kernel/git/stable/linux.git/fs/namespace.c, branch linux-4.16.y

vfs: Undo an overly zealous MS_RDONLY -> SB_RDONLY conversion

2018-06-20T19:01:21+00:00

[ Upstream commit a9e5b73288cf1595ac2e05cf1acd1924ceea05fa ] In do_mount() when the MS_* flags are being converted to MNT_* flags, MS_RDONLY got accidentally convered to SB_RDONLY. Undo this change. Fixes: e462ec50cb5f ("VFS: Differentiate mount flags (MS_*) from internal superblock flags") Signed-off-by: David Howells Signed-off-by: Linus Torvalds Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

Don't leak MNT_INTERNAL away from internal mounts

2018-04-24T07:43:10+00:00

commit 16a34adb9392b2fe4195267475ab5b472e55292c upstream. We want it only for the stuff created by SB_KERNMOUNT mounts, *not* for their copies. As it is, creating a deep stack of bindings of /proc/*/ns/* somewhere in a new namespace and exiting yields a stack overflow. Cc: stable@kernel.org Reported-by: Alexander Aring Bisected-by: Kirill Tkhai Tested-by: Kirill Tkhai Tested-by: Alexander Aring Signed-off-by: Al Viro Signed-off-by: Greg Kroah-Hartman

VFS: Handle lazytime in do_mount()

2017-12-10T01:16:33+00:00

Since commit e462ec50cb5fa ("VFS: Differentiate mount flags (MS_*) from internal superblock flags") the lazytime mount option doesn't get passed on anymore. Fix the issue by handling the option in do_mount(). Reviewed-by: Lukas Czerner Signed-off-by: Markus Trippelsdorf Signed-off-by: Al Viro

locking/atomics: COCCINELLE/treewide: Convert trivial ACCESS_ONCE() patterns to READ_ONCE()/WRITE_ONCE()

2017-10-25T09:01:08+00:00

Please do not apply this to mainline directly, instead please re-run the coccinelle script shown below and apply its output. For several reasons, it is desirable to use {READ,WRITE}_ONCE() in preference to ACCESS_ONCE(), and new code is expected to use one of the former. So far, there's been no reason to change most existing uses of ACCESS_ONCE(), as these aren't harmful, and changing them results in churn. However, for some features, the read/write distinction is critical to correct operation. To distinguish these cases, separate read/write accessors must be used. This patch migrates (most) remaining ACCESS_ONCE() instances to {READ,WRITE}_ONCE(), using the following coccinelle script: ---- // Convert trivial ACCESS_ONCE() uses to equivalent READ_ONCE() and // WRITE_ONCE() // $ make coccicheck COCCI=/home/mark/once.cocci SPFLAGS="--include-headers" MODE=patch virtual patch @ depends on patch @ expression E1, E2; @@ - ACCESS_ONCE(E1) = E2 + WRITE_ONCE(E1, E2) @ depends on patch @ expression E; @@ - ACCESS_ONCE(E) + READ_ONCE(E) ---- Signed-off-by: Mark Rutland Signed-off-by: Paul E. McKenney Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: davem@davemloft.net Cc: linux-arch@vger.kernel.org Cc: mpe@ellerman.id.au Cc: shuah@kernel.org Cc: snitzer@redhat.com Cc: thor.thayer@linux.intel.com Cc: tj@kernel.org Cc: viro@zeniv.linux.org.uk Cc: will.deacon@arm.com Link: http://lkml.kernel.org/r/1508792849-3115-19-git-send-email-paulmck@linux.vnet.ibm.com Signed-off-by: Ingo Molnar

vfs: fix mounting a filesystem with i_version

2017-10-17T06:22:07+00:00

The mount i_version flag is not enabled in the new sb_flags. This patch adds the missing SB_I_VERSION flag. Fixes: e462ec5 "VFS: Differentiate mount flags (MS_*) from internal superblock flags" Signed-off-by: Mimi Zohar Signed-off-by: Al Viro

ovl: fix may_write_real() for overlayfs directories

2017-10-05T13:53:18+00:00

Overlayfs directory file_inode() is the overlay inode whether the real inode is upper or lower. This fixes a regression in xfstest generic/158. Fixes: 7c6893e3c9ab ("ovl: don't allow writing ioctl on lower layer") Signed-off-by: Amir Goldstein Signed-off-by: Miklos Szeredi

