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* ovl: enable xino automatically in more casesAmir Goldstein2020-03-274-18/+33
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | So far, with xino=auto, we only enable xino if we know that all underlying filesystem use 32bit inode numbers. When users configure overlay with xino=auto, they already declare that they are ready to handle 64bit inode number from overlay. It is a very common case, that underlying filesystem uses 64bit ino, but rarely or never uses the high inode number bits (e.g. tmpfs, xfs). Leaving it for the users to declare high ino bits are unused with xino=on is not a recipe for many users to enjoy the benefits of xino. There appears to be very little reason not to enable xino when users declare xino=auto even if we do not know how many bits underlying filesystem uses for inode numbers. In the worst case of xino bits overflow by real inode number, we already fall back to the non-xino behavior - real inode number with unique pseudo dev or to non persistent inode number and overlay st_dev (for directories). The only annoyance from auto enabling xino is that xino bits overflow emits a warning to kmsg. Suppress those warnings unless users explicitly asked for xino=on, suggesting that they expected high ino bits to be unused by underlying filesystem. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: avoid possible inode number collisions with xino=onAmir Goldstein2020-03-273-17/+45
| | | | | | | | | | | | | | | | | | | | When xino feature is enabled and a real directory inode number overflows the lower xino bits, we cannot map this directory inode number to a unique and persistent inode number and we fall back to the real inode st_ino and overlay st_dev. The real inode st_ino with high bits may collide with a lower inode number on overlay st_dev that was mapped using xino. To avoid possible collision with legitimate xino values, map a non persistent inode number to a dedicated range in the xino address space. The dedicated range is created by adding one more bit to the number of reserved high xino bits. We could have added just one more fsid, but that would have had the undesired effect of changing persistent overlay inode numbers on kernel or require more complex xino mapping code. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use a private non-persistent ino poolAmir Goldstein2020-03-273-3/+15
| | | | | | | | | | | | There is no reason to deplete the system's global get_next_ino() pool for overlay non-persistent inode numbers and there is no reason at all to allocate non-persistent inode numbers for non-directories. For non-directories, it is much better to leave i_ino the same as real i_ino, to be consistent with st_ino/d_ino. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix WARN_ON nlink drop to zeroMiklos Szeredi2020-03-271-2/+24
| | | | | | | | | | | | | | | | | | | | | | | | | | Changes to underlying layers should not cause WARN_ON(), but this repro does: mkdir w l u mnt sudo mount -t overlay -o workdir=w,lowerdir=l,upperdir=u overlay mnt touch mnt/h ln u/h u/k rm -rf mnt/k rm -rf mnt/h dmesg ------------[ cut here ]------------ WARNING: CPU: 1 PID: 116244 at fs/inode.c:302 drop_nlink+0x28/0x40 After upper hardlinks were added while overlay is mounted, unlinking all overlay hardlinks drops overlay nlink to zero before all upper inodes are unlinked. After unlink/rename prevent i_nlink from going to zero if there are still hashed aliases (i.e. cached hard links to the victim) remaining. Reported-by: Phasip <phasip@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix a typo in commentChengguang Xu2020-03-171-1/+1
| | | | | | | Fix a typo in comment. (annonate -> annotate) Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: replace zero-length array with flexible-array memberGustavo A. R. Silva2020-03-171-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Fixes: cbe7fba8edfc ("ovl: make sure that real fid is 32bit aligned in memory") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: ovl_obtain_alias(): don't call d_instantiate_anon() for oldAl Viro2020-03-171-17/+21
| | | | | | | | | | | | | The situation is the same as for __d_obtain_alias() (which is what that thing is parallel to) - if we find a preexisting alias, we want to grab it, drop the inode and return the alias we'd found. The only thing d_instantiate_anon() does compared to that is spurious security_d_instiate() that has already been done to that dentry with exact same arguments. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: strict upper fs requirements for remote upper fsAmir Goldstein2020-03-171-6/+18
