summaryrefslogtreecommitdiff
path: root/fs
AgeCommit message (Collapse)Author
2019-11-15fix dget_parent() fastpath raceAl Viro
We are overoptimistic about taking the fast path there; seeing the same value in ->d_parent after having grabbed a reference to that parent does *not* mean that it has remained our parent all along. That wouldn't be a big deal (in the end it is our parent and we have grabbed the reference we are about to return), but... the situation with barriers is messed up. We might have hit the following sequence: d is a dentry of /tmp/a/b CPU1: CPU2: parent = d->d_parent (i.e. dentry of /tmp/a) rename /tmp/a/b to /tmp/b rmdir /tmp/a, making its dentry negative grab reference to parent, end up with cached parent->d_inode (NULL) mkdir /tmp/a, rename /tmp/b to /tmp/a/b recheck d->d_parent, which is back to original decide that everything's fine and return the reference we'd got. The trouble is, caller (on CPU1) will observe dget_parent() returning an apparently negative dentry. It actually is positive, but CPU1 has stale ->d_inode cached. Use d->d_seq to see if it has been moved instead of rechecking ->d_parent. NOTE: we are *NOT* going to retry on any kind of ->d_seq mismatch; we just go into the slow path in such case. We don't wait for ->d_seq to become even either - again, if we are racing with renames, we can bloody well go to slow path anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-15new helper: lookup_positive_unlocked()Al Viro
Most of the callers of lookup_one_len_unlocked() treat negatives are ERR_PTR(-ENOENT). Provide a helper that would do just that. Note that a pinned positive dentry remains positive - it's ->d_inode is stable, etc.; a pinned _negative_ dentry can become positive at any point as long as you are not holding its parent at least shared. So using lookup_one_len_unlocked() needs to be careful; lookup_positive_unlocked() is safer and that's what the callers end up open-coding anyway. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-15fs/namei.c: pull positivity check into follow_managed()Al Viro
There are 4 callers; two proceed to check if result is positive and fail with ENOENT if it isn't; one (in handle_lookup_down()) is guaranteed to yield positive and one (in lookup_fast()) is _preceded_ by positivity check. However, follow_managed() on a negative dentry is a (fairly cheap) no-op on anything other than autofs. And negative autofs dentries are never hashed, so lookup_fast() is not going to run into one of those. Moreover, successful follow_managed() on a _positive_ dentry never yields a negative one (and we significantly rely upon that in callers of lookup_fast()). In other words, we can easily transpose the positivity check and the call of follow_managed() in lookup_fast(). And that allows to fold the positivity check *into* follow_managed(), simplifying life for the code downstream of its calls. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-23cramfs: fix usage on non-MTD deviceMaxime Bizon
When both CONFIG_CRAMFS_MTD and CONFIG_CRAMFS_BLOCKDEV are enabled, if we fail to mount on MTD, we don't try on block device. Note: this relies upon cramfs_mtd_fill_super() leaving no side effects on fc state in case of failure; in general, failing get_tree_...() does *not* mean "fine to try again"; e.g. parsed options might've been consumed by fill_super callback and freed on failure. Fixes: 74f78fc5ef43 ("vfs: Convert cramfs to use the new mount API") Signed-off-by: Maxime Bizon <mbizon@freebox.fr> Signed-off-by: Nicolas Pitre <nico@fluxnic.net> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-10ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable eitherAl Viro
We need to get the underlying dentry of parent; sure, absent the races it is the parent of underlying dentry, but there's nothing to prevent losing a timeslice to preemtion in the middle of evaluation of lower_dentry->d_parent->d_inode, having another process move lower_dentry around and have its (ex)parent not pinned anymore and freed on memory pressure. Then we regain CPU and try to fetch ->d_inode from memory that is freed by that point. dentry->d_parent *is* stable here - it's an argument of ->lookup() and we are guaranteed that it won't be moved anywhere until we feed it to d_add/d_splice_alias. So we safely go that way to get to its underlying dentry. Cc: stable@vger.kernel.org # since 2009 or so Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-10ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stableAl Viro
lower_dentry can't go from positive to negative (we have it pinned), but it *can* go from negative to positive. So fetching ->d_inode into a local variable, doing a blocking allocation, checking that now ->d_inode is non-NULL and feeding the value we'd fetched earlier to a function that won't accept NULL is not a good idea. Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-10ecryptfs: fix unlink and rmdir in face of underlying fs modificationsAl Viro
