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2016-05-28fs/namei.c: Improve dcache hash functionGeorge Spelvin1-40/+81
Patch 0fed3ac866 improved the hash mixing, but the function is slower than necessary; there's a 7-instruction dependency chain (10 on x86) each loop iteration. Word-at-a-time access is a very tight loop (which is good, because link_path_walk() is one of the hottest code paths in the entire kernel), and the hash mixing function must not have a longer latency to avoid slowing it down. There do not appear to be any published fast hash functions that: 1) Operate on the input a word at a time, and 2) Don't need to know the length of the input beforehand, and 3) Have a single iterated mixing function, not needing conditional branches or unrolling to distinguish different loop iterations. One of the algorithms which comes closest is Yann Collet's xxHash, but that's two dependent multiplies per word, which is too much. The key insights in this design are: 1) Barring expensive ops like multiplies, to diffuse one input bit across 64 bits of hash state takes at least log2(64) = 6 sequentially dependent instructions. That is more cycles than we'd like. 2) An operation like "hash ^= hash << 13" requires a second temporary register anyway, and on a 2-operand machine like x86, it's three instructions. 3) A better use of a second register is to hold a two-word hash state. With careful design, no temporaries are needed at all, so it doesn't increase register pressure. And this gets rid of register copying on 2-operand machines, so the code is smaller and faster. 4) Using two words of state weakens the requirement for one-round mixing; we now have two rounds of mixing before cancellation is possible. 5) A two-word hash state also allows operations on both halves to be done in parallel, so on a superscalar processor we get more mixing in fewer cycles. I ended up using a mixing function inspired by the ChaCha and Speck round functions. It is 6 simple instructions and 3 cycles per iteration (assuming multiply by 9 can be done by an "lea" instruction): x ^= *input++; y ^= x; x = ROL(x, K1); x += y; y = ROL(y, K2); y *= 9; Not only is this reversible, two consecutive rounds are reversible: if you are given the initial and final states, but not the intermediate state, it is possible to compute both input words. This means that at least 3 words of input are required to create a collision. (It also has the property, used by hash_name() to avoid a branch, that it hashes all-zero to all-zero.) The rotate constants K1 and K2 were found by experiment. The search took a sample of random initial states (I used 1023) and considered the effect of flipping each of the 64 input bits on each of the 128 output bits two rounds later. Each of the 8192 pairs can be considered a biased coin, and adding up the Shannon entropy of all of them produces a score. The best-scoring shifts also did well in other tests (flipping bits in y, trying 3 or 4 rounds of mixing, flipping all 64*63/2 pairs of input bits), so the choice was made with the additional constraint that the sum of the shifts is odd and not too close to the word size. The final state is then folded into a 32-bit hash value by a less carefully optimized multiply-based scheme. This also has to be fast, as pathname components tend to be short (the most common case is one iteration!), but there's some room for latency, as there is a fair bit of intervening logic before the hash value is used for anything. (Performance verified with "bonnie++ -s 0 -n 1536:-2" on tmpfs. I need a better benchmark; the numbers seem to show a slight dip in performance between 4.6.0 and this patch, but they're too noisy to quote.) Special thanks to Bruce fields for diligent testing which uncovered a nasty fencepost error in an earlier version of this patch. [checkpatch.pl formatting complaints noted and respectfully disagreed with.] Signed-off-by: George Spelvin <linux@sciencehorizons.net> Tested-by: J. Bruce Fields <bfields@redhat.com>
2016-05-28fs/namei.c: Add hashlen_string() functionGeorge Spelvin2-7/+47
We'd like to make more use of the highly-optimized dcache hash functions throughout the kernel, rather than have every subsystem create its own, and a function that hashes basic null-terminated strings is required for that. (The name is to emphasize that it returns both hash and length.) It's actually useful in the dcache itself, specifically d_alloc_name(). Other uses in the next patch. full_name_hash() is also tweaked to make it more generally useful: 1) Take a "char *" rather than "unsigned char *" argument, to be consistent with hash_name(). 2) Handle zero-length inputs. If we want more callers, we don't want to make them worry about corner cases. Signed-off-by: George Spelvin <linux@sciencehorizons.net>
2016-05-16namei: Improve hash mixing if CONFIG_DCACHE_WORD_ACCESSGeorge Spelvin1-7/+26
The hash mixing between adding the next 64 bits of name was just a bit weak. Replaced with a still very fast but slightly more effective mixing function. Signed-off-by: George Spelvin <linux@horizon.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-14Merge branch 'for-linus' of ↵Linus Torvalds6-52/+110
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Overlayfs fixes from Miklos, assorted fixes from me. Stable fodder of varying severity, all sat in -next for a while" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: ovl: ignore permissions on underlying lookup vfs: add lookup_hash() helper vfs: rename: check backing inode being equal vfs: add vfs_select_inode() helper get_rock_ridge_filename(): handle malformed NM entries ecryptfs: fix handling of directory opening atomic_open(): fix the handling of create_error fix the copy vs. map logics in blk_rq_map_user_iov() do_splice_to(): cap the size before passing to ->splice_read()
2016-05-14Merge branch 'for-4.6-fixes' of ↵Linus Torvalds2-3/+18
git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup Pull cgroup fixes from Tejun Heo: "During v4.6-rc1 cgroup namespace support was merged. There is an issue where it's impossible to tell whether a given cgroup mount point is bind mounted or namespaced. Serge has been working on the issue but it took longer than expected to resolve, so the late pull request. Given that it's a completely new feature and the patches don't touch anything else, the risk seems acceptable. However, if this is too late, an alternative is plugging new cgroup ns creation for v4.6 and retrying for v4.7" * 'for-4.6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: cgroup: fix compile warning kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry call cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces kernfs_path_from_node_locked: don't overwrite nlen
