52076 Commits

Author SHA1 Message Date
Al Viro
3cc4349138 exofs_mount(): fix leaks on failure exits
[ Upstream commit 26cb5a328c6b2bda9e859307ce4cfc60df3a2c28 ]

... and don't abuse mount_nodev(), while we are at it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:37:28 +01:00
Josef Bacik
fe6f3973ff btrfs: only track ref_heads in delayed_ref_updates
[ Upstream commit 158ffa364bf723fa1ef128060646d23dc3942994 ]

We use this number to figure out how many delayed refs to run, but
__btrfs_run_delayed_refs really only checks every time we need a new
delayed ref head, so we always run at least one ref head completely no
matter what the number of items on it.  Fix the accounting to only be
adjusted when we add/remove a ref head.

In addition to using this number to limit the number of delayed refs
run, a future patch is also going to use it to calculate the amount of
space required for delayed refs space reservation.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:37:25 +01:00
Darrick J. Wong
23df2afe9d xfs: require both realtime inodes to mount
[ Upstream commit 64bafd2f1e484e27071e7584642005d56516cb77 ]

Since mkfs always formats the filesystem with the realtime bitmap and
summary inodes immediately after the root directory, we should expect
that both of them are present and loadable, even if there isn't a
realtime volume attached.  There's no reason to skip this if rbmino ==
NULLFSINO; in fact, this causes an immediate crash if the there /is/ a
realtime volume and someone writes to it.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:37:18 +01:00
Jeff Layton
06d3f91ed5 ceph: return -EINVAL if given fsc mount option on kernel w/o support
[ Upstream commit ff29fde84d1fc82f233c7da0daa3574a3942bec7 ]

If someone requests fscache on the mount, and the kernel doesn't
support it, it should fail the mount.

[ Drop ceph prefix -- it's provided by pr_err. ]

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-05 15:37:06 +01:00
Gang He
bebf269c6d ocfs2: remove ocfs2_is_o2cb_active()
commit a634644751c46238df58bbfe992e30c1668388db upstream.

Remove ocfs2_is_o2cb_active().  We have similar functions to identify
which cluster stack is being used via osb->osb_cluster_stack.

Secondly, the current implementation of ocfs2_is_o2cb_active() is not
totally safe.  Based on the design of stackglue, we need to get
ocfs2_stack_lock before using ocfs2_stack related data structures, and
that active_stack pointer can be NULL in the case of mount failure.

Link: http://lkml.kernel.org/r/1495441079-11708-1-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>
Acked-by: Changwei Ge <ge.changwei@h3c.com>
Cc: Mark Fasheh <mark@fasheh.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>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-01 09:14:20 +01:00
Tycho Andersen
fcd1fe97ae dlm: don't leak kernel pointer to userspace
[ Upstream commit 9de30f3f7f4d31037cfbb7c787e1089c1944b3a7 ]

In copy_result_to_user(), we first create a struct dlm_lock_result, which
contains a struct dlm_lksb, the last member of which is a pointer to the
lvb. Unfortunately, we copy the entire struct dlm_lksb to the result
struct, which is then copied to userspace at the end of the function,
leaking the contents of sb_lvbptr, which is a valid kernel pointer in some
cases (indeed, later in the same function the data it points to is copied
to userspace).

It is an error to leak kernel pointers to userspace, as it undermines KASLR
protections (see e.g. 65eea8edc31 ("floppy: Do not copy a kernel pointer to
user memory in FDGETPRM ioctl") for another example of this).

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:14:11 +01:00
Tycho Andersen
eabc0324f8 dlm: fix invalid free
[ Upstream commit d968b4e240cfe39d39d80483bac8bca8716fd93c ]

dlm_config_nodes() does not allocate nodes on failure, so we should not
free() nodes when it fails.

Signed-off-by: Tycho Andersen <tycho@tycho.ws>
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:14:11 +01:00
Arnd Bergmann
ab5ef999c7 btrfs: avoid link error with CONFIG_NO_AUTO_INLINE
[ Upstream commit 7e17916b35797396f681a3270245fd29c1e4c250 ]

Note: this patch fixes a problem in a feature outside of btrfs ("kernel
hacking: add a config option to disable compiler auto-inlining") and is
applied ahead of time due to cross-subsystem dependencies.

On 32-bit ARM with gcc-8, I see a link error with the addition of the
CONFIG_NO_AUTO_INLINE option:

fs/btrfs/super.o: In function `btrfs_statfs':
super.c:(.text+0x67b8): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x67fc): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6858): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x6920): undefined reference to `__aeabi_uldivmod'
super.c:(.text+0x693c): undefined reference to `__aeabi_uldivmod'
fs/btrfs/super.o:super.c:(.text+0x6958): more undefined references to `__aeabi_uldivmod' follow

So far this is the only file that shows the behavior, so I'd propose
to just work around it by marking the functions as 'static inline'
that normally get inlined here.

