PF_LESS_THROTTLE has a very specific use case: to avoid deadlocks
and live-locks while writing to the page cache in a loop-back
NFS mount situation.
It therefore makes sense to *only* set PF_LESS_THROTTLE in this
situation.
We now know when a request came from the local-host so it could be a
loop-back mount. We already know when we are handling write requests,
and when we are doing anything else.
So combine those two to allow nfsd to still be throttled (like any
other process) in every situation except when it is known to be
problematic.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We're clearing the SUID/SGID bits on write by hand in nfsd_vfs_write,
even though the subsequent vfs_writev() call will end up doing this for
us (through file system write methods eventually calling
file_remove_suid(), e.g., from __generic_file_aio_write).
So, remove the redundant nfsd code.
The only change in behavior is when the write is by root, in which case
we previously cleared SUID/SGID, but will now leave it alone. The new
behavior is the behavior of every filesystem we've checked.
It seems better to be consistent with local filesystem behavior. And
the security advantage seems limited as root could always restore these
bits by hand if it wanted.
SUID/SGID is not cleared after writing data with (root, local ext4),
File: ‘test’
Size: 0 Blocks: 0 IO Block: 4096 regular
empty file
Device: 803h/2051d Inode: 1200137 Links: 1
Access: (4777/-rwsrwxrwx) Uid: ( 0/ root) Gid: ( 0/ root)
Context: unconfined_u:object_r:admin_home_t:s0
Access: 2014-04-18 21:36:31.016029014 +0800
Modify: 2014-04-18 21:36:31.016029014 +0800
Change: 2014-04-18 21:36:31.026030285 +0800
Birth: -
File: ‘test’
Size: 5 Blocks: 8 IO Block: 4096 regular file
Device: 803h/2051d Inode: 1200137 Links: 1
Access: (4777/-rwsrwxrwx) Uid: ( 0/ root) Gid: ( 0/ root)
Context: unconfined_u:object_r:admin_home_t:s0
Access: 2014-04-18 21:36:31.016029014 +0800
Modify: 2014-04-18 21:36:31.040032065 +0800
Change: 2014-04-18 21:36:31.040032065 +0800
Birth: -
With no_root_squash, (root, remote ext4), SUID/SGID are cleared,
File: ‘test’
Size: 0 Blocks: 0 IO Block: 262144 regular
empty file
Device: 24h/36d Inode: 786439 Links: 1
Access: (4777/-rwsrwxrwx) Uid: ( 1000/ test) Gid: ( 1000/ test)
Context: system_u:object_r:nfs_t:s0
Access: 2014-04-18 21:45:32.155805097 +0800
Modify: 2014-04-18 21:45:32.155805097 +0800
Change: 2014-04-18 21:45:32.168806749 +0800
Birth: -
File: ‘test’
Size: 5 Blocks: 8 IO Block: 262144 regular file
Device: 24h/36d Inode: 786439 Links: 1
Access: (0777/-rwxrwxrwx) Uid: ( 1000/ test) Gid: ( 1000/ test)
Context: system_u:object_r:nfs_t:s0
Access: 2014-04-18 21:45:32.155805097 +0800
Modify: 2014-04-18 21:45:32.184808783 +0800
Change: 2014-04-18 21:45:32.184808783 +0800
Birth: -
Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd updates from Bruce Fields:
"Highlights:
- server-side nfs/rdma fixes from Jeff Layton and Tom Tucker
- xdr fixes (a larger xdr rewrite has been posted but I decided it
would be better to queue it up for 3.16).
- miscellaneous fixes and cleanup from all over (thanks especially to
Kinglong Mee)"
* 'for-3.15' of git://linux-nfs.org/~bfields/linux: (36 commits)
nfsd4: don't create unnecessary mask acl
nfsd: revert v2 half of "nfsd: don't return high mode bits"
nfsd4: fix memory leak in nfsd4_encode_fattr()
nfsd: check passed socket's net matches NFSd superblock's one
SUNRPC: Clear xpt_bc_xprt if xs_setup_bc_tcp failed
NFSD/SUNRPC: Check rpc_xprt out of xs_setup_bc_tcp
SUNRPC: New helper for creating client with rpc_xprt
NFSD: Free backchannel xprt in bc_destroy
NFSD: Clear wcc data between compound ops
nfsd: Don't return NFS4ERR_STALE_STATEID for NFSv4.1+
nfsd4: fix nfs4err_resource in 4.1 case
nfsd4: fix setclientid encode size
nfsd4: remove redundant check from nfsd4_check_resp_size
nfsd4: use more generous NFS4_ACL_MAX
nfsd4: minor nfsd4_replay_cache_entry cleanup
nfsd4: nfsd4_replay_cache_entry should be static
nfsd4: update comments with obsolete function name
rpc: Allow xdr_buf_subsegment to operate in-place
NFSD: Using free_conn free connection
SUNRPC: fix memory leak of peer addresses in XPRT
...
Add new renameat2 syscall, which is the same as renameat with an added
flags argument.
Pass flags to vfs_rename() and to i_op->rename() as well.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Reviewed-by: J. Bruce Fields <bfields@redhat.com>
Looks like this bug has been here since these write counts were
introduced, not sure why it was just noticed now.
Thanks also to Jan Kara for pointing out the problem.
Cc: stable@vger.kernel.org
Reported-by: Matthew Rahtz <mrahtz@rapitasystems.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There is a regression in
208d0ac 2014-01-07 nfsd4: break only delegations when appropriate
which deletes an nfserrno() call in nfsd_setattr() (by accident,
probably), and NFSD becomes ignoring an error from VFS.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd updates from Bruce Fields:
- Handle some loose ends from the vfs read delegation support.
(For example nfsd can stop breaking leases on its own in a
fewer places where it can now depend on the vfs to.)
- Make life a little easier for NFSv4-only configurations
(thanks to Kinglong Mee).
- Fix some gss-proxy problems (thanks Jeff Layton).
- miscellaneous bug fixes and cleanup
* 'for-3.14' of git://linux-nfs.org/~bfields/linux: (38 commits)
nfsd: consider CLAIM_FH when handing out delegation
nfsd4: fix delegation-unlink/rename race
nfsd4: delay setting current_fh in open
nfsd4: minor nfs4_setlease cleanup
gss_krb5: use lcm from kernel lib
nfsd4: decrease nfsd4_encode_fattr stack usage
nfsd: fix encode_entryplus_baggage stack usage
nfsd4: simplify xdr encoding of nfsv4 names
nfsd4: encode_rdattr_error cleanup
nfsd4: nfsd4_encode_fattr cleanup
minor svcauth_gss.c cleanup
nfsd4: better VERIFY comment
nfsd4: break only delegations when appropriate
NFSD: Fix a memory leak in nfsd4_create_session
sunrpc: get rid of use_gssp_lock
sunrpc: fix potential race between setting use_gss_proxy and the upcall rpc_clnt
sunrpc: don't wait for write before allowing reads from use-gss-proxy file
nfsd: get rid of unused function definition
Define op_iattr for nfsd4_open instead using macro
NFSD: fix compile warning without CONFIG_NFSD_V3
...