2016-05-13ocfs2: fix posix_acl_create deadlockJunxiao Bi6-48/+77
Commit 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") refactored code to use posix_acl_create. The problem with this function is that it is not mindful of the cluster wide inode lock making it unsuitable for use with ocfs2 inode creation with ACLs. For example, when used in ocfs2_mknod, this function can cause deadlock as follows. The parent dir inode lock is taken when calling posix_acl_create -> get_acl -> ocfs2_iop_get_acl which takes the inode lock again. This can cause deadlock if there is a blocked remote lock request waiting for the lock to be downconverted. And same deadlock happened in ocfs2_reflink. This fix is to revert back using ocfs2_init_acl. Fixes: 702e5bc68ad2 ("ocfs2: use generic posix ACL infrastructure") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-13ocfs2: revert using ocfs2_acl_chmod to avoid inode cluster lock hangJunxiao Bi3-2/+27
Commit 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") introduced this issue. ocfs2_setattr called by chmod command holds cluster wide inode lock when calling posix_acl_chmod. This latter function in turn calls ocfs2_iop_get_acl and ocfs2_iop_set_acl. These two are also called directly from vfs layer for getfacl/setfacl commands and therefore acquire the cluster wide inode lock. If a remote conversion request comes after the first inode lock in ocfs2_setattr, OCFS2_LOCK_BLOCKED will be set. And this will cause the second call to inode lock from the ocfs2_iop_get_acl() to block indefinetly. The deleted version of ocfs2_acl_chmod() calls __posix_acl_chmod() which does not call back into the filesystem. Therefore, we restore ocfs2_acl_chmod(), modify it slightly for locking as needed, and use that instead. Fixes: 743b5f1434f5 ("ocfs2: take inode lock in ocfs2_iop_set/get_acl()") Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-12kernfs: kernfs_sop_show_path: don't return 0 after seq_dentry callSerge E. Hallyn1-1/+2
Our caller expects 0 on success, not >0. This fixes a bug in the patch cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespaces where /sys does not show up in mountinfo, breaking criu. Thanks for catching this, Andrei. Reported-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-11Merge branch 'ovl-fixes' into for-linusAl Viro274-2566/+2974
2016-05-11ovl: ignore permissions on underlying lookupMiklos Szeredi1-3/+1
Generally permission checking is not necessary when overlayfs looks up a dentry on one of the underlying layers, since search permission on base directory was already checked in ovl_permission(). More specifically using lookup_one_len() causes a problem when the lower directory lacks search permission for a specific user while the upper directory does have search permission. Since lookups are cached, this causes inconsistency in behavior: success depends on who did the first lookup. So instead use lookup_hash() which doesn't do the permission check. Reported-by: Ignacy Gawędzki <ignacy.gawedzki@green-communications.fr> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-11vfs: add lookup_hash() helperMiklos Szeredi1-5/+28
Overlayfs needs lookup without inode_permission() and already has the name hash (in form of dentry->d_name on overlayfs dentry). It also doesn't support filesystems with d_op->d_hash() so basically it only needs the actual hashed lookup from lookup_one_len_unlocked() So add a new helper that does unlocked lookup of a hashed name. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-05-11vfs: rename: check backing inode being equalMiklos Szeredi1-1/+5
If a file is renamed to a hardlink of itself POSIX specifies that rename(2) should do nothing and return success. This condition is checked in vfs_rename(). However it won't detect hard links on overlayfs where these are given separate inodes on the overlayfs layer. Overlayfs itself detects this condition and returns success without doing anything, but then vfs_rename() will proceed as if this was a successful rename (detach_mounts(), d_move()). The correct thing to do is to detect this condition before even calling into overlayfs. This patch does this by calling vfs_select_inode() to get the underlying inodes. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.2+
2016-05-11vfs: add vfs_select_inode() helperMiklos Szeredi1-8/+4
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Cc: <stable@vger.kernel.org> # v4.2+
2016-05-10Revert "proc/base: make prompt shell start from new line after executing ↵Robin Humble1-1/+1
"cat /proc/$pid/wchan"" This reverts the 4.6-rc1 commit 7e2bc81da333 ("proc/base: make prompt shell start from new line after executing "cat /proc/$pid/wchan") because it breaks /proc/$PID/whcan formatting in ps and top. Revert also because the patch is inconsistent - it adds a newline at the end of only the '0' wchan, and does not add a newline when /proc/$PID/wchan contains a symbol name. eg. $ ps -eo pid,stat,wchan,comm PID STAT WCHAN COMMAND ... 1189 S - dbus-launch 1190 Ssl 0 dbus-daemon 1198 Sl 0 lightdm 1299 Ss ep_pol systemd 1301 S - (sd-pam) 1304 Ss wait sh Signed-off-by: Robin Humble <plaguedbypenguins@gmail.com> Cc: Minfei Huang <mnfhuang@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-09cgroup, kernfs: make mountinfo show properly scoped path for cgroup namespacesSerge E. Hallyn1-0/+14
