summaryrefslogtreecommitdiff
path: root/fs/overlayfs
AgeCommit message (Collapse)Author
2016-10-31ovl: fsync after copy-upMiklos Szeredi
Make sure the copied up file hits the disk before renaming to the final destination. If this is not done then the copy-up may corrupt the data in the file in case of a crash. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-10-31ovl: fix get_acl() on tmpfsMiklos Szeredi
tmpfs doesn't have ->get_acl() because it only uses cached acls. This fixes the acl tests in pjdfstest when tmpfs is used as the upper layer of the overlay. Reported-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: 39a25b2b3762 ("ovl: define ->get_acl() for overlay inodes") Cc: <stable@vger.kernel.org> # v4.8
2016-10-31ovl: update S_ISGID when setting posix ACLsMiklos Szeredi
This change fixes xfstest generic/375, which failed to clear the setgid bit in the following test case on overlayfs: touch $testfile chown 100:100 $testfile chmod 2755 $testfile _runas -u 100 -g 101 -- setfacl -m u::rwx,g::rwx,o::rwx $testfile Reported-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Amir Goldstein <amir73il@gmail.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Cc: <stable@vger.kernel.org> # v4.8
2016-10-14Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more misc uaccess and vfs updates from Al Viro: "The rest of the stuff from -next (more uaccess work) + assorted fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: score: traps: Add missing include file to fix build error fs/super.c: don't fool lockdep in freeze_super() and thaw_super() paths fs/super.c: fix race between freeze_super() and thaw_super() overlayfs: Fix setting IOP_XATTR flag iov_iter: kernel-doc import_iovec() and rw_copy_check_uvector() blackfin: no access_ok() for __copy_{to,from}_user() arm64: don't zero in __copy_from_user{,_inatomic} arm: don't zero in __copy_from_user_inatomic()/__copy_from_user() arc: don't leak bits of kernel stack into coredump alpha: get rid of tail-zeroing in __copy_user()
2016-10-14Merge branch 'overlayfs-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs updates from Miklos Szeredi: "This update contains fixes to the "use mounter's permission to access underlying layers" area, and miscellaneous other fixes and cleanups. No new features this time" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: use vfs_get_link() vfs: add vfs_get_link() helper ovl: use generic_readlink ovl: explain error values when removing acl from workdir ovl: Fix info leak in ovl_lookup_temp() ovl: during copy up, switch to mounter's creds early ovl: lookup: do getxattr with mounter's permission ovl: copy_up_xattr(): use strnlen
2016-10-14overlayfs: Fix setting IOP_XATTR flagVivek Goyal
ovl_fill_super calls ovl_new_inode to create a root inode for the new superblock before initializing sb->s_xattr. This wrongly causes IOP_XATTR to be cleared in i_opflags of the new inode, causing SELinux to log the following message: SELinux: (dev overlay, type overlay) has no xattr support Fix this by initializing sb->s_xattr and similar fields before calling ovl_new_inode. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-14ovl: use vfs_get_link()Miklos Szeredi
Resulting in a complete removal of a function basically implementing the inverse of vfs_readlink(). As a bonus, now the proper security hook is also called. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-14ovl: use generic_readlinkMiklos Szeredi
All filesystems that are backers for overlayfs would also use generic_readlink(). Move this logic to the overlay itself, which is a nice cleanup. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-14ovl: explain error values when removing acl from workdirMiklos Szeredi
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-10-10Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull more vfs updates from Al Viro: ">rename2() work from Miklos + current_time() from Deepa" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: Replace current_fs_time() with current_time() fs: Replace CURRENT_TIME_SEC with current_time() for inode timestamps fs: Replace CURRENT_TIME with current_time() for inode timestamps fs: proc: Delete inode time initializations in proc_alloc_inode() vfs: Add current_time() api vfs: add note about i_op->rename changes to porting fs: rename "rename2" i_op to "rename" vfs: remove unused i_op->rename fs: make remaining filesystems use .rename2 libfs: support RENAME_NOREPLACE in simple_rename() fs: support RENAME_NOREPLACE for local filesystems ncpfs: fix unused variable warning
