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2018-03-20fuse: honor AT_STATX_FORCE_SYNCMiklos Szeredi1-2/+9
Force a refresh of attributes from the fuse server in this case. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: honor AT_STATX_DONT_SYNCMiklos Szeredi1-4/+5
The description of this flag says "Don't sync attributes with the server". In other words: always use the attributes cached in the kernel and don't send network or local messages to refresh the attributes. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: Restrict allow_other to the superblock's namespace or a descendantSeth Forshee1-1/+1
Unprivileged users are normally restricted from mounting with the allow_other option by system policy, but this could be bypassed for a mount done with user namespace root permissions. In such cases allow_other should not allow users outside the userns to access the mount as doing so would give the unprivileged user the ability to manipulate processes it would otherwise be unable to manipulate. Restrict allow_other to apply to users in the same userns used at mount or a descendant of that namespace. Also export current_in_userns() for use by fuse when built as a module. Reviewed-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Dongsu Park <dongsu@kinvolk.io> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: Support fuse filesystems outside of init_user_nsEric W. Biederman1-7/+7
In order to support mounts from namespaces other than init_user_ns, fuse must translate uids and gids to/from the userns of the process servicing requests on /dev/fuse. This patch does that, with a couple of restrictions on the namespace: - The userns for the fuse connection is fixed to the namespace from which /dev/fuse is opened. - The namespace must be the same as s_user_ns. These restrictions simplify the implementation by avoiding the need to pass around userns references and by allowing fuse to rely on the checks in setattr_prepare for ownership changes. Either restriction could be relaxed in the future if needed. For cuse the userns used is the opener of /dev/cuse. Semantically the cuse support does not appear safe for unprivileged users. Practically the permissions on /dev/cuse only make it accessible to the global root user. If something slips through the cracks in a user namespace the only users who will be able to use the cuse device are those users mapped into the user namespace. Translation in the posix acl is updated to use the uuser namespace of the filesystem. Avoiding cases which might bypass this translation is handled in a following change. This change is stronlgy based on a similar change from Seth Forshee and Dongsu Park. Cc: Seth Forshee <seth.forshee@canonical.com> Cc: Dongsu Park <dongsu@kinvolk.io> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2018-03-20fuse: atomic_o_trunc should truncate pagecacheMiklos Szeredi1-1/+12
Fuse has an "atomic_o_trunc" mode, where userspace filesystem uses the O_TRUNC flag in the OPEN request to truncate the file atomically with the open. In this mode there's no need to send a SETATTR request to userspace after the open, so fuse_do_setattr() checks this mode and returns. But this misses the important step of truncating the pagecache. Add the missing parts of truncation to the ATTR_OPEN branch. Reported-by: Chad Austin <chadaustin@fb.com> Fixes: 6ff958edbf39 ("fuse: add atomic open+truncate support") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2017-10-25fuse: fix READDIRPLUS skipping an entryMiklos Szeredi1-1/+2
Marios Titas running a Haskell program noticed a problem with fuse's readdirplus: when it is interrupted by a signal, it skips one directory entry. The reason is that fuse erronously updates ctx->pos after a failed dir_emit(). The issue originates from the patch adding readdirplus support. Reported-by: Jakob Unterwurzacher <jakobunt@gmail.com> Tested-by: Marios Titas <redneb@gmx.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 0b05b18381ee ("fuse: implement NFS-like readdirplus support") Cc: <stable@vger.kernel.org> # v3.9
2017-09-12fuse: getattr cleanupMiklos Szeredi1-17/+13
The refreshed argument isn't used by any caller, get rid of it. Use a helper for just updating the inode (no need to fill in a kstat). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-03-03Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuseLinus Torvalds1-1/+1
Pull fuse update from Miklos Szeredi: "A bugfix and cleanups" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: release: private_data cannot be NULL fuse: cleanup fuse_file refcounting fuse: add missing FR_FORCE
2017-03-02statx: Add a system call to make enhanced file info availableDavid Howells1-3/+3
