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* Remove last traces of ->sync_pageMatthew Wilcox2016-06-302-2/+1
| | | | | | | | Commit 7eaceaccab5f removed ->sync_page, but a few mentions of it still existed in documentation and comments, Signed-off-by: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* new helper: d_same_name()Al Viro2016-06-301-91/+36
| | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* dentry_cmp(): use lockless_dereference() instead of smp_read_barrier_depends()He Kuang2016-06-301-4/+3
| | | | | | | | lockless_dereference() was added which can be used in place of hard-coding smp_read_barrier_depends(). Signed-off-by: He Kuang <hekuang@huawei.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* Merge branch 'for-linus' into work.miscAl Viro2016-06-3013-135/+181
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| * namespace: update event counter when umounting a deleted dentryAndrey Ulanov2016-06-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - m_start() in fs/namespace.c expects that ns->event is incremented each time a mount added or removed from ns->list. - umount_tree() removes items from the list but does not increment event counter, expecting that it's done before the function is called. - There are some codepaths that call umount_tree() without updating "event" counter. e.g. from __detach_mounts(). - When this happens m_start may reuse a cached mount structure that no longer belongs to ns->list (i.e. use after free which usually leads to infinite loop). This change fixes the above problem by incrementing global event counter before invoking umount_tree(). Change-Id: I622c8e84dcb9fb63542372c5dbf0178ee86bb589 Cc: stable@vger.kernel.org Signed-off-by: Andrey Ulanov <andreyu@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * 9p: use file_dentry()Miklos Szeredi2016-06-301-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | v9fs may be used as lower layer of overlayfs and accessing f_path.dentry can lead to a crash. In this case it's a NULL pointer dereference in p9_fid_create(). Fix by replacing direct access of file->f_path.dentry with the file_dentry() accessor, which will always return a native object. Reported-by: Alessio Igor Bogani <alessioigorbogani@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Tested-by: Alessio Igor Bogani <alessioigorbogani@gmail.com> Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Cc: <stable@vger.kernel.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * ceph: fix d_obtain_alias() misusesAl Viro2016-06-241-7/+3
| | | | | | | | | | | | on failure d_obtain_alias() will have done iput() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * lockless next_positive()Al Viro2016-06-201-5/+27
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * libfs.c: new helper - next_positive()Al Viro2016-06-201-30/+47
| | | | | | | | | | | | | | | | Return nth positive child after given or NULL if there's less than n left. dcache_readdir() and dcache_dir_lseek() switched to it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * dcache_{readdir,dir_lseek}(): don't bother with nested ->d_lockAl Viro2016-06-201-9/+3
| | | | | | | | | | | | | | | | Make sure that directory is locked shared in dcache_dir_lseek(); for dcache_readdir() it's already tru, and that's enough to make simple_positive() stable. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fix idiotic braino in d_alloc_parallel()Al Viro2016-06-201-5/+12
| | | | | | | | | | | | | | | | | | | | Check for d_unhashed() while searching in in-lookup hash was absolutely wrong. Worse, it masked a deadlock on dget() done under bitlock that nests inside ->d_lock. Thanks to J. R. Okajima for spotting it. Spotted-by: "J. R. Okajima" <hooanon05g@gmail.com> Wearing-brown-paperbag: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * autofs racesAl Viro2016-06-123-22/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | * make autofs4_expire_indirect() skip the dentries being in process of expiry * do *not* mess with list_move(); making sure that dentry with AUTOFS_INF_EXPIRING are not picked for expiry is enough. * do not remove NO_RCU when we set EXPIRING, don't bother with smp_mb() there. Clear it at the same time we clear EXPIRING. Makes a bunch of tests simpler. * rename NO_RCU to WANT_EXPIRE, which is what it really is. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * much milder d_walk() raceAl Viro2016-06-103-9/+54
