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* ovl: mark upper merge dir with type origin entries "impure"Amir Goldstein2017-05-291-26/+5Star
| | | | | | | | | | | | | | | | | | | | An upper dir is marked "impure" to let ovl_iterate() know that this directory may contain non pure upper entries whose d_ino may need to be read from the origin inode. We already mark a non-merge dir "impure" when moving a non-pure child entry inside it, to let ovl_iterate() know not to iterate the non-merge dir directly. Mark also a merge dir "impure" when moving a non-pure child entry inside it and when copying up a child entry inside it. This can be used to optimize ovl_iterate() to perform a "pure merge" of upper and lower directories, merging the content of the directories, without having to read d_ino from origin inodes. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: mark upper dir with type origin entries "impure"Amir Goldstein2017-05-191-0/+45
| | | | | | | | | | | | | When moving a merge dir or non-dir with copy up origin into a non-merge upper dir (a.k.a pure upper dir), we are marking the target parent dir "impure". ovl_iterate() iterates pure upper dirs directly, because there is no need to filter out whiteouts and merge dir content with lower dir. But for the case of an "impure" upper dir, ovl_iterate() will not be able to iterate the real upper dir directly, because it will need to lookup the origin inode and use it to fill d_ino. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: remove unused arg from ovl_lookup_temp()Miklos Szeredi2017-05-191-4/+4
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: handle rename when upper doesn't support xattrAmir Goldstein2017-05-191-10/+19
| | | | | | | | | | | | | | On failure to set opaque/redirect xattr on rename, skip setting xattr and return -EXDEV. On failure to set opaque xattr when creating a new directory, -EIO is returned instead of -EOPNOTSUPP. Any failure to set those xattr will be recorded in super block and then setting any xattr on upper won't be attempted again. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: persistent inode numbers for upper hardlinksAmir Goldstein2017-05-051-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | An upper type non directory dentry that is a copy up target should have a reference to its lower copy up origin. There are three ways for an upper type dentry to be instantiated: 1. A lower type dentry that is being copied up 2. An entry that is found in upper dir by ovl_lookup() 3. A negative dentry is hardlinked to an upper type dentry In the first case, the lower reference is set before copy up. In the second case, the lower reference is found by ovl_lookup(). In the last case of hardlinked upper dentry, it is not easy to update the lower reference of the negative dentry. Instead, drop the newly hardlinked negative dentry from dcache and let the next access call ovl_lookup() to find its lower reference. This makes sure that the inode number reported by stat(2) after the hardlink is created is the same inode number that will be reported by stat(2) after mount cycle, which is the inode number of the lower copy up origin of the hardlink source. NOTE that this does not fix breaking of lower hardlinks on copy up, but only fixes the case of lower nlink == 1, whose upper copy up inode is hardlinked in upper dir. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: merge getattr for dir and nondirMiklos Szeredi2017-05-051-60/+1Star
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: persistent inode number for directoriesAmir Goldstein2017-05-051-4/+33
| | | | | | | | | | | | | | stat(2) on overlay directories reports the overlay temp inode number, which is constant across copy up, but is not persistent. When all layers are on the same fs, report the copy up origin inode number for directories. This inode number is persistent, unique across the overlay mount and constant across copy up. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: do not set overlay.opaque on non-dir createAmir Goldstein2017-04-261-1/+1
| | | | | | | | | | The optimization for opaque dir create was wrongly being applied also to non-dir create. Fixes: 97c684cc9110 ("ovl: create directories inside merged parent opaque") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.10
* statx: Add a system call to make enhanced file info availableDavid Howells2017-03-031-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ovl: clean up kstat usageAl Viro2016-12-161-28/+28
| | | | | | | | | | | | | | | FWIW, there's a bit of abuse of struct kstat in overlayfs object creation paths - for one thing, it ends up with a very small subset of struct kstat (mode + rdev), for another it also needs link in case of symlinks and ends up passing it separately. IMO it would be better to introduce a separate object for that. In principle, we might even lift that thing into general API and switch ->mkdir()/->mknod()/->symlink() to identical calling conventions. Hell knows, perhaps ->create() as well... Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: create directories inside merged parent opaqueAmir Goldstein2016-12-161-2/+12
