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2017-07-11fs/proc/generic.c: switch to ida_simple_get/removeHeiner Kallweit1-25/+7
The code can be much simplified by switching to ida_simple_get/remove. Link: http://lkml.kernel.org/r/8d1cc9f7-5115-c9dc-028e-c0770b6bfe1f@gmail.com Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11fs/dcache.c: fix spin lockup issue on nlru->lockSahitya Tummala1-2/+3
__list_lru_walk_one() acquires nlru spin lock (nlru->lock) for longer duration if there are more number of items in the lru list. As per the current code, it can hold the spin lock for upto maximum UINT_MAX entries at a time. So if there are more number of items in the lru list, then "BUG: spinlock lockup suspected" is observed in the below path: spin_bug+0x90 do_raw_spin_lock+0xfc _raw_spin_lock+0x28 list_lru_add+0x28 dput+0x1c8 path_put+0x20 terminate_walk+0x3c path_lookupat+0x100 filename_lookup+0x6c user_path_at_empty+0x54 SyS_faccessat+0xd0 el0_svc_naked+0x24 This nlru->lock is acquired by another CPU in this path - d_lru_shrink_move+0x34 dentry_lru_isolate_shrink+0x48 __list_lru_walk_one.isra.10+0x94 list_lru_walk_node+0x40 shrink_dcache_sb+0x60 do_remount_sb+0xbc do_emergency_remount+0xb0 process_one_work+0x228 worker_thread+0x2e0 kthread+0xf4 ret_from_fork+0x10 Fix this lockup by reducing the number of entries to be shrinked from the lru list to 1024 at once. Also, add cond_resched() before processing the lru list again. Link: http://marc.info/?t=149722864900001&r=1&w=2 Link: http://lkml.kernel.org/r/1498707575-2472-1-git-send-email-stummala@codeaurora.org Signed-off-by: Sahitya Tummala <stummala@codeaurora.org> Suggested-by: Jan Kara <jack@suse.cz> Suggested-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Alexander Polakov <apolyakov@beget.ru> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11fs/proc/task_mmu.c: remove obsolete comment in show_map_vma()Vasily Averin1-1/+0
After commit 1be7107fbe18 ("mm: larger stack guard gap, between vmas") we do not hide stack guard page in /proc/<pid>/maps Link: http://lkml.kernel.org/r/211f3c2a-f7ef-7c13-82bf-46fd426f6e1b@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11mm: hwpoison: dissolve in-use hugepage in unrecoverable memory errorNaoya Horiguchi1-0/+11
Currently me_huge_page() relies on dequeue_hwpoisoned_huge_page() to keep the error hugepage away from the system, which is OK but not good enough because the hugepage still has a refcount and unpoison doesn't work on the error hugepage (PageHWPoison flags are cleared but pages are still leaked.) And there's "wasting health subpages" issue too. This patch reworks on me_huge_page() to solve these issues. For hugetlb file, recently we have truncating code so let's use it in hugetlbfs specific ->error_remove_page(). For anonymous hugepage, it's helpful to dissolve the error page after freeing it into free hugepage list. Migration entry and PageHWPoison in the head page prevent the access to it. TODO: dissolve_free_huge_page() can fail but we don't considered it yet. It's not critical (and at least no worse that now) because in such case the error hugepage just stays in free hugepage list without being dissolved. By virtue of PageHWPoison in head page, it's never allocated to processes. [akpm@linux-foundation.org: fix unused var warnings] Fixes: 23a003bfd23ea9ea0b7756b920e51f64b284b468 ("mm/madvise: pass return code of memory_failure() to userspace") Link: http://lkml.kernel.org/r/20170417055948.GM31394@yexl-desktop Link: http://lkml.kernel.org/r/1496305019-5493-8-git-send-email-n-horiguchi@ah.jp.nec.com Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-11fs/buffer.c: make bh_lru_install() more efficientEric Biggers1-28/+15
To install a buffer_head into the cpu's LRU queue, bh_lru_install() would construct a new copy of the queue and then memcpy it over the real queue. But it's easily possible to do the update in-place, which is faster and simpler. Some work can also be skipped if the buffer_head was already in the queue. As a microbenchmark I timed how long it takes to run sb_getblk() 10,000,000 times alternating between BH_LRU_SIZE + 1 blocks. Effectively, this benchmarks looking up buffer_heads that are in the page cache but not in the LRU: Before this patch: 1.758s After this patch: 1.653s This patch also removes about 350 bytes of compiled code (on x86_64), partly due to removal of the memcpy() which was being inlined+unrolled. Link: http://lkml.kernel.org/r/20161229193445.1913-1-ebiggers3@gmail.com Signed-off-by: Eric Biggers <ebiggers@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10Merge tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds110-1855/+2110
Pull XFS updates from Darrick Wong: "Here are some changes for you for 4.13. For the most part it's fixes for bugs and deadlock problems, and preparation for online fsck in some future merge window. - Avoid quotacheck deadlocks - Fix transaction overflows when bunmapping fragmented files - Refactor directory readahead - Allow admin to configure if ASSERT is fatal - Improve transaction usage detail logging during overflows - Minor cleanups - Don't leak log items when the log shuts down - Remove double-underscore typedefs - Various preparation for online scrubbing - Introduce new error injection configuration sysfs knobs - Refactor dq_get_next to use extent map directly - Fix problems with iterating the page cache for unwritten data - Implement SEEK_{HOLE,DATA} via iomap - Refactor XFS to use iomap SEEK_HOLE and SEEK_DATA - Don't use MAXPATHLEN to check on-disk symlink target lengths" * tag 'xfs-4.13-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (48 commits) xfs: don't crash on unexpected holes in dir/attr btrees xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLEN xfs: fix contiguous dquot chunk iteration livelock xfs: Switch to iomap for SEEK_HOLE / SEEK_DATA vfs: Add iomap_seek_hole and iomap_seek_data helpers vfs: Add page_cache_seek_hole_data helper xfs: remove a whitespace-only line from xfs_fs_get_nextdqblk xfs: rewrite xfs_dq_get_next_id using xfs_iext_lookup_extent xfs: Check for m_errortag initialization in xfs_errortag_test xfs: grab dquots without taking the ilock xfs: fix semicolon.cocci warnings xfs: Don't clear SGID when inheriting ACLs xfs: free cowblocks and retry on buffered write ENOSPC xfs: replace log_badcrc_factor knob with error injection tag xfs: convert drop_writes to use the errortag mechanism xfs: remove unneeded parameter from XFS_TEST_ERROR xfs: expose errortag knobs via sysfs xfs: make errortag a per-mountpoint structure xfs: free uncommitted transactions during log recovery xfs: don't allow bmap on rt files ...
