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2015-11-09ovl: fix dentry reference leakDavid Howells
commit ab79efab0a0ba01a74df782eb7fa44b044dae8b5 upstream. In ovl_copy_up_locked(), newdentry is leaked if the function exits through out_cleanup as this just to out after calling ovl_cleanup() - which doesn't actually release the ref on newdentry. The out_cleanup segment should instead exit through out2 as certainly newdentry leaks - and possibly upper does also, though this isn't caught given the catch of newdentry. Without this fix, something like the following is seen: BUG: Dentry ffff880023e9eb20{i=f861,n=#ffff880023e82d90} still in use (1) [unmount of tmpfs tmpfs] BUG: Dentry ffff880023ece640{i=0,n=bigfile} still in use (1) [unmount of tmpfs tmpfs] when unmounting the upper layer after an error occurred in copyup. An error can be induced by creating a big file in a lower layer with something like: dd if=/dev/zero of=/lower/a/bigfile bs=65536 count=1 seek=$((0xf000)) to create a large file (4.1G). Overlay an upper layer that is too small (on tmpfs might do) and then induce a copy up by opening it writably. Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-09ovl: use O_LARGEFILE in ovl_copy_up()David Howells
commit 0480334fa60488d12ae101a02d7d9e1a3d03d7dd upstream. Open the lower file with O_LARGEFILE in ovl_copy_up(). Pass O_LARGEFILE unconditionally in ovl_copy_up_data() as it's purely for catching 32-bit userspace dealing with a file large enough that it'll be mishandled if the application isn't aware that there might be an integer overflow. Inside the kernel, there shouldn't be any problems. Reported-by: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-09ovl: free lower_mnt array in ovl_put_superKonstantin Khlebnikov
commit 5ffdbe8bf1e485026e1c7e4714d2841553cf0b40 upstream. This fixes memory leak after umount. Kmemleak report: unreferenced object 0xffff8800ba791010 (size 8): comm "mount", pid 2394, jiffies 4294996294 (age 53.920s) hex dump (first 8 bytes): 20 1c 13 02 00 88 ff ff ....... backtrace: [<ffffffff811f8cd4>] create_object+0x124/0x2c0 [<ffffffff817a059b>] kmemleak_alloc+0x7b/0xc0 [<ffffffff811dffe6>] __kmalloc+0x106/0x340 [<ffffffffa0152bfc>] ovl_fill_super+0x55c/0x9b0 [overlay] [<ffffffff81200ac4>] mount_nodev+0x54/0xa0 [<ffffffffa0152118>] ovl_mount+0x18/0x20 [overlay] [<ffffffff81201ab3>] mount_fs+0x43/0x170 [<ffffffff81220d34>] vfs_kern_mount+0x74/0x170 [<ffffffff812233ad>] do_mount+0x22d/0xdf0 [<ffffffff812242cb>] SyS_mount+0x7b/0xc0 [<ffffffff817b6bee>] entry_SYSCALL_64_fastpath+0x12/0x76 [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Fixes: dd662667e6d3 ("ovl: add mutli-layer infrastructure") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-11-09ovl: free stack of paths in ovl_fill_superKonstantin Khlebnikov
commit 0f95502ad84874b3c05fc7cdd9d4d9d5cddf7859 upstream. This fixes small memory leak after mount. Kmemleak report: unreferenced object 0xffff88003683fe00 (size 16): comm "mount", pid 2029, jiffies 4294909563 (age 33.380s) hex dump (first 16 bytes): 20 27 1f bb 00 88 ff ff 40 4b 0f 36 02 88 ff ff '......@K.6.... backtrace: [<ffffffff811f8cd4>] create_object+0x124/0x2c0 [<ffffffff817a059b>] kmemleak_alloc+0x7b/0xc0 [<ffffffff811dffe6>] __kmalloc+0x106/0x340 [<ffffffffa01b7a29>] ovl_fill_super+0x389/0x9a0 [overlay] [<ffffffff81200ac4>] mount_nodev+0x54/0xa0 [<ffffffffa01b7118>] ovl_mount+0x18/0x20 [overlay] [<ffffffff81201ab3>] mount_fs+0x43/0x170 [<ffffffff81220d34>] vfs_kern_mount+0x74/0x170 [<ffffffff812233ad>] do_mount+0x22d/0xdf0 [<ffffffff812242cb>] SyS_mount+0x7b/0xc0 [<ffffffff817b6bee>] entry_SYSCALL_64_fastpath+0x12/0x76 [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Miklos Szeredi <miklos@szeredi.hu> Fixes: a78d9f0d5d5c ("ovl: support multiple lower layers") Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-22fix a braino in ovl_d_select_inode()Al Viro
commit 9391dd00d13c853ab4f2a85435288ae2202e0e43 upstream. when opening a directory we want the overlayfs inode, not one from the topmost layer. Reported-By: Andrey Jr. Melnikov <temnota.am@gmail.com> Tested-By: Andrey Jr. Melnikov <temnota.am@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: "Kamata, Munehisa" <kamatam@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-22overlayfs: Make f_path always point to the overlay and f_inode to the underlayDavid Howells