The reference to __aeabi_uldivmod comes from a div_u64() which has an
optimization for a constant division that uses a straight '/' operator
when the result should be known to the compiler. My interpretation is
that as we turn off inlining, gcc still expects the result to be constant
but fails to use that constant value.

Link: https://lkml.kernel.org/r/20181103153941.1881966-1-arnd@arndb.de
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Changbin Du <changbin.du@gmail.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
[ add the note ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:14:04 +01:00
Larry Chen
e2017fc025 ocfs2: fix clusters leak in ocfs2_defrag_extent()
[ Upstream commit 6194ae4242dec0c9d604bc05df83aa9260a899e4 ]

ocfs2_defrag_extent() might leak allocated clusters.  When the file
system has insufficient space, the number of claimed clusters might be
less than the caller wants.  If that happens, the original code might
directly commit the transaction without returning clusters.

This patch is based on code in ocfs2_add_clusters_in_btree().

[akpm@linux-foundation.org: include localalloc.h, reduce scope of data_ac]
Link: http://lkml.kernel.org/r/20180904041621.16874-3-lchen@suse.com
Signed-off-by: Larry Chen <lchen@suse.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:14:00 +01:00
Changwei Ge
97e1db17bc ocfs2: don't put and assigning null to bh allocated outside
[ Upstream commit cf76c78595ca87548ca5e45c862ac9e0949c4687 ]

ocfs2_read_blocks() and ocfs2_read_blocks_sync() are both used to read
several blocks from disk.  Currently, the input argument *bhs* can be
NULL or NOT.  It depends on the caller's behavior.  If the function
fails in reading blocks from disk, the corresponding bh will be assigned
to NULL and put.

Obviously, above process for non-NULL input bh is not appropriate.
Because the caller doesn't even know its bhs are put and re-assigned.

If buffer head is managed by caller, ocfs2_read_blocks and
ocfs2_read_blocks_sync() should not evaluate it to NULL.  It will cause
caller accessing illegal memory, thus crash.

Link: http://lkml.kernel.org/r/HK2PR06MB045285E0F4FBB561F9F2F9B3D5680@HK2PR06MB0452.apcprd06.prod.outlook.com
Signed-off-by: Changwei Ge <ge.changwei@h3c.com>
Reviewed-by: Guozhonghua <guozhonghua@h3c.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:14:00 +01:00
Colin Ian King
496a777638 fs/hfs/extent.c: fix array out of bounds read of array extent
[ Upstream commit 6c9a3f843a29d6894dfc40df338b91dbd78f0ae3 ]

Currently extent and index i are both being incremented causing an array
out of bounds read on extent[i].  Fix this by removing the extraneous
increment of extent.

Ernesto said:

: This is only triggered when deleting a file with a resource fork.  I
: may be wrong because the documentation isn't clear, but I don't think
: you can create those under linux.  So I guess nobody was testing them.
:
: > A disk space leak, perhaps?
:
: That's what it looks like in general.  hfs_free_extents() won't do
: anything if the block count doesn't add up, and the error will be
: ignored.  Now, if the block count randomly does add up, we could see
: some corruption.

Detected by CoverityScan, CID#711541 ("Out of bounds read")

Link: http://lkml.kernel.org/r/20180831140538.31566-1-colin.king@canonical.com
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Ernesto A. Fernndez <ernesto.mnd.fernandez@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Hin-Tak Leung <htl10@users.sourceforge.net>
Cc: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:57 +01:00
Ernesto A. Fernández
dcc4cf3be9 hfs: update timestamp on truncate()
[ Upstream commit 8cd3cb5061730af085a3f9890a3352f162b4e20c ]

The vfs takes care of updating mtime on ftruncate(), but on truncate() it
must be done by the module.

Link: http://lkml.kernel.org/r/e1611eda2985b672ed2d8677350b4ad8c2d07e8a.1539316825.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:56 +01:00
Ernesto A. Fernández
47b8860bb8 hfsplus: update timestamps on truncate()
[ Upstream commit dc8844aada735890a6de109bef327f5df36a982e ]

The vfs takes care of updating ctime and mtime on ftruncate(), but on
truncate() it must be done by the module.

This patch can be tested with xfstests generic/313.