2016-10-10Merge branch 'work.xattr' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs xattr updates from Al Viro: "xattr stuff from Andreas This completes the switch to xattr_handler ->get()/->set() from ->getxattr/->setxattr/->removexattr" * 'work.xattr' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Remove {get,set,remove}xattr inode operations xattr: Stop calling {get,set,remove}xattr inode operations vfs: Check for the IOP_XATTR flag in listxattr xattr: Add __vfs_{get,set,remove}xattr helpers libfs: Use IOP_XATTR flag for empty directory handling vfs: Use IOP_XATTR flag for bad-inode handling vfs: Add IOP_XATTR inode operations flag vfs: Move xattr_resolve_name to the front of fs/xattr.c ecryptfs: Switch to generic xattr handlers sockfs: Get rid of getxattr iop sockfs: getxattr: Fail with -EOPNOTSUPP for invalid attribute names kernfs: Switch to generic xattr handlers hfs: Switch to generic xattr handlers jffs2: Remove jffs2_{get,set,remove}xattr macros xattr: Remove unnecessary NULL attribute name check
2016-10-10Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "Assorted misc bits and pieces. There are several single-topic branches left after this (rename2 series from Miklos, current_time series from Deepa Dinamani, xattr series from Andreas, uaccess stuff from from me) and I'd prefer to send those separately" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (39 commits) proc: switch auxv to use of __mem_open() hpfs: support FIEMAP cifs: get rid of unused arguments of CIFSSMBWrite() posix_acl: uapi header split posix_acl: xattr representation cleanups fs/aio.c: eliminate redundant loads in put_aio_ring_file fs/internal.h: add const to ns_dentry_operations declaration compat: remove compat_printk() fs/buffer.c: make __getblk_slow() static proc: unsigned file descriptors fs/file: more unsigned file descriptors fs: compat: remove redundant check of nr_segs cachefiles: Fix attempt to read i_blocks after deleting file [ver #2] cifs: don't use memcpy() to copy struct iov_iter get rid of separate multipage fault-in primitives fs: Avoid premature clearing of capabilities fs: Give dentry to inode_change_ok() instead of inode fuse: Propagate dentry down to inode_change_ok() ceph: Propagate dentry down to inode_change_ok() xfs: Propagate dentry down to inode_change_ok() ...
2016-10-08Merge remote-tracking branch 'jk/vfs' into work.miscAl Viro
2016-10-07vfs: Remove {get,set,remove}xattr inode operationsAndreas Gruenbacher
These inode operations are no longer used; remove them. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-07xattr: Add __vfs_{get,set,remove}xattr helpersAndreas Gruenbacher
Right now, various places in the kernel check for the existence of getxattr, setxattr, and removexattr inode operations and directly call those operations. Switch to helper functions and test for the IOP_XATTR flag instead. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Acked-by: James Morris <james.l.morris@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-10-04Merge branch 'next' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: SELinux/LSM: - overlayfs support, necessary for container filesystems LSM: - finally remove the kernel_module_from_file hook Smack: - treat signal delivery as an 'append' operation TPM: - lots of bugfixes & updates Audit: - new audit data type: LSM_AUDIT_DATA_FILE * 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (47 commits) Revert "tpm/tpm_crb: implement tpm crb idle state" Revert "tmp/tpm_crb: fix Intel PTT hw bug during idle state" Revert "tpm/tpm_crb: open code the crb_init into acpi_add" Revert "tmp/tpm_crb: implement runtime pm for tpm_crb" lsm,audit,selinux: Introduce a new audit data type LSM_AUDIT_DATA_FILE tmp/tpm_crb: implement runtime pm for tpm_crb tpm/tpm_crb: open code the crb_init into acpi_add tmp/tpm_crb: fix Intel PTT hw bug during idle state tpm/tpm_crb: implement tpm crb idle state tpm: add check for minimum buffer size in tpm_transmit() tpm: constify TPM 1.x header structures tpm/tpm_crb: fix the over 80 characters checkpatch warring tpm/tpm_crb: drop useless cpu_to_le32 when writing to registers tpm/tpm_crb: cache cmd_size register value. tmp/tpm_crb: drop include to platform_device tpm/tpm_tis: remove unused itpm variable tpm_crb: fix incorrect values of cmdReady and goIdle bits tpm_crb: refine the naming of constants tpm_crb: remove wmb()'s tpm_crb: fix crb_req_canceled behavior ...
