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* Open with O_CREAT flag set fails to open existing files on non writable ↵Sachin Prabhu2011-04-201-1/+8
| | | | | | | | | | | | | | | | | | | | directories 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>
* nfsd4: Fix filp leakOGAWA Hirofumi2011-04-191-1/+1
| | | | | | | | | | | | | 23fcf2ec93fb8573a653408316af599939ff9a8e (nfsd4: fix oops on lock failure) The above patch breaks free path for stp->st_file. If stp was inserted into sop->so_stateids, we have to free stp->st_file refcount. Because stp->st_file refcount itself is taken whether or not any refcounts are taken on the stp->st_file->fi_fds[]. Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: fix struct file leak on delegationJ. Bruce Fields2011-04-181-0/+1
| | | | | | | | Introduced by acfdf5c383b38f7f4dddae41b97c97f1ae058f49. Cc: stable@kernel.org Reported-by: Gerhard Heift <ml-nfs-linux-20110412-ef47@gheift.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2011-04-122-4/+6
|\ | | | | | | | | | | * 'for-2.6.39' of git://linux-nfs.org/~bfields/linux: nfsd4: fix oops on lock failure nfsd: fix auth_domain reference leak on nlm operations
| * nfsd4: fix oops on lock failureJ. Bruce Fields2011-04-101-3/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Lock stateid's can have access_bmap 0 if they were only partially initialized (due to a failed lock request); handle that case in free_generic_stateid. ------------[ cut here ]------------ kernel BUG at fs/nfsd/nfs4state.c:380! invalid opcode: 0000 [#1] SMP last sysfs file: /sys/kernel/mm/ksm/run Modules linked in: nfs fscache md4 nls_utf8 cifs ip6table_filter ip6_tables ebtable_nat ebtables ipt_MASQUERADE iptable_nat nf_nat bridge stp llc nfsd lockd nfs_acl auth_rpcgss sunrpc ipv6 ppdev parport_pc parport pcnet32 mii pcspkr microcode i2c_piix4 BusLogic floppy [last unloaded: mperf] Pid: 1468, comm: nfsd Not tainted 2.6.38+ #120 VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform EIP: 0060:[<e24f180d>] EFLAGS: 00010297 CPU: 0 EIP is at nfs4_access_to_omode+0x1c/0x29 [nfsd] EAX: ffffffff EBX: dd758120 ECX: 00000000 EDX: 00000004 ESI: dd758120 EDI: ddfe657c EBP: dd54dde0 ESP: dd54dde0 DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 Process nfsd (pid: 1468, ti=dd54c000 task=ddc92580 task.ti=dd54c000) Stack: dd54ddf0 e24f19ca 00000000 ddfe6560 dd54de08 e24f1a5d dd758130 deee3a20 ddfe6560 31270000 dd54df1c e24f52fd 0000000f dd758090 e2505dd0 0be304cf dbb51d68 0000000e ddfe657c ddcd8020 dd758130 dd758128 dd7580d8 dd54de68 Call Trace: [<e24f19ca>] free_generic_stateid+0x1c/0x3e [nfsd] [<e24f1a5d>] release_lockowner+0x71/0x8a [nfsd] [<e24f52fd>] nfsd4_lock+0x617/0x66c [nfsd] [<e24e57b6>] ? nfsd_setuser+0x199/0x1bb [nfsd] [<e24e056c>] ? nfsd_setuser_and_check_port+0x65/0x81 [nfsd] [<c07a0052>] ? _cond_resched+0x8/0x1c [<c04ca61f>] ? slab_pre_alloc_hook.clone.33+0x23/0x27 [<c04cac01>] ? kmem_cache_alloc+0x1a/0xd2 [<c04835a0>] ? __call_rcu+0xd7/0xdd [<e24e0dfb>] ? fh_verify+0x401/0x452 [nfsd] [<e24f0b61>] ? nfsd4_encode_operation+0x52/0x117 [nfsd] [<e24ea0d7>] ? nfsd4_putfh+0x33/0x3b [nfsd] [<e24f4ce6>] ? nfsd4_delegreturn+0xd4/0xd4 [nfsd] [<e24ea2c9>] nfsd4_proc_compound+0x1ea/0x33e [nfsd] [<e24de6ee>] nfsd_dispatch+0xd1/0x1a5 [nfsd] [<e1d6e1c7>] svc_process_common+0x282/0x46f [sunrpc] [<e1d6e578>] svc_process+0xdc/0xfa [sunrpc] [<e24de0fa>] nfsd+0xd6/0x115 [nfsd] [<e24de024>] ? nfsd_shutdown+0x24/0x24 [nfsd] [<c0454322>] kthread+0x62/0x67 [<c04542c0>] ? kthread_worker_fn+0x114/0x114 [<c07a6ebe>] kernel_thread_helper+0x6/0x10 Code: eb 05 b8 00 00 27 4f 8d 65 f4 5b 5e 5f 5d c3 83 e0 03 55 83 f8 02 89 e5 74 17 83 f8 03 74 05 48 75 09 eb 09 b8 02 00 00 00 eb 0b <0f> 0b 31 c0 eb 05 b8 01 00 00 00 5d c3 55 89 e5 57 56 89 d6 8d EIP: [<e24f180d>] nfs4_access_to_omode+0x1c/0x29 [nfsd] SS:ESP 0068:dd54dde0 ---[ end trace 2b0bf6c6557cb284 ]--- The trace route is: -> nfsd4_lock() -> if (lock->lk_is_new) { -> alloc_init_lock_stateid() 3739: stp->st_access_bmap = 0; ->if (status && lock->lk_is_new && lock_sop) -> release_lockowner() -> free_generic_stateid() -> nfs4_access_bmap_to_omode() -> nfs4_access_to_omode() 380: BUG(); ***** This problem was introduced by 0997b173609b9229ece28941c118a2a9b278796e. Reported-by: Mi Jinlong <mijinlong@cn.fujitsu.com> Tested-by: Mi Jinlong <mijinlong@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd: