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2018-04-19ovl: fix lookup with middle layer opaque dir and absolute path redirectsAmir Goldstein
commit 3ec9b3fafcaf441cc4d46b9742cd6ec0c79f8df0 upstream. As of now if we encounter an opaque dir while looking for a dentry, we set d->last=true. This means that there is no need to look further in any of the lower layers. This works fine as long as there are no redirets or relative redircts. But what if there is an absolute redirect on the children dentry of opaque directory. We still need to continue to look into next lower layer. This patch fixes it. Here is an example to demonstrate the issue. Say you have following setup. upper: /redirect (redirect=/a/b/c) lower1: /a/[b]/c ([b] is opaque) (c has absolute redirect=/a/b/d/) lower0: /a/b/d/foo Now "redirect" dir should merge with lower1:/a/b/c/ and lower0:/a/b/d. Note, despite the fact lower1:/a/[b] is opaque, we need to continue to look into lower0 because children c has an absolute redirect. Following is a reproducer. Watch me make foo disappear: $ mkdir lower middle upper work work2 merged $ mkdir lower/origin $ touch lower/origin/foo $ mount -t overlay none merged/ \ -olowerdir=lower,upperdir=middle,workdir=work2 $ mkdir merged/pure $ mv merged/origin merged/pure/redirect $ umount merged $ mount -t overlay none merged/ \ -olowerdir=middle:lower,upperdir=upper,workdir=work $ mv merged/pure/redirect merged/redirect Now you see foo inside a twice redirected merged dir: $ ls merged/redirect foo $ umount merged $ mount -t overlay none merged/ \ -olowerdir=middle:lower,upperdir=upper,workdir=work After mount cycle you don't see foo inside the same dir: $ ls merged/redirect During middle layer lookup, the opaqueness of middle/pure is left in the lookup state and then middle/pure/redirect is wrongly treated as opaque. Fixes: 02b69b284cd7 ("ovl: lookup redirects") Cc: <stable@vger.kernel.org> #v4.10 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-22ovl: hash directory inodes for fsnotifyAmir Goldstein
commit 31747eda41ef3c30c09c5c096b380bf54013746a upstream. fsnotify pins a watched directory inode in cache, but if directory dentry is released, new lookup will allocate a new dentry and a new inode. Directory events will be notified on the new inode, while fsnotify listener is watching the old pinned inode. Hash all directory inodes to reuse the pinned inode on lookup. Pure upper dirs are hashes by real upper inode, merge and lower dirs are hashed by real lower inode. The reference to lower inode was being held by the lower dentry object in the overlay dentry (oe->lowerstack[0]). Releasing the overlay dentry may drop lower inode refcount to zero. Add a refcount on behalf of the overlay inode to prevent that. As a by-product, hashing directory inodes also detects multiple redirected dirs to the same lower dir and uncovered redirected dir target on and returns -ESTALE on lookup. The reported issue dates back to initial version of overlayfs, but this patch depends on ovl_inode code that was introduced in kernel v4.13. Cc: <stable@vger.kernel.org> #v4.13 Reported-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Niklas Cassel <niklas.cassel@axis.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16ovl: take mnt_want_write() for removing impure xattrAmir Goldstein
commit a5a927a7c82e28ea76599dee4019c41e372c911f upstream. The optimization in ovl_cache_get_impure() that tries to remove an unneeded "impure" xattr needs to take mnt_want_write() on upper fs. Fixes: 4edb83bb1041 ("ovl: constant d_ino for non-merge dirs") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-02-16ovl: fix failure to fsync lower dirAmir Goldstein
commit d796e77f1dd541fe34481af2eee6454688d13982 upstream. As a writable mount, it is not expected for overlayfs to return EINVAL/EROFS for fsync, even if dir/file is not changed. This commit fixes the case of fsync of directory, which is easier to address, because overlayfs already implements fsync file operation for directories. The problem reported by Raphael is that new PostgreSQL 10.0 with a database in overlayfs where lower layer in squashfs fails to start. The failure is due to fsync error, when PostgreSQL does fsync on all existing db directories on startup and a specific directory exists lower layer with no changes. Reported-by: Raphael Hertzog <raphael@ouaza.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Raphaël Hertzog <hertzog@debian.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-25locking/barriers: Convert users of lockless_dereference() to READ_ONCE()Will Deacon