| | | | | | | | | | | | | | | | | | Overlayfs works sub-optimally with upper fs that has no xattr/d_type/ RENAME_WHITEOUT support. We should basically deprecate support for those filesystems, but so far, we only issue a warning and don't fail the mount for the sake of backward compat. Some features are already being disabled with no xattr support. For newly supported remote upper fs, we do not need to worry about backward compatibility, so we can fail the mount if upper fs is a sub-optimal filesystem. This reduces the in-tree remote filesystems supported as upper to just FUSE, for which the remote upper fs support was added. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: check if upper fs supports RENAME_WHITEOUTAmir Goldstein2020-03-173-1/+71
| | | | | | | | As with other required upper fs features, we only warn if support is missing to avoid breaking existing sub-optimal setups. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: allow remote upperMiklos Szeredi2020-03-173-4/+9
| | | | | | | | | | No reason to prevent upper layer being a remote filesystem. Do the revalidation in that case, just as we already do for lower layers. This lets virtiofs be used as upper layer, which appears to be a real use case. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: decide if revalidate needed on a per-dentry basisMiklos Szeredi2020-03-176-16/+30
| | | | | | | | | | | | | | | | | | | Allow completely skipping ->revalidate() on a per-dentry basis, in case the underlying layers used for a dentry do not themselves have ->revalidate(). E.g. negative overlay dentry has no underlying layers, hence revalidate is unnecessary. Or if lower layer is remote but overlay dentry is pure-upper, then can skip revalidate. The following places need to update whether the dentry needs revalidate or not: - fill-super (root dentry) - lookup - create - fh_to_dentry Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: separate detection of remote upper layer from stacked overlayMiklos Szeredi2020-03-173-10/+10
| | | | | | | | | Following patch will allow remote as upper layer, but not overlay stacked on upper layer. Separate the two concepts. This patch is doesn't change behavior. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: restructure dentry revalidationMiklos Szeredi2020-03-171-25/+26
| | | | | | | | | Use a common loop for plain and weak revalidation. This will aid doing revalidation on upper layer. This patch doesn't change behavior. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: ignore failure to copy up unknown xattrsMiklos Szeredi2020-03-171-2/+14
| | | | | | | | | | | | | | | | | | | | | | This issue came up with NFSv4 as the lower layer, which generates "system.nfs4_acl" xattrs (even for plain old unix permissions). Prior to this patch this prevented copy-up from succeeding. The overlayfs permission model mandates that permissions are checked locally for the task and remotely for the mounter(*). NFS4 ACLs are not supported by the Linux kernel currently, hence they cannot be enforced locally. Which means it is indifferent whether this attribute is copied or not. Generalize this to any xattr that is not used in access checking (i.e. it's not a POSIX ACL and not in the "security." namespace). Incidentally, best effort copying of xattrs seems to also be the behavior of "cp -a", which is what overlayfs tries to mimic. (*) Documentation/filesystems/overlayfs.txt#Permission model Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: simplify i_ino initializationAmir Goldstein2020-03-174-31/+39
| | | | | | | | | Move i_ino initialization to ovl_inode_init() to avoid the dance of setting i_ino in ovl_fill_inode() sometimes on the first call and sometimes on the seconds call. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: factor out helper ovl_get_root()Amir Goldstein2020-03-171-15/+29
| | | | | | | Allocates and initializes the root dentry and inode. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix out of date comment and unreachable codeAmir Goldstein2020-03-172-5/+5
| | | | | | | | ovl_inode_update() is no longer called from create object code path. Fixes: 01b39dcc9568 ("ovl: use inode_insert5() to hash a newly...") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix value of i_ino for lower hardlink corner caseAmir Goldstein2020-03-171-1/+3
| | | | | | | | | | | | | | | | | | | Commit 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more cases"), relaxed the condition nfs_export=on in order to set the value of i_ino to xino map of real ino. Specifically, it also relaxed the pre-condition that index=on for consistent i_ino. This opened the corner case of lower hardlink in ovl_get_inode(), which calls ovl_fill_inode() with ino=0 and then ovl_init_inode() is called to set i_ino to lower real ino without the xino mapping. Pass the correct values of ino;fsid in this case to ovl_fill_inode(), so it can initialize i_ino correctly. Fixes: 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more ...") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix lockdep warning for async writeMiklos Szeredi2020-03-131-0/+6