A problem similar to the one caught in commit 74dd7c97ea2a ("ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()") exists for unlink/rmdir as well. Instead of playing with dget_parent() of underlying dentry of victim and hoping it's the same as underlying dentry of our directory, do the following: * find the underlying dentry of victim * find the underlying directory of victim's parent (stable since the victim is ecryptfs dentry and inode of its parent is held exclusive by the caller). * lock the inode of dentry underlying the victim's parent * check that underlying dentry of victim is still hashed and has the right parent - it can be moved, but it can't be moved to/from the directory we are holding exclusive. So while ->d_parent itself might not be stable, the result of comparison is. If the check passes, everything is fine - underlying directory is locked, underlying victim is still a child of that directory and we can go ahead and feed them to vfs_unlink(). As in the current mainline we need to pin the underlying dentry of victim, so that it wouldn't go negative under us, but that's the only temporary reference that needs to be grabbed there. Underlying dentry of parent won't go away (it's pinned by the parent, which is held by caller), so there's no need to grab it. The same problem (with the same solution) exists for rmdir. Moreover, rename gets simpler and more robust with the same "don't bother with dget_parent()" approach. Fixes: 74dd7c97ea2 "ecryptfs_rename(): verify that lower dentries are still OK after lock_rename()" Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-11-10exportfs_decode_fh(): negative pinned may become positive without the parent ↵Al Viro
locked Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-25autofs: fix a leak in autofs_expire_indirect()Al Viro
if the second call of should_expire() in there ends up grabbing and returning a new reference to dentry, we need to drop it before continuing. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-21aio: Fix io_pgetevents() struct __compat_aio_sigset layoutGuillem Jover
This type is used to pass the sigset_t from userland to the kernel, but it was using the kernel native pointer type for the member representing the compat userland pointer to the userland sigset_t. This messes up the layout, and makes the kernel eat up both the userland pointer and the size members into the kernel pointer, and then reads garbage into the kernel sigsetsize. Which makes the sigset_t size consistency check fail, and consequently the syscall always returns -EINVAL. This breaks both libaio and strace on 32-bit userland running on 64-bit kernels. And there are apparently no users in the wild of the current broken layout (at least according to codesearch.debian.org and a brief check over github.com search). So it looks safe to fix this directly in the kernel, instead of either letting userland deal with this permanently with the additional overhead or trying to make the syscall infer what layout userland used, even though this is also being worked around in libaio to temporarily cope with kernels that have not yet been fixed. We use a proper compat_uptr_t instead of a compat_sigset_t pointer. Fixes: 7a074e96dee6 ("aio: implement io_pgetevents") Signed-off-by: Guillem Jover <guillem@hadrons.org> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-16fs/namespace.c: fix use-after-free of mount in mnt_warn_timestamp_expiry()Eric Biggers
After do_add_mount() returns success, the caller doesn't hold a reference to the 'struct mount' anymore. So it's invalid to access it in mnt_warn_timestamp_expiry(). Fix it by calling mnt_warn_timestamp_expiry() before do_add_mount() rather than after, and adjusting the warning message accordingly. Reported-by: syzbot+da4f525235510683d855@syzkaller.appspotmail.com Fixes: f8b92ba67c5d ("mount: Add mount warning for impending timestamp expiry") Signed-off-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-13Merge tag 'trace-v5.4-rc2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace Pull tracing fixes from Steven Rostedt: "A few tracing fixes: - Remove lockdown from tracefs itself and moved it to the trace directory. Have the open functions there do the lockdown checks. - Fix a few races with opening an instance file and the instance being deleted (Discovered during the lockdown updates). Kept separate from the clean up code such that they can be backported to stable easier. - Clean up and consolidated the checks done when opening a trace file, as there were multiple checks that need to be done, and it did not make sense having them done in each open instance. - Fix a regression in the record mcount code. - Small hw_lat detector tracer fixes. - A trace_pipe read fix due to not initializing trace_seq" * tag 'trace-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: tracing: Initialize iter->seq after zeroing in tracing_read_pipe() tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency tracing/hwlat: Report total time spent in all NMIs during the sample recordmcount: Fix nop_mcount() function tracing: Do not create tracefs files if tracefs lockdown is in effect tracing: Add locked_down checks to the open calls of files created for tracefs tracing: Add tracing_check_open_get_tr() tracing: Have trace events system open call tracing_open_generic_tr() tracing: Get trace_array reference for available_tracers files ftrace: Get a reference counter for the trace_array on filter files tracefs: Revert ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is locked down")
2019-10-13Merge tag 'for-linus-20191012' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fix from Jens Axboe: "Single small fix for a regression in the sequence logic for linked commands" * tag 'for-linus-20191012' of git://git.kernel.dk/linux-block: io_uring: fix sequence logic for timeout requests
2019-10-12tracing: Do not create tracefs files if tracefs lockdown is in effectSteven Rostedt (VMware)
