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2020-01-15nfs: don't bother setting/restoring export_path around do_nfs_root_mount()Al Viro
nothing in it will be looking at that thing anyway Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15nfs: fold nfs4_remote_fs_type and nfs4_remote_referral_fs_typeAl Viro
They are identical now. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15nfs: lift setting mount_info from nfs4_remote{,_referral}_mountAl Viro
Do that (fhandle allocation, setting struct server up) in nfs4_referral_mount() and nfs4_try_mount() resp. and pass the server and pointer to mount_info into nfs_do_root_mount() so that nfs4_remote_referral_mount()/nfs_remote_mount() could be merged. Since we are moving stuff from ->mount() instances to the points prior to vfs_kern_mount() that would trigger those, we need to make sure that do_nfs_root_mount() will do the corresponding cleanup itself if it doesn't trigger those ->mount() instances. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15nfs: stash server into struct nfs_mount_infoAl Viro
Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15saner calling conventions for nfs_fs_mount_common()Al Viro
Allow it to take ERR_PTR() for server and return ERR_CAST() of it in such case. All callers used to open-code that... Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2020-01-15gfs2: Avoid access time thrashing in gfs2_inode_lookupAndreas Gruenbacher
In gfs2_inode_lookup, we initialize inode->i_atime to the lowest possibly value after gfs2_inode_refresh may already have been called. This should be the other way around, but we didn't notice because usually the inode type is known from the directory entry and so gfs2_inode_lookup won't call gfs2_inode_refresh. In addition, only initialize ip->i_no_formal_ino from no_formal_ino when actually needed. Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
2020-01-15fix autofs regression caused by follow_managed() changesAl Viro
we need to reload ->d_flags after the call of ->d_manage() - the thing might've been called with dentry still negative and have the damn thing turned positive while we'd waited. Fixes: d41efb522e90 "fs/namei.c: pull positivity check into follow_managed()" Reported-by: Ian Kent <raven@themaw.net> Tested-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-15reimplement path_mountpoint() with less magicAl Viro
... and get rid of a bunch of bugs in it. Background: the reason for path_mountpoint() is that umount() really doesn't want attempts to revalidate the root of what it's trying to umount. The thing we want to avoid actually happen from complete_walk(); solution was to do something parallel to normal path_lookupat() and it both went overboard and got the boilerplate subtly (and not so subtly) wrong. A better solution is to do pretty much what the normal path_lookupat() does, but instead of complete_walk() do unlazy_walk(). All it takes to avoid that ->d_weak_revalidate() call... mountpoint_last() goes away, along with everything it got wrong, and so does the magic around LOOKUP_NO_REVAL. Another source of bugs is that when we traverse mounts at the final location (and we need to do that - umount . expects to get whatever's overmounting ., if any, out of the lookup) we really ought to take care of ->d_manage() - as it is, manual umount of autofs automount in progress can lead to unpleasant surprises for the daemon. Easily solved by using handle_lookup_down() instead of follow_mount(). Tested-by: Ian Kent <raven@themaw.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-01-14io_uring: be consistent in assigning next work from handlerJens Axboe
If we pass back dependent work in case of links, we need to always ensure that we call the link setup and work prep handler. If not, we might be missing some setup for the next work item. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-14io-wq: cancel work if we fail getting a mm referenceJens Axboe
If we require mm and user context, mark the request for cancellation if we fail to acquire the desired mm. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-14fs-verity: use u64_to_user_ptr()Eric Biggers
<linux/kernel.h> already provides a macro u64_to_user_ptr(). Use it instead of open-coding the two casts. No change in behavior. Link: https://lore.kernel.org/r/20191231175408.20524-1-ebiggers@kernel.org Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14fs-verity: use mempool for hash requestsEric Biggers