Patch summary: When showing a cgroupfs entry in mountinfo, show the path of the mount root dentry relative to the reader's cgroup namespace root. Short explanation (courtesy of mkerrisk): If we create a new cgroup namespace, then we want both /proc/self/cgroup and /proc/self/mountinfo to show cgroup paths that are correctly virtualized with respect to the cgroup mount point. Previous to this patch, /proc/self/cgroup shows the right info, but /proc/self/mountinfo does not. Long version: When a uid 0 task which is in freezer cgroup /a/b, unshares a new cgroup namespace, and then mounts a new instance of the freezer cgroup, the new mount will be rooted at /a/b. The root dentry field of the mountinfo entry will show '/a/b'. cat > /tmp/do1 << EOF mount -t cgroup -o freezer freezer /mnt grep freezer /proc/self/mountinfo EOF unshare -Gm bash /tmp/do1 > 330 160 0:34 / /sys/fs/cgroup/freezer rw,nosuid,nodev,noexec,relatime - cgroup cgroup rw,freezer > 355 133 0:34 /a/b /mnt rw,relatime - cgroup freezer rw,freezer The task's freezer cgroup entry in /proc/self/cgroup will simply show '/': grep freezer /proc/self/cgroup 9:freezer:/ If instead the same task simply bind mounts the /a/b cgroup directory, the resulting mountinfo entry will again show /a/b for the dentry root. However in this case the task will find its own cgroup at /mnt/a/b, not at /mnt: mount --bind /sys/fs/cgroup/freezer/a/b /mnt 130 25 0:34 /a/b /mnt rw,nosuid,nodev,noexec,relatime shared:21 - cgroup cgroup rw,freezer In other words, there is no way for the task to know, based on what is in mountinfo, which cgroup directory is its own. Example (by mkerrisk): First, a little script to save some typing and verbiage: echo -e "\t/proc/self/cgroup:\t$(cat /proc/self/cgroup | grep freezer)" cat /proc/self/mountinfo | grep freezer | awk '{print "\tmountinfo:\t\t" $4 "\t" $5}' Create cgroup, place this shell into the cgroup, and look at the state of the /proc files: 2653 2653 # Our shell 14254 # cat(1) /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer Create a shell in new cgroup and mount namespaces. The act of creating a new cgroup namespace causes the process's current cgroups directories to become its cgroup root directories. (Here, I'm using my own version of the "unshare" utility, which takes the same options as the util-linux version): Look at the state of the /proc files: /proc/self/cgroup: 10:freezer:/ mountinfo: / /sys/fs/cgroup/freezer The third entry in /proc/self/cgroup (the pathname of the cgroup inside the hierarchy) is correctly virtualized w.r.t. the cgroup namespace, which is rooted at /a/b in the outer namespace. However, the info in /proc/self/mountinfo is not for this cgroup namespace, since we are seeing a duplicate of the mount from the old mount namespace, and the info there does not correspond to the new cgroup namespace. However, trying to create a new mount still doesn't show us the right information in mountinfo: # propagating to other mountns /proc/self/cgroup: 7:freezer:/ mountinfo: /a/b /mnt/freezer The act of creating a new cgroup namespace caused the process's current freezer directory, "/a/b", to become its cgroup freezer root directory. In other words, the pathname directory of the directory within the newly mounted cgroup filesystem should be "/", but mountinfo wrongly shows us "/a/b". The consequence of this is that the process in the cgroup namespace cannot correctly construct the pathname of its cgroup root directory from the information in /proc/PID/mountinfo. With this patch, the dentry root field in mountinfo is shown relative to the reader's cgroup namespace. So the same steps as above: /proc/self/cgroup: 10:freezer:/a/b mountinfo: / /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: /../.. /sys/fs/cgroup/freezer /proc/self/cgroup: 10:freezer:/ mountinfo: / /mnt/freezer cgroup.clone_children freezer.parent_freezing freezer.state tasks cgroup.procs freezer.self_freezing notify_on_release 3164 2653 # First shell that placed in this cgroup 3164 # Shell started by 'unshare' 14197 # cat(1) Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com> Tested-by: Michael Kerrisk <mtk.manpages@gmail.com> Acked-by: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Tejun Heo <tj@kernel.org>
2016-05-08get_rock_ridge_filename(): handle malformed NM entriesAl Viro1-3/+10
Payloads of NM entries are not supposed to contain NUL. When we run into such, only the part prior to the first NUL goes into the concatenation (i.e. the directory entry name being encoded by a bunch of NM entries). We do stop when the amount collected so far + the claimed amount in the current NM entry exceed 254. So far, so good, but what we return as the total length is the sum of *claimed* sizes, not the actual amount collected. And that can grow pretty large - not unlimited, since you'd need to put CE entries in between to be able to get more than the maximum that could be contained in one isofs directory entry / continuation chunk and we are stop once we'd encountered 32 CEs, but you can get about 8Kb easily. And that's what will be passed to readdir callback as the name length. 8Kb __copy_to_user() from a buffer allocated by __get_free_page() Cc: stable@vger.kernel.org # 0.98pl6+ (yes, really) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-06proc: prevent accessing /proc/<PID>/environ until it's readyMathias Krause1-1/+2
If /proc/<PID>/environ gets read before the envp[] array is fully set up in create_{aout,elf,elf_fdpic,flat}_tables(), we might end up trying to read more bytes than are actually written, as env_start will already be set but env_end will still be zero, making the range calculation underflow, allowing to read beyond the end of what has been written. Fix this as it is done for /proc/<PID>/cmdline by testing env_end for zero. It is, apparently, intentionally set last in create_*_tables(). This bug was found by the PaX size_overflow plugin that detected the arithmetic underflow of 'this_len = env_end - (env_start + src)' when env_end is still zero. The expected consequence is that userland trying to access /proc/<PID>/environ of a not yet fully set up process may get inconsistent data as we're in the middle of copying in the environment variables. Fixes: https://forums.grsecurity.net/viewtopic.php?f=3&t=4363 Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=116461 Signed-off-by: Mathias Krause <minipli@googlemail.com> Cc: Emese Revfy <re.emese@gmail.com> Cc: Pax Team <pageexec@freemail.hu> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Mateusz Guzik <mguzik@redhat.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Cyrill Gorcunov <gorcunov@openvz.org> Cc: Jarod Wilson <jarod@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-05Merge branch 'for-linus' of ↵Linus Torvalds1-11/+14
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull userns fix from Eric Biederman: "This contains just a single fix for a nasty oops" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: propogate_mnt: Handle the first propogated copy being a slave
2016-05-05propogate_mnt: Handle the first propogated copy being a slaveEric W. Biederman1-11/+14