If on boot up, lockdown is activated for tracefs, don't even bother creating the files. This can also prevent instances from being created if lockdown is in effect. Link: http://lkml.kernel.org/r/CAHk-=whC6Ji=fWnjh2+eS4b15TnbsS4VPVtvBOwCy1jjEG_JHQ@mail.gmail.com Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-12tracefs: Revert ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is ↵Steven Rostedt (VMware)
locked down") Running the latest kernel through my "make instances" stress tests, I triggered the following bug (with KASAN and kmemleak enabled): mkdir invoked oom-killer: gfp_mask=0x40cd0(GFP_KERNEL|__GFP_COMP|__GFP_RECLAIMABLE), order=0, oom_score_adj=0 CPU: 1 PID: 2229 Comm: mkdir Not tainted 5.4.0-rc2-test #325 Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014 Call Trace: dump_stack+0x64/0x8c dump_header+0x43/0x3b7 ? trace_hardirqs_on+0x48/0x4a oom_kill_process+0x68/0x2d5 out_of_memory+0x2aa/0x2d0 __alloc_pages_nodemask+0x96d/0xb67 __alloc_pages_node+0x19/0x1e alloc_slab_page+0x17/0x45 new_slab+0xd0/0x234 ___slab_alloc.constprop.86+0x18f/0x336 ? alloc_inode+0x2c/0x74 ? irq_trace+0x12/0x1e ? tracer_hardirqs_off+0x1d/0xd7 ? __slab_alloc.constprop.85+0x21/0x53 __slab_alloc.constprop.85+0x31/0x53 ? __slab_alloc.constprop.85+0x31/0x53 ? alloc_inode+0x2c/0x74 kmem_cache_alloc+0x50/0x179 ? alloc_inode+0x2c/0x74 alloc_inode+0x2c/0x74 new_inode_pseudo+0xf/0x48 new_inode+0x15/0x25 tracefs_get_inode+0x23/0x7c ? lookup_one_len+0x54/0x6c tracefs_create_file+0x53/0x11d trace_create_file+0x15/0x33 event_create_dir+0x2a3/0x34b __trace_add_new_event+0x1c/0x26 event_trace_add_tracer+0x56/0x86 trace_array_create+0x13e/0x1e1 instance_mkdir+0x8/0x17 tracefs_syscall_mkdir+0x39/0x50 ? get_dname+0x31/0x31 vfs_mkdir+0x78/0xa3 do_mkdirat+0x71/0xb0 sys_mkdir+0x19/0x1b do_fast_syscall_32+0xb0/0xed I bisected this down to the addition of the proxy_ops into tracefs for lockdown. It appears that the allocation of the proxy_ops and then freeing it in the destroy_inode callback, is causing havoc with the memory system. Reading the documentation about destroy_inode and talking with Linus about this, this is buggy and wrong. When defining the destroy_inode() method, it is expected that the destroy_inode() will also free the inode, and not just the extra allocations done in the creation of the inode. The faulty commit causes a memory leak of the inode data structure when they are deleted. Instead of allocating the proxy_ops (and then having to free it) the checks should be done by the open functions themselves, and not hack into the tracefs directory. First revert the tracefs updates for locked_down and then later we can add the locked_down checks in the kernel/trace files. Link: http://lkml.kernel.org/r/20191011135458.7399da44@gandalf.local.home Fixes: ccbd54ff54e8 ("tracefs: Restrict tracefs when the kernel is locked down") Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
2019-10-11Merge tag 'nfs-for-5.4-2' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client bugfixes from Anna Schumaker: "Stable bugfixes: - Fix O_DIRECT accounting of number of bytes read/written # v4.1+ Other fixes: - Fix nfsi->nrequests count error on nfs_inode_remove_request() - Remove redundant mirror tracking in O_DIRECT - Fix leak of clp->cl_acceptor string - Fix race to sk_err after xs_error_report" * tag 'nfs-for-5.4-2' of git://git.linux-nfs.org/projects/anna/linux-nfs: SUNRPC: fix race to sk_err after xs_error_report NFSv4: Fix leak of clp->cl_acceptor string NFS: Remove redundant mirror tracking in O_DIRECT NFS: Fix O_DIRECT accounting of number of bytes read/written nfs: Fix nfsi->nrequests count error on nfs_inode_remove_request
2019-10-11Merge tag '5.4-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds
Pull cifs fixes from Steve French: "Eight small SMB3 fixes, four for stable, and important fix for the recent regression introduced by filesystem timestamp range patches" * tag '5.4-rc2-smb3' of git://git.samba.org/sfrench/cifs-2.6: CIFS: Force reval dentry if LOOKUP_REVAL flag is set CIFS: Force revalidate inode when dentry is stale smb3: Fix regression in time handling smb3: remove noisy debug message and minor cleanup CIFS: Gracefully handle QueryInfo errors during open cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panic fs: cifs: mute -Wunused-const-variable message smb3: cleanup some recent endian errors spotted by updated sparse
2019-10-11Merge tag 'for-linus-20191010' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: - Fix wbt performance regression introduced with the blk-rq-qos refactoring (Harshad) - Fix io_uring fileset removal inadvertently killing the workqueue (me) - Fix io_uring typo in linked command nonblock submission (Pavel) - Remove spurious io_uring wakeups on request free (Pavel) - Fix null_blk zoned command error return (Keith) - Don't use freezable workqueues for backing_dev, also means we can revert a previous libata hack (Mika) - Fix nbd sysfs mutex dropped too soon at removal time (Xiubo) * tag 'for-linus-20191010' of git://git.kernel.dk/linux-block: nbd: fix possible sysfs duplicate warning null_blk: Fix zoned command return code io_uring: only flush workqueues on fileset removal io_uring: remove wait loop spurious wakeups blk-wbt: fix performance regression in wbt scale_up/scale_down Revert "libata, freezer: avoid block device removal while system is frozen" bdi: Do not use freezable workqueue io_uring: fix reversed nonblock flag for link submission