When initializing an fs-verity hash algorithm, also initialize a mempool that contains a single preallocated hash request object. Then replace the direct calls to ahash_request_alloc() and ahash_request_free() with allocating and freeing from this mempool. This eliminates the possibility of the allocation failing, which is desirable for the I/O path. This doesn't cause deadlocks because there's no case where multiple hash requests are needed at a time to make forward progress. Link: https://lore.kernel.org/r/20191231175545.20709-1-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14fs-verity: implement readahead of Merkle tree pagesEric Biggers
When fs-verity verifies data pages, currently it reads each Merkle tree page synchronously using read_mapping_page(). Therefore, when the Merkle tree pages aren't already cached, fs-verity causes an extra 4 KiB I/O request for every 512 KiB of data (assuming that the Merkle tree uses SHA-256 and 4 KiB blocks). This results in more I/O requests and performance loss than is strictly necessary. Therefore, implement readahead of the Merkle tree pages. For simplicity, we take advantage of the fact that the kernel already does readahead of the file's *data*, just like it does for any other file. Due to this, we don't really need a separate readahead state (struct file_ra_state) just for the Merkle tree, but rather we just need to piggy-back on the existing data readahead requests. We also only really need to bother with the first level of the Merkle tree, since the usual fan-out factor is 128, so normally over 99% of Merkle tree I/O requests are for the first level. Therefore, make fsverity_verify_bio() enable readahead of the first Merkle tree level, for up to 1/4 the number of pages in the bio, when it sees that the REQ_RAHEAD flag is set on the bio. The readahead size is then passed down to ->read_merkle_tree_page() for the filesystem to (optionally) implement if it sees that the requested page is uncached. While we're at it, also make build_merkle_tree_level() set the Merkle tree readahead size, since it's easy to do there. However, for now don't set the readahead size in fsverity_verify_page(), since currently it's only used to verify holes on ext4 and f2fs, and it would need parameters added to know how much to read ahead. This patch significantly improves fs-verity sequential read performance. Some quick benchmarks with 'cat'-ing a 250MB file after dropping caches: On an ARM64 phone (using sha256-ce): Before: 217 MB/s After: 263 MB/s (compare to sha256sum of non-verity file: 357 MB/s) In an x86_64 VM (using sha256-avx2): Before: 173 MB/s After: 215 MB/s (compare to sha256sum of non-verity file: 223 MB/s) Link: https://lore.kernel.org/r/20200106205533.137005-1-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14fs-verity: implement readahead for FS_IOC_ENABLE_VERITYEric Biggers
When it builds the first level of the Merkle tree, FS_IOC_ENABLE_VERITY sequentially reads each page of the file using read_mapping_page(). This works fine if the file's data is already in pagecache, which should normally be the case, since this ioctl is normally used immediately after writing out the file. But in any other case this implementation performs very poorly, since only one page is read at a time. Fix this by implementing readahead using the functions from mm/readahead.c. This improves performance in the uncached case by about 20x, as seen in the following benchmarks done on a 250MB file (on x86_64 with SHA-NI): FS_IOC_ENABLE_VERITY uncached (before) 3.299s FS_IOC_ENABLE_VERITY uncached (after) 0.160s FS_IOC_ENABLE_VERITY cached 0.147s sha256sum uncached 0.191s sha256sum cached 0.145s Note: we could instead switch to kernel_read(). But that would mean we'd no longer be hashing the data directly from the pagecache, which is a nice optimization of its own. And using kernel_read() would require allocating another temporary buffer, hashing the data and tree pages separately, and explicitly zero-padding the last page -- so it wouldn't really be any simpler than direct pagecache access, at least for now. Link: https://lore.kernel.org/r/20200106205410.136707-1-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14fscrypt: document gfp_flags for bounce page allocationEric Biggers
Document that fscrypt_encrypt_pagecache_blocks() allocates the bounce page from a mempool, and document what this means for the @gfp_flags argument. Link: https://lore.kernel.org/r/20191231181026.47400-1-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14fscrypt: optimize fscrypt_zeroout_range()Eric Biggers