If a file is unlinked or renamed between the time when we do the local
open and the time when we get the delegation, then we will return to the
client indicating that it holds a delegation even though the file no
longer exists under the name it was open under.
But a client performing an open-by-name, when it is returned a
delegation, must be able to assume that the file is still linked at the
name it was opened under.
So, hold the parent i_mutex for longer to prevent concurrent renames or
unlinks.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Remove the boilerplate code to marshall and unmarhall ACL objects into
xattrs and operate on the posix_acl objects directly. Also move all
the ACL handling code into nfs?acl.c where it belongs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
As a temporary fix, nfsd was breaking all leases on unlink, link,
rename, and setattr.
Now that we can distinguish between leases and delegations, we can be
nicer and break only the delegations, and not bother lease-holders with
operations they don't care about.
And we get to delete some code while we're at it.
Note that in the presence of delegations the vfs calls here all return
-EWOULDBLOCK instead of blocking, so nfsd threads will not get stuck
waiting for delegation returns.
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There is an inconsistency in the handling of SUID/SGID file
bits after chown() between NFS and other local file systems.
Local file systems (for example, ext3, ext4, xfs, btrfs) revoke
SUID/SGID bits after chown() on a regular file even if
the owner/group of the file has not been changed:
~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec 6 04:49 file
~# chown root file; ls -l file
-rwxr-Sr-- 1 root root 0 Dec 6 04:49 file
but NFS doesn't do that:
~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec 6 04:49 file
~# chown root file; ls -l file
-rwsr-Sr-- 1 root root 0 Dec 6 04:49 file
NFS does that only if the owner/group has been changed:
~# touch file; chmod ug+s file; chmod u+x file
~# ls -l file
-rwsr-Sr-- 1 root root 0 Dec 6 05:02 file
~# chown bin file; ls -l file
-rwxr-Sr-- 1 bin root 0 Dec 6 05:02 file
See: http://pubs.opengroup.org/onlinepubs/9699919799/functions/chown.html
"If the specified file is a regular file, one or more of
the S_IXUSR, S_IXGRP, or S_IXOTH bits of the file mode are set,
and the process has appropriate privileges, it is
implementation-defined whether the set-user-ID and set-group-ID
bits are altered."
So both variants are acceptable by POSIX.
This patch makes NFS to behave like local file systems.
Signed-off-by: Stanislav Kholmanskikh <stanislav.kholmanskikh@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Use a straight goto error label style in nfsd_setattr to make sure
we always do the put_write_access call after we got it earlier.
Note that the we have been failing to do that in the case
nfsd_break_lease() returns an error, a bug introduced into 2.6.38 with
6a76bebefe "nfsd4: break lease on nfsd
setattr".
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Split out two helpers to make the code more readable and easier to verify
for correctness.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: stable@vger.kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
NFSv4 uses leases to guarantee that clients can cache metadata as well
as data.
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: David Howells <dhowells@redhat.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We need to break delegations on any operation that changes the set of
links pointing to an inode. Start with unlink.
Such operations also hold the i_mutex on a parent directory. Breaking a
delegation may require waiting for a timeout (by default 90 seconds) in
the case of a unresponsive NFS client. To avoid blocking all directory
operations, we therefore drop locks before waiting for the delegation.
The logic then looks like:
acquire locks
...
test for delegation; if found:
take reference on inode
release locks
wait for delegation break
drop reference on inode
retry
It is possible this could never terminate. (Even if we take precautions
to prevent another delegation being acquired on the same inode, we could
get a different inode on each retry.) But this seems very unlikely.
The initial test for a delegation happens after the lock on the target
inode is acquired, but the directory inode may have been acquired
further up the call stack. We therefore add a "struct inode **"
argument to any intervening functions, which we use to pass the inode
back up to the caller in the case it needs a delegation synchronously
broken.
Cc: David Howells <dhowells@redhat.com>
Cc: Tyler Hicks <tyhicks@canonical.com>
Cc: Dustin Kirkland <dustin.kirkland@gazzang.com>
Acked-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The following call chain:
------------------------------------------------------------
nfs4_get_vfs_file
- nfsd_open
- dentry_open
- do_dentry_open
- __get_file_write_access
- get_write_access
- return atomic_inc_unless_negative(&inode->i_writecount) ? 0 : -ETXTBSY;
------------------------------------------------------------
can result in the following state:
------------------------------------------------------------
struct nfs4_file {
...
fi_fds = {0xffff880c1fa65c80, 0xffffffffffffffe6, 0x0},
fi_access = {{
counter = 0x1
}, {
counter = 0x0
}},
...
------------------------------------------------------------
1) First time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NULL, hence nfsd_open() is called where we get status set to an error
and fp->fi_fds[O_WRONLY] to -ETXTBSY. Thus we do not reach
nfs4_file_get_access() and fi_access[O_WRONLY] is not incremented.
2) Second time around, in nfs4_get_vfs_file() fp->fi_fds[O_WRONLY] is
NOT NULL (-ETXTBSY), so nfsd_open() is NOT called, but
nfs4_file_get_access() IS called and fi_access[O_WRONLY] is incremented.
Thus we leave a landmine in the form of the nfs4_file data structure in
an incorrect state.
3) Eventually, when __nfs4_file_put_access() is called it finds
fi_access[O_WRONLY] being non-zero, it decrements it and calls
nfs4_file_put_fd() which tries to fput -ETXTBSY.
------------------------------------------------------------
...
[exception RIP: fput+0x9]
RIP: ffffffff81177fa9 RSP: ffff88062e365c90 RFLAGS: 00010282
RAX: ffff880c2b3d99cc RBX: ffff880c2b3d9978 RCX: 0000000000000002
RDX: dead000000100101 RSI: 0000000000000001 RDI: ffffffffffffffe6
RBP: ffff88062e365c90 R8: ffff88041fe797d8 R9: ffff88062e365d58
R10: 0000000000000008 R11: 0000000000000000 R12: 0000000000000001
R13: 0000000000000007 R14: 0000000000000000 R15: 0000000000000000
ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018
#9 [ffff88062e365c98] __nfs4_file_put_access at ffffffffa0562334 [nfsd]
#10 [ffff88062e365cc8] nfs4_file_put_access at ffffffffa05623ab [nfsd]
#11 [ffff88062e365ce8] free_generic_stateid at ffffffffa056634d [nfsd]
#12 [ffff88062e365d18] release_open_stateid at ffffffffa0566e4b [nfsd]
#13 [ffff88062e365d38] nfsd4_close at ffffffffa0567401 [nfsd]
#14 [ffff88062e365d88] nfsd4_proc_compound at ffffffffa0557f28 [nfsd]
#15 [ffff88062e365dd8] nfsd_dispatch at ffffffffa054543e [nfsd]
#16 [ffff88062e365e18] svc_process_common at ffffffffa04ba5a4 [sunrpc]
#17 [ffff88062e365e98] svc_process at ffffffffa04babe0 [sunrpc]
#18 [ffff88062e365eb8] nfsd at ffffffffa0545b62 [nfsd]
#19 [ffff88062e365ee8] kthread at ffffffff81090886
#20 [ffff88062e365f48] kernel_thread at ffffffff8100c14a
------------------------------------------------------------
Cc: stable@vger.kernel.org
Signed-off-by: Harshula Jayasuriya <harshula@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd changes from Bruce Fields:
"Changes this time include:
- 4.1 enabled on the server by default: the last 4.1-specific issues
I know of are fixed, so we're not going to find the rest of the
bugs without more exposure.