2019-10-10io_uring: fix sequence logic for timeout requestsJens Axboe
We have two ways a request can be deferred: 1) It's a regular request that depends on another one 2) It's a timeout that tracks completions We have a shared helper to determine whether to defer, and that attempts to make the right decision based on the request. But we only have some of this information in the caller. Un-share the two timeout/defer helpers so the caller can use the right one. Fixes: 5262f567987d ("io_uring: IORING_OP_TIMEOUT support") Reported-by: yangerkun <yangerkun@huawei.com> Reviewed-by: Jackie Liu <liuyun01@kylinos.cn> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-10NFSv4: Fix leak of clp->cl_acceptor stringChuck Lever
Our client can issue multiple SETCLIENTID operations to the same server in some circumstances. Ensure that calls to nfs4_proc_setclientid() after the first one do not overwrite the previously allocated cl_acceptor string. unreferenced object 0xffff888461031800 (size 32): comm "mount.nfs", pid 2227, jiffies 4294822467 (age 1407.749s) hex dump (first 32 bytes): 6e 66 73 40 6b 6c 69 6d 74 2e 69 62 2e 31 30 31 nfs@klimt.ib.101 35 67 72 61 6e 67 65 72 2e 6e 65 74 00 00 00 00 5granger.net.... backtrace: [<00000000ab820188>] __kmalloc+0x128/0x176 [<00000000eeaf4ec8>] gss_stringify_acceptor+0xbd/0x1a7 [auth_rpcgss] [<00000000e85e3382>] nfs4_proc_setclientid+0x34e/0x46c [nfsv4] [<000000003d9cf1fa>] nfs40_discover_server_trunking+0x7a/0xed [nfsv4] [<00000000b81c3787>] nfs4_discover_server_trunking+0x81/0x244 [nfsv4] [<000000000801b55f>] nfs4_init_client+0x1b0/0x238 [nfsv4] [<00000000977daf7f>] nfs4_set_client+0xfe/0x14d [nfsv4] [<0000000053a68a2a>] nfs4_create_server+0x107/0x1db [nfsv4] [<0000000088262019>] nfs4_remote_mount+0x2c/0x59 [nfsv4] [<00000000e84a2fd0>] legacy_get_tree+0x2d/0x4c [<00000000797e947c>] vfs_get_tree+0x20/0xc7 [<00000000ecabaaa8>] fc_mount+0xe/0x36 [<00000000f15fafc2>] vfs_kern_mount+0x74/0x8d [<00000000a3ff4e26>] nfs_do_root_mount+0x8a/0xa3 [nfsv4] [<00000000d1c2b337>] nfs4_try_mount+0x58/0xad [nfsv4] [<000000004c9bddee>] nfs_fs_mount+0x820/0x869 [nfs] Fixes: f11b2a1cfbf5 ("nfs4: copy acceptor name from context ... ") Signed-off-by: Chuck Lever <chuck.lever@oracle.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-10Merge tag 'xfs-5.4-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds
Pull xfs fixes from Darrick Wong: "A couple of small code cleanups and bug fixes for rounding errors, metadata logging errors, and an extra layer of safeguards against leaking memory contents. - Fix a rounding error in the fallocate code - Minor code cleanups - Make sure to zero memory buffers before formatting metadata blocks - Fix a few places where we forgot to log an inode metadata update - Remove broken error handling that tried to clean up after a failure but still got it wrong" * tag 'xfs-5.4-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: xfs: move local to extent inode logging into bmap helper xfs: remove broken error handling on failed attr sf to leaf change xfs: log the inode on directory sf to block format change xfs: assure zeroed memory buffers for certain kmem allocations xfs: removed unused error variable from xchk_refcountbt_rec xfs: remove unused flags arg from xfs_get_aghdr_buf() xfs: Fix tail rounding in xfs_alloc_file_space()
2019-10-10Merge tag 'for-5.4-rc2-tag' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: "A few more stabitly fixes, one build warning fix. - fix inode allocation under NOFS context - fix leak in fiemap due to concurrent append writes - fix log-root tree updates - fix balance convert of single profile on 32bit architectures - silence false positive warning on old GCCs (code moved in rc1)" * tag 'for-5.4-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: silence maybe-uninitialized warning in clone_range btrfs: fix uninitialized ret in ref-verify btrfs: allocate new inode in NOFS context btrfs: fix balance convert to single on 32-bit host CPUs btrfs: fix incorrect updating of log root tree Btrfs: fix memory leak due to concurrent append writes with fiemap
2019-10-10Merge branch 'work.dcache' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull dcache_readdir() fixes from Al Viro: "The couple of patches you'd been OK with; no hlist conversion yet, and cursors are still in the list of children" [ Al is referring to future work to avoid some nasty O(n**2) behavior with the readdir cursors when you have lots of concurrent readdirs. This is just a fix for a race with a trivial cleanup - Linus ] * 'work.dcache' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: libfs: take cursors out of list when moving past the end of directory Fix the locking in dcache_readdir() and friends
2019-10-10Merge branch 'work.mount3' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull mount fixes from Al Viro: "A couple of regressions from the mount series" * 'work.mount3' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: add missing blkdev_put() in get_tree_bdev() shmem: fix LSM options parsing
2019-10-09libfs: take cursors out of list when moving past the end of directoryAl Viro
that eliminates the last place where we accessed the tail of ->d_subdirs Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-09vfs: add missing blkdev_put() in get_tree_bdev()Ian Kent