Currently fscrypt_zeroout_range() issues and waits on a bio for each block it writes, which makes it very slow. Optimize it to write up to 16 pages at a time instead. Also add a function comment, and improve reliability by allowing the allocations of the bio and the first ciphertext page to wait on the corresponding mempools. Link: https://lore.kernel.org/r/20191226160813.53182-1-ebiggers@kernel.org Reviewed-by: Theodore Ts'o <tytso@mit.edu> Signed-off-by: Eric Biggers <ebiggers@google.com>
2020-01-14Merge branch 'dhowells' (patches from DavidH)Linus Torvalds
Merge misc fixes from David Howells. Two afs fixes and a key refcounting fix. * dhowells: afs: Fix afs_lookup() to not clobber the version on a new dentry afs: Fix use-after-loss-of-ref keys: Fix request_key() cache
2020-01-14afs: Fix afs_lookup() to not clobber the version on a new dentryDavid Howells
Fix afs_lookup() to not clobber the version set on a new dentry by afs_do_lookup() - especially as it's using the wrong version of the version (we need to use the one given to us by whatever op the dir contents correspond to rather than what's in the afs_vnode). Fixes: 9dd0b82ef530 ("afs: Fix missing dentry data version updating") Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-14afs: Fix use-after-loss-of-refDavid Howells
afs_lookup() has a tracepoint to indicate the outcome of d_splice_alias(), passing it the inode to retrieve the fid from. However, the function gave up its ref on that inode when it called d_splice_alias(), which may have failed and dropped the inode. Fix this by caching the fid. Fixes: 80548b03991f ("afs: Add more tracepoints") Reported-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-01-14xfs: fix s_maxbytes computation on 32-bit kernelsDarrick J. Wong
I observed a hang in generic/308 while running fstests on a i686 kernel. The hang occurred when trying to purge the pagecache on a large sparse file that had a page created past MAX_LFS_FILESIZE, which caused an integer overflow in the pagecache xarray and resulted in an infinite loop. I then noticed that Linus changed the definition of MAX_LFS_FILESIZE in commit 0cc3b0ec23ce ("Clarify (and fix) MAX_LFS_FILESIZE macros") so that it is now one page short of the maximum page index on 32-bit kernels. Because the XFS function to compute max offset open-codes the 2005-era MAX_LFS_FILESIZE computation and neither the vfs nor mm perform any sanity checking of s_maxbytes, the code in generic/308 can create a page above the pagecache's limit and kaboom. Fix all this by setting s_maxbytes to MAX_LFS_FILESIZE directly and aborting the mount with a warning if our assumptions ever break. I have no answer for why this seems to have been broken for years and nobody noticed. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-14xfs: truncate should remove all blocks, not just to the end of the page cacheDarrick J. Wong
xfs_itruncate_extents_flags() is supposed to unmap every block in a file from EOF onwards. Oddly, it uses s_maxbytes as the upper limit to the bunmapi range, even though s_maxbytes reflects the highest offset the pagecache can support, not the highest offset that XFS supports. The result of this confusion is that if you create a 20T file on a 64-bit machine, mount the filesystem on a 32-bit machine, and remove the file, we leak everything above 16T. Fix this by capping the bunmapi request at the maximum possible block offset, not s_maxbytes. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-14xfs: introduce XFS_MAX_FILEOFFDarrick J. Wong
Introduce a new #define for the maximum supported file block offset. We'll use this in the next patch to make it more obvious that we're doing some operation for all possible inode fork mappings after a given offset. We can't use ULLONG_MAX here because bunmapi uses that to detect when it's done. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-14debugfs: Return -EPERM when locked downEric Snowberg
When lockdown is enabled, debugfs_is_locked_down returns 1. It will then trigger the following: WARNING: CPU: 48 PID: 3747 CPU: 48 PID: 3743 Comm: bash Not tainted 5.4.0-1946.x86_64 #1 Hardware name: Oracle Corporation ORACLE SERVER X7-2/ASM, MB, X7-2, BIOS 41060400 05/20/2019 RIP: 0010:do_dentry_open+0x343/0x3a0 Code: 00 40 08 00 45 31 ff 48 c7 43 28 40 5b e7 89 e9 02 ff ff ff 48 8b 53 28 4c 8b 72 70 4d 85 f6 0f 84 10 fe ff ff e9 f5 fd ff ff <0f> 0b 41 bf ea ff ff ff e9 3b ff ff ff 41 bf e6 ff ff ff e9 b4 fe RSP: 0018:ffffb8740dde7ca0 EFLAGS: 00010202 RAX: ffffffff89e88a40 RBX: ffff928c8e6b6f00 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff928dbfd97778 RDI: ffff9285cff685c0 RBP: ffffb8740dde7cc8 R08: 0000000000000821 R09: 