- Experimental support for NFSv4.2 MAC Labeling (to allow running
selinux over NFS), from Dave Quigley.
- Fixes for some delicate cache/upcall races that could cause rare
server hangs; thanks to Neil Brown and Bodo Stroesser for extreme
debugging persistence.
- Fixes for some bugs found at the recent NFS bakeathon, mostly v4
and v4.1-specific, but also a generic bug handling fragmented rpc
calls"
* 'for-3.11' of git://linux-nfs.org/~bfields/linux: (31 commits)
nfsd4: support minorversion 1 by default
nfsd4: allow destroy_session over destroyed session
svcrpc: fix failures to handle -1 uid's
sunrpc: Don't schedule an upcall on a replaced cache entry.
net/sunrpc: xpt_auth_cache should be ignored when expired.
sunrpc/cache: ensure items removed from cache do not have pending upcalls.
sunrpc/cache: use cache_fresh_unlocked consistently and correctly.
sunrpc/cache: remove races with queuing an upcall.
nfsd4: return delegation immediately if lease fails
nfsd4: do not throw away 4.1 lock state on last unlock
nfsd4: delegation-based open reclaims should bypass permissions
svcrpc: don't error out on small tcp fragment
svcrpc: fix handling of too-short rpc's
nfsd4: minor read_buf cleanup
nfsd4: fix decoding of compounds across page boundaries
nfsd4: clean up nfs4_open_delegation
NFSD: Don't give out read delegations on creates
nfsd4: allow client to send no cb_sec flavors
nfsd4: fail attempts to request gss on the backchannel
nfsd4: implement minimal SP4_MACH_CRED
...
iterate_dir(): new helper, replacing vfs_readdir().
struct dir_context: contains the readdir callback (and will get more stuff
in it), embedded into whatever data that callback wants to deal with;
eventually, we'll be passing it to ->readdir() replacement instead of
(data,filldir) pair.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Implement labeled NFS on the server: encoding and decoding, and writing
and reading, of file labels.
Enabled with CONFIG_NFSD_V4_SECURITY_LABEL.
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We again check for the EXDEV a little later on, so the first check is
redundant. This check is also slightly racier, since a badly timed
eviction from the export cache could leave us with the two fh_export
pointers pointing to two different cache entries which each refer to the
same underlying export.
It's better to compare vfsmounts as the later check does, but that
leaves a minor security hole in the case where the two exports refer to
two different directories especially if (for example) they have
different root-squashing options.
So, compare ex_path.dentry too.
Reported-by: Joe Habermann <joe.habermann@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
vfs_writev() updates the offset argument - but the code then passes the
offset to vfs_fsync_range(). Since offset now points to the offset after
what was just written, this is probably not what was intended
Introduced by face15025f "nfsd: use
vfs_fsync_range(), not O_SYNC, for stable writes".
Signed-off-by: Kent Overstreet <koverstreet@google.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: stable@vger.kernel.org
Reviewed-by: Zach Brown <zab@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull vfs pile (part one) from Al Viro:
"Assorted stuff - cleaning namei.c up a bit, fixing ->d_name/->d_parent
locking violations, etc.
The most visible changes here are death of FS_REVAL_DOT (replaced with
"has ->d_weak_revalidate()") and a new helper getting from struct file
to inode. Some bits of preparation to xattr method interface changes.
Misc patches by various people sent this cycle *and* ocfs2 fixes from
several cycles ago that should've been upstream right then.
PS: the next vfs pile will be xattr stuff."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (46 commits)
saner proc_get_inode() calling conventions
proc: avoid extra pde_put() in proc_fill_super()
fs: change return values from -EACCES to -EPERM
fs/exec.c: make bprm_mm_init() static
ocfs2/dlm: use GFP_ATOMIC inside a spin_lock
ocfs2: fix possible use-after-free with AIO
ocfs2: Fix oops in ocfs2_fast_symlink_readpage() code path
get_empty_filp()/alloc_file() leave both ->f_pos and ->f_version zero
target: writev() on single-element vector is pointless
export kernel_write(), convert open-coded instances
fs: encode_fh: return FILEID_INVALID if invalid fid_type
kill f_vfsmnt
vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op
nfsd: handle vfs_getattr errors in acl protocol
switch vfs_getattr() to struct path
default SET_PERSONALITY() in linux/elf.h
ceph: prepopulate inodes only when request is aborted
d_hash_and_lookup(): export, switch open-coded instances
9p: switch v9fs_set_create_acl() to inode+fid, do it before d_instantiate()
9p: split dropping the acls from v9fs_set_create_acl()
...
Use uid_eq(uid, GLOBAL_ROOT_UID) instead of !uid.
Use gid_eq(gid, GLOBAL_ROOT_GID) instead of !gid.
Use uid_eq(uid, INVALID_UID) instead of uid == -1
Use gid_eq(uid, INVALID_GID) instead of gid == -1
Use uid = GLOBAL_ROOT_UID instead of uid = 0;
Use gid = GLOBAL_ROOT_GID instead of gid = 0;
Use !uid_eq(uid1, uid2) instead of uid1 != uid2.
Use !gid_eq(gid1, gid2) instead of gid1 != gid2.
Use uid_eq(uid1, uid2) instead of uid1 == uid2.
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
This reverts commit 79f77bf9a4.
This is obviously wrong, and I have no idea how I missed seeing the
warning in testing: I must just not have looked at the right logs. The
caller bumps rq_resused/rq_next_page, so it will always be hit on a
large enough read.
Reported-by: Dave Jones <davej@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As far as I can tell this shouldn't currently happen--or if it does,
something is wrong and data is going to be corrupted.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
With NFSv4, if we create a file then open it we explicit avoid checking
the permissions on the file during the open because the fact that we
created it ensures we should be allow to open it (the create and the
open should appear to be a single operation).
However if the reply to an EXCLUSIVE create gets lots and the client
resends the create, the current code will perform the permission check -
because it doesn't realise that it did the open already..
This patch should fix this.
Note that I haven't actually seen this cause a problem. I was just
looking at the code trying to figure out a different EXCLUSIVE open
related issue, and this looked wrong.