commit 4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01 upstream. Make file->f_path always point to the overlay dentry so that the path in /proc/pid/fd is correct and to ensure that label-based LSMs have access to the overlay as well as the underlay (path-based LSMs probably don't need it). Using my union testsuite to set things up, before the patch I see: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:38 5 -> /a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 13381 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 13381 Links: 1 ... After the patch: [root@andromeda union-testsuite]# bash 5</mnt/a/foo107 [root@andromeda union-testsuite]# ls -l /proc/$$/fd/ ... lr-x------. 1 root root 64 Jun 5 14:22 5 -> /mnt/a/foo107 [root@andromeda union-testsuite]# stat /mnt/a/foo107 ... Device: 23h/35d Inode: 40346 Links: 1 ... [root@andromeda union-testsuite]# stat -L /proc/$$/fd/5 ... Device: 23h/35d Inode: 40346 Links: 1 ... Note the change in where /proc/$$/fd/5 points to in the ls command. It was pointing to /a/foo107 (which doesn't exist) and now points to /mnt/a/foo107 (which is correct). The inode accessed, however, is the lower layer. The union layer is on device 25h/37d and the upper layer on 24h/36d. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: "Kamata, Munehisa" <kamatam@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-10-22overlay: Call ovl_drop_write() earlier in ovl_dentry_open()David Howells
commit f25801ee4680ef1db21e15c112e6e5fe3ffe8da5 upstream. Call ovl_drop_write() earlier in ovl_dentry_open() before we call vfs_open() as we've done the copy up for which we needed the freeze-write lock by that point. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Cc: "Kamata, Munehisa" <kamatam@amazon.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-09-21fs: create and use seq_show_option for escapingKees Cook
commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream. Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Jan Kara <jack@suse.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-08-03ovl: lookup whiteouts outside iterate_dir()Miklos Szeredi
commit cdb672795876d7bc1870aed9a2d7cb59f43d1d96 upstream. If jffs2 can deadlock on overlayfs readdir because it takes the same lock on ->iterate() as in ->lookup(). Fix by moving whiteout checking outside iterate_dir(). Optimized by collecting potential whiteouts (DT_CHR) in a temporary list and if non-empty iterating throug these and checking for a 0/0 chardev. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Fixes: 49c21e1cacd7 ("ovl: check whiteout while reading directory") Reported-by: Roman Yeryomin <leroi.lists@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-05-19ovl: mount read-only if workdir can't be createdMiklos Szeredi
OpenWRT folks reported that overlayfs fails to mount if upper fs is full, because workdir can't be created. Wordir creation can fail for various other reasons too. There's no reason that the mount itself should fail, overlayfs can work fine without a workdir, as long as the overlay isn't modified. So mount it read-only and don't allow remounting read-write. Add a couple of WARN_ON()s for the impossible case of workdir being used despite being read-only. Reported-by: Bastian Bittorf <bittorf@bluebottle.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Cc: <stable@vger.kernel.org> # v3.18+
2015-05-14ovl: don't remove non-empty opaque directoryMiklos Szeredi
When removing an opaque directory we can't just call rmdir() to check for emptiness, because the directory will need to be replaced with a whiteout. The replacement is done with RENAME_EXCHANGE, which doesn't check emptiness. Solution is just to check emptiness by reading the directory. In the future we could add a new rename flag to check for emptiness even for RENAME_EXCHANGE to optimize this case. Reported-by: Vincent Batts <vbatts@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Jordi Pujol Palomer <jordipujolp@gmail.com> Fixes: 263b4a0fee43 ("ovl: dont replace opaque dir") Cc: <stable@vger.kernel.org> # v4.0+
2015-03-18ovl: upper fs should not be R/Ohujianyang
After importing multi-lower layer support, users could mount a r/o partition as the left most lowerdir instead of using it as upperdir. And a r/o upperdir may cause an error like overlayfs: failed to create directory ./workdir/work during mount. This patch check the *s_flags* of upper fs and return an error if it is a r/o partition. The checking of *upper_mnt->mnt_sb->s_flags* can be removed now. This patch also remove /* FIXME: workdir is not needed for a R/O mount */ from ovl_fill_super() because: 1) for upper fs r/o case Setting a r/o partition as upper is prevented, no need to care about workdir in this case. 2) for "mount overlay -o ro" with a r/w upper fs case Users could remount overlayfs to r/w in this case, so workdir should not be omitted. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-03-18ovl: check lowerdir amount for non-upper mounthujianyang