0000000000000030 R10: 0000000000000057 R11: ffffb8740dde7a98 R12: ffff926ec781c900 R13: ffff928c8e6b6f10 R14: ffffffff8936e190 R15: 0000000000000001 FS: 00007f45f6777740(0000) GS:ffff928dbfd80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff95e0d5d8 CR3: 0000001ece562006 CR4: 00000000007606e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 PKRU: 55555554 Call Trace: vfs_open+0x2d/0x30 path_openat+0x2d4/0x1680 ? tty_mode_ioctl+0x298/0x4c0 do_filp_open+0x93/0x100 ? strncpy_from_user+0x57/0x1b0 ? __alloc_fd+0x46/0x150 do_sys_open+0x182/0x230 __x64_sys_openat+0x20/0x30 do_syscall_64+0x60/0x1b0 entry_SYSCALL_64_after_hwframe+0x170/0x1d5 RIP: 0033:0x7f45f5e5ce02 Code: 25 00 00 41 00 3d 00 00 41 00 74 4c 48 8d 05 25 59 2d 00 8b 00 85 c0 75 6d 89 f2 b8 01 01 00 00 48 89 fe bf 9c ff ff ff 0f 05 <48> 3d 00 f0 ff ff 0f 87 a2 00 00 00 48 8b 4c 24 28 64 48 33 0c 25 RSP: 002b:00007fff95e0d2e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000561178c069b0 RCX: 00007f45f5e5ce02 RDX: 0000000000000241 RSI: 0000561178c08800 RDI: 00000000ffffff9c RBP: 00007fff95e0d3e0 R08: 0000000000000020 R09: 0000000000000005 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000003 R14: 0000000000000001 R15: 0000561178c08800 Change the return type to int and return -EPERM when lockdown is enabled to remove the warning above. Also rename debugfs_is_locked_down to debugfs_locked_down to make it sound less like it returns a boolean. Fixes: 5496197f9b08 ("debugfs: Restrict debugfs when the kernel is locked down") Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: stable <stable@vger.kernel.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20191207161603.35907-1-eric.snowberg@oracle.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14fs/kernfs/dir.c: Clean code by removing always true conditionMateusz Nosek
Previously there was an additional check if variable pos is not null. However, this check happens after entering while loop and only then, which can happen only if pos is not null. Therefore the additional check is redundant and can be removed. Signed-off-by: Mateusz Nosek <mateusznosek0@gmail.com> Acked-by: Tejun Heo <tj@kernel.org> Link: https://lore.kernel.org/r/20191230191628.21099-1-mateusznosek0@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-14fs/proc: Introduce /proc/pid/timens_offsetsAndrei Vagin
API to set time namespace offsets for children processes, i.e.: echo "$clockid $offset_sec $offset_nsec" > /proc/self/timens_offsets Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-28-dima@arista.com
2020-01-14fs/proc: Respect boottime inside time namespace for /proc/uptimeDmitry Safonov
Make sure that /proc/uptime is adjusted to the tasks time namespace. Co-developed-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Andrei Vagin <avagin@openvz.org> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-19-dima@arista.com
2020-01-14timerfd: Make timerfd_settime() time namespace awareAndrei Vagin
timerfd_settime() accepts an absolute value of the expiration time if TFD_TIMER_ABSTIME is specified. This value is in the task's time namespace and has to be converted to the host's time namespace. Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://lore.kernel.org/r/20191112012724.250792-14-dima@arista.com
2020-01-14ns: Introduce Time NamespaceAndrei Vagin
Time Namespace isolates clock values. The kernel provides access to several clocks CLOCK_REALTIME, CLOCK_MONOTONIC, CLOCK_BOOTTIME, etc. CLOCK_REALTIME System-wide clock that measures real (i.e., wall-clock) time. CLOCK_MONOTONIC Clock that cannot be set and represents monotonic time since some unspecified starting point. CLOCK_BOOTTIME Identical to CLOCK_MONOTONIC, except it also includes any time that the system is suspended. For many users, the time namespace means the ability to changes date and time in a container (CLOCK_REALTIME). Providing per namespace notions of CLOCK_REALTIME would be complex with a massive overhead, but has a dubious value. But in the context of checkpoint/restore functionality, monotonic and boottime clocks become interesting. Both clocks are monotonic with unspecified starting points. These clocks are widely used to measure time slices and set timers. After restoring or migrating processes, it has to be guaranteed that they never go backward. In an ideal case, the behavior of these clocks should be the same as for a case when a whole system is suspended. All this means that it is required to set CLOCK_MONOTONIC and CLOCK_BOOTTIME clocks, which can be achieved by adding per-namespace offsets for clocks. A time namespace is similar