fix auth_domain reference leak on nlm operationsJ. Bruce Fields2011-03-251-1/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This was noticed by users who performed more than 2^32 lock operations and hence made this counter overflow (eventually leading to use-after-free's). Setting rq_client to NULL here means that it won't later get auth_domain_put() when it should be. Appears to have been introduced in 2.5.42 by "[PATCH] kNFSd: Move auth domain lookup into svcauth" which moved most of the rq_client handling to common svcauth code, but left behind this one line. Cc: Neil Brown <neilb@suse.de> Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | Fix common misspellingsLucas De Marchi2011-03-313-4/+4
| | | | | | | | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* | Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2011-03-248-95/+125
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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()
| * nfsd: wrong index used in inner loopMi Jinlong2011-03-171-4/+1Star
| | | | | | | | | | | | | | | | | | | | We must not use dummy for index. After the first index, READ32(dummy) will change dummy!!!! Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com> [bfields@redhat.com: Trond points out READ_BUF alone is sufficient.] Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * Merge create_session decoding fix into for-2.6.39J. Bruce Fields2011-03-173-9/+10
| |\ | | | | | | | | | This needs a further fixup!
| * | nfsd4: fix comment and remove unused nfsd4_file fieldsJ. Bruce Fields2011-03-171-8/+4Star
| | | | | | | | | | | | | | | | | | | | | A couple fields here were left over from a previous version of a patch, and are no longer used. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfs41: make sure nfs server return right ca_maxresponsesize_cachedMi Jinlong2011-03-161-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | According to rfc5661, ca_maxresponsesize_cached: Like ca_maxresponsesize, but the maximum size of a reply that will be stored in the reply cache (Section 2.10.6.1). For each channel, the server MAY decrease this value, but MUST NOT increase it. the latest kernel(2.6.38-rc8) may increase the value for ignoring request's ca_maxresponsesize_cached value. We should not ignore it. Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfsd: fix compile errorJ. Bruce Fields2011-03-151-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | "fs/built-in.o: In function `supported_enctypes_show': nfsctl.c:(.text+0x7beb0): undefined reference to `gss_mech_get_by_name' nfsctl.c:(.text+0x7bebc): undefined reference to `gss_mech_put' " Reported-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfsd4: fix struct file leakJ. Bruce Fields2011-03-091-11/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make sure we properly reference count the struct files that a lock depends on, and release them when the lock stateid is released. This fixes a major leak of struct files when using locking over nfsv4. Cc: stable@kernel.org Reported-by: Rick Koshi <nfs-bug-report@more-right-rudder.com> Tested-by: Ivo Přikryl <prikryl@eurosat.cz> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfsd4: minor nfs4state.c reshufflingJ. Bruce Fields2011-03-091-64/+61Star
| | | | | | | | | | | | | | | | | | | | | | | | Minor cleanup in preparation for a bugfix--moving some code to avoid forward references, etc. No change in functionality. Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfsd41: modify the members value of nfsd4_op_flagsMi Jinlong2011-03-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The members of nfsd4_op_flags, (ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS) equals to ALLOWED_AS_FIRST_OP, maybe that's not what we want. OP_PUTROOTFH with op_flags = ALLOWED_WITHOUT_FH | ALLOWED_ON_ABSENT_FS, can't appears as the first operation with out SEQUENCE ops. This patch modify the wrong value of ALLOWED_WITHOUT_FH etc which was introduced by f9bb94c4. Cc: stable@kernel.org Reviewed-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: Mi Jinlong <mijinlong@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | nfsd: add proc file listing kernel's gss_krb5 enctypesKevin Coffman2011-03-071-1/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a new proc file which lists the encryption types supported by the kernel's gss_krb5 code. Newer MIT Kerberos libraries support the assertion of acceptor subkeys. This enctype information allows user-land (svcgssd) to request that the Kerberos libraries limit the encryption types that it uses when generating the subkeys. Signed-off-by: Kevin Coffman <kwc@citi.umich.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * | NFSD, VFS: Remove dead code in nfsd_rename()Jesper Juhl2011-03-071-2/+0Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | nfsd: kill unused macro definitionShan Wei2011-03-073-3/+1Star