Add a system call to make extended file information available, including file creation and some attribute flags where available through the underlying filesystem. The getattr inode operation is altered to take two additional arguments: a u32 request_mask and an unsigned int flags that indicate the synchronisation mode. This change is propagated to the vfs_getattr*() function. Functions like vfs_stat() are now inline wrappers around new functions vfs_statx() and vfs_statx_fd() to reduce stack usage. ======== OVERVIEW ======== The idea was initially proposed as a set of xattrs that could be retrieved with getxattr(), but the general preference proved to be for a new syscall with an extended stat structure. A number of requests were gathered for features to be included. The following have been included: (1) Make the fields a consistent size on all arches and make them large. (2) Spare space, request flags and information flags are provided for future expansion. (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an __s64). (4) Creation time: The SMB protocol carries the creation time, which could be exported by Samba, which will in turn help CIFS make use of FS-Cache as that can be used for coherency data (stx_btime). This is also specified in NFSv4 as a recommended attribute and could be exported by NFSD [Steve French]. (5) Lightweight stat: Ask for just those details of interest, and allow a netfs (such as NFS) to approximate anything not of interest, possibly without going to the server [Trond Myklebust, Ulrich Drepper, Andreas Dilger] (AT_STATX_DONT_SYNC). (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks its cached attributes are up to date [Trond Myklebust] (AT_STATX_FORCE_SYNC). And the following have been left out for future extension: (7) Data version number: Could be used by userspace NFS servers [Aneesh Kumar]. Can also be used to modify fill_post_wcc() in NFSD which retrieves i_version directly, but has just called vfs_getattr(). It could get it from the kstat struct if it used vfs_xgetattr() instead. (There's disagreement on the exact semantics of a single field, since not all filesystems do this the same way). (8) BSD stat compatibility: Including more fields from the BSD stat such as creation time (st_btime) and inode generation number (st_gen) [Jeremy Allison, Bernd Schubert]. (9) Inode generation number: Useful for FUSE and userspace NFS servers [Bernd Schubert]. (This was asked for but later deemed unnecessary with the open-by-handle capability available and caused disagreement as to whether it's a security hole or not). (10) Extra coherency data may be useful in making backups [Andreas Dilger]. (No particular data were offered, but things like last backup timestamp, the data version number and the DOS archive bit would come into this category). (11) Allow the filesystem to indicate what it can/cannot provide: A filesystem can now say it doesn't support a standard stat feature if that isn't available, so if, for instance, inode numbers or UIDs don't exist or are fabricated locally... (This requires a separate system call - I have an fsinfo() call idea for this). (12) Store a 16-byte volume ID in the superblock that can be returned in struct xstat [Steve French]. (Deferred to fsinfo). (13) Include granularity fields in the time data to indicate the granularity of each of the times (NFSv4 time_delta) [Steve French]. (Deferred to fsinfo). (14) FS_IOC_GETFLAGS value. These could be translated to BSD's st_flags. Note that the Linux IOC flags are a mess and filesystems such as Ext4 define flags that aren't in linux/fs.h, so translation in the kernel may be a necessity (or, possibly, we provide the filesystem type too). (Some attributes are made available in stx_attributes, but the general feeling was that the IOC flags were to ext[234]-specific and shouldn't be exposed through statx this way). (15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer, Michael Kerrisk]. (Deferred, probably to fsinfo. Finding out if there's an ACL or seclabal might require extra filesystem operations). (16) Femtosecond-resolution timestamps [Dave Chinner]. (A __reserved field has been left in the statx_timestamp struct for this - if there proves to be a need). (17) A set multiple attributes syscall to go with this. =============== NEW SYSTEM CALL =============== The new system call is: int ret = statx(int dfd, const char *filename, unsigned int flags, unsigned int mask, struct statx *buffer); The dfd, filename and flags parameters indicate the file to query, in a similar way to fstatat(). There is no equivalent of lstat() as that can be emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags. There is also no equivalent of fstat() as that can be emulated by passing a NULL filename to statx() with the fd of interest in dfd. Whether or not statx() synchronises the attributes with the backing store can be controlled by OR'ing a value into the flags argument (this typically only affects network filesystems): (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this respect. (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise its attributes with the server - which might require data writeback to occur to get the timestamps correct. (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a network filesystem. The resulting values should be considered approximate. mask is a bitmask indicating the fields in struct statx that are of interest to the caller. The user should set this to STATX_BASIC_STATS to get the basic set