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | d_walk() relies upon the tree not getting rearranged under it without rename_lock being touched. And we do grab rename_lock around the places that change the tree topology. Unfortunately, branch reordering is just as bad from d_walk() POV and we have two places that do it without touching rename_lock - one in handling of cursors (for ramfs-style directories) and another in autofs. autofs one is a separate story; this commit deals with the cursors. * mark cursor dentries explicitly at allocation time * make __dentry_kill() leave ->d_child.next pointing to the next non-cursor sibling, making sure that it won't be moved around unnoticed before the parent is relocked on ascend-to-parent path in d_walk(). * make d_walk() skip cursors explicitly; strictly speaking it's not necessary (all callbacks we pass to d_walk() are no-ops on cursors), but it makes analysis easier. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * coredump: fix dumping through pipesMateusz Guzik2016-06-073-3/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The offset in the core file used to be tracked with ->written field of the coredump_params structure. The field was retired in favour of file->f_pos. However, ->f_pos is not maintained for pipes which leads to breakage. Restore explicit tracking of the offset in coredump_params. Introduce ->pos field for this purpose since ->written was already reused. Fixes: a00839395103 ("get rid of coredump_params->written"). Reported-by: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl> Signed-off-by: Mateusz Guzik <mguzik@redhat.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fix a regression in atomic_open()Al Viro2016-06-071-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | open("/foo/no_such_file", O_RDONLY | O_CREAT) on should fail with EACCES when /foo is not writable; failing with ENOENT is obviously wrong. That got broken by a braino introduced when moving the creat_error logics from atomic_open() to lookup_open(). Easy to fix, fortunately. Spotted-by: "Yan, Zheng" <ukernel@gmail.com> Tested-by: "Yan, Zheng" <ukernel@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fix d_walk()/non-delayed __d_free() raceAl Viro2016-06-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Ascend-to-parent logics in d_walk() depends on all encountered child dentries not getting freed without an RCU delay. Unfortunately, in quite a few cases it is not true, with hard-to-hit oopsable race as the result. Fortunately, the fix is simiple; right now the rule is "if it ever been hashed, freeing must be delayed" and changing it to "if it ever had a parent, freeing must be delayed" closes that hole and covers all cases the old rule used to cover. Moreover, pipes and sockets remain _not_ covered, so we do not introduce RCU delay in the cases which are the reason for having that delay conditional in the first place. Cc: stable@vger.kernel.org # v3.2+ (and watch out for __d_materialise_dentry()) Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * autofs braino fix for do_last()Al Viro2016-06-051-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It's an analogue of commit 7500c38a (fix the braino in "namei: massage lookup_slow() to be usable by lookup_one_len_unlocked()"). The same problem (->lookup()-returned unhashed negative dentry just might be an autofs one with ->d_manage() that would wait until the daemon makes it positive) applies in do_last() - we need to do follow_managed() first. Fortunately, remaining callers of follow_managed() are OK - only autofs has that weirdness (negative dentry that does not mean an instant -ENOENT)) and autofs never has its negative dentries hashed, so we can't pick one from a dcache lookup. ->d_manage() is a bloody mess ;-/ Cc: stable@vger.kernel.org # v4.6 Spotted-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * fix EOPENSTALE bug in do_last()Al Viro2016-06-041-39/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | EOPENSTALE occuring at the last component of a trailing symlink ends up with do_last() retrying its lookup. After the symlink body has been discarded. The thing is, all this retry_lookup logics in there is not needed at all - the upper layers will do the right thing if we simply return that -EOPENSTALE as we would with any other error. Trying to microoptimize in do_last() is a lot of headache for no good reason. Cc: stable@vger.kernel.org # v4.2+ Tested-by: Oleg Drokin <green@linuxhacker.ru> Reviewed-and-Tested-by: Jeff Layton <jlayton@poochiereds.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | binfmt_misc: ->s_root is not going anywhereAl Viro2016-05-291-8/+4
| | | | | | | | | | | | ... no need to dget/dput it. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | drop redundant ->owner initializationsAl Viro2016-05-2920-30/+0
| | | | | | | | | | | | | | it's not needed for file_operations of inodes located on fs defined in the hosting module and for file_operations that go into procfs. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | ufs: get rid of redundant checksAl Viro2016-05-291-16/+1
| | | | | | | | | | | | ufs_check_page() makes sure there's no entries with zero ->reclen Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | orangefs: constify inode_operationsAl Viro2016-05-294-6/+6
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | missed comment updates from ->direct_IO() prototype changeAl Viro2016-05-292-4/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | file_inode(f)->i_mapping is f->f_mappingAl Viro2016-05-294-4/+4
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | trim fsnotify hooks a bitAl Viro2016-05-291-4/+4
| | | | | | | | | | | | | | fsnotify_d_move()/__fsnotify_d_instantiate()/__fsnotify_update_dcache_flags() are identical to each other, regardless of the config. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | 9p: new helper - v9fs_parent_fid()Al Viro2016-05-293-16/+14
