using the same request structure all the way through. The
I/O handlers would then transparently perform any required crypto.
This should make it easier to perform RMW cycles if needed.
The potentially common functions and structs, however, by their names
all proclaim themselves to be associated with the read side of things.
The bulk of these changes alter this in the following ways:
- Rename struct netfs_read_{,sub}request to netfs_io_{,sub}request.
- Rename some enums, members and flags to make them more appropriate.
- Adjust some comments to match.
- Drop "read"/"rreq" from the names of common functions. For
instance, netfs_get_read_request() becomes netfs_get_request().
- The ->init_rreq() and ->issue_op() methods become ->init_request()
and ->issue_read(). I've kept the latter as a read-specific
function and in another branch added an ->issue_write() method.
The driver source is then reorganised into a number of files:
fs/netfs/buffered_read.c Create read reqs to the pagecache
fs/netfs/io.c Dispatchers for read and write reqs
fs/netfs/main.c Some general miscellaneous bits
fs/netfs/objects.c Alloc, get and put functions
fs/netfs/stats.c Optional procfs statistics.
and future development can be fitted into this scheme, e.g.:
fs/netfs/buffered_write.c Modify the pagecache
fs/netfs/buffered_flush.c Writeback from the pagecache
fs/netfs/direct_read.c DIO read support
fs/netfs/direct_write.c DIO write support
fs/netfs/unbuffered_write.c Write modifications directly back
Beyond the above changes, there are also some changes that affect how
things work:
- Make fscache_end_operation() generally available.
- In the netfs tracing header, generate enums from the symbol ->
string mapping tables rather than manually coding them.
- Add a struct for filesystems that uses netfslib to put into their
inode wrapper structs to hold extra state that netfslib is
interested in, such as the fscache cookie. This allows netfslib
functions to be set in filesystem operation tables and jumped to
directly without having to have a filesystem wrapper.
- Add a member to the struct added above to track the remote inode
length as that may differ if local modifications are buffered. We
may need to supply an appropriate EOF pointer when storing data (in
AFS for example).
- Pass extra information to netfs_alloc_request() so that the
->init_request() hook can access it and retain information to
indicate the origin of the operation.
- Make the ->init_request() hook return an error, thereby allowing a
filesystem that isn't allowed to cache an inode (ceph or cifs, for
example) to skip readahead.
- Switch to using refcount_t for subrequests and add tracepoints to
log refcount changes for the request and subrequest structs.
- Add a function to consolidate dispatching a read request. Similar
code is used in three places and another couple are likely to be
added in the future"
Link: https://lore.kernel.org/all/2639515.1648483225@warthog.procyon.org.uk/
* tag 'netfs-prep-20220318' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs:
afs: Maintain netfs_i_context::remote_i_size
netfs: Keep track of the actual remote file size
netfs: Split some core bits out into their own file
netfs: Split fs/netfs/read_helper.c
netfs: Rename read_helper.c to io.c
netfs: Prepare to split read_helper.c
netfs: Add a function to consolidate beginning a read
netfs: Add a netfs inode context
ceph: Make ceph_init_request() check caps on readahead
netfs: Change ->init_request() to return an error code
netfs: Refactor arguments for netfs_alloc_read_request
netfs: Adjust the netfs_failure tracepoint to indicate non-subreq lines
netfs: Trace refcounting on the netfs_io_subrequest struct
netfs: Trace refcounting on the netfs_io_request struct
netfs: Adjust the netfs_rreq tracepoint slightly
netfs: Split netfs_io_* object handling out
netfs: Finish off rename of netfs_read_request to netfs_io_request
netfs: Rename netfs_read_*request to netfs_io_*request
netfs: Generate enums from trace symbol mapping lists
fscache: export fscache_end_operation()
- several changes to how snap context and snap realms are tracked
(Xiubo Li). In particular, this should resolve a long-standing
issue of high kworker CPU usage and various stalls caused by
needless iteration over all inodes in the snap realm.