2017-07-10Merge branch 'nowait-aio-btrfs-fixup' of ↵Linus Torvalds1-12/+14
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fix from David Sterba: "This fixes a user-visible bug introduced by the nowait-aio patches merged in this cycle" * 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: nowait aio: Correct assignment of pos
2017-07-10btrfs: nowait aio: Correct assignment of posGoldwyn Rodrigues1-12/+14
Assigning pos for usage early messes up in append mode, where the pos is re-assigned in generic_write_checks(). Assign pos later to get the correct position to write from iocb->ki_pos. Since check_can_nocow also uses the value of pos, we shift generic_write_checks() before check_can_nocow(). Checks with IOCB_DIRECT are present in generic_write_checks(), so checking for IOCB_NOWAIT is enough. Also, put locking sequence in the fast path. This fixes a user visible bug, as reported: "apparently breaks several shell related features on my system. In zsh history stopped working, because no new entries are added anymore. I fist noticed the issue when I tried to build mplayer. It uses a shell script to generate a help_mp.h file: [...] Here is a simple testcase: % echo "foo" >> test % echo "foo" >> test % cat test foo % " Fixes: edf064e7c6fe ("btrfs: nowait aio support") CC: Jens Axboe <axboe@kernel.dk> Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de> Link: https://lkml.kernel.org/r/20170704042306.GA274@x4 Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-10afs: Add metadata xattrsDavid Howells8-2/+138
Add xattrs to allow the user to get/set metadata in lieu of having pioctl() available. The following xattrs are now available: - "afs.cell" The name of the cell in which the vnode's volume resides. - "afs.fid" The volume ID, vnode ID and vnode uniquifier of the file as three hex numbers separated by colons. - "afs.volume" The name of the volume in which the vnode resides. For example: # getfattr -d -m ".*" /mnt/scratch getfattr: Removing leading '/' from absolute path names # file: mnt/scratch afs.cell="mycell.myorg.org" afs.fid="10000b:1:1" afs.volume="scratch" Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-10afs: Ignore AFS_ACE_READ and AFS_ACE_WRITE for directoriesMarc Dionne1-3/+2
The AFS_ACE_READ and AFS_ACE_WRITE permission bits should not be used to make access decisions for the directory itself. They are meant to control access for the objects contained in that directory. Reading a directory is allowed if the AFS_ACE_LOOKUP bit is set. This would cause an incorrect access denied error for a directory with AFS_ACE_LOOKUP but not AFS_ACE_READ. The AFS_ACE_WRITE bit does not allow operations that modify the directory. For a directory with AFS_ACE_WRITE but neither AFS_ACE_INSERT nor AFS_ACE_DELETE, this would result in trying operations that would ultimately be denied by the server. Signed-off-by: Marc Dionne <marc.dionne@auristor.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-09Merge tag 'ext4_for_linus' of ↵Linus Torvalds27-507/+2071
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 updates from Ted Ts'o: "The first major feature for ext4 this merge window is the largedir feature, which allows ext4 directories to support over 2 billion directory entries (assuming ~64 byte file names; in practice, users will run into practical performance limits first.) This feature was originally written by the Lustre team, and credit goes to Artem Blagodarenko from Seagate for getting this feature upstream. The second major major feature allows ext4 to support extended attribute values up to 64k. This feature was also originally from Lustre, and has been enhanced by Tahsin Erdogan from Google with a deduplication feature so that if multiple files have the same xattr value (for example, Windows ACL's stored by Samba), only one copy will be stored on disk for encoding and caching efficiency. We also have the usual set of bug fixes, cleanups, and optimizations" * tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (47 commits) ext4: fix spelling mistake: "prellocated" -> "preallocated" ext4: fix __ext4_new_inode() journal credits calculation ext4: skip ext4_init_security() and encryption on ea_inodes fs: generic_block_bmap(): initialize all of the fields in the temp bh ext4: change fast symlink test to not rely on i_blocks ext4: require key for truncate(2) of encrypted file ext4: don't bother checking for encryption key in ->mmap() ext4: check return value of kstrtoull correctly in reserved_clusters_store ext4: fix off-by-one fsmap error on 1k block filesystems ext4: return EFSBADCRC if a bad checksum error is found in ext4_find_entry() ext4: return EIO on read error in ext4_find_entry ext4: forbid encrypting root directory ext4: send parallel discards on commit completions ext4: avoid unnecessary stalls in ext4_evict_inode() ext4: add nombcache mount option ext4: strong binding of xattr inode references ext4: eliminate xattr entry e_hash recalculation for removes ext4: reserve space for xattr entries/names quota: add get_inode_usage callback to transfer multi-inode charges ext4: xattr inode deduplication ...