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | debugfs: ->d_parent is never NULL or negativeAl Viro2016-05-291-7/+0
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | nfs_lookup(): remove debris left over from old sillyunlink exclusionAl Viro2016-05-291-7/+4
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | orangefs: don't open-code %pd2Al Viro2016-05-291-6/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | tracefs: ->d_parent is never NULL or negative...Al Viro2016-05-291-7/+0
|/ | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* hash_string: Fix zero-length case for !DCACHE_WORD_ACCESSGeorge Spelvin2016-05-291-2/+2
| | | | | | | | | | The self-test was updated to cover zero-length strings; the function needs to be updated, too. Reported-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: George Spelvin <linux@sciencehorizons.net> Fixes: fcfd2fbf22d2 ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Rename other copy of hash_string to hashlen_stringGeorge Spelvin2016-05-281-2/+2
| | | | | | | | | | | | | | | | The original name was simply hash_string(), but that conflicted with a function with that name in drivers/base/power/trace.c, and I decided that calling it "hashlen_" was better anyway. But you have to do it in two places. [ This caused build errors for architectures that don't define CONFIG_DCACHE_WORD_ACCESS - Linus ] Signed-off-by: George Spelvin <linux@sciencehorizons.net> Reported-by: Guenter Roeck <linux@roeck-us.net> Fixes: fcfd2fbf22d2 ("fs/namei.c: Add hashlen_string() function") Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hpfs: implement the show_options methodMikulas Patocka2016-05-281-11/+32
| | | | | | | | | | | | | | | | The HPFS filesystem used generic_show_options to produce string that is displayed in /proc/mounts. However, there is a problem that the options may disappear after remount. If we mount the filesystem with option1 and then remount it with option2, /proc/mounts should show both option1 and option2, however it only shows option2 because the whole option string is replaced with replace_mount_options in hpfs_remount_fs. To fix this bug, implement the hpfs_show_options function that prints options that are currently selected. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* affs: fix remount failure when there are no options changedMikulas Patocka2016-05-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | Commit c8f33d0bec99 ("affs: kstrdup() memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: c8f33d0bec99 ("affs: kstrdup() memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v4.1+ Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* hpfs: fix remount failure when there are no options changedMikulas Patocka2016-05-281-2/+3
| | | | | | | | | | | | | | | | | | | | | | Commit ce657611baf9 ("hpfs: kstrdup() out of memory handling") checks if the kstrdup function returns NULL due to out-of-memory condition. However, if we are remounting a filesystem with no change to filesystem-specific options, the parameter data is NULL. In this case, kstrdup returns NULL (because it was passed NULL parameter), although no out of memory condition exists. The mount syscall then fails with ENOMEM. This patch fixes the bug. We fail with ENOMEM only if data is non-NULL. The patch also changes the call to replace_mount_options - if we didn't pass any filesystem-specific options, we don't call replace_mount_options (thus we don't erase existing reported options). Fixes: ce657611baf9 ("hpfs: kstrdup() out of memory handling") Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* fs: fix binfmt_aout.c build errorGuenter Roeck2016-05-281-1/+0
| | | | | | | | | | | | | | Various builds (such as i386:allmodconfig) fail with fs/binfmt_aout.c:133:2: error: expected identifier or '(' before 'return' fs/binfmt_aout.c:134:1: error: expected identifier or '(' before '}' token [ Oops. My bad, I had stupidly thought that "allmodconfig" covered this on x86-64 too, but it obviously doesn't. Egg on my face. - Linus ] Fixes: 5d22fc25d4fc ("mm: remove more IS_ERR_VALUE abuses") Signed-off-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'hash' of git://ftp.sciencehorizons.net/linuxLinus Torvalds2016-05-282-40/+125
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull string hash improvements from George Spelvin: "This series does several related things: - Makes the dcache hash (fs/namei.c) useful for general kernel use. (Thanks to Bruce for noticing the zero-length corner case) - Converts the string hashes in <linux/sunrpc/svcauth.h> to use the above. - Avoids 64-bit multiplies in hash_64() on 32-bit platforms. Two 32-bit multiplies will do well enough. - Rids the world of the bad hash multipliers in hash_32. This finishes the job started in commit 689de1d6ca95 ("Minimal fix-up of bad hashing behavior of hash_64()") The vast majority of Linux architectures have hardware support for 32x32-bit multiply and so derive no benefit from "simplified" multipliers. The few processors that do not (68000, h8/300 and some models of Microblaze) have