| | | | | | | | | | | | | The benefit of making directories opaque on creation is that lookups can stop short when they reach the original created directory, instead of continue lookup the entire depth of parent directory stack. The best case is overlay with N layers, performing lookup for first level directory, which exists only in upper. In that case, there will be only one lookup instead of N. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: opaque cleanupMiklos Szeredi2016-12-161-22/+21Star
| | | | | | | | | | | | | | oe->opaque is set for a) whiteouts b) directories having the "trusted.overlay.opaque" xattr Case b can be simplified, since setting the xattr always implies setting oe->opaque. Also once set, the opaque flag is never cleared. Don't need to set opaque flag for non-directories. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: allow setting max size of redirectMiklos Szeredi2016-12-161-3/+7
| | | | | | | | | | Add a module option to allow tuning the max size of absolute redirects. Default is 256. Size of relative redirects is naturally limited by the the underlying filesystem's max filename length (usually 255). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: check for emptiness of redirect dirAmir Goldstein2016-12-161-9/+22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Before introducing redirect_dir feature, the condition !ovl_lower_positive(dentry) for a directory, implied that it is a pure upper directory, which may be removed if empty. Now that directory can be redirect, it is possible that upper does not cover any lower (i.e. !ovl_lower_positive(dentry)), but the directory is a merge (with redirected path) and maybe non empty. Check for this case in ovl_remove_upper(). This change fixes the following test case from rename-pop-dir.py of unionmount-testsuite: """Remove dir and rename old name""" d = ctx.non_empty_dir() d2 = ctx.no_dir() ctx.rmdir(d, err=ENOTEMPTY) ctx.rename(d, d2) ctx.rmdir(d, err=ENOENT) ctx.rmdir(d2, err=ENOTEMPTY) ./run --ov rename-pop-dir /mnt/a/no_dir103: Expected error (Directory not empty) was not produced Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: redirect on rename-dirMiklos Szeredi2016-12-161-14/+124
| | | | | | | | | | | | | | | | Current code returns EXDEV when a directory would need to be copied up to move. We could copy up the directory tree in this case, but there's another, simpler solution: point to old lower directory from moved upper directory. This is achieved with a "trusted.overlay.redirect" xattr storing the path relative to the root of the overlay. After such attribute has been set, the directory can be moved without further actions required. This is a backward incompatible feature, old kernels won't be able to correctly mount an overlay containing redirected directories. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: check lower existence of rename targetMiklos Szeredi2016-12-161-52/+11Star
| | | | | | | | | | | | | | | | Check if something exists on the lower layer(s) under the target or rename to decide if directory needs to be marked "opaque". Marking opaque is done before the rename, and on failure the marking was undone. Also the opaque xattr was removed if the target didn't cover anything. This patch changes behavior so that removal of "opaque" is not done in either of the above cases. This means that directory may have the opaque flag even if it doesn't cover anything. However this shouldn't affect the performance or semantics of the overalay, while simplifying the code. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: rename: simplify handling of lower/merged directoryMiklos Szeredi2016-12-161-18/+12Star
| | | | | | | d_is_dir() is safe to call on a negative dentry. Use this fact to simplify handling of the lower or merged directories. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: get rid of PURE typeMiklos Szeredi2016-12-161-6/+3Star
| | | | | | | The remainging uses of __OVL_PATH_PURE can be replaced by ovl_dentry_is_opaque(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: check lower existence when removingMiklos Szeredi2016-12-161-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently ovl_lookup() checks existence of lower file even if there's a non-directory on upper (which is always opaque). This is done so that remove can decide whether a whiteout is needed or not. It would be better to defer this check to unlink, since most of the time the gathered information about opaqueness will be unused. This adds a helper ovl_lower_positive() that checks if there's anything on the lower layer(s). The following patches also introduce changes to how the "opaque" attribute is updated on directories: this attribute is added when the directory is creted or moved over a whiteout or object covering something on the lower layer. However following changes will allow the attribute to remain on the directory after being moved, even if the new location doesn't cover anything. Because of this, we need to check lower layers even for opaque directories, so that whiteout is only created when necessary. This function will later be also used to decide about marking a directory opaque, so deal with negative dentries as well. When dealing with negative, it's enough to check for being a whiteout If the dentry is positive but not upper then it also obviously needs whiteout/opaque. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: add ovl_dentry_is_whiteout()Miklos Szeredi2016-12-161-3/+3