2016-09-27fs: rename "rename2" i_op to "rename"Miklos Szeredi
Generated patch: sed -i "s/\.rename2\t/\.rename\t\t/" `git grep -wl rename2` sed -i "s/\brename2\b/rename/g" `git grep -wl rename2` Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-22fs: Give dentry to inode_change_ok() instead of inodeJan Kara
inode_change_ok() will be resposible for clearing capabilities and IMA extended attributes and as such will need dentry. Give it as an argument to inode_change_ok() instead of an inode. Also rename inode_change_ok() to setattr_prepare() to better relect that it does also some modifications in addition to checks. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jan Kara <jack@suse.cz>
2016-09-21ovl: Fix info leak in ovl_lookup_temp()Richard Weinberger
The function uses the memory address of a struct dentry as unique id. While the address-based directory entry is only visible to root it is IMHO still worth fixing since the temporary name does not have to be a kernel address. It can be any unique number. Replace it by an atomic integer which is allowed to wrap around. Signed-off-by: Richard Weinberger <richard@nod.at> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v3.18+ Fixes: e9be9d5e76e3 ("overlay filesystem")
2016-09-19ovl: during copy up, switch to mounter's creds earlyVivek Goyal
Now, we have the notion that copy up of a file is done with the creds of mounter of overlay filesystem (as opposed to task). Right now before we switch creds, we do some vfs_getattr() operations in the context of task and that itself can fail. We should do that getattr() using the creds of mounter instead. So this patch switches to mounter's creds early during copy up process so that even vfs_getattr() is done with mounter's creds. Do not call revert_creds() unless we have already called ovl_override_creds(). [Reported by Arnd Bergmann] Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-16ovl: lookup: do getxattr with mounter's permissionMiklos Szeredi
The getxattr() in ovl_is_opaquedir() was missed when converting all operations on underlying fs to be done under mounter's permission. This patch fixes this by moving the ovl_override_creds()/revert_creds() out from ovl_lookup_real() to ovl_lookup(). Also convert to using vfs_getxattr() instead of directly calling i_op->getxattr(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-16ovl: copy_up_xattr(): use strnlenMiklos Szeredi
Be defensive about what underlying fs provides us in the returned xattr list buffer. strlen() may overrun the buffer, so use strnlen() and WARN if the contents are not properly null terminated. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-09-16locks: fix file locking on overlayfsMiklos Szeredi
This patch allows flock, posix locks, ofd locks and leases to work correctly on overlayfs. Instead of using the underlying inode for storing lock context use the overlay inode. This allows locks to be persistent across copy-up. This is done by introducing locks_inode() helper and using it instead of file_inode() to get the inode in locking code. For non-overlayfs the two are equivalent, except for an extra pointer dereference in locks_inode(). Since lock operations are in "struct file_operations" we must also make sure not to call underlying filesystem's lock operations. Introcude a super block flag MS_NOREMOTELOCK to this effect. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: Jeff Layton <jlayton@poochiereds.net> Cc: "J. Bruce Fields" <bfields@fieldses.org>
2016-09-05ovl: fix workdir creationMiklos Szeredi
Workdir creation fails in latest kernel. Fix by allowing EOPNOTSUPP as a valid return value from vfs_removexattr(XATTR_NAME_POSIX_ACL_*). Upper filesystem may not support ACL and still be perfectly able to support overlayfs. Reported-by: Martin Ziegler <ziegler@uni-freiburg.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Fixes: c11b9fdd6a61 ("ovl: remove posix_acl_default from workdir") Cc: <stable@vger.kernel.org>
2016-09-01ovl: listxattr: use strnlen()Miklos Szeredi
Be defensive about what underlying fs provides us in the returned xattr list buffer. If it's not properly null terminated, bail out with a warning insead of BUG. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-09-01ovl: Switch to generic_getxattrAndreas Gruenbacher
Now that overlayfs has xattr handlers for iop->{set,remove}xattr, use those same handlers for iop->getxattr as well. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: copyattr after setting POSIX ACLMiklos Szeredi
Setting POSIX acl may also modify the file mode, so need to copy that up to the overlay inode. Reported-by: Eryu Guan <eguan@redhat.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: Switch to generic_removexattrAndreas Gruenbacher
Commit d837a49bd57f ("ovl: fix POSIX ACL setting") switches from iop->setxattr from ovl_setxattr to generic_setxattr, so switch from ovl_removexattr to generic_removexattr as well. As far as permission checking goes, the same rules should apply in either case. While doing that, rename ovl_setxattr to ovl_xattr_set to indicate that this is not an iop->setxattr implementation and remove the unused inode argument. Move ovl_other_xattr_set above ovl_own_xattr_set so that they match the order of handlers in ovl_xattr_handlers. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: Get rid of ovl_xattr_noacl_handlers arrayAndreas Gruenbacher
Use an ordinary #ifdef to conditionally include the POSIX ACL handlers in ovl_xattr_handlers, like the other filesystems do. Flag the code that is now only used conditionally with __maybe_unused. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: Fix OVL_XATTR_PREFIXAndreas Gruenbacher