arch-specific implementations added. Those patches are last in the series. - Overhauls the dcache hash mixing. The patch in commit 0fed3ac866ea ("namei: Improve hash mixing if CONFIG_DCACHE_WORD_ACCESS") was an off-the-cuff suggestion. Replaced with a much more careful design that's simultaneously faster and better. (My own invention, as there was noting suitable in the literature I could find. Comments welcome!) - Modify the hash_name() loop to skip the initial HASH_MIX(). This would let us salt the hash if we ever wanted to. - Sort out partial_name_hash(). The hash function is declared as using a long state, even though it's truncated to 32 bits at the end and the extra internal state contributes nothing to the result. And some callers do odd things: - fs/hfs/string.c only allocates 32 bits of state - fs/hfsplus/unicode.c uses it to hash 16-bit unicode symbols not bytes - Modify bytemask_from_count to handle inputs of 1..sizeof(long) rather than 0..sizeof(long)-1. This would simplify users other than full_name_hash" Special thanks to Bruce Fields for testing and finding bugs in v1. (I learned some humbling lessons about "obviously correct" code.) On the arch-specific front, the m68k assembly has been tested in a standalone test harness, I've been in contact with the Microblaze maintainers who mostly don't care, as the hardware multiplier is never omitted in real-world applications, and I haven't heard anything from the H8/300 world" * 'hash' of git://ftp.sciencehorizons.net/linux: h8300: Add <asm/hash.h> microblaze: Add <asm/hash.h> m68k: Add <asm/hash.h> <linux/hash.h>: Add support for architecture-specific functions fs/namei.c: Improve dcache hash function Eliminate bad hash multipliers from hash_32() and hash_64() Change hash_64() return value to 32 bits <linux/sunrpc/svcauth.h>: Define hash_str() in terms of hashlen_string() fs/namei.c: Add hashlen_string() function Pull out string hash to <linux/stringhash.h>
| * <linux/hash.h>: Add support for architecture-specific functionsGeorge Spelvin2016-05-281-1/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is just the infrastructure; there are no users yet. This is modelled on CONFIG_ARCH_RANDOM; a CONFIG_ symbol declares the existence of <asm/hash.h>. That file may define its own versions of various functions, and define HAVE_* symbols (no CONFIG_ prefix!) to suppress the generic ones. Included is a self-test (in lib/test_hash.c) that verifies the basics. It is NOT in general required that the arch-specific functions compute the same thing as the generic, but if a HAVE_* symbol is defined with the value 1, then equality is tested. Signed-off-by: George Spelvin <linux@sciencehorizons.net> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: Andreas Schwab <schwab@linux-m68k.org> Cc: Philippe De Muyter <phdm@macq.eu> Cc: linux-m68k@lists.linux-m68k.org Cc: Alistair Francis <alistai@xilinx.com> Cc: Michal Simek <michal.simek@xilinx.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: uclinux-h8-devel@lists.sourceforge.jp
| * fs/namei.c: Improve dcache hash functionGeorge Spelvin2016-05-281-40/+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>
| * fs/namei.c: Add hashlen_string() functionGeorge Spelvin2016-05-282-7/+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>
* | Merge tag 'upstream-4.7-rc1' of git://git.infradead.org/linux-ubifsLinus Torvalds2016-05-271-1/+1
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull UBI/UBIFS updates from Richard Weinberger: "This contains mostly cleanups and minor improvements of UBI and UBIFS" * tag 'upstream-4.7-rc1' of git://git.infradead.org/linux-ubifs: ubifs: ubifs_dump_inode: Fix dumping field bulk_read UBI: Fix static volume checks when Fastmap is used UBI: Set free_count to zero before walking through erase list UBI: Silence an unintialized variable warning UBI: Clean up return in ubi_remove_volume() UBI: Modify wrong comment in ubi_leb_map function. UBI: Don't read back all data in ubi_eba_copy_leb() UBI: Add ro-mode sysfs attribute
| * | ubifs: ubifs_dump_inode: Fix dumping field bulk_readAndreas Gruenbacher2016-05-241-1/+1
| | | | | | | | | | | | | | | | | | | | | The wrong field (xattr) is dumped here due to a copy-and-paste error. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Richard Weinberger <richard@nod.at>
* | | nfs: fix anonymous member initializer build failure with older compilersLinus Torvalds2016-05-271-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Older versions of gcc don't understand named initializers inside a anonymous structure or union member. It can be worked around by adding the bracin gin the initializer for the anonymous member. Without this, gcc 4.4.4 will fail the build with CC fs/nfs/nfs4state.o fs/nfs/nfs4state.c:69: error: unknown field ‘data’ specified in initializer fs/nfs/nfs4state.c:69: warning: missing braces around initializer fs/nfs/nfs4state.c:69: warning: (near initialization for ‘zero_stateid.<anonymous>.data’) make[2]: *** [fs/nfs/nfs4state.o] Error 1 introduced in commit 93b717fd81bf ("NFSv4: Label stateids with the type") Reported-and-tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Anna Schumaker <Anna.Schumaker@netapp.com> Cc: Trond Myklebust <trond.myklebust@primarydata.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2016-05-2748-183/+205