| | | | | | And use it instead of ovl_dentry_is_opaque() where appropriate. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: don't check stickyMiklos Szeredi2016-12-161-24/+0Star
| | | | | | | | Since commit 07a2daab49c5 ("ovl: Copy up underlying inode's ->i_mode to overlay inode") sticky checking on overlay inode is performed by the vfs, so checking against sticky on underlying inode is not needed. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: don't check rename to selfMiklos Szeredi2016-12-161-12/+3Star
| | | | | | | This is redundant, the vfs already performed this check (and was broken, see commit 9409e22acdfc ("vfs: rename: check backing inode being equal")). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: treat special files like a regular fsMiklos Szeredi2016-12-161-1/+1
| | | | | | | | | | No sense in opening special files on the underlying layers, they work just as well if opened on the overlay. Side effect is that it's no longer possible to connect one side of a pipe opened on overlayfs with the other side opened on the underlying layer. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: rename ovl_rename2() to ovl_rename()Miklos Szeredi2016-12-161-4/+4
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge branch 'overlayfs-linus' of ↵Linus Torvalds2016-10-151-1/+4
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This update contains fixes to the "use mounter's permission to access underlying layers" area, and miscellaneous other fixes and cleanups. No new features this time" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: use vfs_get_link() vfs: add vfs_get_link() helper ovl: use generic_readlink ovl: explain error values when removing acl from workdir ovl: Fix info leak in ovl_lookup_temp() ovl: during copy up, switch to mounter's creds early ovl: lookup: do getxattr with mounter's permission ovl: copy_up_xattr(): use strnlen
| * ovl: Fix info leak in ovl_lookup_temp()Richard Weinberger2016-09-211-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The function uses the memory address of a struct dentry as unique id. While the address-based directory entry is only visible to root it is IMHO still worth fixing since the temporary name does not have to be a kernel address. It can be any unique number. Replace it by an atomic integer which is allowed to wrap around. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v3.18+ Fixes: e9be9d5e76e3 ("overlay filesystem")
* | Merge branch 'for-linus' of ↵Linus Torvalds2016-10-111-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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
| * | fs: rename "rename2" i_op to "rename"Miklos Szeredi2016-09-271-1/+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>
* | Merge branch 'work.xattr' of ↵Linus Torvalds2016-10-111-3/+0Star
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 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
| * | vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher2016-10-081-3/+0Star
| |/ | | | | | | | | | | | | 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>
* | Merge branch 'next' of ↵Linus Torvalds2016-10-041-0/+10
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: SELinux/LSM: - overlayfs support, necessary for container filesystems LSM: - finally remove the kernel_module_from_file hook Smack: - treat signal delivery as an 'append' operation TPM: - lots of bugfixes & updates Audit: - new audit data type: LSM_AUDIT_DATA_FILE * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (47 commits) Revert "tpm/tpm_crb: implement tpm crb idle state" Revert "tmp/tpm_crb: fix Intel PTT hw bug during idle state" Revert "tpm/tpm_crb: open code the crb_init into acpi_add" Revert "tmp/tpm_crb: implement runtime pm for tpm_crb" lsm,audit,selinux: Introduce a new audit data type LSM_AUDIT_DATA_FILE tmp/tpm_crb: implement runtime pm for tpm_crb tpm/tpm_crb: open code the crb_init into acpi_add tmp/tpm_crb: fix Intel PTT hw bug during idle state tpm/tpm_crb: implement tpm crb idle state tpm: add check for minimum buffer size in tpm_transmit() tpm: constify TPM 1.x header structures tpm/tpm_crb: fix the over 80 characters checkpatch warring tpm/tpm_crb: drop useless cpu_to_le32 when writing to registers tpm/tpm_crb: cache cmd_size register value. tmp/tpm_crb: drop include to platform_device tpm/tpm_tis: remove unused itpm variable tpm_crb: fix incorrect values of cmdReady and goIdle bits tpm_crb: refine the naming of constants tpm_crb: remove wmb()'s tpm_crb: fix crb_req_canceled behavior ...