2017-07-09Merge tag 'fscrypt_for_linus' of ↵Linus Torvalds7-62/+163
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt Pull fscrypt updates from Ted Ts'o: "Add support for 128-bit AES and some cleanups to fscrypt" * tag 'fscrypt_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/fscrypt: fscrypt: make ->dummy_context() return bool fscrypt: add support for AES-128-CBC fscrypt: inline fscrypt_free_filename()
2017-07-08Merge branch 'work.misc' of ↵Linus Torvalds8-15/+55
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc filesystem updates from Al Viro: "Assorted normal VFS / filesystems stuff..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: dentry name snapshots Make statfs properly return read-only state after emergency remount fs/dcache: init in_lookup_hashtable minix: Deinline get_block, save 2691 bytes fs: Reorder inode_owner_or_capable() to avoid needless fs: warn in case userspace lied about modprobe return
2017-07-08Merge branch 'work.__copy_in_user' of ↵Linus Torvalds1-10/+9
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull __copy_in_user removal from Al Viro: "There used to be 6 places in the entire tree calling __copy_in_user(), all of them bogus. Four got killed off in work.drm branch, this takes care of the remaining ones and kills the definition of that sucker" * 'work.__copy_in_user' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill __copy_in_user() sanitize do_i2c_smbus_ioctl()
2017-07-08Merge branch 'work.read_write' of ↵Linus Torvalds1-2/+4
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull read/write fix from Al Viro: "file_start_write()/file_end_write() got mixed into vfs_iter_write() by accident; that's a deadlock for all existing callers - they already do that, some - quite a bit outside. Easily fixed, fortunately" * 'work.read_write' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: move file_{start,end}_write() out of do_iter_write()
2017-07-08exec: Limit arg stack to at most 75% of _STK_LIMKees Cook1-5/+6
To avoid pathological stack usage or the need to special-case setuid execs, just limit all arg stack usage to at most 75% of _STK_LIM (6MB). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-08Merge tag 'for-linus-v4.13-2' of ↵Linus Torvalds12-34/+43
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull Writeback error handling updates from Jeff Layton: "This pile represents the bulk of the writeback error handling fixes that I have for this cycle. Some of the earlier patches in this pile may look trivial but they are prerequisites for later patches in the series. The aim of this set is to improve how we track and report writeback errors to userland. Most applications that care about data integrity will periodically call fsync/fdatasync/msync to ensure that their writes have made it to the backing store. For a very long time, we have tracked writeback errors using two flags in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a writeback error occurs (via mapping_set_error) and are cleared as a side-effect of filemap_check_errors (as you noted yesterday). This model really sucks for userland. Only the first task to call fsync (or msync or fdatasync) will see the error. Any subsequent task calling fsync on a file will get back 0 (unless another writeback error occurs in the interim). If I have several tasks writing to a file and calling fsync to ensure that their writes got stored, then I need to have them coordinate with one another. That's difficult enough, but in a world of containerized setups that coordination may even not be possible. But wait...it gets worse! The calls to filemap_check_errors can be buried pretty far down in the call stack, and there are internal callers of filemap_write_and_wait and the like that also end up clearing those errors. Many of those callers ignore the error return from that function or return it to userland at nonsensical times (e.g. truncate() or stat()). If I get back -EIO on a truncate, there is no reason to think that it was because some previous writeback failed, and a subsequent fsync() will (incorrectly) return 0. This pile aims to do three things: 1) ensure that when a writeback error occurs that that error will be reported to userland on a subsequent fsync/fdatasync/msync call, regardless of what internal callers are doing 2) report writeback errors on all file descriptions that were open at the time that the error occurred. This is a user-visible change, but I think most applications are written to assume this behavior anyway. Those that aren't are unlikely to be hurt by it. 3) document what filesystems should do when there is a writeback error. Today, there is very little consistency between them, and a lot of cargo-cult copying. We need to make it very clear what filesystems should do in this situation. To achieve this, the set adds a new data type (errseq_t) and then builds new writeback error tracking infrastructure around that. Once all of that is in place, we change the filesystems to use the new infrastructure for reporting wb errors to userland. Note that this is just the initial foray into cleaning up this mess. There is a lot of work remaining here: 1) convert the rest of the filesystems in a similar fashion. Once the initial set is in, then I think most other fs' will be fairly simple to convert. Hopefully most of those can in via individual filesystem trees. 