to a pid namespace in the way how it is created: unshare(CLONE_NEWTIME) system call creates a new time namespace, but doesn't set it to the current process. Then all children of the process will be born in the new time namespace, or a process can use the setns() system call to join a namespace. This scheme allows setting clock offsets for a namespace, before any processes appear in it. All available clone flags have been used, so CLONE_NEWTIME uses the highest bit of CSIGNAL. It means that it can be used only with the unshare() and the clone3() system calls. [ tglx: Adjusted paragraph about clone3() to reality and massaged the changelog a bit. ] Co-developed-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Andrei Vagin <avagin@gmail.com> Signed-off-by: Dmitry Safonov <dima@arista.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: https://criu.org/Time_namespace Link: https://lists.openvz.org/pipermail/criu/2018-June/041504.html Link: https://lore.kernel.org/r/20191112012724.250792-4-dima@arista.com
2020-01-13io_uring: don't setup async context for read/write fixedJens Axboe
We don't need it, and if we have it, then the retry handler will attempt to copy the non-existent iovec with the inline iovec, with a segment count that doesn't make sense. Fixes: f67676d160c6 ("io_uring: ensure async punted read/write requests copy iovec") Reported-by: Jonathan Lemon <jonathan.lemon@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-13btrfs: relocation: fix reloc_root lifespan and accessQu Wenruo
[BUG] There are several different KASAN reports for balance + snapshot workloads. Involved call paths include: should_ignore_root+0x54/0xb0 [btrfs] build_backref_tree+0x11af/0x2280 [btrfs] relocate_tree_blocks+0x391/0xb80 [btrfs] relocate_block_group+0x3e5/0xa00 [btrfs] btrfs_relocate_block_group+0x240/0x4d0 [btrfs] btrfs_relocate_chunk+0x53/0xf0 [btrfs] btrfs_balance+0xc91/0x1840 [btrfs] btrfs_ioctl_balance+0x416/0x4e0 [btrfs] btrfs_ioctl+0x8af/0x3e60 [btrfs] do_vfs_ioctl+0x831/0xb10 create_reloc_root+0x9f/0x460 [btrfs] btrfs_reloc_post_snapshot+0xff/0x6c0 [btrfs] create_pending_snapshot+0xa9b/0x15f0 [btrfs] create_pending_snapshots+0x111/0x140 [btrfs] btrfs_commit_transaction+0x7a6/0x1360 [btrfs] btrfs_mksubvol+0x915/0x960 [btrfs] btrfs_ioctl_snap_create_transid+0x1d5/0x1e0 [btrfs] btrfs_ioctl_snap_create_v2+0x1d3/0x270 [btrfs] btrfs_ioctl+0x241b/0x3e60 [btrfs] do_vfs_ioctl+0x831/0xb10 btrfs_reloc_pre_snapshot+0x85/0xc0 [btrfs] create_pending_snapshot+0x209/0x15f0 [btrfs] create_pending_snapshots+0x111/0x140 [btrfs] btrfs_commit_transaction+0x7a6/0x1360 [btrfs] btrfs_mksubvol+0x915/0x960 [btrfs] btrfs_ioctl_snap_create_transid+0x1d5/0x1e0 [btrfs] btrfs_ioctl_snap_create_v2+0x1d3/0x270 [btrfs] btrfs_ioctl+0x241b/0x3e60 [btrfs] do_vfs_ioctl+0x831/0xb10 [CAUSE] All these call sites are only relying on root->reloc_root, which can undergo btrfs_drop_snapshot(), and since we don't have real refcount based protection to reloc roots, we can reach already dropped reloc root, triggering KASAN. [FIX] To avoid such access to unstable root->reloc_root, we should check BTRFS_ROOT_DEAD_RELOC_TREE bit first. This patch introduces wrappers that provide the correct way to check the bit with memory barriers protection. Most callers don't distinguish merged reloc tree and no reloc tree. The only exception is should_ignore_root(), as merged reloc tree can be ignored, while no reloc tree shouldn't. [CRITICAL SECTION ANALYSIS] Although test_bit()/set_bit()/clear_bit() doesn't imply a barrier, the DEAD_RELOC_TREE bit has extra help from transaction as a higher level barrier, the lifespan of root::reloc_root and DEAD_RELOC_TREE bit are: NULL: reloc_root is NULL PTR: reloc_root is not NULL 0: DEAD_RELOC_ROOT bit not set DEAD: DEAD_RELOC_ROOT bit set (NULL, 0) Initial state __ | /\ Section A btrfs_init_reloc_root() \/ | __ (PTR, 0) reloc_root initialized /\ | | btrfs_update_reloc_root() | Section B | | (PTR, DEAD) reloc_root has been merged \/ | __ === btrfs_commit_transaction() ==================== | /\ clean_dirty_subvols() | | | Section C (NULL, DEAD) reloc_root cleanup starts \/ | __ btrfs_drop_snapshot() /\ | | Section D (NULL, 0) Back to initial state \/ Every have_reloc_root() or test_bit(DEAD_RELOC_ROOT) caller holds transaction handle, so none of such caller can cross transaction boundary. In Section A, every caller just found no DEAD bit, and grab reloc_root. In the cross section A-B, caller may get no DEAD bit, but since reloc_root is still completely valid thus accessing reloc_root is completely safe. No test_bit() caller can cross the boundary of Section B and Section C. In Section C, every caller found the DEAD bit, so no one will access reloc_root. In the cross section C-D, either caller gets the DEAD bit set, avoiding access reloc_root no matter if it's safe or not. Or caller get the DEAD bit cleared, then access reloc_root, which is already NULL, nothing will be wrong. The memory write barriers are between the reloc_root updates and bit set/clear, the pairing read side is before test_bit. Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> Fixes: d2311e698578 ("btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots") CC: stable@vger.kernel.org # 5.4+ Reviewed-by: Josef Bacik <josef@toxicpanda.com> Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> [ barriers ] Signed-off-by: David Sterba <dsterba@suse.com>
2020-01-13vfs, fdtable: Add fget_task helperSargun Dhillon
This introduces a function which can be used to fetch a file, given an arbitrary task. As long as the user holds a reference (refcnt) to the task_struct it is safe to call, and will either return NULL on failure, or a pointer to the file, with a refcnt. This patch is based on Oleg Nesterov's (cf. [1]) patch from September 2018. [1]: Link: https://lore.kernel.org/r/20180915160423.GA31461@redhat.com Signed-off-by: Sargun Dhillon <sargun@sargun.me> Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Reviewed-by: Arnd Bergmann <arnd@arndb.de> Link: https://lore.kernel.org/r/20200107175927.4558-2-sargun@sargun.me Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2020-01-13proc: bootconfig: Add /proc/bootconfig to show boot config listMasami Hiramatsu
Add /proc/bootconfig which shows the list of key-value pairs in boot config. Since after boot, all boot configs and tree are removed, this interface just keep a copy of key-value pairs in text. Link: http://lkml.kernel.org/r/157867225967.17873.12155805787236073787.stgit@devnote2 Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2020-01-13udf: Disallow R/W mode for disk with Metadata partitionPali Rohár
Currently we do not support writing to UDF disks with Metadata partition. There is already check that disks with declared minimal write revision to UDF 2.50 or higher are mounted only in R/O mode but this does not cover situation when minimal write revision is set incorrectly (e.g. to 2.01). Link: https://lore.kernel.org/r/20200112144959.28104-1-pali.rohar@gmail.com Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2020-01-13udf: Fix meaning of ENTITYID_FLAGS_* macros to be really bitwise-or flagsPali Rohár
Currently ENTITYID_FLAGS_* macros definitions are written as hex numbers but their meaning is not bitwise-or flags. But rather bit position. This is unusual and could be misleading. So change meaning of ENTITYID_FLAGS_* macros definitions to be really bitwise-or flags. Link: https://lore.kernel.org/r/20200112221353.29711-1-pali.rohar@gmail.com Signed-off-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2020-01-11erofs: fix out-of-bound read for shifted uncompressed blockGao Xiang
rq->out[1] should be valid before accessing. Otherwise, in very rare cases, out-of-bound dirty onstack rq->out[1] can equal to *in and lead to unintended memmove behavior. Link: https://lore.kernel.org/r/20200107022546.19432-1-gaoxiang25@huawei.com Fixes: 7fc45dbc938a ("staging: erofs: introduce generic decompression backend") Cc: <stable@vger.kernel.org> # 5.3+ Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
2020-01-10Merge tag 'char-misc-5.5-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc Pull char/misc fix from Greg KH: "Here is a single fix, for the chrdev core, for 5.5-rc6 There's been a long-standing race condition triggered by syzbot, and occasionally real people, in the chrdev open() path. Will finally took the time to track it down and fix it for real before the holidays. Here's that one patch, it's been in linux-next for a while with no reported issues and it does fix the reported problem" * tag 'char-misc-5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: chardev: Avoid potential use-after-free in 'chrdev_open()'
2020-01-10Merge tag 'block-5.5-2020-01-10' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "A few fixes that should go into this round. This pull request contains two NVMe fixes via Keith, removal of a dead function, and a fix for the bio op for read truncates (Ming)" * tag 'block-5.5-2020-01-10' of git://git.kernel.dk/linux-block: nvmet: fix per feat data len for get_feature nvme: Translate more status codes to blk_status_t fs: move guard_bio_eod() after bio_set_op_attrs block: remove unused mp_bvec_last_segment