| * security, overlayfs: Provide hook to correctly label newly created filesVivek Goyal2016-08-091-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | During a new file creation we need to make sure new file is created with the right label. New file is created in upper/ so effectively file should get label as if task had created file in upper/. We switched to mounter's creds for actual file creation. Also if there is a whiteout present, then file will be created in work/ dir first and then renamed in upper. In none of the cases file will be labeled as we want it to be. This patch introduces a new hook dentry_create_files_as(), which determines the label/context dentry will get if it had been created by task in upper and modify passed set of creds appropriately. Caller makes use of these new creds for file creation. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: fix whitespace issues found with checkpatch.pl] [PM: changes to use stat->mode in ovl_create_or_link()] Signed-off-by: Paul Moore <paul@paul-moore.com>
* | ovl: Switch to generic_getxattrAndreas Gruenbacher2016-09-011-1/+1
| | | | | | | | | | | | | | | | Now that overlayfs has xattr handlers for iop->{set,remove}xattr, use those same handlers for iop->getxattr as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: Switch to generic_removexattrAndreas Gruenbacher2016-09-011-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit d837a49bd57f ("ovl: fix POSIX ACL setting") switches from iop->setxattr from ovl_setxattr to generic_setxattr, so switch from ovl_removexattr to generic_removexattr as well. As far as permission checking goes, the same rules should apply in either case. While doing that, rename ovl_setxattr to ovl_xattr_set to indicate that this is not an iop->setxattr implementation and remove the unused inode argument. Move ovl_other_xattr_set above ovl_own_xattr_set so that they match the order of handlers in ovl_xattr_handlers. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: handle umask and posix_acl_default correctly on creationMiklos Szeredi2016-09-011-0/+54
|/ | | | | | | | | | | | | | | | | | | | | Setting MS_POSIXACL in sb->s_flags has the side effect of passing mode to create functions without masking against umask. Another problem when creating over a whiteout is that the default posix acl is not inherited from the parent dir (because the real parent dir at the time of creation is the work directory). Fix these problems by: a) If upper fs does not have MS_POSIXACL, then mask mode with umask. b) If creating over a whiteout, call posix_acl_create() to get the inherited acls. After creation (but before moving to the final destination) set these acls on the created file. posix_acl_create() also updates the file creation mode as appropriate. Fixes: 39a25b2b3762 ("ovl: define ->get_acl() for overlay inodes") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: simplify empty checkingMiklos Szeredi2016-07-291-29/+21Star
| | | | | | | | | | | | | | | The empty checking logic is duplicated in ovl_check_empty_and_clear() and ovl_remove_and_whiteout(), except the condition for clearing whiteouts is different: ovl_check_empty_and_clear() checked for being upper ovl_remove_and_whiteout() checked for merge OR lower Move the intersection of those checks (upper AND merge) into ovl_check_empty_and_clear() and simplify ovl_remove_and_whiteout(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: clear nlink on rmdirMiklos Szeredi2016-07-291-2/+6
| | | | | | To make delete notification work on fa/inotify. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix POSIX ACL settingMiklos Szeredi2016-07-291-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | Setting POSIX ACL needs special handling: 1) Some permission checks are done by ->setxattr() which now uses mounter's creds ("ovl: do operations on underlying file system in mounter's context"). These permission checks need to be done with current cred as well. 2) Setting ACL can fail for various reasons. We do not need to copy up in these cases. In the mean time switch to using generic_setxattr. [Arnd Bergmann] Fix link error without POSIX ACL. posix_acl_from_xattr() doesn't have a 'static inline' implementation when CONFIG_FS_POSIX_ACL is disabled, and I could not come up with an obvious way to do it. This instead avoids the link error by defining two sets of ACL operations and letting the compiler drop one of the two at compile time depending on CONFIG_FS_POSIX_ACL. This avoids all references to the ACL code, also leading to smaller code. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: share inode for hard linkMiklos Szeredi2016-07-291-35/+49