commit 3382290ed2d5e275429cef510ab21889d3ccd164 upstream. [ Note, this is a Git cherry-pick of the following commit: 506458efaf15 ("locking/barriers: Convert users of lockless_dereference() to READ_ONCE()") ... for easier x86 PTI code testing and back-porting. ] READ_ONCE() now has an implicit smp_read_barrier_depends() call, so it can be used instead of lockless_dereference() without any change in semantics. Signed-off-by: Will Deacon <will.deacon@arm.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1508840570-22169-4-git-send-email-will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-20ovl: update ctx->pos on impure dir iterationAmir Goldstein
commit b02a16e6413a2f782e542ef60bad9ff6bf212f8a upstream. This fixes a regression with readdir of impure dir in overlayfs that is shared to VM via 9p fs. Reported-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com> Fixes: 4edb83bb1041 ("ovl: constant d_ino for non-merge dirs") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Miguel Bernal Marin <miguel.bernal.marin@linux.intel.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-12-20ovl: Pass ovl_get_nlink() parameters in right orderVivek Goyal
commit 08d8f8a5b094b66b29936e8751b4a818b8db1207 upstream. Right now we seem to be passing index as "lowerdentry" and origin.dentry as "upperdentry". IIUC, we should pass these parameters in reversed order and this looks like a bug. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Amir Goldstein <amir73il@gmail.com> Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-30ovl: Put upperdentry if ovl_check_origin() failsVivek Goyal
commit 5455f92b54e516995a9ca45bbf790d3629c27a93 upstream. If ovl_check_origin() fails, we should put upperdentry. We have a reference on it by now. So goto out_put_upper instead of out. Fixes: a9d019573e88 ("ovl: lookup non-dir copy-up-origin by file handle") Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-10-24ovl: do not cleanup unsupported index entriesAmir Goldstein
With index=on, ovl_indexdir_cleanup() tries to cleanup invalid index entries (e.g. bad index name). This behavior could result in cleaning of entries created by newer kernels and is therefore undesirable. Instead, abort mount if such entries are encountered. We still cleanup 'stale' entries and 'orphan' entries, both those cases can be a result of offline changes to lower and upper dirs. When encoutering an index entry of type directory or whiteout, kernel was supposed to fallback to read-only mount, but the fill_super() operation returns EROFS in this case instead of returning success with read-only mount flag, so mount fails when encoutering directory or whiteout index entries. Bless this behavior by returning -EINVAL on directory and whiteout index entries as we do for all unsupported index entries. Fixes: 61b674710cd9 ("ovl: do not cleanup directory and whiteout index..") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-10-24ovl: handle ENOENT on index lookupAmir Goldstein
Treat ENOENT from index entry lookup the same way as treating a returned negative dentry. Apparently, either could be returned if file is not found, depending on the underlying file system. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-10-24ovl: fix EIO from lookup of non-indexed upperAmir Goldstein
Commit fbaf94ee3cd5 ("ovl: don't set origin on broken lower hardlink") attempt to avoid the condition of non-indexed upper inode with lower hardlink as origin. If this condition is found, lookup returns EIO. The protection of commit mentioned above does not cover the case of lower that is not a hardlink when it is copied up (with either index=off/on) and then lower is hardlinked while overlay is offline. Changes to lower layer while overlayfs is offline should not result in unexpected behavior, so a permanent EIO error after creating a link in lower layer should not be considered as correct behavior. This fix replaces EIO error with success in cases where upper has origin but no index is found, or index is found that does not match upper inode. In those cases, lookup will not fail and the returned overlay inode will be hashed by upper inode instead of by lower origin inode. Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-19ovl: Return -ENOMEM if an allocation fails ovl_lookup()Dan Carpenter
The error code is missing here so it means we return ERR_PTR(0) or NULL. The other error paths all return an error code so this probably should as well. Fixes: 02b69b284cd7 ("ovl: lookup redirects") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-19ovl: add NULL check in ovl_alloc_inodeHirofumi Nakagawa
This was detected by fault injection test Signed-off-by: Hirofumi Nakagawa <nklabs@gmail.com> Fixes: 13cf199d0088 ("ovl: allocate an ovl_inode struct") Cc: <stable@vger.kernel.org> # v4.13
2017-10-05ovl: fix regression caused by exclusive upper/work dir protectionAmir Goldstein