Link: http://lkml.kernel.org/r/9beb0913eea37288599e8e1b7cec8768fb52d1b8.1539316825.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:56 +01:00
Ernesto A. Fernández
42934683c9 hfs: fix return value of hfs_get_block()
[ Upstream commit 1267a07be5ebbff2d2739290f3d043ae137c15b4 ]

Direct writes to empty inodes fail with EIO.  The generic direct-io code
is in part to blame (a patch has been submitted as "direct-io: allow
direct writes to empty inodes"), but hfs is worse affected than the other
filesystems because the fallback to buffered I/O doesn't happen.

The problem is the return value of hfs_get_block() when called with
!create.  Change it to be more consistent with the other modules.

Link: http://lkml.kernel.org/r/4538ab8c35ea37338490525f0f24cbc37227528c.1539195310.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:55 +01:00
Ernesto A. Fernández
0a729bac19 hfsplus: fix return value of hfsplus_get_block()
[ Upstream commit 839c3a6a5e1fbc8542d581911b35b2cb5cd29304 ]

Direct writes to empty inodes fail with EIO.  The generic direct-io code
is in part to blame (a patch has been submitted as "direct-io: allow
direct writes to empty inodes"), but hfsplus is worse affected than the
other filesystems because the fallback to buffered I/O doesn't happen.

The problem is the return value of hfsplus_get_block() when called with
!create.  Change it to be more consistent with the other modules.

Link: http://lkml.kernel.org/r/2cd1301404ec7cf1e39c8f11a01a4302f1460ad6.1539195310.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:55 +01:00
Ernesto A. Fernández
e113185831 hfs: prevent btree data loss on ENOSPC
[ Upstream commit 54640c7502e5ed41fbf4eedd499e85f9acc9698f ]

Inserting a new record in a btree may require splitting several of its
nodes.  If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost.  This could mean lost inodes or
extents.

Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.

There is no need to reserve space before deleting a catalog record, as we
do for hfsplus.  This difference is because hfs index nodes have fixed
length keys.

Link: http://lkml.kernel.org/r/ab5fc8a7d5ffccfd5f27b1cf2cb4ceb6c110da74.1536269131.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:54 +01:00
Ernesto A. Fernández
71db398991 hfsplus: prevent btree data loss on ENOSPC
[ Upstream commit d92915c35bfaf763d78bf1d5ac7f183420e3bd99 ]

Inserting or deleting a record in a btree may require splitting several of
its nodes.  If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost.  This could mean lost inodes,
extents or xattrs.

Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.

The patch can be tested with xfstests generic/027.

Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:54 +01:00
Ernesto A. Fernández
44ddfe1ced hfs: fix BUG on bnode parent update
[ Upstream commit ef75bcc5763d130451a99825f247d301088b790b ]

hfs_brec_update_parent() may hit BUG_ON() if the first record of both a
leaf node and its parent are changed, and if this forces the parent to
be split.  It is not possible for this to happen on a valid hfs
filesystem because the index nodes have fixed length keys.

For reasons I ignore, the hfs module does have support for a number of
hfsplus features.  A corrupt btree header may report variable length
keys and trigger this BUG, so it's better to fix it.

Link: http://lkml.kernel.org/r/cf9b02d57f806217a2b1bf5db8c3e39730d8f603.1535682463.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Viacheslav Dubeyko <slava@dubeyko.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:53 +01:00
Ernesto A. Fernández
30f1d1147a hfsplus: fix BUG on bnode parent update
[ Upstream commit 19a9d0f1acf75e8be8cfba19c1a34e941846fa2b ]

Creating, renaming or deleting a file may hit BUG_ON() if the first
record of both a leaf node and its parent are changed, and if this
forces the parent to be split.  This bug is triggered by xfstests
generic/027, somewhat rarely; here is a more reliable reproducer:

  truncate -s 50M fs.iso
  mkfs.hfsplus fs.iso
  mount fs.iso /mnt
  i=1000
  while [ $i -le 2400 ]; do
    touch /mnt/$i &>/dev/null
    ((++i))
  done
  i=2400
  while [ $i -ge 1000 ]; do
    mv /mnt/$i /mnt/$(perl -e "print $i x61") &>/dev/null
    ((--i))
  done

The issue is that a newly created bnode is being put twice.  Reset
new_node to NULL in hfs_brec_update_parent() before reaching goto again.