(Fix confirmed with pynfs 4.0 test OPEN4--bfields)
Cc: stable@kernel.org
Signed-off-by: NeilBrown <neilb@suse.de>
[bfields: use OWNER_OVERRIDE and update for 4.1]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
NFSv4 shares the same struct file across multiple writes. (And we'd
like NFSv2 and NFSv3 to do that as well some day.)
So setting O_SYNC on the struct file as a way to request a synchronous
write doesn't work.
Instead, do a vfs_fsync_range() in that case.
Reported-by: Peter Staubach <pstaubach@exagrid.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
I don't really see how you could claim to support nfsd and not support
fsync somehow.
And in practice a quick look through the exportable filesystems suggests
the only ones without an ->fsync are read-only (efs, isofs, squashfs) or
in-memory (shmem).
Also, performing a write and then returning an error if the sync fails
(as we would do here in the wgather case) seems unhelpful to clients.
Also remove an incorrect comment.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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nfs: disintegrate UAPI for nfs
This is to complete part of the Userspace API (UAPI) disintegration for which
the preparatory patches were pulled recently. After these patches, userspace
headers will be segregated into:
include/uapi/linux/.../foo.h
for the userspace interface stuff, and:
include/linux/.../foo.h
for the strictly kernel internal stuff.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
- Pass the user namespace the uid and gid values in the xattr are stored
in into posix_acl_from_xattr.
- Pass the user namespace kuid and kgid values should be converted into
when storing uid and gid values in an xattr in posix_acl_to_xattr.
- Modify all callers of posix_acl_from_xattr and posix_acl_to_xattr to
pass in &init_user_ns.
In the short term this change is not strictly needed but it makes the
code clearer. In the longer term this change is necessary to be able to
mount filesystems outside of the initial user namespace that natively
store posix acls in the linux xattr format.
Cc: Theodore Tso <tytso@mit.edu>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andreas Dilger <adilger.kernel@dilger.ca>
Cc: Jan Kara <jack@suse.cz>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Pull second vfs pile from Al Viro:
"The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the
deadlock reproduced by xfstests 068), symlink and hardlink restriction
patches, plus assorted cleanups and fixes.
Note that another fsfreeze deadlock (emergency thaw one) is *not*
dealt with - the series by Fernando conflicts a lot with Jan's, breaks
userland ABI (FIFREEZE semantics gets changed) and trades the deadlock
for massive vfsmount leak; this is going to be handled next cycle.
There probably will be another pull request, but that stuff won't be
in it."
Fix up trivial conflicts due to unrelated changes next to each other in
drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c}
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits)
delousing target_core_file a bit
Documentation: Correct s_umount state for freeze_fs/unfreeze_fs
fs: Remove old freezing mechanism
ext2: Implement freezing
btrfs: Convert to new freezing mechanism
nilfs2: Convert to new freezing mechanism
ntfs: Convert to new freezing mechanism
fuse: Convert to new freezing mechanism
gfs2: Convert to new freezing mechanism
ocfs2: Convert to new freezing mechanism
xfs: Convert to new freezing code
ext4: Convert to new freezing mechanism
fs: Protect write paths by sb_start_write - sb_end_write
fs: Skip atime update on frozen filesystem
fs: Add freezing handling to mnt_want_write() / mnt_drop_write()
fs: Improve filesystem freezing handling
switch the protection of percpu_counter list to spinlock
nfsd: Push mnt_want_write() outside of i_mutex
btrfs: Push mnt_want_write() outside of i_mutex
fat: Push mnt_want_write() outside of i_mutex
...
Pull nfsd changes from J. Bruce Fields:
"This has been an unusually quiet cycle--mostly bugfixes and cleanup.
The one large piece is Stanislav's work to containerize the server's
grace period--but that in itself is just one more step in a
not-yet-complete project to allow fully containerized nfs service.
There are a number of outstanding delegation, container, v4 state, and
gss patches that aren't quite ready yet; 3.7 may be wilder."
* 'nfsd-next' of git://linux-nfs.org/~bfields/linux: (35 commits)
NFSd: make boot_time variable per network namespace
NFSd: make grace end flag per network namespace
Lockd: move grace period management from lockd() to per-net functions
LockD: pass actual network namespace to grace period management functions
LockD: manage grace list per network namespace
SUNRPC: service request network namespace helper introduced
NFSd: make nfsd4_manager allocated per network namespace context.
LockD: make lockd manager allocated per network namespace
LockD: manage grace period per network namespace
Lockd: add more debug to host shutdown functions
Lockd: host complaining function introduced
LockD: manage used host count per networks namespace
LockD: manage garbage collection timeout per networks namespace
LockD: make garbage collector network namespace aware.
LockD: mark host per network namespace on garbage collect
nfsd4: fix missing fault_inject.h include
locks: move lease-specific code out of locks_delete_lock
locks: prevent side-effects of locks_release_private before file_lock is initialized
NFSd: set nfsd_serv to NULL after service destruction
NFSd: introduce nfsd_destroy() helper
...
When mnt_want_write() starts to handle freezing it will get a full lock
semantics requiring proper lock ordering. So push mnt_want_write() call
consistently outside of i_mutex.
CC: linux-nfs@vger.kernel.org
CC: "J. Bruce Fields" <bfields@fieldses.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
We normally allow the owner of a file to override permissions checks on
IO operations, since:
- the client will take responsibility for doing an access check
on open;
- the permission checks offer no protection against malicious
clients--if they can authenticate as the file's owner then
they can always just change its permissions;
- checking permission on each IO operation breaks the usual
posix rule that permission is checked only on open.
However, we've never allowed the owner to override permissions on
readdir operations, even though the above logic would also apply to
directories. I've never heard of this causing a problem, probably
because a) simultaneously opening and creating a directory (with
restricted mode) isn't possible, and b) opening a directory, then
chmod'ing it, is rare.
Our disallowal of owner-override on directories appears to be an
accident, though--the readdir itself succeeds, and then we fail just
because lookup_one_len() calls in our filldir methods fail.
I'm not sure what the easiest fix for that would be. For now, just make
this behavior obvious by denying the override right at the start.
This also fixes some odd v4 behavior: with the rdattr_error attribute
requested, it would perform the readdir but return an ACCES error with
each entry.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
They're equivalent, but SEEK_SET is more informative...
Cc: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Allow a v3 unchecked open of a non-regular file succeed as if it were a
lookup; typically a client in such a case will want to fall back on a
local open, so succeeding and giving it the filehandle is more useful
than failing with nfserr_exist, which makes it appear that nothing at
all exists by that name.
Similarly for v4, on an open-create, return the same errors we would on
an attempt to open a non-regular file, instead of returning
nfserr_exist.
This fixes a problem found doing a v4 open of a symlink with
O_RDONLY|O_CREAT, which resulted in the current client returning EEXIST.