2) convert internal waiters on writeback to use errseq_t for detecting errors instead of relying on the AS_* flags. I have some draft patches for this for ext4, but they are not quite ready for prime time yet. This was a discussion topic this year at LSF/MM too. If you're interested in the gory details, LWN has some good articles about this: https://lwn.net/Articles/718734/ https://lwn.net/Articles/724307/" * tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: btrfs: minimal conversion to errseq_t writeback error reporting on fsync xfs: minimal conversion to errseq_t writeback error reporting ext4: use errseq_t based error handling for reporting data writeback errors fs: convert __generic_file_fsync to use errseq_t based reporting block: convert to errseq_t based writeback error tracking dax: set errors in mapping when writeback fails Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error fs: new infrastructure for writeback error handling and reporting lib: add errseq_t type and infrastructure for handling it mm: don't TestClearPageError in __filemap_fdatawait_range mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails jbd2: don't clear and reset errors after waiting on writeback buffer: set errors in mapping at the time that the error occurs fs: check for writeback errors after syncing out buffers in generic_file_fsync buffer: use mapping_set_error instead of setting the flag mm: fix mapping_set_error call in me_pagecache_dirty
2017-07-08xfs: don't crash on unexpected holes in dir/attr btreesDarrick J. Wong4-5/+5
In quite a few places we call xfs_da_read_buf with a mappedbno that we don't control, then assume that the function passes back either an error code or a buffer pointer. Unfortunately, if mappedbno == -2 and bno maps to a hole, we get a return code of zero and a NULL buffer, which means that we crash if we actually try to use that buffer pointer. This happens immediately when we set the buffer type for transaction context. Therefore, check that we have no error code and a non-NULL bp before trying to use bp. This patch is a follow-up to an incomplete fix in 96a3aefb8ffde231 ("xfs: don't crash if reading a directory results in an unexpected hole"). Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2017-07-08Merge tag 'for-linus-v4.13-1' of ↵Linus Torvalds8-8/+12
git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux Pull Writeback error handling fixes from Jeff Layton: "The main rationale for all of these changes is to tighten up writeback error reporting to userland. There are many ways now that writeback errors can be lost, such that fsync/fdatasync/msync return 0 when writeback actually failed. This pile contains a small set of cleanups and writeback error handling fixes that I was able to break off from the main pile (#2). Two of the patches in this pile are trivial. The exceptions are the patch to fix up error handling in write_one_page, and the patch to make JFS pay attention to write_one_page errors" * tag 'for-linus-v4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux: fs: remove call_fsync helper function mm: clean up error handling in write_one_page JFS: do not ignore return code from write_one_page() mm: drop "wait" parameter from write_one_page()
2017-07-08Merge tag 'cifs-bug-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds8-24/+218
Pull cifs fixes from Steve French: "First set of CIFS/SMB3 fixes for the merge window. Also improves POSIX character mapping for SMB3" * tag 'cifs-bug-fixes-for-4.13' of git://git.samba.org/sfrench/cifs-2.6: CIFS: fix circular locking dependency cifs: set oparms.create_options rather than or'ing in CREATE_OPEN_BACKUP_INTENT cifs: Do not modify mid entry after submitting I/O in cifs_call_async CIFS: add SFM mapping for 0x01-0x1F cifs: hide unused functions cifs: Use smb 2 - 3 and cifsacl mount options getacl functions cifs: prototype declaration and definition for smb 2 - 3 and cifsacl mount options CIFS: add CONFIG_CIFS_DEBUG_KEYS to dump encryption keys cifs: set mapping error when page writeback fails in writepage or launder_pages SMB3: Enable encryption for SMB3.1.1
2017-07-08Merge tag 'gfs2-4.13.fixes.addendum' of ↵Linus Torvalds2-2/+10
git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2 Pull GFS2 fix from Bob Peterson: "Sorry for the additional merge request, but Andreas discovered this problem soon after you processed our last gfs2 merge. This fixes a regression introduced by a patch we did in mid-2015 (commit 88ffbf3e037e: "GFS2: Use resizable hash table for glocks"), so best to get it fixed. Some code was reverted that should not have been. The patch from Andreas Gruenbacher just re-adds code that had been there originally" * tag 'gfs2-4.13.fixes.addendum' of git://git.kernel.org/pub/scm/linux/kernel/git/gfs2/linux-gfs2: gfs2: Fix glock rhashtable rcu bug
2017-07-08dentry name snapshotsAl Viro4-11/+42
take_dentry_name_snapshot() takes a safe snapshot of dentry name; if the name is a short one, it gets copied into caller-supplied structure, otherwise an extra reference to external name is grabbed (those are never modified). In either case the pointer to stable string is stored into the same structure. dentry must be held by the caller of take_dentry_name_snapshot(), but may be freely dropped afterwards - the snapshot will stay until destroyed by release_dentry_name_snapshot(). Intended use: struct name_snapshot s; take_dentry_name_snapshot(&s, dentry); ... access s.name ... release_dentry_name_snapshot(&s); Replaces fsnotify_oldname_...(), gets used in fsnotify to obtain the name to pass down with event. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-07vfs: fix flock compat thinkoLinus Torvalds1-15/+15
Michael Ellerman reported that commit 8c6657cb50cb ("Switch flock copyin/copyout primitives to copy_{from,to}_user()") broke his networking on a bunch of PPC machines (64-bit kernel, 32-bit userspace). The reason is a brown-paper bug by that commit, which had the arguments to "copy_flock_fields()" in the wrong order, breaking the compat handling for file locking. Apparently very few people run 32-bit user space on x86 any more, so the PPC people got the honor of noticing this "feature". Michael also sent a minimal diff that just changed the order of the arguments in that macro. This is not that minimal diff. This not only changes the order of the arguments in the macro, it also changes them to be pointers (to be consistent with all the other uses of those pointers), and makes the functions that do all of this also have the proper "const" attribution on the source pointers in order to make issues like that (using the source as a destination) be really obvious. Reported-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07gfs2: Fix glock rhashtable rcu bugAndreas Gruenbacher2-2/+10
