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* ovl: re-structure overlay lower layers in-memoryChandan Rajendra2017-11-091-1/+6
| | | | | | | | | | | | | | | | | | | | | | | Define new structures to represent overlay instance lower layers and overlay merge dir lower layers to make room for storing more per layer information in-memory. Instead of keeping the fs instance lower layers in an array of struct vfsmount, keep them in an array of new struct ovl_layer, that has a pointer to struct vfsmount. Instead of keeping the dentry lower layers in an array of struct path, keep them in an array of new struct ovl_path, that has a pointer to struct dentry and to struct ovl_layer. Add a small helper to find the fs layer id that correspopnds to a lower struct ovl_path and use it in ovl_lookup(). [amir: split re-structure from anonymous bdev patch] Signed-off-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move include of ovl_entry.h into overlayfs.hAmir Goldstein2017-11-091-1/+0
| | | | | | | | | | | | | Most overlayfs c files already explicitly include ovl_entry.h to use overlay entry struct definitions and upcoming changes are going to require even more c files to include this header. All overlayfs c files include overlayfs.h and overlayfs.h itself refers to some structs defined in ovl_entry.h, so it seems more logic to include ovl_entry.h from overlayfs.h than from c files. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: no direct iteration for dir with origin xattrAmir Goldstein2017-11-091-0/+13
| | | | | | | | | | | | | | | | If a non-merge dir in an overlay mount has an overlay.origin xattr, it means it was once an upper merge dir, which may contain whiteouts and then the lower dir was removed under it. Do not iterate real dir directly in this case to avoid exposing whiteouts. [SzM] Set OVL_WHITEOUT for all merge directories as well. [amir] A directory that was just copied up does not have the OVL_WHITEOUTS flag. We need to set it to fix merge dir iteration. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix missing unlock_rename() in ovl_do_copy_up()Amir Goldstein2017-10-051-0/+19
| | | | | | | | | | Use the ovl_lock_rename_workdir() helper which requires unlock_rename() only on lock success. Fixes: ("fd210b7d67ee ovl: move copy up lock out") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix dput() of ERR_PTR in ovl_cleanup_index()Amir Goldstein2017-10-051-1/+4
| | | | | | | Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: constant d_ino for non-merge dirsMiklos Szeredi2017-07-271-6/+18
| | | | | | | | | | | | | | | | | | | | | | Impure directories are ones which contain objects with origins (i.e. those that have been copied up). These are relevant to readdir operation only because of the d_ino field, no other transformation is necessary. Also a directory can become impure between two getdents(2) calls. This patch creates a cache for impure directories. Unlike the cache for merged directories, this one only contains entries with origin and is not refcounted but has a its lifetime tied to that of the dentry. Similarly to the merged cache, the impure cache is invalidated based on a version number. This version number is incremented when an entry with origin is added or removed from the directory. If the cache is empty, then the impure xattr is removed from the directory. This patch also fixes up handling of d_ino for the ".." entry if the parent directory is merged. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix xattr get and set with selinuxMiklos Szeredi2017-07-201-1/+6
| | | | | | | | | | | | | inode_doinit_with_dentry() in SELinux wants to read the upper inode's xattr to get security label, and ovl_xattr_get() calls ovl_dentry_real(), which depends on dentry->d_inode, but d_inode is null and not initialized yet at this point resulting in an Oops. Fix by getting the upperdentry info from the inode directly in this case. Reported-by: Eryu Guan <eguan@redhat.com> Fixes: 09d8b586731b ("ovl: move __upperdentry to ovl_inode") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: cleanup orphan index entriesAmir Goldstein2017-07-041-1/+65
| | | | | | | | | | | | | | | | | index entry should live only as long as there are upper or lower hardlinks. Cleanup orphan index entries on mount and when dropping the last overlay inode nlink. When about to cleanup or link up to orphan index and the index inode nlink > 1, admit that something went wrong and adjust overlay nlink to index inode nlink - 1 to prevent it from dropping below zero. This could happen when adding lower hardlinks underneath a mounted overlay and then trying to unlink them. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: persistent overlay inode nlink for indexed inodesAmir Goldstein2017-07-041-0/+66