Is there are a couple of missing blkdev_put() in get_tree_bdev()? Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-10-09io_uring: only flush workqueues on fileset removalJens Axboe
We should not remove the workqueue, we just need to ensure that the workqueues are synced. The workqueues are torn down on ctx removal. Cc: stable@vger.kernel.org Fixes: 6b06314c47e1 ("io_uring: add file set registration") Reported-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-09xfs: move local to extent inode logging into bmap helperBrian Foster
The callers of xfs_bmap_local_to_extents_empty() log the inode external to the function, yet this function is where the on-disk format value is updated. Push the inode logging down into the function itself to help prevent future mistakes. Note that internal bmap callers track the inode logging flags independently and thus may log the inode core twice due to this change. This is harmless, so leave this code around for consistency with the other attr fork conversion functions. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-09xfs: remove broken error handling on failed attr sf to leaf changeBrian Foster
xfs_attr_shortform_to_leaf() attempts to put the shortform fork back together after a failed attempt to convert from shortform to leaf format. While this code reallocates and copies back the shortform attr fork data, it never resets the inode format field back to local format. Further, now that the inode is properly logged after the initial switch from local format, any error that triggers the recovery code will eventually abort the transaction and shutdown the fs. Therefore, remove the broken and unnecessary error handling code. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-09xfs: log the inode on directory sf to block format changeBrian Foster
When a directory changes from shortform (sf) to block format, the sf format is copied to a temporary buffer, the inode format is modified and the updated format filled with the dentries from the temporary buffer. If the inode format is modified and attempt to grow the inode fails (due to I/O error, for example), it is possible to return an error while leaving the directory in an inconsistent state and with an otherwise clean transaction. This results in corruption of the associated directory and leads to xfs_dabuf_map() errors as subsequent lookups cannot accurately determine the format of the directory. This problem is reproduced occasionally by generic/475. The fundamental problem is that xfs_dir2_sf_to_block() changes the on-disk inode format without logging the inode. The inode is eventually logged by the bmapi layer in the common case, but error checking introduces the possibility of failing the high level request before this happens. Update both of the dir2 and attr callers of xfs_bmap_local_to_extents_empty() to log the inode core as consistent with the bmap local to extent format change codepath. This ensures that any subsequent errors after the format has changed cause the transaction to abort. Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-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>
2019-10-09NFS: Remove redundant mirror tracking in O_DIRECTTrond Myklebust
We no longer need the extra mirror length tracking in the O_DIRECT code, as we are able to track the maximum contiguous length in dreq->max_count. Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-09NFS: Fix O_DIRECT accounting of number of bytes read/writtenTrond Myklebust
When a series of O_DIRECT reads or writes are truncated, either due to eof or due to an error, then we should return the number of contiguous bytes that were received/sent starting at the offset specified by the application. Currently, we are failing to correctly check contiguity, and so we're failing the generic/465 in xfstests when the race between the read and write RPCs causes the file to get extended while the 2 reads are outstanding. If the first read RPC call wins the race and returns with eof set, we should treat the second read RPC as being truncated. Reported-by: Su Yanjun <suyj.fnst@cn.fujitsu.com> Fixes: 1ccbad9f9f9bd ("nfs: fix DIO good bytes calculation") Cc: stable@vger.kernel.org # 4.1+ Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
2019-10-09CIFS: Force reval dentry if LOOKUP_REVAL flag is setPavel Shilovsky
Mark inode for force revalidation if LOOKUP_REVAL flag is set. This tells the client to actually send a QueryInfo request to the server to obtain the latest metadata in case a directory or a file were changed remotely. Only do that if the client doesn't have a lease for the file to avoid unneeded round trips to the server. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-09CIFS: Force revalidate inode when dentry is stalePavel Shilovsky
Currently the client indicates that a dentry is stale when inode numbers or type types between a local inode and a remote file don't match. If this is the case attributes is not being copied from remote to local, so, it is already known that the local copy has stale metadata. That's why the inode needs to be marked for revalidation in order to tell the VFS to lookup the dentry again before openning a file. This prevents unexpected stale errors to be returned to the user space when openning a file. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-09smb3: Fix regression in time handlingSteve French