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-09-15T03:01:41+00:00

Pull misc leftovers from Al Viro. * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fix the __user misannotations in asm-generic get_user/put_user fput: Don't reinvent the wheel but use existing llist API namespace.c: Don't reinvent the wheel but use existing llist API

Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2017-09-15T01:54:01+00:00

Pull mount flag updates from Al Viro: "Another chunk of fmount preparations from dhowells; only trivial conflicts for that part. It separates MS_... bits (very grotty mount(2) ABI) from the struct super_block ->s_flags (kernel-internal, only a small subset of MS_... stuff). This does *not* convert the filesystems to new constants; only the infrastructure is done here. The next step in that series is where the conflicts would be; that's the conversion of filesystems. It's purely mechanical and it's better done after the merge, so if you could run something like list=$(for i in MS_RDONLY MS_NOSUID MS_NODEV MS_NOEXEC MS_SYNCHRONOUS MS_MANDLOCK MS_DIRSYNC MS_NOATIME MS_NODIRATIME MS_SILENT MS_POSIXACL MS_KERNMOUNT MS_I_VERSION MS_LAZYTIME; do git grep -l $i fs drivers/staging/lustre drivers/mtd ipc mm include/linux; done|sort|uniq|grep -v '^fs/namespace.c$') sed -i -e 's/\/SB_RDONLY/g' \ -e 's/\/SB_NOSUID/g' \ -e 's/\/SB_NODEV/g' \ -e 's/\/SB_NOEXEC/g' \ -e 's/\/SB_SYNCHRONOUS/g' \ -e 's/\/SB_MANDLOCK/g' \ -e 's/\/SB_DIRSYNC/g' \ -e 's/\/SB_NOATIME/g' \ -e 's/\/SB_NODIRATIME/g' \ -e 's/\/SB_SILENT/g' \ -e 's/\/SB_POSIXACL/g' \ -e 's/\/SB_KERNMOUNT/g' \ -e 's/\/SB_I_VERSION/g' \ -e 's/\/SB_LAZYTIME/g' \ $list and commit it with something along the lines of 'convert filesystems away from use of MS_... constants' as commit message, it would save a quite a bit of headache next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: VFS: Differentiate mount flags (MS_*) from internal superblock flags VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb) vfs: Add sb_rdonly(sb) to query the MS_RDONLY flag on s_flags

ovl: don't allow writing ioctl on lower layer

2017-09-05T10:53:12+00:00

Problem with ioctl() is that it's a file operation, yet often used as an inode operation (i.e. modify the inode despite the file being opened for read-only). mnt_want_write_file() is used by filesystems in such cases to get write access on an arbitrary open file. Since overlayfs lets filesystems do all file operations, including ioctl, this can lead to mnt_want_write_file() returning OK for a lower file and modification of that lower file. This patch prevents modification by checking if the file is from an overlayfs lower layer and returning EPERM in that case. Need to introduce a mnt_want_write_file_path() variant that still does the old thing for inode operations that can do the copy up + modification correctly in such cases (fchown, fsetxattr, fremovexattr). This does not address the correctness of such ioctls on overlayfs (the correct way would be to copy up and attempt to perform ioctl on upper file). In theory this could be a regression. We very much hope that nobody is relying on such a hack in any sane setup. While this patch meddles in VFS code, it has no effect on non-overlayfs filesystems. Reported-by: "zhangyi (F)" Signed-off-by: Miklos Szeredi

namespace.c: Don't reinvent the wheel but use existing llist API

2017-08-28T04:50:22+00:00

Although llist provides proper APIs, they are not used. Make them used. Signed-off-by: Byungchul Park Signed-off-by: Al Viro