Enforcing exclusive ownership on upper/work dirs caused a docker regression: https://github.com/moby/moby/issues/34672. Euan spotted the regression and pointed to the offending commit. Vivek has brought the regression to my attention and provided this reproducer: Terminal 1: mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ Terminal 2: unshare -m Terminal 1: umount merged mount -t overlay -o workdir=work,lowerdir=lower,upperdir=upper none merged/ mount: /root/overlay-testing/merged: none already mounted or mount point busy To fix the regression, I replaced the error with an alarming warning. With index feature enabled, mount does fail, but logs a suggestion to override exclusive dir protection by disabling index. Note that index=off mount does take the inuse locks, so a concurrent index=off will issue the warning and a concurrent index=on mount will fail. Documentation was updated to reflect this change. Fixes: 2cac0c00a6cd ("ovl: get exclusive ownership on upper/work dirs") Cc: <stable@vger.kernel.org> # v4.13 Reported-by: Euan Kemp <euank@euank.com> Reported-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-05ovl: fix missing unlock_rename() in ovl_do_copy_up()Amir Goldstein
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>
2017-10-05ovl: fix dentry leak in ovl_indexdir_cleanup()Amir Goldstein
index dentry was not released when breaking out of the loop due to index verification error. Fixes: 415543d5c64f ("ovl: cleanup bad and stale index entries on mount") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-10-05ovl: fix dput() of ERR_PTR in ovl_cleanup_index()Amir Goldstein
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>
2017-10-05ovl: fix error value printed in ovl_lookup_index()Amir Goldstein
Fixes: 359f392ca53e ("ovl: lookup index entry for copy up origin") Cc: <stable@vger.kernel.org> # v4.13 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-14Merge branch 'work.mount' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\<MS_RDONLY\>/SB_RDONLY/g' \ -e 's/\<MS_NOSUID\>/SB_NOSUID/g' \ -e 's/\<MS_NODEV\>/SB_NODEV/g' \ -e 's/\<MS_NOEXEC\>/SB_NOEXEC/g' \ -e 's/\<MS_SYNCHRONOUS\>/SB_SYNCHRONOUS/g' \ -e 's/\<MS_MANDLOCK\>/SB_MANDLOCK/g' \ -e 's/\<MS_DIRSYNC\>/SB_DIRSYNC/g' \ -e 's/\<MS_NOATIME\>/SB_NOATIME/g' \ -e 's/\<MS_NODIRATIME\>/SB_NODIRATIME/g' \ -e 's/\<MS_SILENT\>/SB_SILENT/g' \ -e 's/\<MS_POSIXACL\>/SB_POSIXACL/g' \ -e 's/\<MS_KERNMOUNT\>/SB_KERNMOUNT/g' \ -e 's/\<MS_I_VERSION\>/SB_I_VERSION/g' \ -e 's/\<MS_LAZYTIME\>/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags
2017-09-13mm: treewide: remove GFP_TEMPORARY allocation flagMichal Hocko
GFP_TEMPORARY was introduced by commit e12ba74d8ff3 ("Group short-lived and reclaimable kernel allocations") along with __GFP_RECLAIMABLE. It's primary motivation was to allow users to tell that an allocation is short lived and so the allocator can try to place such allocations close together and prevent long term fragmentation. As much as this sounds like a reasonable semantic it becomes much less clear when to use the highlevel GFP_TEMPORARY allocation flag. How long is temporary? Can the context holding that memory sleep? Can it take locks? It seems there is no good answer for those questions. The current implementation of GFP_TEMPORARY is basically GFP_KERNEL | __GFP_RECLAIMABLE which in itself is tricky because basically none of the existing caller provide a way to reclaim the allocated memory. So this is rather misleading and hard to evaluate for any benefits. I have checked some random users and none of them has added the flag with a specific justification. I suspect most of them just copied from other existing users and others just thought it might be a good idea to use without any measuring. This suggests that GFP_TEMPORARY just motivates for cargo cult usage without any reasoning. I believe that our gfp flags are quite complex already and especially those with highlevel semantic should be clearly defined to prevent from confusion and abuse. Therefore I propose dropping GFP_TEMPORARY and replace all existing users to simply use GFP_KERNEL. Please note that SLAB users with shrinkers will still get __GFP_RECLAIMABLE heuristic and so they will be placed properly for memory fragmentation prevention. I can see reasons we might want some gfp flag to reflect shorterm allocations but I propose starting from a clear semantic definition and only then add users with proper justification. This was been brought up before LSF this year by Matthew [1] and it turned out that GFP_TEMPORARY really doesn't have a clear semantic. It seems to be a heuristic without any measured advantage for most (if not all) its current users. The follow up discussion has revealed that opinions on what might be temporary allocation differ a lot between developers. So rather than trying to tweak existing users into a semantic which they haven't expected I propose to simply remove the flag and start from scratch if we really need a semantic for short term allocations. [1] http://lkml.kernel.org/r/20170118054945.GD18349@bombadil.infradead.org [akpm@linux-foundation.org: fix typo] [akpm@linux-foundation.org: coding-style fixes] [sfr@canb.auug.org.au: drm/i915: fix up] Link: http://lkml.kernel.org/r/20170816144703.378d4f4d@canb.auug.org.au Link: http://lkml.kernel.org/r/20170728091904.14627-1-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Mel Gorman <mgorman@suse.de> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Matthew Wilcox <willy@infradead.org> Cc: Neil Brown <neilb@suse.de> Cc: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-09-13Merge branch 'overlayfs-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This fixes d_ino correctness in readdir, which brings overlayfs on par with normal filesystems regarding inode number semantics, as long as all layers are on the same filesystem. There are also some bug fixes, one in particular (random ioctl's shouldn't be able to modify lower layers) that touches some vfs code, but of course no-op for non-overlay fs" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: fix false positive ESTALE on lookup ovl: don't allow writing ioctl on lower layer ovl: fix relatime for directories vfs: add flags to d_real() ovl: cleanup d_real for negative ovl: constant d_ino for non-merge dirs ovl: constant d_ino across copy up ovl: fix readdir error value ovl: check snprintf return
2017-09-12ovl: fix false positive ESTALE on lookupAmir Goldstein
Commit b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up origin") verifies that the origin lower inode stored in the overlayfs inode matched the inode of a copy up origin dentry found by lookup. There is a false positive result in that check when lower fs does not support file handles and copy up origin cannot be followed by file handle at lookup time. The false negative happens when finding an overlay inode in cache on a copied up overlay dentry lookup. The overlay inode still 'remembers' the copy up origin inode, but the copy up origin dentry is not available for verification. Relax the check in case copy up origin dentry is not available. Fixes: b9ac5c274b8c ("ovl: hash overlay non-dir inodes by copy up...") Cc: <stable@vger.kernel.org> # v4.13 Reported-by: Jordi Pujol <jordipujolp@gmail.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-05ovl: fix relatime for directoriesMiklos Szeredi
Need to treat non-regular overlayfs files the same as regular files when checking for an atime update. Add a d_real() flag to make it return the upper dentry for all file types. Reported-by: "zhangyi (F)" <yi.zhang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-04vfs: add flags to d_real()Miklos Szeredi
Add a separate flags argument (in addition to the open flags) to control the behavior of d_real(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-09-04ovl: cleanup d_real for negativeMiklos Szeredi
d_real() is never called with a negative dentry. So remove the d_is_negative() check (which would never trigger anyway, since d_is_reg() returns false for a negative dentry). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-08-10overlayfs, locking: Remove smp_mb__before_spinlock() usagePeter Zijlstra
While we could replace the smp_mb__before_spinlock() with the new smp_mb__after_spinlock(), the normal pattern is to use smp_store_release() to publish an object that is used for lockless_dereference() -- and mirrors the regular rcu_assign_pointer() / rcu_dereference() patterns. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-07-27ovl: constant d_ino for non-merge dirsMiklos Szeredi
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>
2017-07-27ovl: constant d_ino across copy upAmir Goldstein
When all layers are on the same fs, and iterating a directory which may contain copy up entries, call vfs_getattr() on the overlay entries to make sure that d_ino will be consistent with st_ino from stat(2). There is an overhead of lookup per upper entry in readdir. The overhead is minimal if the iterated entries are already in dcache. It is also quite useful for the common case of 'ls -l' that readdir() pre populates the dcache with the listed entries, making the following stat() calls faster. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-27ovl: fix readdir error valueMiklos Szeredi
actor's return value is taken as a bool (filled/not filled) so we need to return the error in the context. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-27ovl: check snprintf returnMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-20ovl: check for bad and whiteout index on lookupAmir Goldstein
Index should always be of the same file type as origin, except for the case of a whiteout index. A whiteout index should only exist if all lower aliases have been unlinked, which means that finding a lower origin on lookup whose index is a whiteout should be treated as a lookup error. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-20ovl: do not cleanup directory and whiteout index entriesAmir Goldstein