Link: http://lkml.kernel.org/r/5ee1db09b60373a15890f6a7c835d00e76bf601d.1535682461.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:53 +01:00
Darrick J. Wong
850fc69e08 vfs: avoid problematic remapping requests into partial EOF block
[ Upstream commit 07d19dc9fbe9128378b9e226abe886fd8fd473df ]

A deduplication data corruption is exposed in XFS and btrfs. It is
caused by extending the block match range to include the partial EOF
block, but then allowing unknown data beyond EOF to be considered a
"match" to data in the destination file because the comparison is only
made to the end of the source file. This corrupts the destination file
when the source extent is shared with it.

The VFS remapping prep functions  only support whole block dedupe, but
we still need to appear to support whole file dedupe correctly.  Hence
if the dedupe request includes the last block of the souce file, don't
include it in the actual dedupe operation. If the rest of the range
dedupes successfully, then reject the entire request.  A subsequent
patch will enable us to shorten dedupe requests correctly.

When reflinking sub-file ranges, a data corruption can occur when the
source file range includes a partial EOF block. This shares the unknown
data beyond EOF into the second file at a position inside EOF, exposing
stale data in the second file.

If the reflink request includes the last block of the souce file, only
proceed with the reflink operation if it lands at or past the
destination file's current EOF. If it lands within the destination file
EOF, reject the entire request with -EINVAL and make the caller go the
hard way.  A subsequent patch will enable us to shorten reflink requests
correctly.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:51 +01:00
Jia-Ju Bai
4308d2f4cf fs/ocfs2/dlm/dlmdebug.c: fix a sleep-in-atomic-context bug in dlm_print_one_mle()
[ Upstream commit 999865764f5f128896402572b439269acb471022 ]

The kernel module may sleep with holding a spinlock.

The function call paths (from bottom to top) in Linux-4.16 are:

[FUNC] get_zeroed_page(GFP_NOFS)
fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle
fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 255: __dlm_put_mle in dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 254: spin_lock in dlm_put_ml

[FUNC] get_zeroed_page(GFP_NOFS)
fs/ocfs2/dlm/dlmdebug.c, 332: get_zeroed_page in dlm_print_one_mle
fs/ocfs2/dlm/dlmmaster.c, 240: dlm_print_one_mle in __dlm_put_mle
fs/ocfs2/dlm/dlmmaster.c, 222: __dlm_put_mle in dlm_put_mle_inuse
fs/ocfs2/dlm/dlmmaster.c, 219: spin_lock in dlm_put_mle_inuse

To fix this bug, GFP_NOFS is replaced with GFP_ATOMIC.

This bug is found by my static analysis tool DSAC.

Link: http://lkml.kernel.org/r/20180901112528.27025-1-baijiaju1990@gmail.com
Signed-off-by: Jia-Ju Bai <baijiaju1990@gmail.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Joseph Qi <jiangqi903@gmail.com>
Cc: Changwei Ge <ge.changwei@h3c.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:48 +01:00
Chao Yu
18acb44252 f2fs: fix to spread clear_cold_data()
[ Upstream commit 2baf07818549c8bb8d7b3437e889b86eab56d38e ]

We need to drop PG_checked flag on page as well when we clear PG_uptodate
flag, in order to avoid treating the page as GCing one later.

Signed-off-by: Weichao Guo <guoweichao@huawei.com>
Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:44 +01:00
Yan, Zheng
1a62bbf3ed ceph: fix dentry leak in ceph_readdir_prepopulate
[ Upstream commit c58f450bd61511d897efc2ea472c69630635b557 ]

Signed-off-by: "Yan, Zheng" <zyan@redhat.com>
Reviewed-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:44 +01:00
Dave Chinner
5506ef8616 xfs: fix use-after-free race in xfs_buf_rele
[ Upstream commit 37fd1678245f7a5898c1b05128bc481fb403c290 ]

When looking at a 4.18 based KASAN use after free report, I noticed
that racing xfs_buf_rele() may race on dropping the last reference
to the buffer and taking the buffer lock. This was the symptom
displayed by the KASAN report, but the actual issue that was
reported had already been fixed in 4.19-rc1 by commit e339dd8d8b04
("xfs: use sync buffer I/O for sync delwri queue submission").

Despite this, I think there is still an issue with xfs_buf_rele()
in this code:

        release = atomic_dec_and_lock(&bp->b_hold, &pag->pag_buf_lock);
        spin_lock(&bp->b_lock);
        if (!release) {
.....

If two threads race on the b_lock after both dropping a reference
and one getting dropping the last reference so release = true, we
end up with:

CPU 0				CPU 1
atomic_dec_and_lock()
				atomic_dec_and_lock()
				spin_lock(&bp->b_lock)
spin_lock(&bp->b_lock)
<spins>
				<release = true bp->b_lru_ref = 0>
				<remove from lists>
				freebuf = true
				spin_unlock(&bp->b_lock)
				xfs_buf_free(bp)
<gets lock, reading and writing freed memory>
<accesses freed memory>
spin_unlock(&bp->b_lock) <reads/writes freed memory>

IOWs, we can't safely take bp->b_lock after dropping the hold
reference because the buffer may go away at any time after we
drop that reference. However, this can be fixed simply by taking the
bp->b_lock before we drop the reference.