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With inodes index enabled, an overlay inode nlink counts the union of upper and non-covered lower hardlinks. During the lifetime of a non-pure upper inode, the following nlink modifying operations can happen: 1. Lower hardlink copy up 2. Upper hardlink created, unlinked or renamed over 3. Lower hardlink whiteout or renamed over For the first, copy up case, the union nlink does not change, whether the operation succeeds or fails, but the upper inode nlink may change. Therefore, before copy up, we store the union nlink value relative to the lower inode nlink in the index inode xattr trusted.overlay.nlink. For the second, upper hardlink case, the union nlink should be incremented or decremented IFF the operation succeeds, aligned with nlink change of the upper inode. Therefore, before link/unlink/rename, we store the union nlink value relative to the upper inode nlink in the index inode. For the last, lower cover up case, we simplify things by preceding the whiteout or cover up with copy up. This makes sure that there is an index upper inode where the nlink xattr can be stored before the copied up upper entry is unlink. Return the overlay inode nlinks for indexed upper inodes on stat(2). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: implement index dir copy upAmir Goldstein2017-07-041-1/+1
| | | | | | | | | | | | | | | | | | | | | Implement a copy up method for non-dir objects using index dir to prevent breaking lower hardlinks on copy up. This method requires that the inodes index dir feature was enabled and that all underlying fs support file handle encoding/decoding. On the first lower hardlink copy up, upper file is created in index dir, named after the hex representation of the lower origin inode file handle. On the second lower hardlink copy up, upper file is found in index dir, by the same lower handle key. On either case, the upper indexed inode is then linked to the copy up upper path. The index entry remains linked for future lower hardlink copy up and for lower to upper inode map, that is needed for exporting overlayfs to NFS. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: add flag for upper in ovl_entryMiklos Szeredi2017-07-041-0/+19
| | | | | | | | For rename, we need to ensure that an upper alias exists for hard links before attempting the operation. Introduce a flag in ovl_entry to track the state of the upper alias. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: defer upper dir lock to tempfile linkAmir Goldstein2017-07-041-1/+0
| | | | | | | | On copy up of regular file using an O_TMPFILE, lock upper dir only before linking the tempfile in place. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: hash overlay non-dir inodes by copy up originMiklos Szeredi2017-07-041-2/+1
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: introduce the inodes index dir featureAmir Goldstein2017-07-041-0/+15
| | | | | | | | | | | | | | | Create the index dir on mount. The index dir will contain hardlinks to upper inodes, named after the hex representation of their origin lower inodes. The index dir is going to be used to prevent breaking lower hardlinks on copy up and to implement overlayfs NFS export. Because the feature is not fully backward compat, enabling the feature is opt-in by config/module/mount option. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* vfs: introduce inode 'inuse' lockAmir Goldstein2017-07-041-0/+31
| | | | | | | | | | | | | | Added an i_state flag I_INUSE and helpers to set/clear/test the bit. The 'inuse' lock is an 'advisory' inode lock, that can be used to extend exclusive create protection beyond parent->i_mutex lock among cooperating users. This is going to be used by overlayfs to get exclusive ownership on upper and work dirs among overlayfs mounts. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move cache and version to ovl_inodeMiklos Szeredi2017-07-041-12/+8
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use ovl_inode mutex to synchronize concurrent copy upAmir Goldstein2017-07-041-17/+6
| | | | | | | | | | | | Use the new ovl_inode mutex to synchonize concurrent copy up instead of the super block copy up workqueue. Moving the synchronization object from the overlay dentry to the overlay inode is needed for synchonizing concurrent copy up of lower hardlinks to the same upper inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move impure to ovl_inodeMiklos Szeredi2017-07-041-10/+12
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move redirect to ovl_inodeMiklos Szeredi2017-07-041-6/+4
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: move __upperdentry to ovl_inodeMiklos Szeredi2017-07-041-57/+32
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use i_private only as a keyMiklos Szeredi2017-07-041-6/+29
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: simplify getting inodeMiklos Szeredi2017-07-041-1/+6
| | | | Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: mark upper merge dir with type origin entries "impure"Amir Goldstein2017-05-291-7/+35
| | | | | | | | | | | | | | | | | | | | 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/+14
| | | | | | | | | | | | | 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: handle rename when upper doesn't support xattrAmir Goldstein2017-05-191-8/+1
| | | | | | | | | | | | | | 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: check on mount time if upper fs supports setting xattrAmir Goldstein2017-05-181-0/+21
| | | | | | | | | | | xattr are needed by overlayfs for setting opaque dir, redirect dir and copy up origin. Check at mount time by trying to set the overlay.opaque xattr on the workdir and if that fails issue a warning message. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge branch 'overlayfs-linus' of ↵Linus Torvalds2017-05-101-5/+14
