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path: root/fs/nfsd/vfs.c
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2012-09-18userns: Pass a userns parameter into posix_acl_to_xattr and posix_acl_from_xattrEric W. Biederman
- 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>
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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 ...
2012-07-31Merge branch 'nfsd-next' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
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 ...
2012-07-31nfsd: Push mnt_want_write() outside of i_mutexJan Kara
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>
2012-07-23switch dentry_open() to struct path, make it grab references itselfAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14don't pass nameidata * to vfs_create()Al Viro
all we want is a boolean flag, same as the method gets now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-10nfsd: allow owner_override only for regular filesJ. Bruce Fields
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>
2012-04-25nfsd: trivial: use SEEK_SET instead of 0 in vfs_llseekJeff Layton
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>
2012-04-11nfsd: don't fail unchecked creates of non-special filesJ. Bruce Fields
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>
2012-03-29Merge branch 'for-3.4' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
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 ...
2012-03-20switch touch_atime to struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-18nfsd: vfs_llseek() with 32 or 64 bit offsets (hashes)Bernd Schubert
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>
2012-03-18nfsd: rename 'int access' to 'int may_flags' in nfsd_open()Bernd Schubert
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>
2012-01-14Merge branch 'for-3.3' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* '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 ...
2012-01-05NFSD: Change name of extended attribute containing junctionChuck Lever
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>
2012-01-03fs: propagate umode_t, misc bitsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03new helpers: fh_{want,drop}_write()Al Viro
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>
2011-10-17nfsd4: warn on open failure after createJ. Bruce Fields
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>
2011-09-13NFSD: Add a cache for fs_locations informationTrond Myklebust
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>
2011-08-27nfsd4: permit read opens of executable-only filesJ. Bruce Fields
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 dc730e173785e29b297aa605786c94adaffe2544 "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>
2011-08-26nfsd4: fix incorrect comment in nfsd4_set_nfs4_aclJ. Bruce Fields
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>
2011-08-26nfsd: open-code special directory-hardlink checkJ. Bruce Fields
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>
2011-06-20nfsd4: fix break_lease flags on nfsd openJ. Bruce Fields
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>
2011-06-06nfsd: link returns nfserr_delay when breaking leaseCasey Bodley
fix for commit 4795bb37effb7b8fe77e2d2034545d062d3788a8, 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>
2011-05-29Merge branch 'for-2.6.40' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* '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 ...
2011-04-29NFSD: Remove setting unused variable in nfsd_vfs_read()Bryan Schumaker
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>
2011-04-29nfsd41: make sure nfs server process OPEN with EXCLUSIVE4_1 correctlyMi Jinlong
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>
2011-04-20Open with O_CREAT flag set fails to open existing files on non writable ↵Sachin Prabhu
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>
2011-04-11nfsd4: make fh_verify responsibility of nfsd_lookup_dentry callerJ. Bruce Fields
The secinfo caller actually won't want this. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-04-11nfsd: distinguish functions of NFSD_MAY_* flagsJ. Bruce Fields
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>
2011-03-24Merge branch 'for-2.6.39' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* '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()
2011-03-18don't pass 'mounting_here' flag to follow_down()Al Viro
it's always false now Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-03-07NFSD, VFS: Remove dead code in nfsd_rename()Jesper Juhl
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>
2011-02-14nfsd: break lease on unlink due to renameJ. Bruce Fields
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>
2011-02-14NFSD: memory corruption due to writing beyond the stat arrayKonstantin Khorenko
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>
2011-02-14nfsd: don't leak dentry count on mnt_want_write failureJ. Bruce Fields
The exit cleanup isn't quite right here. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-16Merge branch 'for-linus' of ↵Linus Torvalds
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 ...
2011-01-15Add a dentry op to allow processes to be held during pathwalk transitDavid Howells
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>
2011-01-14Merge branch 'for-2.6.38' of git://linux-nfs.org/~bfields/linuxLinus Torvalds
* '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.
2011-01-13nfsd: break lease on unlink, link, and renameJ. Bruce Fields
Any change to any of the links pointing to an entry should also break delegations. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-13nfsd4: break lease on nfsd setattrJ. Bruce Fields
Leases (delegations) should really be broken on any metadata change, not just on size change. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-13nfsd: don't support msnfs export optionJ. Bruce Fields
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>
2011-01-13Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds
* '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() ...
2011-01-07fs: dcache scale dentry refcountNick Piggin
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>
2011-01-04nfsd4: move idmap and acl header files into fs/nfsdJ. Bruce Fields
These are internal nfsd interfaces. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2011-01-04nfsd: remove some unnecessary dropit handlingJ. Bruce Fields
We no longer need a few of these special cases. Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2010-12-20Fix compile warnings due to missing removal of a 'ret' variableJens Axboe
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>
2010-12-17fs/splice: Pull buf->ops->confirm() from splice_from_pipe actorsMichał Mirosław
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 6313e3c21743cc88bb5bd8aa72948ee1e83937b6. Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl> Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
2010-10-25fs: add sync_inode_metadataChristoph Hellwig
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>
2010-08-26nfsd: fix NULL dereference in nfsd_statfs()Takashi Iwai
The commit ebabe9a9001af0af56c0c2780ca1576246e7a74b 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>