Thanks also to Trond for analysis.
Cc: stable@kernel.org
Reported-by: Orion Poplawski <orion@cora.nwra.com>
Tested-by: Orion Poplawski <orion@cora.nwra.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Pull nfsd changes from Bruce Fields:
Highlights:
- Benny Halevy and Tigran Mkrtchyan implemented some more 4.1 features,
moving us closer to a complete 4.1 implementation.
- Bernd Schubert fixed a long-standing problem with readdir cookies on
ext2/3/4.
- Jeff Layton performed a long-overdue overhaul of the server reboot
recovery code which will allow us to deprecate the current code (a
rather unusual user of the vfs), and give us some needed flexibility
for further improvements.
- Like the client, we now support numeric uid's and gid's in the
auth_sys case, allowing easier upgrades from NFSv2/v3 to v4.x.
Plus miscellaneous bugfixes and cleanup.
Thanks to everyone!
There are also some delegation fixes waiting on vfs review that I
suppose will have to wait for 3.5. With that done I think we'll finally
turn off the "EXPERIMENTAL" dependency for v4 (though that's mostly
symbolic as it's been on by default in distro's for a while).
And the list of 4.1 todo's should be achievable for 3.5 as well:
http://wiki.linux-nfs.org/wiki/index.php/Server_4.0_and_4.1_issues
though we may still want a bit more experience with it before turning it
on by default.
* 'for-3.4' of git://linux-nfs.org/~bfields/linux: (55 commits)
nfsd: only register cld pipe notifier when CONFIG_NFSD_V4 is enabled
nfsd4: use auth_unix unconditionally on backchannel
nfsd: fix NULL pointer dereference in cld_pipe_downcall
nfsd4: memory corruption in numeric_name_to_id()
sunrpc: skip portmap calls on sessions backchannel
nfsd4: allow numeric idmapping
nfsd: don't allow legacy client tracker init for anything but init_net
nfsd: add notifier to handle mount/unmount of rpc_pipefs sb
nfsd: add the infrastructure to handle the cld upcall
nfsd: add a header describing upcall to nfsdcld
nfsd: add a per-net-namespace struct for nfsd
sunrpc: create nfsd dir in rpc_pipefs
nfsd: add nfsd4_client_tracking_ops struct and a way to set it
nfsd: convert nfs4_client->cl_cb_flags to a generic flags field
NFSD: Fix nfs4_verifier memory alignment
NFSD: Fix warnings when NFSD_DEBUG is not defined
nfsd: vfs_llseek() with 32 or 64 bit offsets (hashes)
nfsd: rename 'int access' to 'int may_flags' in nfsd_open()
ext4: return 32/64-bit dir name hash according to usage type
fs: add new FMODE flags: FMODE_32bithash and FMODE_64bithash
...
Use 32-bit or 64-bit llseek() hashes for directory offsets depending on
the NFS version. NFSv2 gets 32-bit hashes only.
NOTE: This patch got rather complex as Christoph asked to set the
filp->f_mode flag in the open call or immediatly after dentry_open()
in nfsd_open() to avoid races.
Personally I still do not see a reason for that and in my opinion
FMODE_32BITHASH/FMODE_64BITHASH flags could be set nfsd_readdir(), as it
follows directly after nfsd_open() without a chance of races.
Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: J. Bruce Fields<bfields@redhat.com>
Just rename this variable, as the next patch will add a flag and
'access' as variable name would not be correct any more.
Signed-off-by: Bernd Schubert <bernd.schubert@itwm.fraunhofer.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Acked-by: J. Bruce Fields<bfields@redhat.com>
* 'for-3.3' of git://linux-nfs.org/~bfields/linux: (31 commits)
nfsd4: nfsd4_create_clid_dir return value is unused
NFSD: Change name of extended attribute containing junction
svcrpc: don't revert to SVC_POOL_DEFAULT on nfsd shutdown
svcrpc: fix double-free on shutdown of nfsd after changing pool mode
nfsd4: be forgiving in the absence of the recovery directory
nfsd4: fix spurious 4.1 post-reboot failures
NFSD: forget_delegations should use list_for_each_entry_safe
NFSD: Only reinitilize the recall_lru list under the recall lock
nfsd4: initialize special stateid's at compile time
NFSd: use network-namespace-aware cache registering routines
SUNRPC: create svc_xprt in proper network namespace
svcrpc: update outdated BKL comment
nfsd41: allow non-reclaim open-by-fh's in 4.1
svcrpc: avoid memory-corruption on pool shutdown
svcrpc: destroy server sockets all at once
svcrpc: make svc_delete_xprt static
nfsd: Fix oops when parsing a 0 length export
nfsd4: Use kmemdup rather than duplicating its implementation
nfsd4: add a separate (lockowner, inode) lookup
nfsd4: fix CONFIG_NFSD_FAULT_INJECTION compile error
...
As of fedfs-utils-0.8.0, user space stores all NFS junction
information in a single extended attribute: "trusted.junction.nfs".
Both FedFS and NFS basic junctions are stored in this one attribute,
and the intention is that all future forms of NFS junction metadata
will be stored in this attribute. Other protocols may use a different
extended attribute.
Thus NFSD needs to look only for that one extended attribute. The
"trusted.junction.type" xattr is deprecated. fedfs-utils-0.8.0 will
continue to attach a "trusted.junction.type" xattr to junctions, but
future fedfs-utils releases may no longer do that.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A bunch of places in nfsd does mnt_{want,drop}_write on vfsmount of
export of given fhandle. Switched to obvious inlined helpers...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If we create the object and then return failure to the client, we're
left with an unexpected file in the filesystem.
I'm trying to eliminate such cases but not 100% sure I have so an
assertion might be helpful for now.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
[ cel: since this is server-side, use nfsd4_ prefix instead of nfs4_ prefix. ]
[ cel: implement S_ISVTX filter in bfields-normal form ]
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
A client that wants to execute a file must be able to read it. Read
opens over nfs are therefore implicitly allowed for executable files
even when those files are not readable.
NFSv2/v3 get this right by using a passed-in NFSD_MAY_OWNER_OVERRIDE on
read requests, but NFSv4 has gotten this wrong ever since
dc730e1737 "nfsd4: fix owner-override on
open", when we realized that the file owner shouldn't override
permissions on non-reclaim NFSv4 opens.
So we can't use NFSD_MAY_OWNER_OVERRIDE to tell nfsd_permission to allow
reads of executable files.
So, do the same thing we do whenever we encounter another weird NFS
permission nit: define yet another NFSD_MAY_* flag.
The industry's future standardization on 128-bit processors will be
motivated primarily by the need for integers with enough bits for all
the NFSD_MAY_* flags.