returned by stat(). It should be noted that asking for more information may entail extra I/O operations. buffer points to the destination for the data. This must be 256 bytes in size. ====================== MAIN ATTRIBUTES RECORD ====================== The following structures are defined in which to return the main attribute set: struct statx_timestamp { __s64 tv_sec; __s32 tv_nsec; __s32 __reserved; }; struct statx { __u32 stx_mask; __u32 stx_blksize; __u64 stx_attributes; __u32 stx_nlink; __u32 stx_uid; __u32 stx_gid; __u16 stx_mode; __u16 __spare0[1]; __u64 stx_ino; __u64 stx_size; __u64 stx_blocks; __u64 __spare1[1]; struct statx_timestamp stx_atime; struct statx_timestamp stx_btime; struct statx_timestamp stx_ctime; struct statx_timestamp stx_mtime; __u32 stx_rdev_major; __u32 stx_rdev_minor; __u32 stx_dev_major; __u32 stx_dev_minor; __u64 __spare2[14]; }; The defined bits in request_mask and stx_mask are: STATX_TYPE Want/got stx_mode & S_IFMT STATX_MODE Want/got stx_mode & ~S_IFMT STATX_NLINK Want/got stx_nlink STATX_UID Want/got stx_uid STATX_GID Want/got stx_gid STATX_ATIME Want/got stx_atime{,_ns} STATX_MTIME Want/got stx_mtime{,_ns} STATX_CTIME Want/got stx_ctime{,_ns} STATX_INO Want/got stx_ino STATX_SIZE Want/got stx_size STATX_BLOCKS Want/got stx_blocks STATX_BASIC_STATS [The stuff in the normal stat struct] STATX_BTIME Want/got stx_btime{,_ns} STATX_ALL [All currently available stuff] stx_btime is the file creation time, stx_mask is a bitmask indicating the data provided and __spares*[] are where as-yet undefined fields can be placed. Time fields are structures with separate seconds and nanoseconds fields plus a reserved field in case we want to add even finer resolution. Note that times will be negative if before 1970; in such a case, the nanosecond fields will also be negative if not zero. The bits defined in the stx_attributes field convey information about a file, how it is accessed, where it is and what it does. The following attributes map to FS_*_FL flags and are the same numerical value: STATX_ATTR_COMPRESSED File is compressed by the fs STATX_ATTR_IMMUTABLE File is marked immutable STATX_ATTR_APPEND File is append-only STATX_ATTR_NODUMP File is not to be dumped STATX_ATTR_ENCRYPTED File requires key to decrypt in fs Within the kernel, the supported flags are listed by: KSTAT_ATTR_FS_IOC_FLAGS [Are any other IOC flags of sufficient general interest to be exposed through this interface?] New flags include: STATX_ATTR_AUTOMOUNT Object is an automount trigger These are for the use of GUI tools that might want to mark files specially, depending on what they are. Fields in struct statx come in a number of classes: (0) stx_dev_*, stx_blksize. These are local system information and are always available. (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino, stx_size, stx_blocks. These will be returned whether the caller asks for them or not. The corresponding bits in stx_mask will be set to indicate whether they actually have valid values. If the caller didn't ask for them, then they may be approximated. For example, NFS won't waste any time updating them from the server, unless as a byproduct of updating something requested. If the values don't actually exist for the underlying object (such as UID or GID on a DOS file), then the bit won't be set in the stx_mask, even if the caller asked for the value. In such a case, the returned value will be a fabrication. Note that there are instances where the type might not be valid, for instance Windows reparse points. (2) stx_rdev_*. This will be set only if stx_mode indicates we're looking at a blockdev or a chardev, otherwise will be 0. (3) stx_btime. Similar to (1), except this will be set to 0 if it doesn't exist. ======= TESTING ======= The following test program can be used to test the statx system call: samples/statx/test-statx.c Just compile and run, passing it paths to the files you want to examine. The file is built automatically if CONFIG_SAMPLES is enabled. Here's some example output. Firstly, an NFS directory that crosses to another FSID. Note that the AUTOMOUNT attribute is set because transiting this directory will cause d_automount to be invoked by the VFS. [root@andromeda ~]# /tmp/test-statx -A /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:26 Inode: 1703937 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------) Secondly, the result of automounting on that directory. [root@andromeda ~]# /tmp/test-statx /warthog/data statx(/warthog/data) = 0 results=7ff Size: 4096 Blocks: 8 IO Block: 1048576 directory Device: 00:27 Inode: 2 Links: 125 Access: (3777/drwxrwxrwx) Uid: 0 Gid: 4041 Access: 2016-11-24 09:02:12.219699527+0000 Modify: 2016-11-17 10:44:36.225653653+0000 Change: 2016-11-17 10:44:36.225653653+0000 Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-02-22fuse: cleanup fuse_file refcountingMiklos Szeredi1-1/+1
struct fuse_file is stored in file->private_data. Make this always be a counting reference for consistency. This also allows fuse_sync_release() to call fuse_file_put() instead of partially duplicating its functionality. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-01-13fuse: fix time_to_jiffies nsec sanity checkDavid Sheets1-1/+1