Fixes: cb7a69e60590 ("cifs: Initialize filesystem timestamp ranges") Only very old servers (e.g. OS/2 and DOS) did not support DCE TIME (100 nanosecond granularity). Fix the checks used to set minimum and maximum times. Fixes xfstest generic/258 (on 5.4-rc1 and later) CC: Deepa Dinamani <deepa.kernel@gmail.com> Acked-by: Jeff Layton <jlayton@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-10-08smb3: remove noisy debug message and minor cleanupSteve French
Message was intended only for developer temporary build In addition cleanup two minor warnings noticed by Coverity and a trivial change to workaround a sparse warning Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
2019-10-08btrfs: silence maybe-uninitialized warning in clone_rangeAustin Kim
GCC throws warning message as below: ‘clone_src_i_size’ may be used uninitialized in this function [-Wmaybe-uninitialized] #define IS_ALIGNED(x, a) (((x) & ((typeof(x))(a) - 1)) == 0) ^ fs/btrfs/send.c:5088:6: note: ‘clone_src_i_size’ was declared here u64 clone_src_i_size; ^ The clone_src_i_size is only used as call-by-reference in a call to get_inode_info(). Silence the warning by initializing clone_src_i_size to 0. Note that the warning is a false positive and reported by older versions of GCC (eg. 7.x) but not eg 9.x. As there have been numerous people, the patch is applied. Setting clone_src_i_size to 0 does not otherwise make sense and would not do any action in case the code changes in the future. Signed-off-by: Austin Kim <austindh.kim@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add note ] Signed-off-by: David Sterba <dsterba@suse.com>
2019-10-07io_uring: remove wait loop spurious wakeupsPavel Begunkov
Any changes interesting to tasks waiting in io_cqring_wait() are commited with io_cqring_ev_posted(). However, io_ring_drop_ctx_refs() also tries to do that but with no reason, that means spurious wakeups every io_free_req() and io_uring_enter(). Just use percpu_ref_put() instead. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-10-07Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc fixes from Andrew Morton: "The usual shower of hotfixes. Chris's memcg patches aren't actually fixes - they're mature but a few niggling review issues were late to arrive. The ocfs2 fixes are quite old - those took some time to get reviewer attention. Subsystems affected by this patch series: ocfs2, hotfixes, mm/memcg, mm/slab-generic" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm, sl[aou]b: guarantee natural alignment for kmalloc(power-of-two) mm, sl[ou]b: improve memory accounting mm, memcg: make scan aggression always exclude protection mm, memcg: make memory.emin the baseline for utilisation determination mm, memcg: proportional memory.{low,min} reclaim mm/vmpressure.c: fix a signedness bug in vmpressure_register_event() mm/page_alloc.c: fix a crash in free_pages_prepare() mm/z3fold.c: claim page in the beginning of free kernel/sysctl.c: do not override max_threads provided by userspace memcg: only record foreign writebacks with dirty pages when memcg is not disabled mm: fix -Wmissing-prototypes warnings writeback: fix use-after-free in finish_writeback_work() mm/memremap: drop unused SECTION_SIZE and SECTION_MASK panic: ensure preemption is disabled during panic() fs: ocfs2: fix a possible null-pointer dereference in ocfs2_info_scan_inode_alloc() fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock() fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry() ocfs2: clear zero in unaligned direct IO
2019-10-07writeback: fix use-after-free in finish_writeback_work()Tejun Heo
finish_writeback_work() reads @done->waitq after decrementing @done->cnt. However, once @done->cnt reaches zero, @done may be freed (from stack) at any moment and @done->waitq can contain something unrelated by the time finish_writeback_work() tries to read it. This led to the following crash. "BUG: kernel NULL pointer dereference, address: 0000000000000002" #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP DEBUG_PAGEALLOC CPU: 40 PID: 555153 Comm: kworker/u98:50 Kdump: loaded Not tainted ... Workqueue: writeback wb_workfn (flush-btrfs-1) RIP: 0010:_raw_spin_lock_irqsave+0x10/0x30 Code: 48 89 d8 5b c3 e8 50 db 6b ff eb f4 0f 1f 40 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 53 9c 5b fa 31 c0 ba 01 00 00 00 <f0> 0f b1 17 75 05 48 89 d8 5b c3 89 c6 e8 fe ca 6b ff eb f2 66 90 RSP: 0018:ffffc90049b27d98 EFLAGS: 00010046 RAX: 0000000000000000 RBX: 0000000000000246 RCX: 0000000000000000 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 0000000000000002 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001 R10: ffff889fff407600 R11: ffff88ba9395d740 R12: 000000000000e300 R13: 0000000000000003 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88bfdfa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000002 CR3: 0000000002409005 CR4: 00000000001606e0 Call Trace: __wake_up_common_lock+0x63/0xc0 wb_workfn+0xd2/0x3e0 process_one_work+0x1f5/0x3f0 worker_thread+0x2d/0x3d0 kthread+0x111/0x130 ret_from_fork+0x1f/0x30 Fix it by reading and caching @done->waitq before decrementing @done->cnt. Link: http://lkml.kernel.org/r/20190924010631.GH2233839@devbig004.ftw2.facebook.com Fixes: 5b9cce4c7eb069 ("writeback: Generalize and expose wb_completion") Signed-off-by: Tejun Heo <tj@kernel.org> Debugged-by: Chris Mason <clm@fb.com> Reviewed-by: Jens Axboe <axboe@kernel.dk> Cc: Jan Kara <jack@suse.cz> Cc: <stable@vger.kernel.org> [5.2+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-07fs: ocfs2: fix a possible null-pointer dereference in ↵Jia-Ju Bai