Make sure ovl_own_xattr_handler only matches attribute names starting with "overlay.", not "overlayXXX". Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Fixes: d837a49bd57f ("ovl: fix POSIX ACL setting") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: fix spelling mistake: "directries" -> "directories"Colin Ian King
Trivial fix to spelling mistake in pr_err message. Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: don't cache acl on overlay layerMiklos Szeredi
Some operations (setxattr/chmod) can make the cached acl stale. We either need to clear overlay's acl cache for the affected inode or prevent acl caching on the overlay altogether. Preventing caching has the following advantages: - no double caching, less memory used - overlay cache doesn't go stale when fs clears it's own cache Possible disadvantage is performance loss. If that becomes a problem get_acl() can be optimized for overlayfs. This patch disables caching by pre setting i_*acl to a value that - has bit 0 set, so is_uncached_acl() will return true - is not equal to ACL_NOT_CACHED, so get_acl() will not overwrite it The constant -3 was chosen for this purpose. Fixes: 39a25b2b3762 ("ovl: define ->get_acl() for overlay inodes") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: use cached acl on underlying layerMiklos Szeredi
Instead of calling ->get_acl() directly, use get_acl() to get the cached value. We will have the acl cached on the underlying inode anyway, because we do permission checking on the both the overlay and the underlying fs. So, since we already have double caching, this improves performance without any cost. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-09-01ovl: proper cleanup of workdirMiklos Szeredi
When mounting overlayfs it needs a clean "work" directory under the supplied workdir. Previously the mount code removed this directory if it already existed and created a new one. If the removal failed (e.g. directory was not empty) then it fell back to a read-only mount not using the workdir. While this has never been reported, it is possible to get a non-empty "work" dir from a previous mount of overlayfs in case of crash in the middle of an operation using the work directory. In this case the left over state should be discarded and the overlay filesystem will be consistent, guaranteed by the atomicity of operations on moving to/from the workdir to the upper layer. This patch implements cleaning out any files left in workdir. It is implemented using real recursion for simplicity, but the depth is limited to 2, because the worst case is that of a directory containing whiteouts under "work". Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-09-01ovl: remove posix_acl_default from workdirMiklos Szeredi
Clear out posix acl xattrs on workdir and also reset the mode after creation so that an inherited sgid bit is cleared. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-09-01ovl: handle umask and posix_acl_default correctly on creationMiklos Szeredi
Setting MS_POSIXACL in sb->s_flags has the side effect of passing mode to create functions without masking against umask. Another problem when creating over a whiteout is that the default posix acl is not inherited from the parent dir (because the real parent dir at the time of creation is the work directory). Fix these problems by: a) If upper fs does not have MS_POSIXACL, then mask mode with umask. b) If creating over a whiteout, call posix_acl_create() to get the inherited acls. After creation (but before moving to the final destination) set these acls on the created file. posix_acl_create() also updates the file creation mode as appropriate. Fixes: 39a25b2b3762 ("ovl: define ->get_acl() for overlay inodes") Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-08-08security, overlayfs: Provide hook to correctly label newly created filesVivek Goyal
During a new file creation we need to make sure new file is created with the right label. New file is created in upper/ so effectively file should get label as if task had created file in upper/. We switched to mounter's creds for actual file creation. Also if there is a whiteout present, then file will be created in work/ dir first and then renamed in upper. In none of the cases file will be labeled as we want it to be. This patch introduces a new hook dentry_create_files_as(), which determines the label/context dentry will get if it had been created by task in upper and modify passed set of creds appropriately. Caller makes use of these new creds for file creation. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: fix whitespace issues found with checkpatch.pl] [PM: changes to use stat->mode in ovl_create_or_link()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-08security,overlayfs: Provide security hook for copy up of xattrs for overlay fileVivek Goyal
Provide a security hook which is called when xattrs of a file are being copied up. This hook is called once for each xattr and LSM can return 0 if the security module wants the xattr to be copied up, 1 if the security module wants the xattr to be discarded on the copy, -EOPNOTSUPP if the security module does not handle/manage the xattr, or a -errno upon an error. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup for checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-08security, overlayfs: provide copy up security hook for unioned filesVivek Goyal