When the first propgated copy was a slave the following oops would result: > BUG: unable to handle kernel NULL pointer dereference at 0000000000000010 > IP: [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > PGD bacd4067 PUD bac66067 PMD 0 > Oops: 0000 [#1] SMP > Modules linked in: > CPU: 1 PID: 824 Comm: mount Not tainted 4.6.0-rc5userns+ #1523 > Hardware name: Bochs Bochs, BIOS Bochs 01/01/2007 > task: ffff8800bb0a8000 ti: ffff8800bac3c000 task.ti: ffff8800bac3c000 > RIP: 0010:[<ffffffff811fba4e>] [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > RSP: 0018:ffff8800bac3fd38 EFLAGS: 00010283 > RAX: 0000000000000000 RBX: ffff8800bb77ec00 RCX: 0000000000000010 > RDX: 0000000000000000 RSI: ffff8800bb58c000 RDI: ffff8800bb58c480 > RBP: ffff8800bac3fd48 R08: 0000000000000001 R09: 0000000000000000 > R10: 0000000000001ca1 R11: 0000000000001c9d R12: 0000000000000000 > R13: ffff8800ba713800 R14: ffff8800bac3fda0 R15: ffff8800bb77ec00 > FS: 00007f3c0cd9b7e0(0000) GS:ffff8800bfb00000(0000) knlGS:0000000000000000 > CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 > CR2: 0000000000000010 CR3: 00000000bb79d000 CR4: 00000000000006e0 > Stack: > ffff8800bb77ec00 0000000000000000 ffff8800bac3fd88 ffffffff811fbf85 > ffff8800bac3fd98 ffff8800bb77f080 ffff8800ba713800 ffff8800bb262b40 > 0000000000000000 0000000000000000 ffff8800bac3fdd8 ffffffff811f1da0 > Call Trace: > [<ffffffff811fbf85>] propagate_mnt+0x105/0x140 > [<ffffffff811f1da0>] attach_recursive_mnt+0x120/0x1e0 > [<ffffffff811f1ec3>] graft_tree+0x63/0x70 > [<ffffffff811f1f6b>] do_add_mount+0x9b/0x100 > [<ffffffff811f2c1a>] do_mount+0x2aa/0xdf0 > [<ffffffff8117efbe>] ? strndup_user+0x4e/0x70 > [<ffffffff811f3a45>] SyS_mount+0x75/0xc0 > [<ffffffff8100242b>] do_syscall_64+0x4b/0xa0 > [<ffffffff81988f3c>] entry_SYSCALL64_slow_path+0x25/0x25 > Code: 00 00 75 ec 48 89 0d 02 22 22 01 8b 89 10 01 00 00 48 89 05 fd 21 22 01 39 8e 10 01 00 00 0f 84 e0 00 00 00 48 8b 80 d8 00 00 00 <48> 8b 50 10 48 89 05 df 21 22 01 48 89 15 d0 21 22 01 8b 53 30 > RIP [<ffffffff811fba4e>] propagate_one+0xbe/0x1c0 > RSP <ffff8800bac3fd38> > CR2: 0000000000000010 > ---[ end trace 2725ecd95164f217 ]--- This oops happens with the namespace_sem held and can be triggered by non-root users. An all around not pleasant experience. To avoid this scenario when finding the appropriate source mount to copy stop the walk up the mnt_master chain when the first source mount is encountered. Further rewrite the walk up the last_source mnt_master chain so that it is clear what is going on. The reason why the first source mount is special is that it it's mnt_parent is not a mount in the dest_mnt propagation tree, and as such termination conditions based up on the dest_mnt mount propgation tree do not make sense. To avoid other kinds of confusion last_dest is not changed when computing last_source. last_dest is only used once in propagate_one and that is above the point of the code being modified, so changing the global variable is meaningless and confusing. Cc: stable@vger.kernel.org fixes: f2ebb3a921c1ca1e2ddd9242e95a1989a50c4c68 ("smarter propagate_mnt()") Reported-by: Tycho Andersen <tycho.andersen@canonical.com> Reviewed-by: Seth Forshee <seth.forshee@canonical.com> Tested-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2016-05-04ecryptfs: fix handling of directory openingAl Viro1-16/+55
First of all, trying to open them r/w is idiocy; it's guaranteed to fail. Moreover, assigning ->f_pos and assuming that everything will work is blatantly broken - try that with e.g. tmpfs as underlying layer and watch the fireworks. There may be a non-trivial amount of state associated with current IO position, well beyond the numeric offset. Using the single struct file associated with underlying inode is really not a good idea; we ought to open one for each ecryptfs directory struct file. Additionally, file_operations both for directories and non-directories are full of pointless methods; non-directories should *not* have ->iterate(), directories should not have ->flush(), ->fasync() and ->splice_read(). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-05-04Merge branch 'for-linus' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse fixes from Miklos Szeredi: "Fix a regression and update the MAINTAINERS entry for fuse" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: update mailing list in MAINTAINERS fuse: Fix return value from fuse_get_user_pages()
2016-05-02Merge branch 'for_linus' of ↵Linus Torvalds3-5/+17
git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs Pull UDF fix from Jan Kara: "A fix of a regression in UDF that got introduced in 4.6-rc1 by one of the charset encoding fixes" * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs: udf: Fix conversion of 'dstring' fields to UTF8
2016-05-02kernfs_path_from_node_locked: don't overwrite nlenSerge Hallyn1-3/+3
We've calculated @len to be the bytes we need for '/..' entries from @kn_from to the common ancestor, and calculated @nlen to be the extra bytes we need to get from the common ancestor to @kn_to. We use them as such at the end. But in the loop copying the actual entries, we overwrite @nlen. Use a temporary variable for that instead. Without this, the return length, when the buffer is large enough, is wrong. (When the buffer is NULL or too small, the returned value is correct. The buffer contents are also correct.) Interestingly, no callers of this function are affected by this as of yet. However the upcoming cgroup_show_path() will be. Signed-off-by: Serge Hallyn <serge.hallyn@ubuntu.com>
2016-04-30atomic_open(): fix the handling of create_errorAl Viro1-16/+4
* if we have a hashed negative dentry and either CREAT|EXCL on r/o filesystem, or CREAT|TRUNC on r/o filesystem, or CREAT|EXCL with failing may_o_create(), we should fail with EROFS or the error may_o_create() has returned, but not ENOENT. Which is what the current code ends up returning. * if we have CREAT|TRUNC hitting a regular file on a read-only filesystem, we can't fail with EROFS here. At the very least, not until we'd done follow_managed() - we might have a writable file (or a device, for that matter) bound on top of that one. Moreover, the code downstream will see that O_TRUNC and attempt to grab the write access (*after* following possible mount), so if we really should fail with EROFS, it will happen. No need to do that inside atomic_open(). The real logics is much simpler than what the current code is trying to do - if we decided to go for simple lookup, ended up with a negative dentry *and* had create_error set, fail with create_error. No matter whether we'd got that negative dentry from lookup_real() or had found it in dcache. Cc: stable@vger.kernel.org # v3.6+ Acked-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2016-04-29Merge branch 'akpm' (patches from Andrew)Linus Torvalds2-3/+32