2020-01-10Merge tag 'io_uring-5.5-2020-01-10' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fix from Jens Axboe: "Single fix for this series, fixing a regression with the short read handling. This just removes it, as it cannot safely be done for all cases" * tag 'io_uring-5.5-2020-01-10' of git://git.kernel.dk/linux-block: io_uring: remove punt of short reads to async context
2020-01-09Merge tag 'pstore-v5.5-rc6' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull pstore fix from Kees Cook: "Cengiz Can forwarded a Coverity report about more problems with a rare pstore initialization error path, so the allocation lifetime was rearranged to avoid needing to share the kfree() responsibilities between caller and callee" * tag 'pstore-v5.5-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: pstore/ram: Regularize prz label allocation lifetime
2020-01-09kunit: allow kunit tests to be loaded as a moduleAlan Maguire
As tests are added to kunit, it will become less feasible to execute all built tests together. By supporting modular tests we provide a simple way to do selective execution on a running system; specifying CONFIG_KUNIT=y CONFIG_KUNIT_EXAMPLE_TEST=m ...means we can simply "insmod example-test.ko" to run the tests. To achieve this we need to do the following: o export the required symbols in kunit o string-stream tests utilize non-exported symbols so for now we skip building them when CONFIG_KUNIT_TEST=m. o drivers/base/power/qos-test.c contains a few unexported interface references, namely freq_qos_read_value() and freq_constraints_init(). Both of these could be potentially defined as static inline functions in include/linux/pm_qos.h, but for now we simply avoid supporting module build for that test suite. o support a new way of declaring test suites. Because a module cannot do multiple late_initcall()s, we provide a kunit_test_suites() macro to declare multiple suites within the same module at once. o some test module names would have been too general ("test-test" and "example-test" for kunit tests, "inode-test" for ext4 tests); rename these as appropriate ("kunit-test", "kunit-example-test" and "ext4-inode-test" respectively). Also define kunit_test_suite() via kunit_test_suites() as callers in other trees may need the old definition. Co-developed-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Knut Omang <knut.omang@oracle.com> Signed-off-by: Alan Maguire <alan.maguire@oracle.com> Reviewed-by: Brendan Higgins <brendanhiggins@google.com> Acked-by: Theodore Ts'o <tytso@mit.edu> # for ext4 bits Acked-by: David Gow <davidgow@google.com> # For list-test Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org>
2020-01-09xfs: remove bogus assertion when online repair isn't enabledDarrick J. Wong
We don't need to assert on !REPAIR in the stub version of xrep_calc_ag_resblks that is called when online repair hasn't been compiled into the kernel because none of the repair code will ever run. Reported-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-01-09xfs: Remove all strlen in all xfs_attr_* functions for attr names.Allison Henderson
This helps to pre-simplify the extra handling of the null terminator in delayed operations which use memcpy rather than strlen. Later when we introduce parent pointers, attribute names will become binary, so strlen will not work at all. Removing uses of strlen now will help reduce complexities later Signed-off-by: Allison Collins <allison.henderson@oracle.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-09xfs: fix misuse of the XFS_ATTR_INCOMPLETE flagChristoph Hellwig
XFS_ATTR_INCOMPLETE is a flag in the on-disk attribute format, and thus in a different namespace as the ATTR_* flags in xfs_da_args.flags. Switch to using a XFS_DA_OP_INCOMPLETE flag in op_flags instead. Without this users might be able to inject this flag into operations using the attr by handle ioctl. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-09xfs: also remove cached ACLs when removing the underlying attrChristoph Hellwig
We should not just invalidate the ACL when setting the underlying attribute, but also when removing it. The ioctl interface gets that right, but the normal xattr inteface skipped the xfs_forget_acl due to an early return. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-09xfs: reject invalid flags combinations in XFS_IOC_ATTRMULTI_BY_HANDLEChristoph Hellwig