Reported-by: Leonardo Borda <leonardoborda@gmail.com>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Zero means "I don't care what kind of file this is". And that's
probably what we want--acls are also settable at least on directories,
and if the filesystem doesn't want them on other objects, leave it to it
to complain.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
We allow the fh_verify caller to specify that any object *except* those
of a given type is allowed, by passing a negative type. But only one
caller actually uses it. Open-code that check in the one caller.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Thanks to Casey Bodley for pointing out that on a read open we pass 0,
instead of O_RDONLY, to break_lease, with the result that a read open is
treated like a write open for the purposes of lease breaking!
Reported-by: Casey Bodley <cbodley@citi.umich.edu>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fix for commit 4795bb37ef, nfsd: break
lease on unlink, link, and rename
if the LINK operation breaks a delegation, it returns NFS4ERR_NOENT
(which is not a valid error in rfc 5661) instead of NFS4ERR_DELAY.
the return value of nfsd_break_lease() in nfsd_link() must be
converted from host_err to err
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-2.6.40' of git://linux-nfs.org/~bfields/linux: (22 commits)
nfsd: make local functions static
NFSD: Remove unused variable from nfsd4_decode_bind_conn_to_session()
NFSD: Check status from nfsd4_map_bcts_dir()
NFSD: Remove setting unused variable in nfsd_vfs_read()
nfsd41: error out on repeated RECLAIM_COMPLETE
nfsd41: compare request's opcnt with session's maxops at nfsd4_sequence
nfsd v4.1 lOCKT clientid field must be ignored
nfsd41: add flag checking for create_session
nfsd41: make sure nfs server process OPEN with EXCLUSIVE4_1 correctly
nfsd4: fix wrongsec handling for PUTFH + op cases
nfsd4: make fh_verify responsibility of nfsd_lookup_dentry caller
nfsd4: introduce OPDESC helper
nfsd4: allow fh_verify caller to skip pseudoflavor checks
nfsd: distinguish functions of NFSD_MAY_* flags
svcrpc: complete svsk processing on cb receive failure
svcrpc: take advantage of tcp autotuning
SUNRPC: Don't wait for full record to receive tcp data
svcrpc: copy cb reply instead of pages
svcrpc: close connection if client sends short packet
svcrpc: note network-order types in svc_process_calldir
...
Compiling gave me this warning:
fs/nfsd/vfs.c: In function ‘nfsd_vfs_read’:
fs/nfsd/vfs.c:880:16: warning: variable ‘inode’ set but not used
[-Wunused-but-set-variable]
I discovered that a local variable "inode" was being set towards the
beginning of nfsd_vfs_read() and then ignored for the rest of the
function.
Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The NFS server uses nfsd_create_v3 to handle EXCLUSIVE4_1 opens, but
that function is not prepared to handle them.
Rename nfsd_create_v3() to do_nfsd_create(), and add handling of
EXCLUSIVE4_1.
Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
An open on a NFS4 share using the O_CREAT flag on an existing file for
which we have permissions to open but contained in a directory with no
write permissions will fail with EACCES.
A tcpdump shows that the client had set the open mode to UNCHECKED which
indicates that the file should be created if it doesn't exist and
encountering an existing flag is not an error. Since in this case the
file exists and can be opened by the user, the NFS server is wrong in
attempting to check create permissions on the parent directory.
The patch adds a conditional statement to check for create permissions
only if the file doesn't exist.
Signed-off-by: Sachin S. Prabhu <sprabhu@redhat.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Most of the NFSD_MAY_* flags actually request permissions, but over the
years we've accreted a few that modify the behavior of the permission or
open code in other ways.
Distinguish the two cases a little more. In particular, allow the
shortcut at the start of nfsd_permission to ignore the
non-permission-requesting bits.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-2.6.39' of git://linux-nfs.org/~bfields/linux:
SUNRPC: Remove resource leak in svc_rdma_send_error()
nfsd: wrong index used in inner loop
nfsd4: fix comment and remove unused nfsd4_file fields
nfs41: make sure nfs server return right ca_maxresponsesize_cached
nfsd: fix compile error
svcrpc: fix bad argument in unix_domain_find
nfsd4: fix struct file leak
nfsd4: minor nfs4state.c reshuffling
svcrpc: fix rare race on unix_domain creation
nfsd41: modify the members value of nfsd4_op_flags
nfsd: add proc file listing kernel's gss_krb5 enctypes
gss:krb5 only include enctype numbers in gm_upcall_enctypes
NFSD, VFS: Remove dead code in nfsd_rename()
nfsd: kill unused macro definition
locks: use assign_type()
Currently we have the following code in fs/nfsd/vfs.c::nfsd_rename() :
...
host_err = nfsd_break_lease(odentry->d_inode);
if (host_err)
goto out_drop_write;
if (ndentry->d_inode) {
host_err = nfsd_break_lease(ndentry->d_inode);
if (host_err)
goto out_drop_write;
}
if (host_err)
goto out_drop_write;
...
'host_err' is guaranteed to be 0 by the time we test 'ndentry->d_inode'.
If 'host_err' becomes != 0 inside the 'if' statement, then we goto
'out_drop_write'. So, after the 'if' statement there is no way that
'host_err' can be anything but 0, so the test afterwards is just dead
code.
This patch removes the dead code.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
4795bb37ef "nfsd: break lease on unlink,
link, and rename", only broke the lease on the file that was being
renamed, and didn't handle the case where the target path refers to an
already-existing file that will be unlinked by a rename--in that case
the target file should have any leases broken as well.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If nfsd fails to find an exported via NFS file in the readahead cache, it
should increment corresponding nfsdstats counter (ra_depth[10]), but due to a
bug it may instead write to ra_depth[11], corrupting the following field.
In a kernel with NFSDv4 compiled in the corruption takes the form of an
increment of a counter of the number of NFSv4 operation 0's received; since
there is no operation 0, this is harmless.
In a kernel with NFSDv4 disabled it corrupts whatever happens to be in the
memory beyond nfsdstats.
Signed-off-by: Konstantin Khorenko <khorenko@openvz.org>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (23 commits)
sanitize vfsmount refcounting changes
fix old umount_tree() breakage
autofs4: Merge the remaining dentry ops tables
Unexport do_add_mount() and add in follow_automount(), not ->d_automount()
Allow d_manage() to be used in RCU-walk mode
Remove a further kludge from __do_follow_link()
autofs4: Bump version
autofs4: Add v4 pseudo direct mount support
autofs4: Fix wait validation
autofs4: Clean up autofs4_free_ino()
autofs4: Clean up dentry operations
autofs4: Clean up inode operations
autofs4: Remove unused code
autofs4: Add d_manage() dentry operation
autofs4: Add d_automount() dentry operation
Remove the automount through follow_link() kludge code from pathwalk
CIFS: Use d_automount() rather than abusing follow_link()
NFS: Use d_automount() rather than abusing follow_link()
AFS: Use d_automount() rather than abusing follow_link()
Add an AT_NO_AUTOMOUNT flag to suppress terminal automount
...