| | | | | | | | | | | | | Lockdep reports "WARNING: lock held when returning to user space!" due to async write holding freeze lock over the write. Apparently aio.c already deals with this by lying to lockdep about the state of the lock. Do the same here. No need to check for S_IFREG() here since these file ops are regular-only. Reported-by: syzbot+9331a354f4f624a52a55@syzkaller.appspotmail.com Fixes: 2406a307ac7d ("ovl: implement async IO routines") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix some xino configurationsAmir Goldstein2020-03-132-1/+9
| | | | | | | | | | | | | | | | | | Fix up two bugs in the coversion to xino_mode: 1. xino=off does not always end up in disabled mode 2. xino=auto on 32bit arch should end up in disabled mode Take a proactive approach to disabling xino on 32bit kernel: 1. Disable XINO_AUTO config during build time 2. Disable xino with a warning on mount time As a by product, xino=on on 32bit arch also ends up in disabled mode. We never intended to enable xino on 32bit arch and this will make the rest of the logic simpler. Fixes: 0f831ec85eda ("ovl: simplify ovl_same_sb() helper") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix lock in ovl_llseek()Amir Goldstein2020-03-122-3/+8
| | | | | | | | | | | | | ovl_inode_lock() is interruptible. When inode_lock() in ovl_llseek() was replaced with ovl_inode_lock(), we did not add a check for error. Fix this by making ovl_inode_lock() uninterruptible and change the existing call sites to use an _interruptible variant. Reported-by: syzbot+66a9752fa927f745385e@syzkaller.appspotmail.com Fixes: b1f9d3858f72 ("ovl: use ovl_inode_lock in ovl_llseek()") Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix lseek overflow on 32bitMiklos Szeredi2020-02-031-1/+1
| | | | | | | | | | | | ovl_lseek() is using ssize_t to return the value from vfs_llseek(). On a 32-bit kernel ssize_t is a 32-bit signed int, which overflows above 2 GB. Assign the return value of vfs_llseek() to loff_t to fix this. Reported-by: Boris Gjenero <boris.gjenero@gmail.com> Fixes: 9e46b840c705 ("ovl: support stacked SEEK_HOLE/SEEK_DATA") Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: add splice file read write helperMurphy Zhou2020-01-241-0/+47
| | | | | | | | | | | Now overlayfs falls back to use default file splice read and write, which is not compatiple with overlayfs, returning EFAULT. xfstests generic/591 can reproduce part of this. Tested this patch with xfstests auto group tests. Signed-off-by: Murphy Zhou <jencce.kernel@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: implement async IO routinesJiufei Xue2020-01-243-15/+110
| | | | | | | | | | | | | | | | | | | | | | A performance regression was observed since linux v4.19 with aio test using fio with iodepth 128 on overlayfs. The queue depth of the device was always 1 which is unexpected. After investigation, it was found that commit 16914e6fc7e1 ("ovl: add ovl_read_iter()") and commit 2a92e07edc5e ("ovl: add ovl_write_iter()") resulted in vfs_iter_{read,write} being called on underlying filesystem, which always results in syncronous IO. Implement async IO for stacked reading and writing. This resolves the performance regresion. This is implemented by allocating a new kiocb for submitting the AIO request on the underlying filesystem. When the request is completed, the new kiocb is freed and the completion callback is called on the original iocb. Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: layer is constMiklos Szeredi2020-01-246-22/+23
| | | | | | The ovl_layer struct is never modified except at initialization. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix corner case of non-constant st_dev;st_inoAmir Goldstein2020-01-242-17/+14
| | | | | | | | | | | | | | | | | | | | | | | On non-samefs overlay without xino, non pure upper inodes should use a pseudo_dev assigned to each unique lower fs, but if lower layer is on the same fs and upper layer, it has no pseudo_dev assigned. In this overlay layers setup: - two filesystems, A and B - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B Non pure upper overlay inode, whose origin is in layer 1 will have the st_dev;st_ino values of the real lower inode before copy up and the st_dev;st_ino values of the real upper inode after copy up. Fix this inconsitency by assigning a unique pseudo_dev also for upper fs, that will be used as st_dev value along with the lower inode st_dev for overlay inodes in the case above. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix corner case of conflicting lower layer uuidAmir Goldstein2020-01-242-2/+8