Merge fixes from Andrew Morton: "20 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: Documentation/sysctl/vm.txt: update numa_zonelist_order description lib/stackdepot.c: allow the stack trace hash to be zero rapidio: fix potential NULL pointer dereference mm/memory-failure: fix race with compound page split/merge ocfs2/dlm: return zero if deref_done message is successfully handled Ananth has moved kcov: don't profile branches in kcov kcov: don't trace the code coverage code mm: wake kcompactd before kswapd's short sleep .mailmap: add Frank Rowand mm/hwpoison: fix wrong num_poisoned_pages accounting mm: call swap_slot_free_notify() with page lock held mm: vmscan: reclaim highmem zone if buffer_heads is over limit numa: fix /proc/<pid>/numa_maps for THP mm/huge_memory: replace VM_NO_THP VM_BUG_ON with actual VMA check mailmap: fix Krzysztof Kozlowski's misspelled name thp: keep huge zero page pinned until tlb flush mm: exclude HugeTLB pages from THP page_mapped() logic kexec: export OFFSET(page.compound_head) to find out compound tail page kexec: update VMCOREINFO for compound_order/dtor
2016-04-29ocfs2/dlm: return zero if deref_done message is successfully handledxuejiufei1-0/+2
dlm_deref_lockres_done_handler() should return zero if the message is successfully handled. Fixes: 60d663cb5273 ("ocfs2/dlm: add DEREF_DONE message"). Signed-off-by: xuejiufei <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-29numa: fix /proc/<pid>/numa_maps for THPGerald Schaefer1-3/+30
In gather_pte_stats() a THP pmd is cast into a pte, which is wrong because the layouts may differ depending on the architecture. On s390 this will lead to inaccurate numa_maps accounting in /proc because of misguided pte_present() and pte_dirty() checks on the fake pte. On other architectures pte_present() and pte_dirty() may work by chance, but there may be an issue with direct-access (dax) mappings w/o underlying struct pages when HAVE_PTE_SPECIAL is set and THP is available. In vm_normal_page() the fake pte will be checked with pte_special() and because there is no "special" bit in a pmd, this will always return false and the VM_PFNMAP | VM_MIXEDMAP checking will be skipped. On dax mappings w/o struct pages, an invalid struct page pointer would then be returned that can crash the kernel. This patch fixes the numa_maps THP handling by introducing new "_pmd" variants of the can_gather_numa_stats() and vm_normal_page() functions. Signed-off-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Kirill A . Shutemov" <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Jerome Marchand <jmarchan@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> [4.3+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-29Merge branch 'for-linus' of ↵Linus Torvalds1-4/+2
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client Pull Ceph fixes from Sage Weil: "There is a lifecycle fix in the auth code, a fix for a narrow race condition on map, and a helpful message in the log when there is a feature mismatch (which happens frequently now that the default server-side options have changed)" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: rbd: report unsupported features to syslog rbd: fix rbd map vs notify races libceph: make authorizer destruction independent of ceph_auth_client
2016-04-27devpts: more pty driver interface cleanupsLinus Torvalds1-41/+12
This is more prep-work for the upcoming pty changes. Still just code cleanup with no actual semantic changes. This removes a bunch pointless complexity by just having the slave pty side remember the dentry associated with the devpts slave rather than the inode. That allows us to remove all the "look up the dentry" code for when we want to remove it again. Together with moving the tty pointer from "inode->i_private" to "dentry->d_fsdata" and getting rid of pointless inode locking, this removes about 30 lines of code. Not only is the end result smaller, it's simpler and easier to understand. The old code, for example, depended on the d_find_alias() to not just find the dentry, but also to check that it is still hashed, which in turn validated the tty pointer in the inode. That is a _very_ roundabout way to say "invalidate the cached tty pointer when the dentry is removed". The new code just does dentry->d_fsdata = NULL; in devpts_pty_kill() instead, invalidating the tty pointer rather more directly and obviously. Don't do something complex and subtle when the obvious straightforward approach will do. The rest of the patch (ie apart from code deletion and the above tty pointer clearing) is just switching the calling convention to pass the dentry or file pointer around instead of the inode. Cc: Eric Biederman <ebiederm@xmission.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Jann Horn <jann@thejh.net> Cc: Greg KH <greg@kroah.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Florian Weimer <fw@deneb.enyo.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-25libceph: make authorizer destruction independent of ceph_auth_clientIlya Dryomov1-4/+2
Starting the kernel client with cephx disabled and then enabling cephx and restarting userspace daemons can result in a crash: [262671.478162] BUG: unable to handle kernel paging request at ffffebe000000000 [262671.531460] IP: [<ffffffff811cd04a>] kfree+0x5a/0x130 [262671.584334] PGD 0 [262671.635847] Oops: 0000 [#1] SMP [262672.055841] CPU: 22 PID: 2961272 Comm: kworker/22:2 Not tainted 4.2.0-34-generic #39~14.04.1-Ubuntu [262672.162338] Hardware name: Dell Inc. PowerEdge R720/068CDY, BIOS 2.4.3 07/09/2014 [262672.268937] Workqueue: ceph-msgr con_work [libceph] [262672.322290] task: ffff88081c2d0dc0 ti: ffff880149ae8000 task.ti: ffff880149ae8000 [262672.428330] RIP: 0010:[<ffffffff811cd04a>] [<ffffffff811cd04a>] kfree+0x5a/0x130 [262672.535880] RSP: 0018:ffff880149aeba58 EFLAGS: 00010286 [262672.589486] RAX: 000001e000000000 RBX: 0000000000000012 RCX: ffff8807e7461018 [262672.695980] RDX: 000077ff80000000 RSI: ffff88081af2be04 RDI: 0000000000000012 [262672.803668] RBP: ffff880149aeba78 R08: 