Recently multi-lower layer mount support allow upperdir and workdir to be omitted, then cause overlayfs can be mount with only one lowerdir directory. This action make no sense and have potential risk. This patch check the total number of lower directories to prevent mounting overlayfs with only one directory. Also, an error message is added to indicate lower directories exceed OVL_MAX_STACK limit. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-03-18ovl: print error message for invalid mount optionshujianyang
Overlayfs should print an error message if an incorrect mount option is caught like other filesystems. After this patch, improper option input could be clearly known. Reported-by: Fabian Sturm <fabian.sturm@aduu.de> Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-02-22VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)David Howells
Convert the following where appropriate: (1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry). (2) S_ISREG(dentry->d_inode) to d_is_reg(dentry). (3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more complicated than it appears as some calls should be converted to d_can_lookup() instead. The difference is whether the directory in question is a real dir with a ->lookup op or whether it's a fake dir with a ->d_automount op. In some circumstances, we can subsume checks for dentry->d_inode not being NULL into this, provided we the code isn't in a filesystem that expects d_inode to be NULL if the dirent really *is* negative (ie. if we're going to use d_inode() rather than d_backing_inode() to get the inode pointer). Note that the dentry type field may be set to something other than DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS manages the fall-through from a negative dentry to a lower layer. In such a case, the dentry type of the negative union dentry is set to the same as the type of the lower dentry. However, if you know d_inode is not NULL at the call site, then you can use the d_is_xxx() functions even in a filesystem. There is one further complication: a 0,0 chardev dentry may be labelled DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was intended for special directory entry types that don't have attached inodes. The following perl+coccinelle script was used: use strict; my @callers; open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') || die "Can't grep for S_ISDIR and co. callers"; @callers = <$fd>; close($fd); unless (@callers) { print "No matches\n"; exit(0); } my @cocci = ( '@@', 'expression E;', '@@', '', '- S_ISLNK(E->d_inode->i_mode)', '+ d_is_symlink(E)', '', '@@', 'expression E;', '@@', '', '- S_ISDIR(E->d_inode->i_mode)', '+ d_is_dir(E)', '', '@@', 'expression E;', '@@', '', '- S_ISREG(E->d_inode->i_mode)', '+ d_is_reg(E)' ); my $coccifile = "tmp.sp.cocci"; open($fd, ">$coccifile") || die $coccifile; print($fd "$_\n") || die $coccifile foreach (@cocci); close($fd); foreach my $file (@callers) { chomp $file; print "Processing ", $file, "\n"; system("spatch", "--sp-file", $coccifile, $file, "--in-place", "--no-show-diff") == 0 || die "spatch failed"; } [AV: overlayfs parts skipped] Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2015-02-20Merge branch 'overlayfs-next' of ↵Al Viro
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs into for-next
2015-01-09ovl: discard independent cursor in readdir()hujianyang
Since the ovl_dir_cache is stable during a directory reading, the cursor of struct ovl_dir_file don't need to be an independent entry in the list of a merged directory. This patch changes *cursor* to a pointer which points to the entry in the ovl_dir_cache. After this, we don't need to check *is_cursor* either. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-01-08ovl: Prevent rw remount when it should be ro mountSeunghun Lee
Overlayfs should be mounted read-only when upper-fs is read-only or nonexistent. But now it can be remounted read-write and this can cause kernel panic. So we should prevent read-write remount when the above situation happens. Signed-off-by: Seunghun Lee <waydi1@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-01-08ovl: Fix opaque regression in ovl_lookuphujianyang
Current multi-layer support overlayfs has a regression in .lookup(). If there is a directory in upperdir and a regular file has same name in lowerdir in a merged directory, lower file is hidden and upper directory is set to opaque in former case. But it is changed in present code. In lowerdir lookup path, if a found inode is not directory, the type checking of previous inode is missing. This inode will be copied to the lowerstack of ovl_entry directly. That will lead to several wrong conditions, for example, the reading of the directory in upperdir may return an error like: ls: reading directory .: Not a directory This patch makes the lowerdir lookup path check the opaque for non-directory file too. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2015-01-08ovl: Fix kernel panic while mounting overlayfshujianyang