| | | | | | | | | | | | | | | | | | | This fixes ovl_lower_uuid_ok() to correctly detect the corner case: - two filesystems, A and B, both have null uuid - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B In this case, bad_uuid would not have been set for B, because the check only involved the list of lower fs. Hence we'll try to decode a layer 2 origin on layer 1 and fail. We check for conflicting (and null) uuid among all lower layers, including those layers that are on the same fs as the upper layer. Reported-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: generalize the lower_fs[] arrayAmir Goldstein2020-01-243-46/+46
| | | | | | | | | | | Rename lower_fs[] array to fs[], extend its size by one and use index fsid (instead of fsid-1) to access the fs[] array. Initialize fs[0] with upper fs values. fsid 0 is reserved even with lower only overlay, so fs[0] remains null in this case. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: simplify ovl_same_sb() helperAmir Goldstein2020-01-246-34/+37
| | | | | | | | | | | | | | | | No code uses the sb returned from this helper, so make it retrun a boolean and rename it to ovl_same_fs(). The xino mode is irrelevant when all layers are on same fs, so instead of describing samefs with mode OVL_XINO_OFF, use a new xino_mode state, which is 0 in the case of samefs, -1 in the case of xino=off and > 0 with xino enabled. Create a new helper ovl_same_dev(), to use instead of the common check for (ovl_same_fs() || xinobits). Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: generalize the lower_layers[] arrayAmir Goldstein2020-01-224-31/+35
| | | | | | | | | | | | | Rename lower_layers[] array to layers[], extend its size by one and initialize layers[0] with upper layer values. Lower layers are now addressed with index 1..numlower. layers[0] is reserved even with lower only overlay. [SzM: replace ofs->numlower with ofs->numlayer, the latter's value is incremented by one] Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: improving copy-up efficiency for big sparse fileChengguang Xu2020-01-221-2/+39
| | | | | | | | | | | | | | | | | | | | | | | | | Current copy-up is not efficient for big sparse file, It's not only slow but also wasting more disk space when the target lower file has huge hole inside. This patch tries to recognize file hole and skip it during copy-up. Detail logic of hole detection as below: When we detect next data position is larger than current position we will skip that hole, otherwise we copy data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually, it may not recognize all kind of holes and sometimes only skips partial of hole area. However, it will be enough for most of the use cases. Additionally, this optimization relies on lseek(2) SEEK_DATA implementation, so for some specific filesystems which do not support this feature will behave as before on copy-up. Reviewed-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use ovl_inode_lock in ovl_llseek()Amir Goldstein2020-01-222-2/+23
| | | | | | | | | | | | | | | | | | | | In ovl_llseek() we use the overlay inode rwsem to protect against concurrent modifications to real file f_pos, because we copy the overlay file f_pos to/from the real file f_pos. This caused a lockdep warning of locking order violation when the ovl_llseek() operation was called on a lower nested overlay layer while the upper layer fs sb_writers is held (with patch improving copy-up efficiency for big sparse file). Use the internal ovl_inode_lock() instead of the overlay inode rwsem in those cases. It is meant to be used for protecting against concurrent changes to overlay inode internal state changes. The locking order rules are documented to explain this case. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: use pr_fmt auto generate prefixlijiazi2020-01-229-81/+85
| | | | | | | Use pr_fmt auto generate "overlayfs: " prefix. Signed-off-by: lijiazi <lijiazi@xiaomi.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix wrong WARN_ON() in ovl_cache_update_ino()Amir Goldstein2020-01-221-1/+7
| | | | | | | | | | | | | | The WARN_ON() that child entry is always on overlay st_dev became wrong when we allowed this function to update d_ino in non-samefs setup with xino enabled. It is not true in case of xino bits overflow on a non-dir inode. Leave the WARN_ON() only for directories, where assertion is still true. Fixes: adbf4f7ea834 ("ovl: consistent d_ino for non-samefs with xino") Cc: <stable@vger.kernel.org> # v4.17+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge tag 'ovl-fixes-5.5-rc2' of ↵Linus Torvalds2019-12-148-96/+159
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs fixes from Miklos Szeredi: "Fix some bugs and documentation" * tag 'ovl-fixes-5.5-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: docs: filesystems: overlayfs: Fix restview warnings docs: filesystems: overlayfs: Rename overlayfs.txt to .rst ovl: relax WARN_ON() on rename to self ovl: fix corner case of non-unique st_dev;st_ino ovl: don't use a temp buf for encoding real fh ovl: make sure that real fid is 32bit aligned in memory ovl: fix lookup failure on multi lower squashfs