| | | | | | | | | | | | | | | | | | | | | | | | These macros had never been used for several years. So, remove them. Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | | don't pass 'mounting_here' flag to follow_down()Al Viro2011-03-181-1/+1
| |/ |/| | | | | | | | | it's always false now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | nfsd: wrong index used in inner looproel2011-03-091-2/+2
| | | | | | | | | | | | | | | | Index i was already used in the outer loop Cc: stable@kernel.org Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | nfsd4: fix bad pointer on failure to find delegationJ. Bruce Fields2011-03-071-6/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In case of a nonempty list, the return on error here is obviously bogus; it ends up being a pointer to the list head instead of to any valid delegation on the list. In particular, if nfsd4_delegreturn() hits this case, and you're quite unlucky, then renew_client may oops, and it may take an embarassingly long time to figure out why. Facepalm. BUG: unable to handle kernel NULL pointer dereference at 0000000000000090 IP: [<ffffffff81292965>] nfsd4_delegreturn+0x125/0x200 ... Cc: stable@kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* | NFSD: fix decode_cb_sequence4resokBenny Halevy2011-02-231-1/+1
|/ | | | | | | | | | | | Fix bug introduced in patch 85a56480 NFSD: Update XDR decoders in NFSv4 callback client Although decode_cb_sequence4resok ignores highest slotid and target highest slotid it must account for their space in their xdr stream when calling xdr_inline_decode Cc: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: correctly handle return value from nfsd_map_name_to_*NeilBrown2011-02-171-4/+4
| | | | | | | | | | | | | | These functions return an nfs status, not a host_err. So don't try to convert before returning. This is a regression introduced by 3c726023402a2f3b28f49b9d90ebf9e71151157d; I fixed up two of the callers, but missed these two. Cc: stable@kernel.org Reported-by: Herbert Poetzl <herbert@13thfloor.at> Signed-off-by: NeilBrown <neilb@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: break lease on unlink due to renameJ. Bruce Fields2011-02-141-0/+7
| | | | | | | | | | 4795bb37effb7b8fe77e2d2034545d062d3788a8 "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>
* nfsd4: acquire only one lease per fileJ. Bruce Fields2011-02-142-42/+58
| | | | | | | | | | | | | | | | | | | | | Instead of acquiring one lease each time another client opens a file, nfsd can acquire just one lease to represent all of them, and reference count it to determine when to release it. This fixes a regression introduced by c45821d263a8a5109d69a9e8942b8d65bcd5f31a "locks: eliminate fl_mylease callback": after that patch, only the struct file * is used to determine who owns a given lease. But since we recently converted the server to share a single struct file per open, if we acquire multiple leases on the same file from nfsd, it then becomes impossible on unlocking a lease to determine which of those leases (all of whom share the same struct file *) we meant to remove. Thanks to Takashi Iwai <tiwai@suse.de> for catching a bug in a previous version of this patch. Tested-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: modify fi_delegations under recall_lockJ. Bruce Fields2011-02-141-4/+4
| | | | | | | | | Modify fi_delegations only under the recall_lock, allowing us to use that list on lease breaks. Also some trivial cleanup to simplify later changes. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: remove unused deleg dprintk's.J. Bruce Fields2011-02-141-4/+0Star
| | | | | | These aren't all that useful, and get in the way of the next steps. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: split lease setting into separate functionJ. Bruce Fields2011-02-141-13/+19