0000000000000000 R09: 0000000000000000 [262672.912299] R10: ffffebe000000000 R11: ffff880819a60e78 R12: ffff8800aec8df40 [262673.021769] R13: ffffffffc035f70f R14: ffff8807e5b138e0 R15: ffff880da9785840 [262673.131722] FS: 0000000000000000(0000) GS:ffff88081fac0000(0000) knlGS:0000000000000000 [262673.245377] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [262673.303281] CR2: ffffebe000000000 CR3: 0000000001c0d000 CR4: 00000000001406e0 [262673.417556] Stack: [262673.472943] ffff880149aeba88 ffff88081af2be04 ffff8800aec8df40 ffff88081af2be04 [262673.583767] ffff880149aeba98 ffffffffc035f70f ffff880149aebac8 ffff8800aec8df00 [262673.694546] ffff880149aebac8 ffffffffc035c89e ffff8807e5b138e0 ffff8805b047f800 [262673.805230] Call Trace: [262673.859116] [<ffffffffc035f70f>] ceph_x_destroy_authorizer+0x1f/0x50 [libceph] [262673.968705] [<ffffffffc035c89e>] ceph_auth_destroy_authorizer+0x3e/0x60 [libceph] [262674.078852] [<ffffffffc0352805>] put_osd+0x45/0x80 [libceph] [262674.134249] [<ffffffffc035290e>] remove_osd+0xae/0x140 [libceph] [262674.189124] [<ffffffffc0352aa3>] __reset_osd+0x103/0x150 [libceph] [262674.243749] [<ffffffffc0354703>] kick_requests+0x223/0x460 [libceph] [262674.297485] [<ffffffffc03559e2>] ceph_osdc_handle_map+0x282/0x5e0 [libceph] [262674.350813] [<ffffffffc035022e>] dispatch+0x4e/0x720 [libceph] [262674.403312] [<ffffffffc034bd91>] try_read+0x3d1/0x1090 [libceph] [262674.454712] [<ffffffff810ab7c2>] ? dequeue_entity+0x152/0x690 [262674.505096] [<ffffffffc034cb1b>] con_work+0xcb/0x1300 [libceph] [262674.555104] [<ffffffff8108fb3e>] process_one_work+0x14e/0x3d0 [262674.604072] [<ffffffff810901ea>] worker_thread+0x11a/0x470 [262674.652187] [<ffffffff810900d0>] ? rescuer_thread+0x310/0x310 [262674.699022] [<ffffffff810957a2>] kthread+0xd2/0xf0 [262674.744494] [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0 [262674.789543] [<ffffffff817bd81f>] ret_from_fork+0x3f/0x70 [262674.834094] [<ffffffff810956d0>] ? kthread_create_on_node+0x1c0/0x1c0 What happens is the following: (1) new MON session is established (2) old "none" ac is destroyed (3) new "cephx" ac is constructed ... (4) old OSD session (w/ "none" authorizer) is put ceph_auth_destroy_authorizer(ac, osd->o_auth.authorizer) osd->o_auth.authorizer in the "none" case is just a bare pointer into ac, which contains a single static copy for all services. By the time we get to (4), "none" ac, freed in (2), is long gone. On top of that, a new vtable installed in (3) points us at ceph_x_destroy_authorizer(), so we end up trying to destroy a "none" authorizer with a "cephx" destructor operating on invalid memory! To fix this, decouple authorizer destruction from ac and do away with a single static "none" authorizer by making a copy for each OSD or MDS session. Authorizers themselves are independent of ac and so there is no reason for destroy_authorizer() to be an ac op. Make it an op on the authorizer itself by turning ceph_authorizer into a real struct. Fixes: http://tracker.ceph.com/issues/15447 Reported-by: Alan Zhang <alan.zhang@linux.com> Signed-off-by: Ilya Dryomov <idryomov@gmail.com> Reviewed-by: Sage Weil <sage@redhat.com>
2016-04-25udf: Fix conversion of 'dstring' fields to UTF8Andrew Gabbasov3-5/+17
Commit 9293fcfbc1812a22ad5ce1b542eb90c1bbe01be1 ("udf: Remove struct ustr as non-needed intermediate storage"), while getting rid of 'struct ustr', does not take any special care of 'dstring' fields and effectively use fixed field length instead of actual string length, encoded in the last byte of the field. Also, commit 484a10f49387e4386bf2708532e75bf78ffea2cb ("udf: Merge linux specific translation into CS0 conversion function") introduced checking of the length of the string being converted, requiring proper alignment to number of bytes constituing each character. The UDF volume identifier is represented as a 32-bytes 'dstring', and needs to be converted from CS0 to UTF8, while mounting UDF filesystem. The changes in mentioned commits can in some cases lead to incorrect handling of volume identifier: - if the actual string in 'dstring' is of maximal length and does not have zero bytes separating it from dstring encoded length in last byte, that last byte may be included in conversion, thus making incorrect resulting string; - if the identifier is encoded with 2-bytes characters (compression code is 16), the length of 31 bytes (32 bytes of field length minus 1 byte of compression code), taken as the string length, is reported as an incorrect (unaligned) length, and the conversion fails, which in its turn leads to volume mounting failure. This patch introduces handling of 'dstring' encoded length field in udf_CS0toUTF8 function, that is used in all and only cases when 'dstring' fields are converted. Currently these cases are processing of Volume Identifier and Volume Set Identifier fields. The function is also renamed to udf_dstrCS0toUTF8 to distinctly indicate that it handles 'dstring' input. Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com> Signed-off-by: Jan Kara <jack@suse.cz>
2016-04-25fuse: Fix return value from fuse_get_user_pages()Ashish Samant1-1/+1
fuse_get_user_pages() should return error or 0. Otherwise fuse_direct_io read will not return 0 to indicate that read has completed. Fixes: 742f992708df ("fuse: return patrial success from fuse_direct_io()") Signed-off-by: Ashish Samant <ashish.samant@oracle.com> Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2016-04-20Merge branch 'ptmx-cleanup'Linus Torvalds1-25/+24
Merge the ptmx internal interface cleanup branch. This doesn't change semantics, but it should be a sane basis for eventually getting the multi-instance devpts code into some sane shape where we can get rid of the kernel config option. Which we can hopefully get done next merge window.. * ptmx-cleanup: devpts: clean up interface to pty drivers
2016-04-18devpts: clean up interface to pty driversLinus Torvalds1-25/+24