Commit bcb6f6d2b9c2 ("fuse: use timespec64") introduced clamped nsec values in time_to_jiffies but used the max of nsec and NSEC_PER_SEC - 1 instead of the min. Because of this, dentries would stay in the cache longer than requested and go stale in scenarios that relied on their timely eviction. Fixes: bcb6f6d2b9c2 ("fuse: use timespec64") Signed-off-by: David Sheets <dsheets@docker.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # 4.9
2016-12-17Merge uncontroversial parts of branch 'readlink' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfsLinus Torvalds1-1/+0
Pull partial readlink cleanups from Miklos Szeredi. This is the uncontroversial part of the readlink cleanup patch-set that simplifies the default readlink handling. Miklos and Al are still discussing the rest of the series. * git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: vfs: make generic_readlink() static vfs: remove ".readlink = generic_readlink" assignments vfs: default to generic_readlink() vfs: replace calling i_op->readlink with vfs_readlink() proc/self: use generic_readlink ecryptfs: use vfs_get_link() bad_inode: add missing i_op initializers
2016-12-09vfs: remove ".readlink = generic_readlink" assignmentsMiklos Szeredi1-1/+0
If .readlink == NULL implies generic_readlink(). Generated by: to_del="\.readlink.*=.*generic_readlink" for i in `git grep -l $to_del`; do sed -i "/$to_del"/d $i; done Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-12-06fuse: fix clearing suid, sgid for chown()Miklos Szeredi1-5/+2
Basically, the pjdfstests set the ownership of a file to 06555, and then chowns it (as root) to a new uid/gid. Prior to commit a09f99eddef4 ("fuse: fix killing s[ug]id in setattr"), fuse would send down a setattr with both the uid/gid change and a new mode. Now, it just sends down the uid/gid change. Technically this is NOTABUG, since POSIX doesn't _require_ that we clear these bits for a privileged process, but Linux (wisely) has done that and I think we don't want to change that behavior here. This is caused by the use of should_remove_suid(), which will always return 0 when the process has CAP_FSETID. In fact we really don't need to be calling should_remove_suid() at all, since we've already been indicated that we should remove the suid, we just don't want to use a (very) stale mode for that. This patch should fix the above as well as simplify the logic. Reported-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: a09f99eddef4 ("fuse: fix killing s[ug]id in setattr") Cc: <stable@vger.kernel.org> Reviewed-by: Jeff Layton <jlayton@redhat.com>
2016-10-18fuse: fix root dentry initializationMiklos Szeredi1-0/+5
Add missing dentry initialization to root dentry. Fixes: f75fdf22b0a8 ("fuse: don't use ->d_time") Reported-by: Andreas Reis <andreas.reis@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-10Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-2/+2
Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-10Merge remote-tracking branch 'ovl/rename2' into for-linusAl Viro1-1/+1
2016-10-10Merge branch 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-9/+0
Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check
2016-10-10Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-3/+4
Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-07vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher1-9/+0
These inode operations are no longer used; remove them. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-01fuse: Use generic xattr opsSeth Forshee1-175/+11
In preparation for posix acl support, rework fuse to use xattr handlers and the generic setxattr/getxattr/listxattr callbacks. Split the xattr code out into it's own file, and promote symbols to module-global scope as needed. Functionally these changes have no impact, as fuse still uses a single handler for all xattrs which uses the old callbacks. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: get rid of fc->flagsMiklos Szeredi1-4/+4
Only two flags: "default_permissions" and "allow_other". All other flags are handled via bitfields. So convert these two as well. They don't change during the lifetime of the filesystem, so this is quite safe. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: listxattr: verify xattr listMiklos Szeredi1-0/+19
Make sure userspace filesystem is returning a well formed list of xattr names (zero or more nonzero length, null terminated strings). [Michael Theall: only verify in the nonzero size case] Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-10-01fuse: use timespec64Miklos Szeredi1-3/+7
And check for valid nsec value before passing into timespec64_to_jiffies(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: don't use ->d_timeMiklos Szeredi1-20/+23
Store in memory pointed to by ->d_fsdata. Use ->d_init() to allocate the storage. Need to use RCU freeing because the data is used in RCU lookup mode. We could cast ->d_fsdata directly on 64bit archs, but I don't think this is worth the extra complexity. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: Add posix ACL supportSeth Forshee1-0/+16