| * ovl: relax WARN_ON() on rename to selfAmir Goldstein2019-12-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In ovl_rename(), if new upper is hardlinked to old upper underneath overlayfs before upper dirs are locked, user will get an ESTALE error and a WARN_ON will be printed. Changes to underlying layers while overlayfs is mounted may result in unexpected behavior, but it shouldn't crash the kernel and it shouldn't trigger WARN_ON() either, so relax this WARN_ON(). Reported-by: syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com Fixes: 804032fabb3b ("ovl: don't check rename to self") Cc: <stable@vger.kernel.org> # v4.9+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix corner case of non-unique st_dev;st_inoAmir Goldstein2019-12-101-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On non-samefs overlay without xino, non pure upper inodes should use a pseudo_dev assigned to each unique lower fs and pure upper inodes use the real upper st_dev. It is fine for an overlay pure upper inode to use the same st_dev;st_ino values as the real upper inode, because the content of those two different filesystem objects is always the same. In this case, however: - two filesystems, A and B - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B Non pure upper overlay inode, whose origin is in layer 1 will have the same st_dev;st_ino values as the real lower inode. This may result with a false positive results of 'diff' between the real lower and copied up overlay inode. Fix this by using the upper st_dev;st_ino values in this case. This breaks the property of constant st_dev;st_ino across copy up of this case. This breakage will be fixed by a later patch. Fixes: 5148626b806a ("ovl: allocate anon bdev per unique lower fs") Cc: stable@vger.kernel.org # v4.17+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: don't use a temp buf for encoding real fhAmir Goldstein2019-12-101-21/+16
| | | | | | | | | | | | | | | | We can allocate maximum fh size and encode into it directly. Suggested-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: make sure that real fid is 32bit aligned in memoryAmir Goldstein2019-12-104-73/+115
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Seprate on-disk encoding from in-memory and on-wire resresentation of overlay file handle. In-memory and on-wire we only ever pass around pointers to struct ovl_fh, which encapsulates at offset 3 the on-disk format struct ovl_fb. struct ovl_fb encapsulates at offset 21 the real file handle. That makes sure that the real file handle is always 32bit aligned in-memory when passed down to the underlying filesystem. On-disk format remains the same and store/load are done into correctly aligned buffer. New nfs exported file handles are exported with aligned real fid. Old nfs file handles are copied to an aligned buffer before being decoded. Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * ovl: fix lookup failure on multi lower squashfsAmir Goldstein2019-12-103-7/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In the past, overlayfs required that lower fs have non null uuid in order to support nfs export and decode copy up origin file handles. Commit 9df085f3c9a2 ("ovl: relax requirement for non null uuid of lower fs") relaxed this requirement for nfs export support, as long as uuid (even if null) is unique among all lower fs. However, said commit unintentionally also relaxed the non null uuid requirement for decoding copy up origin file handles, regardless of the unique uuid requirement. Amend this mistake by disabling decoding of copy up origin file handle from lower fs with a conflicting uuid. We still encode copy up origin file handles from those fs, because file handles like those already exist in the wild and because they might provide useful information in the future. There is an unhandled corner case described by Miklos this way: - two filesystems, A and B, both have null uuid - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B In this case bad_uuid won't be set for B, because the check only involves the list of lower fs. Hence we'll try to decode a layer 2 origin on layer 1 and fail. We will deal with this corner case later. Reported-by: Colin Ian King <colin.king@canonical.com> Tested-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/lkml/20191106234301.283006-1-colin.king@canonical.com/ Fixes: 9df085f3c9a2 ("ovl: relax requirement for non null uuid ...") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | new helper: lookup_positive_unlocked()Al Viro2019-11-151-16/+8
|/ | | | | | | | | | | | | Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* ovl: filter of trusted xattr results in auditMark Salyzyn2019-09-111-1/+2