The function ovl_fill_super() in recently multi-layer support version will incorrectly return 0 at error handling path and then cause kernel panic. This failure can be reproduced by mounting a overlayfs with upperdir and workdir in different mounts. And also, If the memory allocation of *lower_mnt* fail, this function may return an zero either. This patch fix this problem by setting *err* to proper error number before jumping to error handling path. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: Use macros to present ovl_xattrhujianyang
This patch adds two macros: OVL_XATTR_PRE_NAME and OVL_XATTR_PRE_LEN to present ovl_xattr name prefix and its length. Also, a new macro OVL_XATTR_OPAQUE is introduced to replace old *ovl_opaque_xattr*. Fix the length of "trusted.overlay." to *16*. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: Cleanup redundant blank lineshujianyang
This patch removes redundant blanks lines in overlayfs. Signed-off-by: hujianyang <hujianyang@huawei.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: support multiple lower layersMiklos Szeredi
Allow "lowerdir=" option to contain multiple lower directories separated by a colon (e.g. "lowerdir=/bin:/usr/bin"). Colon characters in filenames can be escaped with a backslash. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: make upperdir optionalMiklos Szeredi
Make "upperdir=" mount option optional. If "upperdir=" is not given, then the "workdir=" option is also optional (and ignored if given). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: improve mount helpersMiklos Szeredi
Move common checks into ovl_mount_dir() helper. Create helper for looking up lower directories. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: mount: change order of initializationMiklos Szeredi
Move allocation of root entry above to where it's needed. Move initializations related to upperdir and workdir near each other. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: allow statfs if no upper layerMiklos Szeredi
Handle "no upper layer" case in statfs. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: lookup ENAMETOOLONG on lower means ENOENTMiklos Szeredi
"Suppose you have in one of the lower layers a filesystem with ->lookup()-enforced upper limit on name length. Pretty much every local fs has one, but... they are not all equal. 255 characters is the common upper limit, but e.g. jffs2 stops at 254, minixfs upper limit is somewhere from 14 to 60, depending upon version, etc. You are doing a lookup for something that is present in upper layer, but happens to be too long for one of the lower layers. Too bad - ENAMETOOLONG for you..." Reported-by: Al Viro <viro@ZenIV.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: check whiteout on lowest layer as wellMiklos Szeredi
Not checking whiteouts on lowest layer was an optimization (there's nothing to white out there), but it could result in inconsitent behavior when a layer previously used as upper/middle is later used as lowest. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: multi-layer lookupMiklos Szeredi
Look up dentry in all relevant layers. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: multi-layer readdirMiklos Szeredi
If multiple lower layers exist, merge them as well in readdir according to the same rules as merging upper with lower. I.e. take whiteouts and opaque directories into account on all but the lowers layer. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: helper to iterate layersMiklos Szeredi
Add helper to iterate through all the layers, starting from the upper layer (if exists) and continuing down through the lower layers. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: add mutli-layer infrastructureMiklos Szeredi
Add multiple lower layers to 'struct ovl_fs' and 'struct ovl_entry'. ovl_entry will have an array of paths, instead of just the dentry. This allows a compact array containing just the layers which exist at current point in the tree (which is expected to be a small number for the majority of dentries). The number of layers is not limited by this infrastructure. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: dont replace opaque dirMiklos Szeredi
When removing an empty opaque directory, then it makes no sense to replace it with an exact replica of itself before removal. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: make path-type a bitmapMiklos Szeredi
OVL_PATH_PURE_UPPER -> __OVL_PATH_UPPER | __OVL_PATH_PURE OVL_PATH_UPPER -> __OVL_PATH_UPPER OVL_PATH_MERGE -> __OVL_PATH_UPPER | __OVL_PATH_MERGE OVL_PATH_LOWER -> 0 Multiple R/O layers will allow __OVL_PATH_MERGE without __OVL_PATH_UPPER. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-13ovl: check whiteout while reading directoryMiklos Szeredi