- async create fixes to address hangs in some edge cases (Jeff Layton)
- support for getvxattr MDS op for querying server-side xattrs, such
as file/directory layouts and ephemeral pins (Milind Changire)
- average latency is now maintained for all metrics (Venky Shankar)
- some tweaks around handling inline data to make it fit better with
netfs helper library (David Howells)
Also a couple of memory leaks got plugged along with a few assorted
fixups. Last but not least, Xiubo has stepped up to serve as a CephFS
co-maintainer.
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEydHwtzie9C7TfviiSn/eOAIR84sFAmI8qE4THGlkcnlvbW92
QGdtYWlsLmNvbQAKCRBKf944AhHzi9UvB/kBZt4mkyjqRC+KJ5rukw5q7lyAYGC1
QYVbuTuIJydyDvqQp9pXYFndlj10pb7ULnUlQlcBfntVAr9s7xx7ZKrKciE48MPT
vLiJmq3MpEedM4oE4FgcJbmHtltDgZWvOxXB7renpHNeHuPeezNpKzaKQXGUHUDo
+7cX5XWBzZk+AYbEvxQUsjDozcgDp31qf015mAX3r0P7XFkBB7xwZA7sb7Cw1GEr
S6ZdlNoFcWUq0ULUdh2C7l5a2mKQnVnpOO3TMjE6tSqJ74iozRy4tO9aFgj99NEn
D1rQbCLr3JPfY//JFyqEOIDYf3hepOMmEkoGHOFukckFKUe3yfJJxa3r
=ESr5
-----END PGP SIGNATURE-----
Merge tag 'ceph-for-5.18-rc1' of https://github.com/ceph/ceph-client
Pull ceph updates from Ilya Dryomov:
"The highlights are:
- several changes to how snap context and snap realms are tracked
(Xiubo Li). In particular, this should resolve a long-standing
issue of high kworker CPU usage and various stalls caused by
needless iteration over all inodes in the snap realm.
- async create fixes to address hangs in some edge cases (Jeff
Layton)
- support for getvxattr MDS op for querying server-side xattrs, such
as file/directory layouts and ephemeral pins (Milind Changire)
- average latency is now maintained for all metrics (Venky Shankar)
- some tweaks around handling inline data to make it fit better with
netfs helper library (David Howells)
Also a couple of memory leaks got plugged along with a few assorted
fixups. Last but not least, Xiubo has stepped up to serve as a CephFS
co-maintainer"
* tag 'ceph-for-5.18-rc1' of https://github.com/ceph/ceph-client: (27 commits)
ceph: fix memory leak in ceph_readdir when note_last_dentry returns error
ceph: uninitialized variable in debug output
ceph: use tracked average r/w/m latencies to display metrics in debugfs
ceph: include average/stdev r/w/m latency in mds metrics
ceph: track average r/w/m latency
ceph: use ktime_to_timespec64() rather than jiffies_to_timespec64()
ceph: assign the ci only when the inode isn't NULL
ceph: fix inode reference leakage in ceph_get_snapdir()
ceph: misc fix for code style and logs
ceph: allocate capsnap memory outside of ceph_queue_cap_snap()
ceph: do not release the global snaprealm until unmounting
ceph: remove incorrect and unused CEPH_INO_DOTDOT macro
MAINTAINERS: add Xiubo Li as cephfs co-maintainer
ceph: eliminate the recursion when rebuilding the snap context
ceph: do not update snapshot context when there is no new snapshot
ceph: zero the dir_entries memory when allocating it
ceph: move to a dedicated slabcache for ceph_cap_snap
ceph: add getvxattr op
libceph: drop else branches in prepare_read_data{,_cont}
ceph: fix comments mentioning i_mutex
...
The inode allocation is supposed to use alloc_inode_sb(), so convert
kmem_cache_alloc() of all filesystems to alloc_inode_sb().
Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com
Signed-off-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Theodore Ts'o <tytso@mit.edu> [ext4]
Acked-by: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Alex Shi <alexs@kernel.org>
Cc: Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc: Chao Yu <chao@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Fam Zheng <fam.zheng@bytedance.com>
Cc: Jaegeuk Kim <jaegeuk@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kari Argillander <kari.argillander@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Shakeel Butt <shakeelb@google.com>
Cc: Trond Myklebust <trond.myklebust@hammerspace.com>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Xiongchun Duan <duanxiongchun@bytedance.com>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The ceph_get_inode() will search for or insert a new inode into the
hash for the given vino, and return a reference to it. If new is
non-NULL, its reference is consumed.
We should release the reference when in error handing cases.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Problem:
Some directory vxattrs (e.g. ceph.dir.pin.random) are governed by
information that isn't necessarily shared with the client. Add support
for the new GETVXATTR operation, which allows the client to query the
MDS directly for vxattrs.
When the client is queried for a vxattr that doesn't have a special
handler, have it issue a GETVXATTR to the MDS directly.
Solution:
Adds new getvxattr op to fetch ceph.dir.pin*, ceph.dir.layout* and
ceph.file.layout* vxattrs.
If the entire layout for a dir or a file is being set, then it is
expected that the layout be set in standard JSON format. Individual
field value retrieval is not wrapped in JSON. The JSON format also
applies while setting the vxattr if the entire layout is being set in
one go.
As a temporary measure, setting a vxattr can also be done in the old
format. The old format will be deprecated in the future.
URL: https://tracker.ceph.com/issues/51062
Signed-off-by: Milind Changire <mchangir@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
inode->i_mutex has been replaced with inode->i_rwsem long ago. Fix
comments still mentioning i_mutex.
Signed-off-by: hongnanli <hongnan.li@linux.alibaba.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
If the new size is the same as the current size, the MDS will do nothing
but change the mtime/atime. POSIX doesn't mandate that the filesystems
must update them in this case, so just ignore it instead.
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add proper error handling for when an async create fails. The inode
never existed, so any dirty caps or data are now toast. We already
d_drop the dentry in that case, but the now-stale inode may still be
around. We want to shut down access to these inodes, and ensure that
they can't harbor any more dirty data, which can cause problems at
umount time.
When this occurs, flag such inodes as being SHUTDOWN, and trash any caps
and cap flushes that may be in flight for them, and invalidate the
pagecache for the inode. Add a new helper that can check whether an
inode or an entire mount is now shut down, and call it instead of
accessing the mount_state directly in places where we test that now.
URL: https://tracker.ceph.com/issues/51279
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
We have a lot of log messages that print inode pointer values. This is
of dubious utility. Switch a random assortment of the ones I've found
most useful to use ceph_vinop to print the snap:inum tuple instead.
[ idryomov: use . as a separator, break unnecessarily long lines ]
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Currently, we check the wb_err too early for directories, before all of
the unsafe child requests have been waited on. In order to fix that we
need to check the mapping->wb_err later nearer to the end of ceph_fsync.
We also have an overly-complex method for tracking errors after
blocklisting. The errors recorded in cleanup_session_requests go to a
completely separate field in the inode, but we end up reporting them the
same way we would for any other error (in fsync).
There's no real benefit to tracking these errors in two different
places, since the only reporting mechanism for them is in fsync, and
we'd need to advance them both every time.
Given that, we can just remove i_meta_err, and convert the places that
used it to instead just use mapping->wb_err instead. That also fixes
the original problem by ensuring that we do a check_and_advance of the
wb_err at the end of the fsync op.
Cc: stable@vger.kernel.org
URL: https://tracker.ceph.com/issues/52864
Reported-by: Patrick Donnelly <pdonnell@redhat.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Consolidate some fiddly code for changing an inode's snap_realm
into a new helper function, and change the callers to use it.
While we're in here, nothing uses the i_snap_realm_counter field, so
remove that from the inode.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Now that we don't need to hold session->s_mutex or the snap_rwsem when
calling ceph_check_caps, we can eliminate ceph_async_iput and just use
normal iput calls.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Turn s_cap_gen field into an atomic_t, and just rely on the fact that we
hold the s_mutex when changing the s_cap_ttl field.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
...and add a lockdep assertion for it to ceph_fill_inode().