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: "The biggest part of this is making st_dev/st_ino on the overlay behave like a normal filesystem (i.e. st_ino doesn't change on copy up, st_dev is the same for all files and directories). Currently this only works if all layers are on the same filesystem, but future work will move the general case towards more sane behavior. There are also miscellaneous fixes, including fixes to handling append-only files. There's a small change in the VFS, but that only has an effect on overlayfs, since otherwise file->f_path.dentry->inode and file_inode(file) are always the same" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: update documentation w.r.t. constant inode numbers ovl: persistent inode numbers for upper hardlinks ovl: merge getattr for dir and nondir ovl: constant st_ino/st_dev across copy up ovl: persistent inode number for directories ovl: set the ORIGIN type flag ovl: lookup non-dir copy-up-origin by file handle ovl: use an auxiliary var for overlay root entry ovl: store file handle of lower inode on copy up ovl: check if all layers are on the same fs ovl: do not set overlay.opaque on non-dir create ovl: check IS_APPEND() on real upper inode vfs: ftruncate check IS_APPEND() on real upper inode ovl: Use designated initializers ovl: lockdep annotate of nested stacked overlayfs inode lock
| * ovl: set the ORIGIN type flagAmir Goldstein2017-05-051-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | For directory entries, non zero oe->numlower implies OVL_TYPE_MERGE. Define a new type flag OVL_TYPE_ORIGIN to indicate that an entry holds a reference to its lower copy up origin. For directory entries ORIGIN := MERGE && UPPER. For non-dir entries ORIGIN means that a lower type dentry has been recently copied up or that we were able to find the copy up origin from overlay.origin xattr. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: check if all layers are on the same fsAmir Goldstein2017-05-051-0/+7
| | | | | | | | | | | | | | | | | | | | | | Some features can only work when all layers are on the same fs. Test this condition during mount time, so features can check them later. Add helper ovl_same_sb() to return the common super block in case all layers are on the same fs. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: Use designated initializersKees Cook2017-04-201-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Prepare to mark sensitive kernel structures for randomization by making sure they're using designated initializers. These were identified during allyesconfig builds of x86, arm, and arm64, with most initializer fixes extracted from grsecurity. For these cases, use { }, which will be zero-filled, instead of undesignated NULLs. Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | overlayfs: remove now unnecessary header file includeLinus Torvalds2017-03-081-1/+0
|/ | | | | | | | | | | | This removes the extra include header file that was added in commit e58bc927835a "Pull overlayfs updates from Miklos Szeredi" now that it is no longer needed. There are probably other such includes that got added during the scheduler header splitup series, but this is the one that annoyed me personally and I know about. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'overlayfs-linus' of ↵Linus Torvalds2017-03-031-0/+31
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "Because copy up can take a long time, serialized copy ups could be a big performance bottleneck. This update allows concurrent copy up of regular files eliminating this potential problem. There are also minor fixes" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: drop CAP_SYS_RESOURCE from saved mounter's credentials ovl: properly implement sync_filesystem() ovl: concurrent copy up of regular files ovl: introduce copy up waitqueue ovl: copy up regular file using O_TMPFILE ovl: rearrange code in ovl_copy_up_locked() ovl: check if upperdir fs supports O_TMPFILE
| * ovl: introduce copy up waitqueueAmir Goldstein2017-02-071-0/+30
| | | | | | | | | | | | | | | | | | | | The overlay sb 'copyup_wq' and overlay inode 'copying' condition variable are about to replace the upper sb rename_lock, as finer grained synchronization objects for concurrent copy up. Suggested-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | sched/headers: Prepare to remove <linux/cred.h> inclusion from <linux/sched.h>Ingo Molnar2017-03-021-0/+1
|/ | | | | | | | | | | | | | | | Add #include <linux/cred.h> dependencies to all .c files rely on sched.h doing that for them. Note that even if the count where we need to add extra headers seems high, it's still a net win, because <linux/sched.h> is included in over 2,200 files ... Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
* ovl: opaque cleanupMiklos Szeredi2016-12-161-2/+3
| | | | | | | | | | | | | | 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: redirect on rename-dirMiklos Szeredi2016-12-161-0/+29
| | | | | | | | | | | | | | | | 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: split super.cMiklos Szeredi2016-12-161-0/+235
fs/overlayfs/super.c is the biggest of the overlayfs source files and it contains various utility functions as well as the rather complicated lookup code. Split these parts out to separate files. Before: 1446 fs/overlayfs/super.c After: 919 fs/overlayfs/super.c 267 fs/overlayfs/namei.c 235 fs/overlayfs/util.c 51 fs/overlayfs/ovl_entry.h Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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