| | | | | | | Splitting some code into a separate function which we'll be adding some more to. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: fix leak on allocation errorJ. Bruce Fields2011-02-141-8/+10
| | | | | | Also share some common exit code. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: add helper function for lease setupJ. Bruce Fields2011-02-141-12/+21
| | | | Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd4: split up nfsd_break_deleg_cbJ. Bruce Fields2011-02-141-18/+16Star
| | | | | | We'll be adding some more code here soon. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* NFSD: memory corruption due to writing beyond the stat arrayKonstantin Khorenko2011-02-141-1/+1
| | | | | | | | | | | | | | | | | 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>
* NFSD: use nfserr for status after decode_cb_op_statusBenny Halevy2011-02-141-4/+2Star
| | | | | | | | | Bugs introduced in 85a56480191ca9f08fc775c129b9eb5c8c1f2c05 "NFSD: Update XDR decoders in NFSv4 callback client" Cc: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* nfsd: don't leak dentry count on mnt_want_write failureJ. Bruce Fields2011-02-141-6/+6
| | | | | | The exit cleanup isn't quite right here. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* Merge branch 'for-linus' of ↵Linus Torvalds2011-01-161-2/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * '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 to allow processes to be held during pathwalk transitDavid Howells2011-01-161-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linuxLinus Torvalds2011-01-1418-270/+572
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * '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.
| * nfsd4: fix callback restartingJ. Bruce Fields2011-01-141-12/+9Star
| | | | | | | | | | | | | | Ensure a new callback is added to the client's list of callbacks at most once. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd: break lease on unlink, link, and renameJ. Bruce Fields2011-01-141-4/+23
| | | | | | | | | | | | | | Any change to any of the links pointing to an entry should also break delegations. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: break lease on nfsd setattrJ. Bruce Fields2011-01-141-8/+4Star
| | | | | | | | | | | | | | Leases (delegations) should really be broken on any metadata change, not just on size change. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd: don't support msnfs export optionJ. Bruce Fields2011-01-142-43/+2Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * nfsd4: initialize cb_per_clientJ. Bruce Fields2011-01-141-0/+1
| | | | | | | | | | | | | | Otherwise a callback that is aborted before it runs will result in a list_del on an uninitialized list head. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: allow restarting callbacksJ. Bruce Fields2011-01-113-6/+32
| | | | | | | | | | | | | | | | | | | | If we lose the backchannel and then the client repairs the problem, resend any callbacks. We use a new cb_done flag to track whether there is still work to be done for the callback or whether it can be destroyed with the rpc. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: simplify nfsd4_cb_prepareJ. Bruce Fields2011-01-111-22/+4Star
| | | | | | | | | | | | Remove handling for a nonexistant case (status && !-EAGAIN). Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: give out delegations more quickly in 4.1 caseJ. Bruce Fields2011-01-111-2/+15
| | | | | | | | Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: add helper function to run callbacksJ. Bruce Fields2011-01-111-2/+7
| | | | | | | | Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: make sure sequence flags are set after destroy_sessionJ. Bruce Fields2011-01-113-2/+8
| | | | | | | | | | | | | | If this loses any backchannel, make sure we have a chance to notice that and set the sequence flags. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: re-probe callback on connection lossJ. Bruce Fields2011-01-111-1/+1
| | | | | | | | | | | | This makes sure we set the sequence flag when necessary. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
| * nfsd4: set sequence flag when backchannel is downJ. Bruce Fields2011-01-113-8/+8
| | | | | | | | | | | | Implement the SEQ4_STATUS_CB_PATH_DOWN flag. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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