| | | | | | | | | | | | | | | | | | | Inode attributes are copied up to overlay inode (uid, gid, mode, atime, mtime, ctime) so generic code using these fields works correcty. If a hard link is created in overlayfs separate inodes are allocated for each link. If chmod/chown/etc. is performed on one of the links then the inode belonging to the other ones won't be updated. This patch attempts to fix this by sharing inodes for hard links. Use inode hash (with real inode pointer as a key) to make sure overlay inodes are shared for hard links on upper. Hard links on lower are still split (which is not user observable until the copy-up happens, see Documentation/filesystems/overlayfs.txt under "Non-standard behavior"). The inode is only inserted in the hash if it is non-directoy and upper. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: store real inode pointer in ->i_privateMiklos Szeredi2016-07-291-1/+2
| | | | | | | | | | | | | | | | To get from overlay inode to real inode we currently use 'struct ovl_entry', which has lifetime connected to overlay dentry. This is okay, since each overlay dentry had a new overlay inode allocated. Following patch will break that assumption, so need to leave out ovl_entry. This patch stores the real inode directly in i_private, with the lowest bit used to indicate whether the inode is upper or lower. Lifetime rules remain, using ovl_inode_real() must only be done while caller holds ref on overlay dentry (and hence on real dentry), or within RCU protected regions. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: update atime on upperMiklos Szeredi2016-07-291-0/+1
| | | | | | | | | | | | | | | | | Fix atime update logic in overlayfs. This patch adds an i_op->update_time() handler to overlayfs inodes. This forwards atime updates to the upper layer only. No atime updates are done on lower layers. Remove implicit atime updates to underlying files and directories with O_NOATIME. Remove explicit atime update in ovl_readlink(). Clear atime related mnt flags from cloned upper mount. This means atime updates are controlled purely by overlayfs mount options. Reported-by: Konstantin Khlebnikov <koct9i@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix sgid on directoryMiklos Szeredi2016-07-291-4/+27
| | | | | | | | | | | | | When creating directory in workdir, the group/sgid inheritance from the parent dir was omitted completely. Fix this by calling inode_init_owner() on overlay inode and using the resulting uid/gid/mode to create the file. Unfortunately the sgid bit can be stripped off due to umask, so need to reset the mode in this case in workdir before moving the directory in place. Reported-by: Eryu Guan <eguan@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: do operations on underlying file system in mounter's contextVivek Goyal2016-07-291-31/+29Star
| | | | | | | | | | | | Given we are now doing checks both on overlay inode as well underlying inode, we should be able to do checks and operations on underlying file system using mounter's context. So modify all operations to do checks/operations on underlying dentry/inode in the context of mounter. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: define ->get_acl() for overlay inodesVivek Goyal2016-07-291-0/+1
| | | | | | | | | | Now we are planning to do DAC permission checks on overlay inode itself. And to make it work, we will need to make sure we can get acls from underlying inode. So define ->get_acl() for overlay inodes and this in turn calls into underlying filesystem to get acls, if any. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move some common code in a functionVivek Goyal2016-07-291-8/+12