Before commit 88ffbf3e03 "GFS2: Use resizable hash table for glocks", glocks were freed via call_rcu to allow reading the glock hashtable locklessly using rcu. This was then changed to free glocks immediately, which made reading the glock hashtable unsafe. Bring back the original code for freeing glocks via call_rcu. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Bob Peterson <rpeterso@redhat.com> Cc: stable@vger.kernel.org # 4.3+
2017-07-07Merge tag 'libnvdimm-for-4.13' of ↵Linus Torvalds1-4/+5
git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm Pull libnvdimm updates from Dan Williams: "libnvdimm updates for the latest ACPI and UEFI specifications. This pull request also includes new 'struct dax_operations' enabling to undo the abuse of copy_user_nocache() for copy operations to pmem. The dax work originally missed 4.12 to address concerns raised by Al. Summary: - Introduce the _flushcache() family of memory copy helpers and use them for persistent memory write operations on x86. The _flushcache() semantic indicates that the cache is either bypassed for the copy operation (movnt) or any lines dirtied by the copy operation are written back (clwb, clflushopt, or clflush). - Extend dax_operations with ->copy_from_iter() and ->flush() operations. These operations and other infrastructure updates allow all persistent memory specific dax functionality to be pushed into libnvdimm and the pmem driver directly. It also allows dax-specific sysfs attributes to be linked to a host device, for example: /sys/block/pmem0/dax/write_cache - Add support for the new NVDIMM platform/firmware mechanisms introduced in ACPI 6.2 and UEFI 2.7. This support includes the v1.2 namespace label format, extensions to the address-range-scrub command set, new error injection commands, and a new BTT (block-translation-table) layout. These updates support inter-OS and pre-OS compatibility. - Fix a longstanding memory corruption bug in nfit_test. - Make the pmem and nvdimm-region 'badblocks' sysfs files poll(2) capable. - Miscellaneous fixes and small updates across libnvdimm and the nfit driver. Acknowledgements that came after the branch was pushed: commit 6aa734a2f38e ("libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime") was reviewed by Toshi Kani <toshi.kani@hpe.com>" * tag 'libnvdimm-for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/nvdimm/nvdimm: (42 commits) libnvdimm, namespace: record 'lbasize' for pmem namespaces acpi/nfit: Issue Start ARS to retrieve existing records libnvdimm: New ACPI 6.2 DSM functions acpi, nfit: Show bus_dsm_mask in sysfs libnvdimm, acpi, nfit: Add bus level dsm mask for pass thru. acpi, nfit: Enable DSM pass thru for root functions. libnvdimm: passthru functions clear to send libnvdimm, btt: convert some info messages to warn/err libnvdimm, region, pmem: fix 'badblocks' sysfs_get_dirent() reference lifetime libnvdimm: fix the clear-error check in nsio_rw_bytes libnvdimm, btt: fix btt_rw_page not returning errors acpi, nfit: quiet invalid block-aperture-region warnings libnvdimm, btt: BTT updates for UEFI 2.7 format acpi, nfit: constify *_attribute_group libnvdimm, pmem: disable dax flushing when pmem is fronting a volatile region libnvdimm, pmem, dax: export a cache control attribute dax: convert to bitmask for flags dax: remove default copy_from_iter fallback libnvdimm, nfit: enable support for volatile ranges libnvdimm, pmem: fix persistence warning ...
2017-07-07xfs: rename MAXPATHLEN to XFS_SYMLINK_MAXLENDarrick J. Wong6-8/+8
XFS has a maximum symlink target length of 1024 bytes; this is a holdover from the Irix days. Unfortunately, the constant establishing this is 'MAXPATHLEN' and is /not/ the same as the Linux MAXPATHLEN, which is 4096. The kernel enforces its 1024 byte MAXPATHLEN on symlink targets, but xfsprogs picks up the (Linux) system 4096 byte MAXPATHLEN, which means that xfs_repair doesn't complain about oversized symlinks. Since this is an on-disk format constraint, put the define in the XFS namespace and move everything over to use the new name. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com>
2017-07-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds11-66/+24
Merge misc updates from Andrew Morton: - a few hotfixes - various misc updates - ocfs2 updates - most of MM * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (108 commits) mm, memory_hotplug: move movable_node to the hotplug proper mm, memory_hotplug: drop CONFIG_MOVABLE_NODE mm, memory_hotplug: drop artificial restriction on online/offline mm: memcontrol: account slab stats per lruvec mm: memcontrol: per-lruvec stats infrastructure mm: memcontrol: use generic mod_memcg_page_state for kmem pages mm: memcontrol: use the node-native slab memory counters mm: vmstat: move slab statistics from zone to node counters mm/zswap.c: delete an error message for a failed memory allocation in zswap_dstmem_prepare() mm/zswap.c: improve a size determination in zswap_frontswap_init() mm/zswap.c: delete an error message for a failed memory allocation in zswap_pool_create() mm/swapfile.c: sort swap entries before free mm/oom_kill: count global and memory cgroup oom kills mm: per-cgroup memory reclaim stats mm: kmemleak: treat vm_struct as alternative reference to vmalloc'ed objects mm: kmemleak: factor object reference updating out of scan_block() mm: kmemleak: slightly reduce the size of some structures on 64-bit architectures mm, mempolicy: don't check cpuset seqlock where it doesn't matter mm, cpuset: always use seqlock when changing task's nodemask mm, mempolicy: simplify rebinding mempolicies when updating cpusets ...