Add a dentry op (d_manage) to permit a filesystem to hold a process and make it
sleep when it tries to transit away from one of that filesystem's directories
during a pathwalk. The operation is keyed off a new dentry flag
(DCACHE_MANAGE_TRANSIT).
The filesystem is allowed to be selective about which processes it holds and
which it permits to continue on or prohibits from transiting from each flagged
directory. This will allow autofs to hold up client processes whilst letting
its userspace daemon through to maintain the directory or the stuff behind it
or mounted upon it.
The ->d_manage() dentry operation:
int (*d_manage)(struct path *path, bool mounting_here);
takes a pointer to the directory about to be transited away from and a flag
indicating whether the transit is undertaken by do_add_mount() or
do_move_mount() skipping through a pile of filesystems mounted on a mountpoint.
It should return 0 if successful and to let the process continue on its way;
-EISDIR to prohibit the caller from skipping to overmounted filesystems or
automounting, and to use this directory; or some other error code to return to
the user.
->d_manage() is called with namespace_sem writelocked if mounting_here is true
and no other locks held, so it may sleep. However, if mounting_here is true,
it may not initiate or wait for a mount or unmount upon the parameter
directory, even if the act is actually performed by userspace.
Within fs/namei.c, follow_managed() is extended to check with d_manage() first
on each managed directory, before transiting away from it or attempting to
automount upon it.
follow_down() is renamed follow_down_one() and should only be used where the
filesystem deliberately intends to avoid management steps (e.g. autofs).
A new follow_down() is added that incorporates the loop done by all other
callers of follow_down() (do_add/move_mount(), autofs and NFSD; whilst AFS, NFS
and CIFS do use it, their use is removed by converting them to use
d_automount()). The new follow_down() calls d_manage() as appropriate. It
also takes an extra parameter to indicate if it is being called from mount code
(with namespace_sem writelocked) which it passes to d_manage(). follow_down()
ignores automount points so that it can be used to mount on them.
__follow_mount_rcu() is made to abort rcu-walk mode if it hits a directory with
DCACHE_MANAGE_TRANSIT set on the basis that we're probably going to have to
sleep. It would be possible to enter d_manage() in rcu-walk mode too, and have
that determine whether to abort or not itself. That would allow the autofs
daemon to continue on in rcu-walk mode.
Note that DCACHE_MANAGE_TRANSIT on a directory should be cleared when it isn't
required as every tranist from that directory will cause d_manage() to be
invoked. It can always be set again when necessary.
==========================
WHAT THIS MEANS FOR AUTOFS
==========================
Autofs currently uses the lookup() inode op and the d_revalidate() dentry op to
trigger the automounting of indirect mounts, and both of these can be called
with i_mutex held.
autofs knows that the i_mutex will be held by the caller in lookup(), and so
can drop it before invoking the daemon - but this isn't so for d_revalidate(),
since the lock is only held on _some_ of the code paths that call it. This
means that autofs can't risk dropping i_mutex from its d_revalidate() function
before it calls the daemon.
The bug could manifest itself as, for example, a process that's trying to
validate an automount dentry that gets made to wait because that dentry is
expired and needs cleaning up:
mkdir S ffffffff8014e05a 0 32580 24956
Call Trace:
[<ffffffff885371fd>] :autofs4:autofs4_wait+0x674/0x897
[<ffffffff80127f7d>] avc_has_perm+0x46/0x58
[<ffffffff8009fdcf>] autoremove_wake_function+0x0/0x2e
[<ffffffff88537be6>] :autofs4:autofs4_expire_wait+0x41/0x6b
[<ffffffff88535cfc>] :autofs4:autofs4_revalidate+0x91/0x149
[<ffffffff80036d96>] __lookup_hash+0xa0/0x12f
[<ffffffff80057a2f>] lookup_create+0x46/0x80
[<ffffffff800e6e31>] sys_mkdirat+0x56/0xe4
versus the automount daemon which wants to remove that dentry, but can't
because the normal process is holding the i_mutex lock:
automount D ffffffff8014e05a 0 32581 1 32561
Call Trace:
[<ffffffff80063c3f>] __mutex_lock_slowpath+0x60/0x9b
[<ffffffff8000ccf1>] do_path_lookup+0x2ca/0x2f1
[<ffffffff80063c89>] .text.lock.mutex+0xf/0x14
[<ffffffff800e6d55>] do_rmdir+0x77/0xde
[<ffffffff8005d229>] tracesys+0x71/0xe0
[<ffffffff8005d28d>] tracesys+0xd5/0xe0
which means that the system is deadlocked.
This patch allows autofs to hold up normal processes whilst the daemon goes
ahead and does things to the dentry tree behind the automouter point without
risking a deadlock as almost no locks are held in d_manage() and none in
d_automount().
Signed-off-by: David Howells <dhowells@redhat.com>
Was-Acked-by: Ian Kent <raven@themaw.net>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-2.6.38' of git://linux-nfs.org/~bfields/linux: (62 commits)
nfsd4: fix callback restarting
nfsd: break lease on unlink, link, and rename
nfsd4: break lease on nfsd setattr
nfsd: don't support msnfs export option
nfsd4: initialize cb_per_client
nfsd4: allow restarting callbacks
nfsd4: simplify nfsd4_cb_prepare
nfsd4: give out delegations more quickly in 4.1 case
nfsd4: add helper function to run callbacks
nfsd4: make sure sequence flags are set after destroy_session
nfsd4: re-probe callback on connection loss
nfsd4: set sequence flag when backchannel is down
nfsd4: keep finer-grained callback status
rpc: allow xprt_class->setup to return a preexisting xprt
rpc: keep backchannel xprt as long as server connection
rpc: move sk_bc_xprt to svc_xprt
nfsd4: allow backchannel recovery
nfsd4: support BIND_CONN_TO_SESSION
nfsd4: modify session list under cl_lock
Documentation: fl_mylease no longer exists
...
Fix up conflicts in fs/nfsd/vfs.c with the vfs-scale work. The
vfs-scale work touched some msnfs cases, and this merge removes support
for that entirely, so the conflict was trivial to resolve.
We've long had these pointless #ifdef MSNFS's sprinkled throughout the
code--pointless because MSNFS is always defined (and we give no config
option to make that easy to change). So we could just remove the
ifdef's and compile the resulting code unconditionally.
But as long as we're there: why not just rip out this code entirely?
The only purpose is to implement the "msnfs" export option which turns
on Windows-like behavior in some cases, and:
- the export option isn't documented anywhere;
- the userland utilities (which would need to be able to parse
"msnfs" in an export file) don't support it;
- I don't know how to maintain this, as I don't know what the
proper behavior is; and
- google shows no evidence that anyone has ever used this.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
block: ensure that completion error gets properly traced
blktrace: add missing probe argument to block_bio_complete
block cfq: don't use atomic_t for cfq_group
block cfq: don't use atomic_t for cfq_queue
block: trace event block fix unassigned field
block: add internal hd part table references
block: fix accounting bug on cross partition merges
kref: add kref_test_and_get
bio-integrity: mark kintegrityd_wq highpri and CPU intensive
block: make kblockd_workqueue smarter
Revert "sd: implement sd_check_events()"
block: Clean up exit_io_context() source code.