ocfs2_info_scan_inode_alloc() In ocfs2_info_scan_inode_alloc(), there is an if statement on line 283 to check whether inode_alloc is NULL: if (inode_alloc) When inode_alloc is NULL, it is used on line 287: ocfs2_inode_lock(inode_alloc, &bh, 0); ocfs2_inode_lock_full_nested(inode, ...) struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); Thus, a possible null-pointer dereference may occur. To fix this bug, inode_alloc is checked on line 286. This bug is found by a static analysis tool STCheck written by us. Link: http://lkml.kernel.org/r/20190726033717.32359-1-baijiaju1990@gmail.com Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-07fs: ocfs2: fix a possible null-pointer dereference in ocfs2_write_end_nolock()Jia-Ju Bai
In ocfs2_write_end_nolock(), there are an if statement on lines 1976, 2047 and 2058, to check whether handle is NULL: if (handle) When handle is NULL, it is used on line 2045: ocfs2_update_inode_fsync_trans(handle, inode, 1); oi->i_sync_tid = handle->h_transaction->t_tid; Thus, a possible null-pointer dereference may occur. To fix this bug, handle is checked before calling ocfs2_update_inode_fsync_trans(). This bug is found by a static analysis tool STCheck written by us. Link: http://lkml.kernel.org/r/20190726033705.32307-1-baijiaju1990@gmail.com Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-07fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()Jia-Ju Bai
In ocfs2_xa_prepare_entry(), there is an if statement on line 2136 to check whether loc->xl_entry is NULL: if (loc->xl_entry) When loc->xl_entry is NULL, it is used on line 2158: ocfs2_xa_add_entry(loc, name_hash); loc->xl_entry->xe_name_hash = cpu_to_le32(name_hash); loc->xl_entry->xe_name_offset = cpu_to_le16(loc->xl_size); and line 2164: ocfs2_xa_add_namevalue(loc, xi); loc->xl_entry->xe_value_size = cpu_to_le64(xi->xi_value_len); loc->xl_entry->xe_name_len = xi->xi_name_len; Thus, possible null-pointer dereferences may occur. To fix these bugs, if loc-xl_entry is NULL, ocfs2_xa_prepare_entry() abnormally returns with -EINVAL. These bugs are found by a static analysis tool STCheck written by us. [akpm@linux-foundation.org: remove now-unused ocfs2_xa_add_entry()] Link: http://lkml.kernel.org/r/20190726101447.9153-1-baijiaju1990@gmail.com Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com> Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Changwei Ge <gechangwei@live.cn> Cc: Gang He <ghe@suse.com> Cc: Jun Piao <piaojun@huawei.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-07ocfs2: clear zero in unaligned direct IOJia Guo
Unused portion of a part-written fs-block-sized block is not set to zero in unaligned append direct write.This can lead to serious data inconsistencies. Ocfs2 manage disk with cluster size(for example, 1M), part-written in one cluster will change the cluster state from UN-WRITTEN to WRITTEN, VFS(function dio_zero_block) doesn't do the cleaning because bh's state is not set to NEW in function ocfs2_dio_wr_get_block when we write a WRITTEN cluster. For example, the cluster size is 1M, file size is 8k and we direct write from 14k to 15k, then 12k~14k and 15k~16k will contain dirty data. We have to deal with two cases: 1.The starting position of direct write is outside the file. 2.The starting position of direct write is located in the file. We need set bh's state to NEW in the first case. In the second case, we need mapped twice because bh's state of area out file should be set to NEW while area in file not. [akpm@linux-foundation.org: coding style fixes] Link: http://lkml.kernel.org/r/5292e287-8f1a-fd4a-1a14-661e555e0bed@huawei.com Signed-off-by: Jia Guo <guojia12@huawei.com> Reviewed-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Mark Fasheh <mark@fasheh.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-07uaccess: implement a proper unsafe_copy_to_user() and switch filldir over to itLinus Torvalds
In commit 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()") I made filldir() use unsafe_put_user(), which improves code generation on x86 enormously. But because we didn't have a "unsafe_copy_to_user()", the dirent name copy was also done by hand with unsafe_put_user() in a loop, and it turns out that a lot of other architectures didn't like that, because unlike x86, they have various alignment issues. Most non-x86 architectures trap and fix it up, and some (like xtensa) will just fail unaligned put_user() accesses unconditionally. Which makes that "copy using put_user() in a loop" not work for them at all. I could make that code do explicit alignment etc, but the architectures that don't like unaligned accesses also don't really use the fancy "user_access_begin/end()" model, so they might just use the regular old __copy_to_user() interface. So this commit takes that looping implementation, turns it into the x86 version of "unsafe_copy_to_user()", and makes other architectures implement the unsafe copy version as __copy_to_user() (the same way they do for the other unsafe_xyz() accessor functions). Note that it only does this for the copying _to_ user space, and we still don't have a unsafe version of copy_from_user(). That's partly because we have no current users of it, but also partly because the copy_from_user() case is slightly different and cannot efficiently be implemented in terms of a unsafe_get_user() loop (because gcc can't do asm goto with outputs). It would be trivial to do this using "rep movsb", which would work really nicely on newer x86 cores, but really badly on some older ones. Al Viro is looking at cleaning up all our user copy routines to make this all a non-issue, but for now we have this simple-but-stupid version for x86 that works fine for the dirent name copy case because those names are short strings and we simply don't need anything fancier. Fixes: 9f79b78ef744 ("Convert filldir[64]() from __put_user() to unsafe_put_user()") Reported-by: Guenter Roeck <linux@roeck-us.net> Reported-and-tested-by: Tony Luck <tony.luck@intel.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Max Filippov <jcmvbkbc@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-10-06CIFS: Gracefully handle QueryInfo errors during openPavel Shilovsky