Directory index entries are going to be used for looking up redirected upper dirs by lower dir fh when decoding an overlay file handle of a merge dir. Whiteout index entries are going to be used as an indication that an exported overlay file handle should be treated as stale (i.e. after unlink of the overlay inode). We don't know the verification rules for directory and whiteout index entries, because they have not been implemented yet, so fail to mount overlay rw if those entries are found to avoid corrupting an index that was created by a newer kernel. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-20ovl: fix xattr get and set with selinuxMiklos Szeredi
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>
2017-07-17VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)David Howells
Firstly by applying the following with coccinelle's spatch: @@ expression SB; @@ -SB->s_flags & MS_RDONLY +sb_rdonly(SB) to effect the conversion to sb_rdonly(sb), then by applying: @@ expression A, SB; @@ ( -(!sb_rdonly(SB)) && A +!sb_rdonly(SB) && A | -A != (sb_rdonly(SB)) +A != sb_rdonly(SB) | -A == (sb_rdonly(SB)) +A == sb_rdonly(SB) | -!(sb_rdonly(SB)) +!sb_rdonly(SB) | -A && (sb_rdonly(SB)) +A && sb_rdonly(SB) | -A || (sb_rdonly(SB)) +A || sb_rdonly(SB) | -(sb_rdonly(SB)) != A +sb_rdonly(SB) != A | -(sb_rdonly(SB)) == A +sb_rdonly(SB) == A | -(sb_rdonly(SB)) && A +sb_rdonly(SB) && A | -(sb_rdonly(SB)) || A +sb_rdonly(SB) || A ) @@ expression A, B, SB; @@ ( -(sb_rdonly(SB)) ? 1 : 0 +sb_rdonly(SB) | -(sb_rdonly(SB)) ? A : B +sb_rdonly(SB) ? A : B ) to remove left over excess bracketage and finally by applying: @@ expression A, SB; @@ ( -(A & MS_RDONLY) != sb_rdonly(SB) +(bool)(A & MS_RDONLY) != sb_rdonly(SB) | -(A & MS_RDONLY) == sb_rdonly(SB) +(bool)(A & MS_RDONLY) == sb_rdonly(SB) ) to make comparisons against the result of sb_rdonly() (which is a bool) work correctly. Signed-off-by: David Howells <dhowells@redhat.com>
2017-07-13ovl: remove unneeded check for IS_ERR()Amir Goldstein
ovl_workdir_create() returns a valid index dentry or NULL. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: fix origin verification of index dirAmir Goldstein
Commit 54fb347e836f ("ovl: verify index dir matches upper dir") introduced a new ovl_fh flag OVL_FH_FLAG_PATH_UPPER to indicate an upper file handle, but forgot to add the flag to the mask of valid flags, so index dir origin verification always discards existing origin and stores a new one. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: mark parent impure on ovl_link()Amir Goldstein
When linking a file with copy up origin into a new parent, mark the new parent dir "impure". Fixes: ee1d6d37b6b8 ("ovl: mark upper dir with type origin entries "impure"") Cc: <stable@vger.kernel.org> # v4.12 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-13ovl: fix random return value on mountAmir Goldstein
On failure to prepare_creds(), mount fails with a random return value, as err was last set to an integer cast of a valid lower mnt pointer or set to 0 if inodes index feature is enabled. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Fixes: 3fe6e52f0626 ("ovl: override creds with the ones from ...") Cc: <stable@vger.kernel.org> # v4.7 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: mark parent impure and restore timestamp on ovl_link_up()Amir Goldstein
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
2017-07-04ovl: cleanup orphan index entriesAmir Goldstein
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>
2017-07-04ovl: persistent overlay inode nlink for indexed inodesAmir Goldstein
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>
2017-07-04ovl: implement index dir copy upAmir Goldstein
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>
2017-07-04ovl: move copy up lock outMiklos Szeredi
Move ovl_copy_up_start()/ovl_copy_up_end() out so that it's used for both tempfile and workdir copy ups. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: rearrange copy upMiklos Szeredi
Split up and rearrange copy up functions to make them better readable. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: add flag for upper in ovl_entryMiklos Szeredi
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>
2017-07-04ovl: use struct copy_up_ctx as function argumentMiklos Szeredi
This cleans up functions with too many arguments. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: base tmpfile in workdir tooMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: factor out ovl_copy_up_inode() helperAmir Goldstein
Factor out helper for copying lower inode data and metadata to temp upper inode, that is common to copy up using O_TMPFILE and workdir. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: extract helper to get temp file in copy upMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2017-07-04ovl: defer upper dir lock to tempfile linkAmir Goldstein
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>
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