Fix compile warnings due to missing removal of a 'ret' variable
fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
cfq-iosched: don't check cfqg in choose_service_tree()
fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
cdrom: export cdrom_check_events()
sd: implement sd_check_events()
sr: implement sr_check_events()
...
Make d_count non-atomic and protect it with d_lock. This allows us to ensure a
0 refcount dentry remains 0 without dcache_lock. It is also fairly natural when
we start protecting many other dentry members with d_lock.
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Commit a8adbe3 forgot to remove the return variable, kill it.
drivers/block/loop.c: In function 'lo_splice_actor':
drivers/block/loop.c:398: warning: unused variable 'ret'
[...]
fs/nfsd/vfs.c: In function 'nfsd_splice_actor':
fs/nfsd/vfs.c:848: warning: unused variable 'ret'
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This patch pulls calls to buf->ops->confirm() from all actors passed
(also indirectly) to splice_from_pipe_feed().
Is avoiding the call to buf->ops->confirm() while splice()ing to
/dev/null is an intentional optimization? No other user does that
and this will remove this special case.
Against current linux.git 6313e3c217.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
Add a new helper to write out the inode using the writeback code,
that is including the correct dirty bit and list manipulation. A few
of filesystems already opencode this, and a lot of others should be
using it instead of using write_inode_now which also writes out the
data.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The commit ebabe9a900
pass a struct path to vfs_statfs
introduced the struct path initialization, and this seems to trigger
an Oops on my machine.
fh_dentry field may be NULL and set later in fh_verify(), thus the
initialization of path must be after fh_verify().
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Minchan Kim <minchan.kim@gmail.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
fanotify: use both marks when possible
fsnotify: pass both the vfsmount mark and inode mark
fsnotify: walk the inode and vfsmount lists simultaneously
fsnotify: rework ignored mark flushing
fsnotify: remove global fsnotify groups lists
fsnotify: remove group->mask
fsnotify: remove the global masks
fsnotify: cleanup should_send_event
fanotify: use the mark in handler functions
audit: use the mark in handler functions
dnotify: use the mark in handler functions
inotify: use the mark in handler functions
fsnotify: send fsnotify_mark to groups in event handling functions
fsnotify: Exchange list heads instead of moving elements
fsnotify: srcu to protect read side of inode and vfsmount locks
fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
fsnotify: use _rcu functions for mark list traversal
fsnotify: place marks on object in order of group memory address
vfs/fsnotify: fsnotify_close can delay the final work in fput
fsnotify: store struct file not struct path
...
Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (96 commits)
no need for list_for_each_entry_safe()/resetting with superblock list
Fix sget() race with failing mount
vfs: don't hold s_umount over close_bdev_exclusive() call
sysv: do not mark superblock dirty on remount
sysv: do not mark superblock dirty on mount
btrfs: remove junk sb_dirt change
BFS: clean up the superblock usage
AFFS: wait for sb synchronization when needed
AFFS: clean up dirty flag usage
cifs: truncate fallout
mbcache: fix shrinker function return value
mbcache: Remove unused features
add f_flags to struct statfs(64)
pass a struct path to vfs_statfs
update VFS documentation for method changes.
All filesystems that need invalidate_inode_buffers() are doing that explicitly
convert remaining ->clear_inode() to ->evict_inode()
Make ->drop_inode() just return whether inode needs to be dropped
fs/inode.c:clear_inode() is gone
fs/inode.c:evict() doesn't care about delete vs. non-delete paths now
...
Fix up trivial conflicts in fs/nilfs2/super.c
We'll need the path to implement the flags field for statvfs support.
We do have it available in all callers except:
- ecryptfs_statfs. This one doesn't actually need vfs_statfs but just
needs to do a caller to the lower filesystem statfs method.
- sys_ustat. Add a non-exported statfs_by_dentry helper for it which
doesn't won't be able to fill out the flags field later on.
In addition rename the helpers for statfs vs fstatfs to do_*statfs instead
of the misleading vfs prefix.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* 'for-2.6.36' of git://linux-nfs.org/~bfields/linux: (34 commits)
nfsd4: fix file open accounting for RDWR opens
nfsd: don't allow setting maxblksize after svc created
nfsd: initialize nfsd versions before creating svc
net: sunrpc: removed duplicated #include
nfsd41: Fix a crash when a callback is retried
nfsd: fix startup/shutdown order bug
nfsd: minor nfsd read api cleanup
gcc-4.6: nfsd: fix initialized but not read warnings
nfsd4: share file descriptors between stateid's
nfsd4: fix openmode checking on IO using lock stateid
nfsd4: miscellaneous process_open2 cleanup
nfsd4: don't pretend to support write delegations
nfsd: bypass readahead cache when have struct file
nfsd: minor nfsd_svc() cleanup
nfsd: move more into nfsd_startup()
nfsd: just keep single lockd reference for nfsd
nfsd: clean up nfsd_create_serv error handling
nfsd: fix error handling in __write_ports_addxprt
nfsd: fix error handling when starting nfsd with rpcbind down
nfsd4: fix v4 state shutdown error paths
...
Christoph points that the NFSv2/v3 callers know which case they want
here, so we may as well just call the file=NULL case directly instead of
making this conditional.
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Fixes at least one real minor bug: the nfs4 recovery dir sysctl
would not return its status properly.
Also I finished Al's 1e41568d73 ("Take ima_path_check() in nfsd
past dentry_open() in nfsd_open()") commit, it moved the IMA
code, but left the old path initializer in there.
The rest is just dead code removed I think, although I was not
fully sure about the "is_borc" stuff. Some more review
would be still good.
Found by gcc 4.6's new warnings.
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
fanotify, the upcoming notification system actually needs a struct path so it can
do opens in the context of listeners, and it needs a file so it can get f_flags
from the original process. Close was the only operation that already was passing
a struct file to the notification hook. This patch passes a file for access,
modify, and open as well as they are easily available to these hooks.
Signed-off-by: Eric Paris <eparis@redhat.com>
The readahead cache compensates for the fact that the NFS server
currently does an open and close on every IO operation in the NFSv2 and
NFSv3 case.
In the NFSv4 case we have long-lived struct files associated with client
opens, so there's no need for this. In fact, concurrent IO's using
trying to modify the same file->f_ra may cause problems.
So, don't bother with the readahead cache in that case.
Note eventually we'll likely do this in the v2/v3 case as well by
keeping a cache of struct files instead of struct file_ra_state's.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'for-2.6.35' of git://linux-nfs.org/~bfields/linux:
nfsd4: shut down callback queue outside state lock
nfsd: nfsd_setattr needs to call commit_metadata
J. Bruce Fields