While the flags field in the ABI and the on-disk format allows for multiple namespace flags, that is a logically invalid combination that scrub complains about. Reject it at the ioctl level, as all other interface already get this right at higher levels. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-09xfs: clear kernel only flags in XFS_IOC_ATTRMULTI_BY_HANDLEChristoph Hellwig
Don't allow passing arbitrary flags as they change behavior including memory allocation that the call stack is not prepared for. Fixes: ddbca70cc45c ("xfs: allocate xattr buffer on demand") Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-01-09udf: Fix free space reporting for metadata and virtual partitionsJan Kara
Free space on filesystems with metadata or virtual partition maps currently gets misreported. This is because these partitions are just remapped onto underlying real partitions from which keep track of free blocks. Take this remapping into account when counting free blocks as well. Reviewed-by: Pali Rohár <pali.rohar@gmail.com> Reported-by: Pali Rohár <pali.rohar@gmail.com> Signed-off-by: Jan Kara <jack@suse.cz>
2020-01-09fs: move guard_bio_eod() after bio_set_op_attrsMing Lei
Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") adds bio_truncate() for handling bio EOD. However, bio_truncate() doesn't use the passed 'op' parameter from guard_bio_eod's callers. So bio_trunacate() may retrieve wrong 'op', and zering pages may not be done for READ bio. Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs() in submit_bh_wbc() so that bio_truncate() can always retrieve correct op info. Meantime remove the 'op' parameter from guard_bio_eod() because it isn't used any more. Cc: Carlos Maiolino <cmaiolino@redhat.com> Cc: linux-fsdevel@vger.kernel.org Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") Signed-off-by: Ming Lei <ming.lei@redhat.com> Fold in kerneldoc and bio_op() change. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-01-08pstore/ram: Regularize prz label allocation lifetimeKees Cook
In my attempt to fix a memory leak, I introduced a double-free in the pstore error path. Instead of trying to manage the allocation lifetime between persistent_ram_new() and its callers, adjust the logic so persistent_ram_new() always takes a kstrdup() copy, and leaves the caller's allocation lifetime up to the caller. Therefore callers are _always_ responsible for freeing their label. Before, it only needed freeing when the prz itself failed to allocate, and not in any of the other prz failure cases, which callers would have no visibility into, which is the root design problem that lead to both the leak and now double-free bugs. Reported-by: Cengiz Can <cengiz@kernel.wtf> Link: https://lore.kernel.org/lkml/d4ec59002ede4aaf9928c7f7526da87c@kernel.wtf Fixes: 8df955a32a73 ("pstore/ram: Fix error-path memory leak in persistent_ram_new() callers") Cc: stable@vger.kernel.org Signed-off-by: Kees Cook <keescook@chromium.org>
2020-01-08btrfs: fix memory leak in qgroup accountingJohannes Thumshirn
When running xfstests on the current btrfs I get the following splat from kmemleak: unreferenced object 0xffff88821b2404e0 (size 32): comm "kworker/u4:7", pid 26663, jiffies 4295283698 (age 8.776s) hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 10 ff fd 26 82 88 ff ff ...........&.... 10 ff fd 26 82 88 ff ff 20 ff fd 26 82 88 ff ff ...&.... ..&.... backtrace: [<00000000f94fd43f>] ulist_alloc+0x25/0x60 [btrfs] [<00000000fd023d99>] btrfs_find_all_roots_safe+0x41/0x100 [btrfs] [<000000008f17bd32>] btrfs_find_all_roots+0x52/0x70 [btrfs] [<00000000b7660afb>] btrfs_qgroup_rescan_worker+0x343/0x680 [btrfs] [<0000000058e66778>] btrfs_work_helper+0xac/0x1e0 [btrfs] [<00000000f0188930>] process_one_work+0x1cf/0x350 [<00000000af5f2f8e>] worker_thread+0x28/0x3c0 [<00000000b55a1add>] kthread+0x109/0x120 [<00000000f88cbd17>] ret_from_fork+0x35/0x40 This corresponds to: (gdb) l *(btrfs_find_all_roots_safe+0x41) 0x8d7e1 is in btrfs_find_all_roots_safe (fs/btrfs/backref.c:1413). 1408 1409 tmp = ulist_alloc(GFP_NOFS); 1410 if (!tmp) 1411 return -ENOMEM; 1412 *roots = ulist_alloc(GFP_NOFS); 1413 if (!*roots) { 1414 ulist_free(tmp); 1415 return -ENOMEM; 1416 } 1417 Following the lifetime of the allocated 'roots' ulist, it gets freed again in btrfs_qgroup_account_extent(). But this does not happen if the function is called with the 'BTRFS_FS_QUOTA_ENABLED' flag cleared, then btrfs_qgroup_account_extent() does a short leave and directly returns. Instead of directly returning we should jump to the 'out_free' in order to free all resources as expected. CC: stable@vger.kernel.org # 4.14+ Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> [ add comment ] Signed-off-by: David Sterba <dsterba@suse.com>