This gets rid of the horrible notion of having that struct inode *ptmx_inode be the linchpin of the interface between the pty code and devpts. By de-emphasizing the ptmx inode, a lot of things actually get cleaner, and we will have a much saner way forward. In particular, this will allow us to associate with any particular devpts instance at open-time, and not be artificially tied to one particular ptmx inode. The patch itself is actually fairly straightforward, and apart from some locking and return path cleanups it's pretty mechanical: - the interfaces that devpts exposes all take "struct pts_fs_info *" instead of "struct inode *ptmx_inode" now. NOTE! The "struct pts_fs_info" thing is a completely opaque structure as far as the pty driver is concerned: it's still declared entirely internally to devpts. So the pty code can't actually access it in any way, just pass it as a "cookie" to the devpts code. - the "look up the pts fs info" is now a single clear operation, that also does the reference count increment on the pts superblock. So "devpts_add/del_ref()" is gone, and replaced by a "lookup and get ref" operation (devpts_get_ref(inode)), along with a "put ref" op (devpts_put_ref()). - the pty master "tty->driver_data" field now contains the pts_fs_info, not the ptmx inode. - because we don't care about the ptmx inode any more as some kind of base index, the ref counting can now drop the inode games - it just gets the ref on the superblock. - the pts_fs_info now has a back-pointer to the super_block. That's so that we can easily look up the information we actually need. Although quite often, the pts fs info was actually all we wanted, and not having to look it up based on some magical inode makes things more straightforward. In particular, now that "devpts_get_ref(inode)" operation should really be the *only* place we need to look up what devpts instance we're associated with, and we do it exactly once, at ptmx_open() time. The other side of this is that one ptmx node could now be associated with multiple different devpts instances - you could have a single /dev/ptmx node, and then have multiple mount namespaces with their own instances of devpts mounted on /dev/pts/. And that's all perfectly sane in a model where we just look up the pts instance at open time. This will eventually allow us to get rid of our odd single-vs-multiple pts instance model, but this patch in itself changes no semantics, only an internal binding model. Cc: Eric Biederman <ebiederm@xmission.com> Cc: Peter Anvin <hpa@zytor.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Peter Hurley <peter@hurleysoftware.com> Cc: Serge Hallyn <serge.hallyn@ubuntu.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Aurelien Jarno <aurelien@aurel32.net> Cc: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Cc: Jann Horn <jann@thejh.net> Cc: Greg KH <greg@kroah.com> Cc: Jiri Slaby <jslaby@suse.com> Cc: Florian Weimer <fw@deneb.enyo.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-17Merge tag 'driver-core-4.6-rc4' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull misc fixes from Greg KH: "Here are three small fixes for 4.6-rc4. Two fix up some lz4 issues with big endian systems, and the remaining one resolves a minor debugfs issue that was reported. All have been in linux-next with no reported issues" * tag 'driver-core-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: lib: lz4: cleanup unaligned access efficiency detection lib: lz4: fixed zram with lz4 on big endian machines debugfs: Make automount point inodes permanently empty
2016-04-15Merge tag 'for-linus-4.6-rc4' of ↵Linus Torvalds4-25/+56
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs/fscrypto fixes from Jaegeuk Kim: "In addition to f2fs/fscrypto fixes, I've added one patch which prevents RCU mode lookup in d_revalidate, as Al mentioned. These patches fix f2fs and fscrypto based on -rc3 bug fixes in ext4 crypto, which have not yet been fully propagated as follows. - use of dget_parent and file_dentry to avoid crashes - disallow RCU-mode lookup in d_invalidate - disallow -ENOMEM in the core data encryption path" * tag 'for-linus-4.6-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: ext4/fscrypto: avoid RCU lookup in d_revalidate fscrypto: don't let data integrity writebacks fail with ENOMEM f2fs: use dget_parent and file_dentry in f2fs_file_open fscrypto: use dget_parent() in fscrypt_d_revalidate()
2016-04-14Make file credentials available to the seqfile interfacesLinus Torvalds1-3/+4
A lot of seqfile users seem to be using things like %pK that uses the credentials of the current process, but that is actually completely wrong for filesystem interfaces. The unix semantics for permission checking files is to check permissions at _open_ time, not at read or write time, and that is not just a small detail: passing off stdin/stdout/stderr to a suid application and making the actual IO happen in privileged context is a classic exploit technique. So if we want to be able to look at permissions at read time, we need to use the file open credentials, not the current ones. Normal file accesses can just use "f_cred" (or any of the helper functions that do that, like file_ns_capable()), but the seqfile interfaces do not have any such options. It turns out that seq_file _does_ save away the user_ns information of the file, though. Since user_ns is just part of the full credential information, replace that special case with saving off the cred pointer instead, and suddenly seq_file has all the permission information it needs. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-13ext4/fscrypto: avoid RCU lookup in d_revalidateJaegeuk Kim2-0/+8
As Al pointed, d_revalidate should return RCU lookup before using d_inode. This was originally introduced by: commit 34286d666230 ("fs: rcu-walk aware d_revalidate method"). Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> Cc: Theodore Ts'o <tytso@mit.edu> Cc: stable <stable@vger.kernel.org>
2016-04-13debugfs: Make automount point inodes permanently emptySeth Forshee1-1/+1
Starting with 4.1 the tracing subsystem has its own filesystem which is automounted in the tracing subdirectory of debugfs. Prior to this debugfs could be bind mounted in a cloned mount namespace, but if tracefs has been mounted under debugfs this now fails because there is a locked child mount. This creates a regression for container software which bind mounts debugfs to satisfy the assumption of some userspace software. In other pseudo filesystems such as proc and sysfs we're already creating mountpoints like this in such a way that no dirents can be created in the directories, allowing them to be exceptions to some MNT_LOCKED tests. In fact we're already do this for the tracefs mountpoint in sysfs. Do the same in debugfs_create_automount(), since the intention here is clearly to create a mountpoint. This fixes the regression, as locked child mounts on permanently empty directories do not cause a bind mount to fail. Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Seth Forshee <seth.forshee@canonical.com> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-04-12fscrypto: don't let data integrity writebacks fail with ENOMEMJaegeuk Kim2-19/+33