| | | | | | | | | ovl_create_upper() and ovl_create_over_whiteout() seem to be sharing some common code which can be moved into a separate function. No functionality change. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: verify upper dentry in ovl_remove_and_whiteout()Maxim Patlasov2016-07-221-30/+24Star
| | | | | | | | | | | | | | | | The upper dentry may become stale before we call ovl_lock_rename_workdir. For example, someone could (mistakenly or maliciously) manually unlink(2) it directly from upperdir. To ensure it is not stale, let's lookup it after ovl_lock_rename_workdir and and check if it matches the upper dentry. Essentially, it is the same problem and similar solution as in commit 11f3710417d0 ("ovl: verify upper dentry before unlink and rename"). Signed-off-by: Maxim Patlasov <mpatlasov@virtuozzo.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
* ovl: fix uid/gid when creating over whiteoutMiklos Szeredi2016-06-151-2/+11
| | | | | | | | | | | | | | | | | | | | Fix a regression when creating a file over a whiteout. The new file/directory needs to use the current fsuid/fsgid, not the ones from the mounter's credentials. The refcounting is a bit tricky: prepare_creds() sets an original refcount, override_creds() gets one more, which revert_cred() drops. So 1) we need to expicitly put the mounter's credentials when overriding with the updated one 2) we need to put the original ref to the updated creds (and this can safely be done before revert_creds(), since we'll still have the ref from override_creds()). Reported-by: Stephen Smalley <sds@tycho.nsa.gov> Fixes: 3fe6e52f0626 ("ovl: override creds with the ones from the superblock mounter") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: override creds with the ones from the superblock mounterAntonio Murdaca2016-05-271-62/+5Star
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In user namespace the whiteout creation fails with -EPERM because the current process isn't capable(CAP_SYS_ADMIN) when setting xattr. A simple reproducer: $ mkdir upper lower work merged lower/dir $ sudo mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged $ unshare -m -p -f -U -r bash Now as root in the user namespace: \# touch merged/dir/{1,2,3} # this will force a copy up of lower/dir \# rm -fR merged/* This ends up failing with -EPERM after the files in dir has been correctly deleted: unlinkat(4, "2", 0) = 0 unlinkat(4, "1", 0) = 0 unlinkat(4, "3", 0) = 0 close(4) = 0 unlinkat(AT_FDCWD, "merged/dir", AT_REMOVEDIR) = -1 EPERM (Operation not permitted) Interestingly, if you don't place files in merged/dir you can remove it, meaning if upper/dir does not exist, creating the char device file works properly in that same location. This patch uses ovl_sb_creator_cred() to get the cred struct from the superblock mounter and override the old cred with these new ones so that the whiteout creation is possible because overlay is wrong in assuming that the creds it will get with prepare_creds will be in the initial user namespace. The old cap_raise game is removed in favor of just overriding the old cred struct. This patch also drops from ovl_copy_up_one() the following two lines: override_cred->fsuid = stat->uid; override_cred->fsgid = stat->gid; This is because the correct uid and gid are taken directly with the stat struct and correctly set with ovl_set_attr(). Signed-off-by: Antonio Murdaca <runcom@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: cleanup unused var in rename2Miklos Szeredi2016-03-211-2/+0Star
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: verify upper dentry before unlink and renameMiklos Szeredi2016-03-211-21/+38
| | | | | | | | | | | | | Unlink and rename in overlayfs checked the upper dentry for staleness by verifying upper->d_parent against upperdir. However the dentry can go stale also by being unhashed, for example. Expand the verification to actually look up the name again (under parent lock) and check if it matches the upper dentry. This matches what the VFS does before passing the dentry to filesytem's unlink/rename methods, which excludes any inconsistency caused by overlayfs. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>