Add a new INIT flag, FUSE_POSIX_ACL, for negotiating ACL support with userspace. When it is set in the INIT response, ACL support will be enabled. ACL support also implies "default_permissions". When ACL support is enabled, the kernel will cache and have responsibility for enforcing ACLs. ACL xattrs will be passed to userspace, which is responsible for updating the ACLs in the filesystem, keeping the file mode in sync, and inheritance of default ACLs when new filesystem nodes are created. Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: handle killpriv in userspace fsMiklos Szeredi1-17/+27
Only userspace filesystem can do the killing of suid/sgid without races. So introduce an INIT flag and negotiate support for this. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-01fuse: fix killing s[ug]id in setattrMiklos Szeredi1-4/+28
Fuse allowed VFS to set mode in setattr in order to clear suid/sgid on chown and truncate, and (since writeback_cache) write. The problem with this is that it'll potentially restore a stale mode. The poper fix would be to let the filesystems do the suid/sgid clearing on the relevant operations. Possibly some are already doing it but there's no way we can detect this. So fix this by refreshing and recalculating the mode. Do this only if ATTR_KILL_S[UG]ID is set to not destroy performance for writes. This is still racy but the size of the window is reduced. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-10-01fuse: invalidate dir dentry after chmodMiklos Szeredi1-2/+10
Without "default_permissions" the userspace filesystem's lookup operation needs to perform the check for search permission on the directory. If directory does not allow search for everyone (this is quite rare) then userspace filesystem has to set entry timeout to zero to make sure permissions are always performed. Changing the mode bits of the directory should also invalidate the (previously cached) dentry to make sure the next lookup will have a chance of updating the timeout, if needed. Reported-by: Jean-Pierre André <jean-pierre.andre@wanadoo.fr> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-09-27fs: Replace current_fs_time() with current_time()Deepa Dinamani1-1/+1
current_fs_time() uses struct super_block* as an argument. As per Linus's suggestion, this is changed to take struct inode* as a parameter instead. This is because the function is primarily meant for vfs inode timestamps. Also the function was renamed as per Arnd's suggestion. Change all calls to current_fs_time() to use the new current_time() function instead. current_fs_time() will be deleted. Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-09-27fs: rename "rename2" i_op to "rename"Miklos Szeredi1-1/+1
Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-22fs: Give dentry to inode_change_ok() instead of inodeJan Kara1-1/+1
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-22fuse: Propagate dentry down to inode_change_ok()Jan Kara1-3/+4
To avoid clearing of capabilities or security related extended attributes too early, inode_change_ok() will need to take dentry instead of inode. Propagate it down to fuse_do_setattr(). Acked-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-08-06Merge branch 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-2/+2
Pull qstr constification updates from Al Viro: "Fairly self-contained bunch - surprising lot of places passes struct qstr * as an argument when const struct qstr * would suffice; it complicates analysis for no good reason. I'd prefer to feed that separately from the assorted fixes (those are in #for-linus and with somewhat trickier topology)" * 'work.const-qstr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: qstr: constify instances in adfs qstr: constify instances in lustre qstr: constify instances in f2fs qstr: constify instances in ext2 qstr: constify instances in vfat qstr: constify instances in procfs qstr: constify instances in fuse qstr constify instances in fs/dcache.c qstr: constify instances in nfs qstr: constify instances in ocfs2 qstr: constify instances in autofs4 qstr: constify instances in hfs qstr: constify instances in hfsplus qstr: constify instances in logfs qstr: constify dentry_init_security
2016-07-30qstr: constify instances in fuseAl Viro1-2/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-07-28Merge branch 'salted-string-hash'Linus Torvalds1-1/+2
This changes the vfs dentry hashing to mix in the parent pointer at the _beginning_ of the hash, rather than at the end. That actually improves both the hash and the code generation, because we can move more of the computation to the "static" part of the dcache setup, and do less at lookup runtime. It turns out that a lot of other hash users also really wanted to mix in a base pointer as a 'salt' for the hash, and so the slightly extended interface ends up working well for other cases too. Users that want a string hash that is purely about the string pass in a 'salt' pointer of NULL. * merge branch 'salted-string-hash': fs/dcache.c: Save one 32-bit multiply in dcache lookup vfs: make the string hashes salt the hash