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs fixes from Al Viro: "Followups to the parallel lookup work: - update docs - restore killability of the places that used to take ->i_mutex killably now that we have down_write_killable() merged - Additionally, it turns out that I missed a prerequisite for security_d_instantiate() stuff - ->getxattr() wasn't the only thing that could be called before dentry is attached to inode; with smack we needed the same treatment applied to ->setxattr() as well" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: switch ->setxattr() to passing dentry and inode separately switch xattr_handler->set() to passing dentry and inode separately restore killability of old mutex_lock_killable(&inode->i_mutex) users add down_write_killable_nested() update D/f/directory-locking
| * | | switch ->setxattr() to passing dentry and inode separatelyAl Viro2016-05-2714-35/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | smack ->d_instantiate() uses ->setxattr(), so to be able to call it before we'd hashed the new dentry and attached it to inode, we need ->setxattr() instances getting the inode as an explicit argument rather than obtaining it from dentry. Similar change for ->getxattr() had been done in commit ce23e64. Unlike ->getxattr() (which is used by both selinux and smack instances of ->d_instantiate()) ->setxattr() is used only by smack one and unfortunately it got missed back then. Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com> Tested-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | switch xattr_handler->set() to passing dentry and inode separatelyAl Viro2016-05-2732-130/+150
| | | | | | | | | | | | | | | | | | | | | | | | | | | | preparation for similar switch in ->setxattr() (see the next commit for rationale). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | restore killability of old mutex_lock_killable(&inode->i_mutex) usersAl Viro2016-05-263-20/+14
| | | | | | | | | | | | | | | | | | | | | | | | The ones that are taking it exclusive, that is... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | Merge branch 'overlayfs-linus' of ↵Linus Torvalds2016-05-275-107/+38
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs Pull overlayfs update from Miklos Szeredi: "The meat of this is a change to use the mounter's credentials for operations that require elevated privileges (such as whiteout creation). This fixes behavior under user namespaces as well as being a nice cleanup" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: Do d_type check only if work dir creation was successful ovl: update documentation ovl: override creds with the ones from the superblock mounter
| * | | | ovl: Do d_type check only if work dir creation was successfulVivek Goyal2016-05-271-8/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | d_type check requires successful creation of workdir as iterates through work dir and expects work dir to be present in it. If that's not the case, this check will always return d_type not supported even if underlying filesystem might be supporting it. So don't do this check if work dir creation failed in previous step. Signed-off-by: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
| * | | | ovl: override creds with the ones from the superblock mounterAntonio Murdaca2016-05-275-99/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In user namespace the whiteout creation fails with -EPERM because the current process isn't capable(CAP_SYS_ADMIN) when setting xattr. A simple reproducer: $ mkdir upper lower work merged lower/dir $ sudo mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merged $ unshare -m -p -f -U -r bash Now as root in the user namespace: \# touch merged/dir/{1,2,3} # this will force a copy up of lower/dir \# rm -fR merged/* This ends up failing with -EPERM after the files in dir has been correctly deleted: unlinkat(4, "2", 0) = 0 unlinkat(4, "1", 0) = 0 unlinkat(4, "3", 0) = 0 close(4) = 0 unlinkat(AT_FDCWD, "merged/dir", AT_REMOVEDIR) = -1 EPERM (Operation not permitted) Interestingly, if you don't place files in merged/dir you can remove it, meaning if upper/dir does not exist, creating the char device file works properly in that same location. This patch uses ovl_sb_creator_cred() to get the cred struct from the superblock mounter and override the old cred with these new ones so that the whiteout creation is possible because overlay is wrong in assuming that the creds it will get with prepare_creds will be in the initial user namespace. The old cap_raise game is removed in favor of just overriding the old cred struct. This patch also drops from ovl_copy_up_one() the following two lines: override_cred->fsuid = stat->uid; override_cred->fsgid = stat->gid; This is because the correct uid and gid are taken directly with the stat struct and correctly set with ovl_set_attr(). Signed-off-by: Antonio Murdaca <runcom@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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