2017-07-07Merge branch 'misc.compat' of ↵Linus Torvalds1-39/+5
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc compat stuff updates from Al Viro: "This part is basically untangling various compat stuff. Compat syscalls moved to their native counterparts, getting rid of quite a bit of double-copying and/or set_fs() uses. A lot of field-by-field copyin/copyout killed off. - kernel/compat.c is much closer to containing just the copyin/copyout of compat structs. Not all compat syscalls are gone from it yet, but it's getting there. - ipc/compat_mq.c killed off completely. - block/compat_ioctl.c cleaned up; floppy compat ioctls moved to drivers/block/floppy.c where they belong. Yes, there are several drivers that implement some of the same ioctls. Some are m68k and one is 32bit-only pmac. drivers/block/floppy.c is the only one in that bunch that can be built on biarch" * 'misc.compat' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: mqueue: move compat syscalls to native ones usbdevfs: get rid of field-by-field copyin compat_hdio_ioctl: get rid of set_fs() take floppy compat ioctls to sodding floppy.c ipmi: get rid of field-by-field __get_user() ipmi: get COMPAT_IPMICTL_RECEIVE_MSG in sync with the native one rt_sigtimedwait(): move compat to native select: switch compat_{get,put}_fd_set() to compat_{get,put}_bitmap() put_compat_rusage(): switch to copy_to_user() sigpending(): move compat to native getrlimit()/setrlimit(): move compat to native times(2): move compat to native compat_{get,put}_bitmap(): use unsafe_{get,put}_user() fb_get_fscreeninfo(): don't bother with do_fb_ioctl() do_sigaltstack(): lift copying to/from userland into callers take compat_sys_old_getrlimit() to native syscall trim __ARCH_WANT_SYS_OLD_GETRLIMIT
2017-07-07mm: per-cgroup memory reclaim statsRoman Gushchin2-2/+2
Track the following reclaim counters for every memory cgroup: PGREFILL, PGSCAN, PGSTEAL, PGACTIVATE, PGDEACTIVATE, PGLAZYFREE and PGLAZYFREED. These values are exposed using the memory.stats interface of cgroup v2. The meaning of each value is the same as for global counters, available using /proc/vmstat. Also, for consistency, rename mem_cgroup_count_vm_event() to count_memcg_event_mm(). Link: http://lkml.kernel.org/r/1494530183-30808-1-git-send-email-guro@fb.com Signed-off-by: Roman Gushchin <guro@fb.com> Suggested-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Vladimir Davydov <vdavydov.dev@gmail.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Cc: Li Zefan <lizefan@huawei.com> Cc: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm/hugetlb: add size parameter to huge_pte_offset()Punit Agrawal1-2/+5
A poisoned or migrated hugepage is stored as a swap entry in the page tables. On architectures that support hugepages consisting of contiguous page table entries (such as on arm64) this leads to ambiguity in determining the page table entry to return in huge_pte_offset() when a poisoned entry is encountered. Let's remove the ambiguity by adding a size parameter to convey additional information about the requested address. Also fixup the definition/usage of huge_pte_offset() throughout the tree. Link: http://lkml.kernel.org/r/20170522133604.11392-4-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> (odd fixer:METAG ARCHITECTURE) Cc: Ralf Baechle <ralf@linux-mips.org> (supporter:MIPS) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07mm: update callers to use HASH_ZERO flagPavel Tatashin3-34/+8
Update dcache, inode, pid, mountpoint, and mount hash tables to use HASH_ZERO, and remove initialization after allocations. In case of places where HASH_EARLY was used such as in __pv_init_lock_hash the zeroed hash table was already assumed, because memblock zeroes the memory. CPU: SPARC M6, Memory: 7T Before fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 11.798s After fix: Dentry cache hash table entries: 1073741824 Inode-cache hash table entries: 536870912 Mount-cache hash table entries: 16777216 Mountpoint-cache hash table entries: 16777216 ftrace: allocating 20414 entries in 40 pages Total time: 3.198s CPU: Intel Xeon E5-2630, Memory: 2.2T: Before fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.245s After fix: Dentry cache hash table entries: 536870912 Inode-cache hash table entries: 268435456 Mount-cache hash table entries: 8388608 Mountpoint-cache hash table entries: 8388608 CPU: Physical Processor ID: 0 Total time: 3.244s Link: http://lkml.kernel.org/r/1488432825-92126-4-git-send-email-pasha.tatashin@oracle.com Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com> Reviewed-by: Babu Moger <babu.moger@oracle.com> Cc: David Miller <davem@davemloft.net> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07fs/userfaultfd.c: drop dead codeMike Rapoport1-5/+0
Calculation of start end end in __wake_userfault function are not used and can be removed. Link: http://lkml.kernel.org/r/1494930917-3134-1-git-send-email-rppt@linux.vnet.ibm.com Signed-off-by: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07fs/file.c: replace alloc_fdmem() with kvmalloc() alternativeMichal Hocko1-18/+4
There is no real reason to duplicate kvmalloc* helpers so drop alloc_fdmem and replace it with the appropriate library function. Link: http://lkml.kernel.org/r/20170531155145.17111-2-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07ocfs2: constify attribute_group structuresArvind Yadav1-1/+1