Cc: stable@vger.kernel.org # v5.7+
Fixes: 9a8d03ca2e ("ceph: attempt to do async create when possible")
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
netfs helper library from Jeff, three new filesystem client metrics
from Xiubo, ceph.dir.rsnaps vxattr from Yanhu and two auth-related
fixes from myself, marked for stable. Interspersed is a smattering
of assorted fixes and cleanups across the filesystem.
-----BEGIN PGP SIGNATURE-----
iQFHBAABCAAxFiEEydHwtzie9C7TfviiSn/eOAIR84sFAmCT8IITHGlkcnlvbW92
QGdtYWlsLmNvbQAKCRBKf944AhHzizgqCACYbyY4Yr/2C8fZsn+P9rd97zRTbcC6
eufTZwnlECLnc89BxJQRk9a2UpDJfC8RMM3/9tmiulc8G4M+ggVbdFQTCzsZox3c
vLAunGeVyfKIY+16Bv2RNuoO3KeeZm5aB3jXJ5QcUPcXmd4XnHKI1FU2ebC56UJb
pxxfHpE6fb59r6Ek1e5uUFyta4KDMrvwXozghuAPEgT1GpKeA9zMIGI0CkQbBHlW
PWHpcahTiT6GWa/d9ud0CnfssiBxVydWyKTz9xppYC6LNdsZUf9tBmYYGRklcjoA
yAwPSuqxNmg+7uWubEawc0+a/3fXORgp2SF7Rbp1XYE+HpfnMF1J+nIn
=IO5c
-----END PGP SIGNATURE-----
Merge tag 'ceph-for-5.13-rc1' of git://github.com/ceph/ceph-client
Pull ceph updates from Ilya Dryomov:
"Notable items here are
- a series to take advantage of David Howells' netfs helper library
from Jeff
- three new filesystem client metrics from Xiubo
- ceph.dir.rsnaps vxattr from Yanhu
- two auth-related fixes from myself, marked for stable.
Interspersed is a smattering of assorted fixes and cleanups across the
filesystem"
* tag 'ceph-for-5.13-rc1' of git://github.com/ceph/ceph-client: (24 commits)
libceph: allow addrvecs with a single NONE/blank address
libceph: don't set global_id until we get an auth ticket
libceph: bump CephXAuthenticate encoding version
ceph: don't allow access to MDS-private inodes
ceph: fix up some bare fetches of i_size
ceph: convert some PAGE_SIZE invocations to thp_size()
ceph: support getting ceph.dir.rsnaps vxattr
ceph: drop pinned_page parameter from ceph_get_caps
ceph: fix inode leak on getattr error in __fh_to_dentry
ceph: only check pool permissions for regular files
ceph: send opened files/pinned caps/opened inodes metrics to MDS daemon
ceph: avoid counting the same request twice or more
ceph: rename the metric helpers
ceph: fix kerneldoc copypasta over ceph_start_io_direct
ceph: use attach/detach_page_private for tracking snap context
ceph: don't use d_add in ceph_handle_snapdir
ceph: don't clobber i_snap_caps on non-I_NEW inode
ceph: fix fall-through warnings for Clang
ceph: convert ceph_readpages to ceph_readahead
ceph: convert ceph_write_begin to netfs_write_begin
...
The MDS reserves a set of inodes for its own usage, and these should
never be accessible to clients. Add a new helper to vet a proposed
inode number against that range, and complain loudly and refuse to
create or look it up if it's in it.
Also, ensure that the MDS doesn't try to delegate inodes that are in
that range or lower. Print a warning if it does, and don't save the
range in the xarray.
URL: https://tracker.ceph.com/issues/49922
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
We need to use i_size_read(), which properly handles the torn read
case on 32-bit arches.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add support for grabbing the rsnaps value out of the inode info in
traces, and exposing that via ceph.dir.rsnaps xattr.