This patch fixes the issue introduced by the ext4 crypto fix in a same manner. For F2FS, however, we flush the pending IOs and wait for a while to acquire free memory. Fixes: c9af28fdd4492 ("ext4 crypto: don't let data integrity writebacks fail with ENOMEM") Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12f2fs: use dget_parent and file_dentry in f2fs_file_openJaegeuk Kim1-3/+7
This patch synced with the below two ext4 crypto fixes together. In 4.6-rc1, f2fs newly introduced accessing f_path.dentry which crashes overlayfs. To fix, now we need to use file_dentry() to access that field. Fixes: c0a37d487884 ("ext4: use file_dentry()") Fixes: 9dd78d8c9a7b ("ext4: use dget_parent() in ext4_file_open()") Cc: Miklos Szeredi <mszeredi@redhat.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-12fscrypto: use dget_parent() in fscrypt_d_revalidate()Jaegeuk Kim1-3/+8
This patch updates fscrypto along with the below ext4 crypto change. Fixes: 3d43bcfef5f0 ("ext4 crypto: use dget_parent() in ext4_d_revalidate()") Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-04-11Revert "ext4: allow readdir()'s of large empty directories to be interrupted"Linus Torvalds2-10/+0
This reverts commit 1028b55bafb7611dda1d8fed2aeca16a436b7dff. It's broken: it makes ext4 return an error at an invalid point, causing the readdir wrappers to write the the position of the last successful directory entry into the position field, which means that the next readdir will now return that last successful entry _again_. You can only return fatal errors (that terminate the readdir directory walk) from within the filesystem readdir functions, the "normal" errors (that happen when the readdir buffer fills up, for example) happen in the iterorator where we know the position of the actual failing entry. I do have a very different patch that does the "signal_pending()" handling inside the iterator function where it is allowable, but while that one passes all the sanity checks, I screwed up something like four times while emailing it out, so I'm not going to commit it today. So my track record is not good enough, and the stars will have to align better before that one gets committed. And it would be good to get some review too, of course, since celestial alignments are always an iffy debugging model. IOW, let's just revert the commit that caused the problem for now. Reported-by: Greg Thelen <gthelen@google.com> Cc: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-04-09Merge branch 'for-linus-4.6' of ↵Linus Torvalds8-32/+215
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "These are bug fixes, including a really old fsync bug, and a few trace points to help us track down problems in the quota code" * 'for-linus-4.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix file/data loss caused by fsync after rename and new inode btrfs: Reset IO error counters before start of device replacing btrfs: Add qgroup tracing Btrfs: don't use src fd for printk btrfs: fallback to vmalloc in btrfs_compare_tree btrfs: handle non-fatal errors in btrfs_qgroup_inherit() btrfs: Output more info for enospc_debug mount option Btrfs: fix invalid reference in replace_path Btrfs: Improve FL_KEEP_SIZE handling in fallocate
2016-04-09Merge tag 'for-linus-4.6-ofs1' of ↵Linus Torvalds6-53/+28
git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux Pull orangefs fixes from Mike Marshall: "Orangefs cleanups and a strncpy vulnerability fix. Cleanups: - remove an unused variable from orangefs_readdir. - clean up printk wrapper used for ofs "gossip" debugging. - clean up truncate ctime and mtime setting in inode.c - remove a useless null check found by coccinelle. - optimize some memcpy/memset boilerplate code. - remove some useless sanity checks from xattr.c Fix: - fix a potential strncpy vulnerability" * tag 'for-linus-4.6-ofs1' of git://git.kernel.org/pub/scm/linux/kernel/git/hubcap/linux: orangefs: remove unused variable orangefs: Add KERN_<LEVEL> to gossip_<level> macros orangefs: strncpy -> strscpy orangefs: clean up truncate ctime and mtime setting Orangefs: fix ifnullfree.cocci warnings Orangefs: optimize boilerplate code. Orangefs: xattr.c cleanup
2016-04-08orangefs: remove unused variableMartin Brandenburg1-3/+1
Signed-off-by: Martin Brandenburg <martin@omnibond.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08orangefs: Add KERN_<LEVEL> to gossip_<level> macrosJoe Perches1-14/+17
Emit the logging messages at the appropriate levels. Miscellanea: o Change format to fmt o Use the more common ##__VA_ARGS__ Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08orangefs: strncpy -> strscpyMartin Brandenburg1-1/+5
It would have been possible for a rogue client-core to send in a symlink target which is not NUL terminated. This returns EIO if the client-core gives us corrupt data. Leave debugfs and superblock code as is for now. Other dcache.c and namei.c strncpy instances are safe because ORANGEFS_NAME_MAX = NAME_MAX + 1; there is always enough space for a name plus a NUL byte. Signed-off-by: Martin Brandenburg <martin@omnibond.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08orangefs: clean up truncate ctime and mtime settingMartin Brandenburg1-15/+1
The ctime and mtime are always updated on a successful ftruncate and only updated on a successful truncate where the size changed. We handle the ``if the size changed'' bit. This matches FUSE's behavior. Signed-off-by: Martin Brandenburg <martin@omnibond.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>
2016-04-08Orangefs: fix ifnullfree.cocci warningskbuild test robot1-2/+1
fs/orangefs/orangefs-debugfs.c:130:2-26: WARNING: NULL check before freeing functions like kfree, debugfs_remove, debugfs_remove_recursive or usb_free_urb is not needed. Maybe consider reorganizing relevant code to avoid passing NULL values. NULL check before some freeing functions is not needed. Based on checkpatch warning "kfree(NULL) is safe this check is probably not required" and kfreeaddr.cocci by Julia Lawall. Generated by: scripts/coccinelle/free/ifnullfree.cocci Signed-off-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Mike Marshall <hubcap@omnibond.com>