Currently if the client identifies problems when processing metadata returned in CREATE response, the open handle is being leaked. This causes multiple problems like a file missing a lease break by that client which causes high latencies to other clients accessing the file. Another side-effect of this is that the file can't be deleted. Fix this by closing the file after the client hits an error after the file was opened and the open descriptor wasn't returned to the user space. Also convert -ESTALE to -EOPENSTALE to allow the VFS to revalidate a dentry and retry the open. Cc: <stable@vger.kernel.org> Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-06cifs: use cifsInodeInfo->open_file_lock while iterating to avoid a panicDave Wysochanski
Commit 487317c99477 ("cifs: add spinlock for the openFileList to cifsInodeInfo") added cifsInodeInfo->open_file_lock spin_lock to protect the openFileList, but missed a few places where cifs_inode->openFileList was enumerated. Change these remaining tcon->open_file_lock to cifsInodeInfo->open_file_lock to avoid panic in is_size_safe_to_change. [17313.245641] RIP: 0010:is_size_safe_to_change+0x57/0xb0 [cifs] [17313.245645] Code: 68 40 48 89 ef e8 19 67 b7 f1 48 8b 43 40 48 8d 4b 40 48 8d 50 f0 48 39 c1 75 0f eb 47 48 8b 42 10 48 8d 50 f0 48 39 c1 74 3a <8b> 80 88 00 00 00 83 c0 01 a8 02 74 e6 48 89 ef c6 07 00 0f 1f 40 [17313.245649] RSP: 0018:ffff94ae1baefa30 EFLAGS: 00010202 [17313.245654] RAX: dead000000000100 RBX: ffff88dc72243300 RCX: ffff88dc72243340 [17313.245657] RDX: dead0000000000f0 RSI: 00000000098f7940 RDI: ffff88dd3102f040 [17313.245659] RBP: ffff88dd3102f040 R08: 0000000000000000 R09: ffff94ae1baefc40 [17313.245661] R10: ffffcdc8bb1c4e80 R11: ffffcdc8b50adb08 R12: 00000000098f7940 [17313.245663] R13: ffff88dc72243300 R14: ffff88dbc8f19600 R15: ffff88dc72243428 [17313.245667] FS: 00007fb145485700(0000) GS:ffff88dd3e000000(0000) knlGS:0000000000000000 [17313.245670] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [17313.245672] CR2: 0000026bb46c6000 CR3: 0000004edb110003 CR4: 00000000007606e0 [17313.245753] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [17313.245756] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [17313.245759] PKRU: 55555554 [17313.245761] Call Trace: [17313.245803] cifs_fattr_to_inode+0x16b/0x580 [cifs] [17313.245838] cifs_get_inode_info+0x35c/0xa60 [cifs] [17313.245852] ? kmem_cache_alloc_trace+0x151/0x1d0 [17313.245885] cifs_open+0x38f/0x990 [cifs] [17313.245921] ? cifs_revalidate_dentry_attr+0x3e/0x350 [cifs] [17313.245953] ? cifsFileInfo_get+0x30/0x30 [cifs] [17313.245960] ? do_dentry_open+0x132/0x330 [17313.245963] do_dentry_open+0x132/0x330 [17313.245969] path_openat+0x573/0x14d0 [17313.245974] do_filp_open+0x93/0x100 [17313.245979] ? __check_object_size+0xa3/0x181 [17313.245986] ? audit_alloc_name+0x7e/0xd0 [17313.245992] do_sys_open+0x184/0x220 [17313.245999] do_syscall_64+0x5b/0x1b0 Fixes: 487317c99477 ("cifs: add spinlock for the openFileList to cifsInodeInfo") CC: Stable <stable@vger.kernel.org> Signed-off-by: Dave Wysochanski <dwysocha@redhat.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-06fs: cifs: mute -Wunused-const-variable messageAustin Kim
After 'Initial git repository build' commit, 'mapping_table_ERRHRD' variable has not been used. So 'mapping_table_ERRHRD' const variable could be removed to mute below warning message: fs/cifs/netmisc.c:120:40: warning: unused variable 'mapping_table_ERRHRD' [-Wunused-const-variable] static const struct smb_to_posix_error mapping_table_ERRHRD[] = { ^ Signed-off-by: Austin Kim <austindh.kim@gmail.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-10-06smb3: cleanup some recent endian errors spotted by updated sparseSteve French
Now that sparse has been fixed, it spotted a couple recent minor endian errors (and removed one additional sparse warning). Thanks to Luc Van Oostenryck for his help fixing sparse. Signed-off-by: Steve French <stfrench@microsoft.com> Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-10-06xfs: assure zeroed memory buffers for certain kmem allocationsBill O'Donnell
Guarantee zeroed memory buffers for cases where potential memory leak to disk can occur. In these cases, kmem_alloc is used and doesn't zero the buffer, opening the possibility of information leakage to disk. Use existing infrastucture (xfs_buf_allocate_memory) to obtain the already zeroed buffer from kernel memory. This solution avoids the performance issue that would occur if a wholesale change to replace kmem_alloc with kmem_zalloc was done. Signed-off-by: Bill O'Donnell <billodo@redhat.com> [darrick: fix bitwise complaint about kmflag_mask] Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>