attribute_groups are not supposed to change at runtime. All functions working with attribute_groups provided by <linux/sysfs.h> work with const attribute_group. So mark the non-const structs as const. File size before: text data bss dec hex filename 4402 1088 38 5528 1598 fs/ocfs2/stackglue.o File size After adding 'const': text data bss dec hex filename 4442 1024 38 5504 1580 fs/ocfs2/stackglue.o Link: http://lkml.kernel.org/r/cab4e59b4918db3ed2ec77073a4cb310c4429ef5.1498808026.git.arvind.yadav.cs@gmail.com Signed-off-by: Arvind Yadav <arvind.yadav.cs@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07ocfs2: free 'dummy_sc' in sc_fop_release() to prevent memory leakpiaojun1-0/+1
'sd->dbg_sock' is malloced in sc_common_open(), but not freed at the end of sc_fop_release(). Link: http://lkml.kernel.org/r/594FB0A4.2050105@huawei.com Signed-off-by: Jun Piao <piaojun@huawei.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Cc: Mark Fasheh <mfasheh@versity.com> 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>
2017-07-07ocfs2: use magic.hFabian Frederick1-3/+2
Filesystems generally use SUPER_MAGIC values from magic.h instead of a local definition. Link: http://lkml.kernel.org/r/20170521154217.27917-1-fabf@skynet.be Signed-off-by: Fabian Frederick <fabf@skynet.be> Reviewed-by: Mark Fasheh <mfasheh@versity.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <jiangqi903@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07ocfs2: fix a static checker warningGang He1-1/+1
Fix a static code checker warning: fs/ocfs2/inode.c:179 ocfs2_iget() warn: passing zero to 'ERR_PTR' Fixes: d56a8f32e4c6 ("ocfs2: check/fix inode block for online file check") Link: http://lkml.kernel.org/r/1495516634-1952-1-git-send-email-ghe@suse.com Signed-off-by: Gang He <ghe@suse.com> Reviewed-by: Joseph Qi <jiangqi903@gmail.com> Reviewed-by: Eric Ren <zren@suse.com> Cc: Mark Fasheh <mfasheh@versity.com> 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>
2017-07-06ext4: fix spelling mistake: "prellocated" -> "preallocated"Colin Ian King1-1/+1
Trivial fix to spelling mistake in mb_debug debug message Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2017-07-06Merge branch 'for-4.13' of ↵Linus Torvalds4-15/+15
git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu Pull percpu updates from Tejun Heo: "These are the percpu changes for the v4.13-rc1 merge window. There are a couple visibility related changes - tracepoints and allocator stats through debugfs, along with __ro_after_init markings and a cosmetic rename in percpu_counter. Please note that the simple O(#elements_in_the_chunk) area allocator used by percpu allocator is again showing scalability issues, primarily with bpf allocating and freeing large number of counters. Dennis is working on the replacement allocator and the percpu allocator will be seeing increased churns in the coming cycles" * 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu: percpu: fix static checker warnings in pcpu_destroy_chunk percpu: fix early calls for spinlock in pcpu_stats percpu: resolve err may not be initialized in pcpu_alloc percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch percpu: add tracepoint support for percpu memory percpu: expose statistics about percpu memory via debugfs percpu: migrate percpu data structures to internal header percpu: add missing lockdep_assert_held to func pcpu_free_area mark most percpu globals as __ro_after_init
2017-07-06move file_{start,end}_write() out of do_iter_write()Al Viro1-2/+4
... and do *not* grab it in vfs_write_iter(). Fixes: "fs: implement vfs_iter_read using do_iter_read" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-06btrfs: minimal conversion to errseq_t writeback error reporting on fsyncJeff Layton1-5/+8
Just check and advance the errseq_t in the file before returning, and use an errseq_t based check for writeback errors. Other internal callers of filemap_* functions are left as-is. Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06xfs: minimal conversion to errseq_t writeback error reportingJeff Layton1-1/+1
Just check and advance the data errseq_t in struct file before before returning from fsync on normal files. Internal filemap_* callers are left as-is. Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06ext4: use errseq_t based error handling for reporting data writeback errorsJeff Layton1-1/+1
Add a call to filemap_report_wb_err at the end of ext4_sync_file. This will ensure that we check and advance the errseq_t in the file, which allows us to track and report errors on all open fds when they occur. Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06fs: convert __generic_file_fsync to use errseq_t based reportingJeff Layton1-4/+6
Many simple, block-based filesystems use generic_file_fsync as their fsync operation. Some others (ext* and fat) also call this function to handle syncing out data. Switch this code over to use errseq_t based error reporting so that all of these filesystems get reliable error reporting via fsync, fdatasync and msync. Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06block: convert to errseq_t based writeback error trackingJeff Layton1-1/+1
This is a very minimal conversion to errseq_t based error tracking for raw block device access. Just have it use the standard file_write_and_wait_range call. Note that there are internal callers that call sync_blockdev and the like that are not affected by this. They'll continue to use the AS_EIO/AS_ENOSPC flags for error reporting like they always have for now. Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06dax: set errors in mapping when writeback failsJeff Layton1-1/+3