Provide a security hook to label new file correctly when a file is copied up from lower layer to upper layer of a overlay/union mount. This hook can prepare a new set of creds which are suitable for new file creation during copy up. Caller will use new creds to create file and then revert back to old creds and release new creds. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespace cleanup to appease checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-08-08ovl: don't copy up opaquenessMiklos Szeredi
When a copy up of a directory occurs which has the opaque xattr set, the xattr remains in the upper directory. The immediate behavior with overlayfs is that the upper directory is not treated as opaque, however after a remount the opaque flag is used and upper directory is treated as opaque. This causes files created in the lower layer to be hidden when using multiple lower directories. Fix by not copying up the opaque flag. To reproduce: ----8<---------8<---------8<---------8<---------8<---------8<---- mkdir -p l/d/s u v w mnt mount -t overlay overlay -olowerdir=l,upperdir=u,workdir=w mnt rm -rf mnt/d/ mkdir -p mnt/d/n umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt touch mnt/d/foo umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt ls mnt/d ----8<---------8<---------8<---------8<---------8<---------8<---- output should be: "foo n" Reported-by: Derek McGowan <dmcg@drizz.net> Link: https://bugzilla.kernel.org/show_bug.cgi?id=151291 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-07-29ovl: simplify empty checkingMiklos Szeredi
The empty checking logic is duplicated in ovl_check_empty_and_clear() and ovl_remove_and_whiteout(), except the condition for clearing whiteouts is different: ovl_check_empty_and_clear() checked for being upper ovl_remove_and_whiteout() checked for merge OR lower Move the intersection of those checks (upper AND merge) into ovl_check_empty_and_clear() and simplify ovl_remove_and_whiteout(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29qstr: constify instances in overlayfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: clear nlink on rmdirMiklos Szeredi
To make delete notification work on fa/inotify. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: disallow overlayfs as upperdirMiklos Szeredi
This does not work and does not make sense. So instead of fixing it (probably not hard) just disallow. Reported-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org>
2016-07-29ovl: fix warningMiklos Szeredi
There's a superfluous newline in the warning message in ovl_d_real(). Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: remove duplicated include from super.cWei Yongjun
Remove duplicated include. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: append MAY_READ when diluting write checksVivek Goyal
Right now we remove MAY_WRITE/MAY_APPEND bits from mask if realfile is on lower/. This is done as files on lower will never be written and will be copied up. But to copy up a file, mounter should have MAY_READ permission otherwise copy up will fail. So set MAY_READ in mask when MAY_WRITE is reset. Dan Walsh noticed this when he did access(lowerfile, W_OK) and it returned True (context mounts) but when he tried to actually write to file, it failed as mounter did not have permission on lower file. [SzM] don't set MAY_READ if only MAY_APPEND is set without MAY_WRITE; this won't trigger a copy-up. Reported-by: Dan Walsh <dwalsh@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: dilute permission checks on lower only if not special fileVivek Goyal
Right now if file is on lower/, we remove MAY_WRITE/MAY_APPEND bits from mask as lower/ will never be written and file will be copied up. But this is not true for special files. These files are not copied up and are opened in place. So don't dilute the checks for these types of files. Reported-by: Dan Walsh <dwalsh@redhat.com> Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: fix POSIX ACL settingMiklos Szeredi
Setting POSIX ACL needs special handling: 1) Some permission checks are done by ->setxattr() which now uses mounter's creds ("ovl: do operations on underlying file system in mounter's context"). These permission checks need to be done with current cred as well. 2) Setting ACL can fail for various reasons. We do not need to copy up in these cases. In the mean time switch to using generic_setxattr. [Arnd Bergmann] Fix link error without POSIX ACL. posix_acl_from_xattr() doesn't have a 'static inline' implementation when CONFIG_FS_POSIX_ACL is disabled, and I could not come up with an obvious way to do it. This instead avoids the link error by defining two sets of ACL operations and letting the compiler drop one of the two at compile time depending on CONFIG_FS_POSIX_ACL. This avoids all references to the ACL code, also leading to smaller code. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-07-29ovl: share inode for hard linkMiklos Szeredi
Inode attributes are copied up to overlay inode (uid, gid, mode, atime, mtime, ctime) so generic code using these fields works correcty. If a hard link is created in overlayfs separate inodes are allocated for each link. If chmod/chown/etc. is performed on one of the links then the inode belonging to the other ones won't be updated. This patch attempts to fix this by sharing inodes for hard links. Use inode hash (with real inode pointer as a key) to make sure overlay inodes are shared for hard links on upper. Hard links on lower are still split (which is not user observable until the copy-up happens, see Documentation/filesystems/overlayfs.txt under "Non-standard behavior"). The inode is only inserted in the hash if it is non-directoy and upper. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>