| | | | | | | | | | | | | | | | | When filtering xattr list for reading, presence of trusted xattr results in a security audit log. However, if there is other content no errno will be set, and if there isn't, the errno will be -ENODATA and not -EPERM as is usually associated with a lack of capability. The check does not block the request to list the xattrs present. Switch to ns_capable_noaudit to reflect a more appropriate check. Signed-off-by: Mark Salyzyn <salyzyn@android.com> Cc: linux-security-module@vger.kernel.org Cc: kernel-team@android.com Cc: stable@vger.kernel.org # v3.18+ Fixes: a082c6f680da ("ovl: filter trusted xattr for non-admin") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: Fix dereferencing possible ERR_PTR()Ding Xiang2019-09-111-2/+1
| | | | | | | | | | if ovl_encode_real_fh() fails, no memory was allocated and the error in the error-valued pointer should be returned. Fixes: 9b6faee07470 ("ovl: check ERR_PTR() return value from ovl_encode_fh()") Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com> Cc: <stable@vger.kernel.org> # v4.16+ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* ovl: fix regression caused by overlapping layers detectionAmir Goldstein2019-07-162-26/+48
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Once upon a time, commit 2cac0c00a6cd ("ovl: get exclusive ownership on upper/work dirs") in v4.13 added some sanity checks on overlayfs layers. This change caused a docker regression. The root cause was mount leaks by docker, which as far as I know, still exist. To mitigate the regression, commit 85fdee1eef1a ("ovl: fix regression caused by exclusive upper/work dir protection") in v4.14 turned the mount errors into warnings for the default index=off configuration. Recently, commit 146d62e5a586 ("ovl: detect overlapping layers") in v5.2, re-introduced exclusive upper/work dir checks regardless of index=off configuration. This changes the status quo and mount leak related bug reports have started to re-surface. Restore the status quo to fix the regressions. To clarify, index=off does NOT relax overlapping layers check for this ovelayfs mount. index=off only relaxes exclusive upper/work dir checks with another overlayfs mount. To cover the part of overlapping layers detection that used the exclusive upper/work dir checks to detect overlap with self upper/work dir, add a trap also on the work base dir. Link: https://github.com/moby/moby/issues/34672 Link: https://lore.kernel.org/linux-fsdevel/20171006121405.GA32700@veci.piliscsaba.szeredi.hu/ Link: https://github.com/containers/libpod/issues/3540 Fixes: 146d62e5a586 ("ovl: detect overlapping layers") Cc: <stable@vger.kernel.org> # v4.19+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Tested-by: Colin Walters <walters@verbum.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* Merge tag 'spdx-5.2-rc6' of ↵Linus Torvalds2019-06-2111-44/+11
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx Pull still more SPDX updates from Greg KH: "Another round of SPDX updates for 5.2-rc6 Here is what I am guessing is going to be the last "big" SPDX update for 5.2. It contains all of the remaining GPLv2 and GPLv2+ updates that were "easy" to determine by pattern matching. The ones after this are going to be a bit more difficult and the people on the spdx list will be discussing them on a case-by-case basis now. Another 5000+ files are fixed up, so our overall totals are: Files checked: 64545 Files with SPDX: 45529 Compared to the 5.1 kernel which was: Files checked: 63848 Files with SPDX: 22576 This is a huge improvement. Also, we deleted another 20000 lines of boilerplate license crud, always nice to see in a diffstat" * tag 'spdx-5.2-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/spdx: (65 commits) treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 507 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 506 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 505 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 504 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 503 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 502 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 501 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 499 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 498 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 497 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 496 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 495 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 491 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 490 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 489 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 488 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 487 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 486 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 485 ...
| * treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500Thomas Gleixner2019-06-1911-44/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Based on 2 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation this program is free software you can redistribute it and or modify it under the terms of the gnu general public license version 2 as published by the free software foundation # extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 4122 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Enrico Weigelt <info@metux.net> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | ovl: make i_ino consistent with st_ino in more casesAmir Goldstein2019-06-191-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Relax the condition that overlayfs supports nfs export, to require that i_ino is consistent with st_ino/d_ino. It is enough to require that st_ino and d_ino are consistent. This fixes the failure of xfstest generic/504, due to mismatch of st_ino to inode number in the output of /proc/locks. Fixes: 12574a9f4c9c ("ovl: consistent i_ino for non-samefs with xino") Cc: <stable@vger.kernel.org> # v4.19 Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: fix typo in MODULE_PARM_DESCNicolas Schier2019-06-183-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change first argument to MODULE_PARM_DESC() calls, that each of them matched the actual module parameter name. The matching results in changing (the 'parm' section from) the output of `modinfo overlay` from: parm: ovl_check_copy_up:Obsolete; does nothing parm: redirect_max:ushort parm: ovl_redirect_max:Maximum length of absolute redirect xattr value parm: redirect_dir:bool parm: ovl_redirect_dir_def:Default to on or off for the redirect_dir feature parm: redirect_always_follow:bool parm: ovl_redirect_always_follow:Follow redirects even if redirect_dir feature is turned off parm: index:bool parm: ovl_index_def:Default to on or off for the inodes index feature parm: nfs_export:bool parm: ovl_nfs_export_def:Default to on or off for the NFS export feature parm: xino_auto:bool parm: ovl_xino_auto_def:Auto enable xino feature parm: metacopy:bool parm: ovl_metacopy_def:Default to on or off for the metadata only copy up feature into: parm: check_copy_up:Obsolete; does nothing parm: redirect_max:Maximum length of absolute redirect xattr value (ushort) parm: redirect_dir:Default to on or off for the redirect_dir feature (bool) parm: redirect_always_follow:Follow redirects even if redirect_dir feature is turned off (bool) parm: index:Default to on or off for the inodes index feature (bool) parm: nfs_export:Default to on or off for the NFS export feature (bool) parm: xino_auto:Auto enable xino feature (bool) parm: metacopy:Default to on or off for the metadata only copy up feature (bool) Signed-off-by: Nicolas Schier <n.schier@avm.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: fix bogus -Wmaybe-unitialized warningArnd Bergmann2019-06-181-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gcc gets a bit confused by the logic in ovl_setup_trap() and can't figure out whether the local 'trap' variable in the caller was initialized or not: fs/overlayfs/super.c: In function 'ovl_fill_super': fs/overlayfs/super.c:1333:4: error: 'trap' may be used uninitialized in this function [-Werror=maybe-uninitialized] iput(trap); ^~~~~~~~~~ fs/overlayfs/super.c:1312:17: note: 'trap' was declared here Reword slightly to make it easier for the compiler to understand. Fixes: 146d62e5a586 ("ovl: detect overlapping layers") Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
* | ovl: don't fail with disconnected lower NFSMiklos Szeredi2019-06-181-17/+9
| | | | | | | | | | | | | | | | | | | | | | | | NFS mounts can be disconnected from fs root. Don't fail the overlapping layer check because of this. The check is not authoritative anyway, since topology can change during or after the check. Reported-by: Antti Antinoja <antti@fennosys.fi> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
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