Jan Kara's description for this patch is much better than mine, so I'm quoting it verbatim here: DAX currently doesn't set errors in the mapping when cache flushing fails in dax_writeback_mapping_range(). Since this function can get called only from fsync(2) or sync(2), this is actually as good as it can currently get since we correctly propagate the error up from dax_writeback_mapping_range() to filemap_fdatawrite() However, in the future better writeback error handling will enable us to properly report these errors on fsync(2) even if there are multiple file descriptors open against the file or if sync(2) gets called before fsync(2). So convert DAX to using standard error reporting through the mapping. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-and-tested-by: Ross Zwisler <ross.zwisler@linux.intel.com>
2017-07-06fs: new infrastructure for writeback error handling and reportingJeff Layton3-0/+5
Most filesystems currently use mapping_set_error and filemap_check_errors for setting and reporting/clearing writeback errors at the mapping level. filemap_check_errors is indirectly called from most of the filemap_fdatawait_* functions and from filemap_write_and_wait*. These functions are called from all sorts of contexts to wait on writeback to finish -- e.g. mostly in fsync, but also in truncate calls, getattr, etc. The non-fsync callers are problematic. We should be reporting writeback errors during fsync, but many places spread over the tree clear out errors before they can be properly reported, or report errors at nonsensical times. If I get -EIO on a stat() call, there is no reason for me to assume that it is because some previous writeback failed. The fact that it also clears out the error such that a subsequent fsync returns 0 is a bug, and a nasty one since that's potentially silent data corruption. This patch adds a small bit of new infrastructure for setting and reporting errors during address_space writeback. While the above was my original impetus for adding this, I think it's also the case that current fsync semantics are just problematic for userland. Most applications that call fsync do so to ensure that the data they wrote has hit the backing store. In the case where there are multiple writers to the file at the same time, this is really hard to determine. The first one to call fsync will see any stored error, and the rest get back 0. The processes with open fds may not be associated with one another in any way. They could even be in different containers, so ensuring coordination between all fsync callers is not really an option. One way to remedy this would be to track what file descriptor was used to dirty the file, but that's rather cumbersome and would likely be slow. However, there is a simpler way to improve the semantics here without incurring too much overhead. This set adds an errseq_t to struct address_space, and a corresponding one is added to struct file. Writeback errors are recorded in the mapping's errseq_t, and the one in struct file is used as the "since" value. This changes the semantics of the Linux fsync implementation such that applications can now use it to determine whether there were any writeback errors since fsync(fd) was last called (or since the file was opened in the case of fsync having never been called). Note that those writeback errors may have occurred when writing data that was dirtied via an entirely different fd, but that's the case now with the current mapping_set_error/filemap_check_error infrastructure. This will at least prevent you from getting a false report of success. The new behavior is still consistent with the POSIX spec, and is more reliable for application developers. This patch just adds some basic infrastructure for doing this, and ensures that the f_wb_err "cursor" is properly set when a file is opened. Later patches will change the existing code to use this new infrastructure for reporting errors at fsync time. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz>
2017-07-06jbd2: don't clear and reset errors after waiting on writebackJeff Layton1-12/+4
Resetting this flag is almost certainly racy, and will be problematic with some coming changes. Make filemap_fdatawait_keep_errors return int, but not clear the flag(s). Have jbd2 call it instead of filemap_fdatawait and don't attempt to re-set the error flag if it fails. Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06buffer: set errors in mapping at the time that the error occursJeff Layton2-8/+14
I noticed on xfs that I could still sometimes get back an error on fsync on a fd that was opened after the error condition had been cleared. The problem is that the buffer code sets the write_io_error flag and then later checks that flag to set the error in the mapping. That flag perisists for quite a while however. If the file is later opened with O_TRUNC, the buffers will then be invalidated and the mapping's error set such that a subsequent fsync will return error. I think this is incorrect, as there was no writeback between the open and fsync. Add a new mark_buffer_write_io_error operation that sets the flag and the error in the mapping at the same time. Replace all calls to set_buffer_write_io_error with mark_buffer_write_io_error, and remove the places that check this flag in order to set the error in the mapping. This sets the error in the mapping earlier, at the time that it's first detected. Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
2017-07-06fs: check for writeback errors after syncing out buffers in generic_file_fsyncJeff Layton2-5/+4
ext2 currently does a test+clear of the AS_EIO flag, which is is problematic for some coming changes. What we really need to do instead is call filemap_check_errors in __generic_file_fsync after syncing out the buffers. That will be sufficient for this case, and help other callers detect these errors properly as well. With that, we don't need to twiddle it in ext2. Suggested-by: Jan Kara <jack@suse.cz> Signed-off-by: Jeff Layton <jlayton@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>