Signed-off-by: Yanhu Cao <gmayyyha@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
We want the snapdir to mirror the non-snapped directory's attributes for
most things, but i_snap_caps represents the caps granted on the snapshot
directory by the MDS itself. A misbehaving MDS could issue different
caps for the snapdir and we lose them here.
Only reset i_snap_caps when the inode is I_NEW. Also, move the setting
of i_op and i_fop inside the if block since they should never change
anyway.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Ensure that we invalidate the fscache whenever we invalidate the
pagecache.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Al pointed out that a malicious or broken MDS could change the type or
device number of a given inode number. It may also be possible for the
MDS to reuse an old inode number.
Ensure that we never allow fill_inode to change the type part of the
i_mode or the i_rdev unless I_NEW is set. Throw warnings if the MDS ever
changes these on us mid-stream, and return an error.
Don't set i_rdev directly, and rely on init_special_inode to do it.
Also, fix up error handling in the callers of ceph_get_inode.
In handle_cap_grant, check for and warn if the inode type changes, and
only overwrite the mode if it didn't.
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
There are several warts in the snapdir error handling. The -EOPNOTSUPP
return in __snapfh_to_dentry is currently lost, and the call to
ceph_handle_snapdir is not currently checked at all.
Fix all of this up and eliminate a BUG_ON in ceph_get_snapdir. We can
handle that case with a warning and return an error.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
-----BEGIN PGP SIGNATURE-----
iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCYCegywAKCRCRxhvAZXjc
ouJ6AQDlf+7jCQlQdeKKoN9QDFfMzG1ooemat36EpRRTONaGuAD8D9A4sUsG4+5f
4IU5Lj9oY4DEmF8HenbWK2ZHsesL2Qg=
=yPaw
-----END PGP SIGNATURE-----
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
...
Testing with the fscache overhaul has triggered some lockdep warnings
about circular lock dependencies involving page_mkwrite and the
mmap_lock. It'd be better to do the "real work" without the mmap lock
being held.
Change the skip_checking_caps parameter in __ceph_put_cap_refs to an
enum, and use that to determine whether to queue check_caps, do it
synchronously or not at all. Change ceph_page_mkwrite to do a
ceph_put_cap_refs_async().
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Add a generic function for taking an inode reference, setting the I_WORK
bit and queueing i_work. Turn the ceph_queue_* functions into static
inline wrappers that pass in the right bit.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
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 <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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 <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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 <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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 <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
The two helpers inode_permission() and generic_permission() are used by
the vfs to perform basic permission checking by verifying that the
caller is privileged over an inode. In order to handle idmapped mounts
we extend the two helpers with an additional user namespace argument.
On idmapped mounts the two helpers will make sure to map the inode
according to the mount's user namespace and then peform identical
permission checks to inode_permission() and generic_permission(). 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/20210121131959.646623-6-christian.brauner@ubuntu.com
Cc: Christoph Hellwig <hch@lst.de>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Acked-by: Serge Hallyn <serge@hallyn.com>
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
We already have a pointer to the argument struct in req->r_args. Use that
instead of groveling around in the ceph_mds_request_head.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Xiubo Li <xiubli@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Geng Jichao reported a rather complex deadlock involving several
moving parts:
1) readahead is issued against an inode and some of its pages are locked
while the read is in flight
2) the same inode is evicted from the cache, and this task gets stuck
waiting for the page lock because of the above readahead
3) another task is processing a reply trace, and looks up the inode
being evicted while holding the s_mutex. That ends up waiting for the
eviction to complete
4) a write reply for an unrelated inode is then processed in the
ceph_con_workfn job. It calls ceph_check_caps after putting wrbuffer
caps, and that gets stuck waiting on the s_mutex held by 3.
The reply to "1" is stuck behind the write reply in "4", so we deadlock
at that point.
This patch changes the trace processing to call ceph_get_inode outside
of the s_mutex and snap_rwsem, which should break the cycle above.
[ idryomov: break unnecessarily long lines ]
URL: https://tracker.ceph.com/issues/47998
Reported-by: Geng Jichao <gengjichao@jd.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Luis Henriques <lhenriques@suse.de>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Linus Torvalds