2016-07-05Use the right predicate in ->atomic_open() instancesAl Viro1-1/+1
->atomic_open() can be given an in-lookup dentry *or* a negative one found in dcache. Use d_in_lookup() to tell one from another, rather than d_unhashed(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-06-30fuse: serialize dirops by defaultMiklos Szeredi1-0/+4
Negotiate with userspace filesystems whether they support parallel readdir and lookup. Disable parallelism by default for fear of breaking fuse filesystems. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 9902af79c01a ("parallel lookups: actual switch to rwsem") Fixes: d9b3dbdcfd62 ("fuse: switch to ->iterate_shared()")
2016-06-10vfs: make the string hashes salt the hashLinus Torvalds1-1/+2
We always mixed in the parent pointer into the dentry name hash, but we did it late at lookup time. It turns out that we can simplify that lookup-time action by salting the hash with the parent pointer early instead of late. A few other users of our string hashes also wanted to mix in their own pointers into the hash, and those are updated to use the same mechanism. Hash users that don't have any particular initial salt can just use the NULL pointer as a no-salt. Cc: Vegard Nossum <vegard.nossum@oracle.com> Cc: George Spelvin <linux@sciencehorizons.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27switch ->setxattr() to passing dentry and inode separatelyAl Viro1-3/+3
smack ->d_instantiate() uses ->setxattr(), so to be able to call it before we'd hashed the new dentry and attached it to inode, we need ->setxattr() instances getting the inode as an explicit argument rather than obtaining it from dentry. Similar change for ->getxattr() had been done in commit ce23e64. Unlike ->getxattr() (which is used by both selinux and smack instances of ->d_instantiate()) ->setxattr() is used only by smack one and unfortunately it got missed back then. Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-02fuse: switch to ->iterate_shared()Al Viro1-49/+45
Switch dcache pre-seeding on readdir to d_alloc_parallel(); nothing else is needed. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-11->getxattr(): pass dentry and inode as separate argumentsAl Viro1-3/+2
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-01-22wrappers for ->i_mutex accessAl Viro1-5/+5
parallel to mutex_{lock,unlock,trylock,is_locked,lock_nested}, inode_foo(inode) being mutex_foo(&inode->i_mutex). Please, use those for access to ->i_mutex; over the coming cycle ->i_mutex will become rwsem, with ->lookup() done with it held only shared. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-30switch ->get_link() to delayed_call, kill ->put_link()Al Viro1-3/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-29kill free_page_put_link()Al Viro1-3/+3
all callers are better off with kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-12-08replace ->follow_link() with new method that could stay in RCU modeAl Viro1-3/+6
new method: ->get_link(); replacement of ->follow_link(). The differences are: * inode and dentry are passed separately * might be called both in RCU and non-RCU mode; the former is indicated by passing it a NULL dentry. * when called that way it isn't allowed to block and should return ERR_PTR(-ECHILD) if it needs to be called in non-RCU mode. It's a flagday change - the old method is gone, all in-tree instances converted. Conversion isn't hard; said that, so far very few instances do not immediately bail out when called in RCU mode. That'll change in the next commits. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11new helper: free_page_put_link()Al Viro1-6/+1
similar to kfree_put_link() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-11switch ->put_link() from dentry to inodeAl Viro1-1/+1
only one instance looks at that argument at all; that sole exception wants inode rather than dentry. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10don't pass nameidata to ->follow_link()Al Viro1-1/+1
its only use is getting passed to nd_jump_link(), which can obtain it from current->nameidata Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-05-10new ->follow_link() and ->put_link() calling conventionsAl Viro1-15/+4
a) instead of storing the symlink body (via nd_set_link()) and returning an opaque pointer later passed to ->put_link(), ->follow_link() _stores_ that opaque pointer (into void * passed by address by caller) and returns the symlink body. Returning ERR_PTR() on error, NULL on jump (procfs magic symlinks) and pointer to symlink body for normal symlinks. Stored pointer is ignored in all cases except the last one. Storing NULL for opaque pointer (or not storing it at all) means no call of ->put_link(). b) the body used to be passed to ->put_link() implicitly (via nameidata). Now only the opaque pointer is. In the cases when we used the symlink body to free stuff, ->follow_link() now should store it as opaque pointer in addition to returning it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>