Don't make a separate pass for checking whiteouts, since we can do it while reading the upper directory. This will make it easier to handle multiple layers. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-12-08Merge branch 'iov_iter' into for-nextAl Viro
2014-11-20ovl: ovl_dir_fsync() cleanupMiklos Szeredi
Check against !OVL_PATH_LOWER instead of OVL_PATH_MERGE. For a copied up directory the two are currently equivalent. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: pass dentry into ovl_dir_read_merged()Miklos Szeredi
Pass dentry into ovl_dir_read_merged() insted of upperpath and lowerpath. This cleans up callers and paves the way for multi-layer directory reads. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: use lockless_dereference() for upperdentryMiklos Szeredi
Don't open code lockless_dereference() in ovl_upperdentry_dereference(). Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: allow filenames with commaMiklos Szeredi
Allow option separator (comma) to be escaped with backslash. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: fix race in private xattr checksMiklos Szeredi
Xattr operations can race with copy up. This does not matter as long as we consistently fiter out "trunsted.overlay.opaque" attribute on upper directories. Previously we checked parent against OVL_PATH_MERGE. This is too general, and prone to race with copy-up. I.e. we found the parent to be on the lower layer but ovl_dentry_real() would return the copied-up dentry, possibly with the "opaque" attribute. So instead use ovl_path_real() and decide to filter the attributes based on the actual type of the dentry we'll use. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: fix remove/copy-up raceMiklos Szeredi
ovl_remove_and_whiteout() needs to check if upper dentry exists or not after having locked upper parent directory. Previously we used a "type" value computed before locking the upper parent directory, which is susceptible to racing with copy-up. There's a similar check in ovl_check_empty_and_clear(). This one is not actually racy, since copy-up doesn't change the "emptyness" property of a directory. Add a comment to this effect, and check the existence of upper dentry locally to make the code cleaner. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
2014-11-20ovl: rename filesystem type to "overlay"Miklos Szeredi
Some distributions carry an "old" format of overlayfs while mainline has a "new" format. The distros will possibly want to keep the old overlayfs alongside the new for compatibility reasons. To make it possible to differentiate the two versions change the name of the new one from "overlayfs" to "overlay". Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Reported-by: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Andy Whitcroft <apw@canonical.com>
2014-11-05ovl: don't poison cursorMiklos Szeredi
ovl_cache_put() can be called from ovl_dir_reset() if the cache needs to be rebuilt. We did list_del() on the cursor, which results in an Oops on the poisoned pointer in ovl_seek_cursor(). Reported-by: Jordi Pujol Palomer <jordipujolp@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: Jordi Pujol Palomer <jordipujolp@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31vfs: make first argument of dir_context.actor typedMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-31ovl: initialize ->is_cursorMiklos Szeredi
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28overlayfs: fix lockdep misannotationMiklos Szeredi
In an overlay directory that shadows an empty lower directory, say /mnt/a/empty102, do: touch /mnt/a/empty102/x unlink /mnt/a/empty102/x rmdir /mnt/a/empty102 It's actually harmless, but needs another level of nesting between I_MUTEX_CHILD and I_MUTEX_NORMAL. Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Tested-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28ovl: fix check for cursorMiklos Szeredi
ovl_cache_entry.name is now an array not a pointer, so it makes no sense test for it being NULL. Detected by coverity. From: Miklos Szeredi <mszeredi@suse.cz> Fixes: 68bf8611076a ("overlayfs: make ovl_cache_entry->name an array instead of +pointer") Signed-off-by: Miklos Szeredi <mszeredi@suse.cz> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-10-28overlayfs: barriers for opening upper-layer directoryAl Viro
make sure that a) all stores done by opening struct file don't leak past storing the reference in od->upperfile b) the lockless side has read dependency barrier Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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