It is safe to nest the pag_buf_lock inside bp->b_lock as the
pag_buf_lock is only used to serialise against lookup in
xfs_buf_find() and no other locks are held over or under the
pag_buf_lock there. Make this clear by documenting the buffer lock
orders at the top of the file.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com
Signed-off-by: Dave Chinner <david@fromorbit.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:37 +01:00
Nikolay Borisov
67631651aa btrfs: handle error of get_old_root
[ Upstream commit 315bed43fea532650933e7bba316a7601d439edf ]

In btrfs_search_old_slot get_old_root is always used with the assumption
it cannot fail. However, this is not true in rare circumstance it can
fail and return null. This will lead to null point dereference when the
header is read. Fix this by checking the return value and properly
handling NULL by setting ret to -EIO and returning gracefully.

Coverity-id: 1087503
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:22 +01:00
Andreas Gruenbacher
2e3be85994 gfs2: Fix marking bitmaps non-full
[ Upstream commit ec23df2b0cf3e1620f5db77972b7fb735f267eff ]

Reservations in gfs can span multiple gfs2_bitmaps (but they won't span
multiple resource groups).  When removing a reservation, we want to
clear the GBF_FULL flags of all involved gfs2_bitmaps, not just that of
the first bitmap.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Reviewed-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-12-01 09:13:17 +01:00
Joseph Qi
151ec39119 Revert "fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()"
commit 94b07b6f9e2e996afff7395de6b35f34f4cb10bf upstream.

This reverts commit 56e94ea132bb5c2c1d0b60a6aeb34dcb7d71a53d.

Commit 56e94ea132bb ("fs: ocfs2: fix possible null-pointer dereferences
in ocfs2_xa_prepare_entry()") introduces a regression that fail to
create directory with mount option user_xattr and acl.  Actually the
reported NULL pointer dereference case can be correctly handled by
loc->xl_ops->xlo_add_entry(), so revert it.

Link: http://lkml.kernel.org/r/1573624916-83825-1-git-send-email-joseph.qi@linux.alibaba.com
Fixes: 56e94ea132bb ("fs: ocfs2: fix possible null-pointer dereferences in ocfs2_xa_prepare_entry()")
Signed-off-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Reported-by: Thomas Voegtle <tv@lio96.de>
Acked-by: Changwei Ge <gechangwei@live.cn>
Cc: Jia-Ju Bai <baijiaju1990@gmail.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-12-01 09:13:14 +01:00
Colin Ian King
fff32b6c51 orangefs: rate limit the client not running info message
[ Upstream commit 2978d873471005577e7b68a528b4f256a529b030 ]

Currently accessing various /sys/fs/orangefs files will spam the
kernel log with the following info message when the client is not
running:

[  491.489284] sysfs_service_op_show: Client not running :-5:

Rate limit this info message to make it less spammy.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:23:30 +01:00
Tim Smith
e30c1d9fc2 GFS2: Flush the GFS2 delete workqueue before stopping the kernel threads
[ Upstream commit 1eb8d7387908022951792a46fa040ad3942b3b08 ]

Flushing the workqueue can cause operations to happen which might
call gfs2_log_reserve(), or get stuck waiting for locks taken by such
operations.  gfs2_log_reserve() can io_schedule(). If this happens, it
will never wake because the only thing which can wake it is gfs2_logd()
which was already stopped.

This causes umount of a gfs2 filesystem to wedge permanently if, for
example, the umount immediately follows a large delete operation.

When this occured, the following stack trace was obtained from the
umount command

[<ffffffff81087968>] flush_workqueue+0x1c8/0x520
[<ffffffffa0666e29>] gfs2_make_fs_ro+0x69/0x160 [gfs2]
[<ffffffffa0667279>] gfs2_put_super+0xa9/0x1c0 [gfs2]
[<ffffffff811b7edf>] generic_shutdown_super+0x6f/0x100
[<ffffffff811b7ff7>] kill_block_super+0x27/0x70
[<ffffffffa0656a71>] gfs2_kill_sb+0x71/0x80 [gfs2]
[<ffffffff811b792b>] deactivate_locked_super+0x3b/0x70
[<ffffffff811b79b9>] deactivate_super+0x59/0x60
[<ffffffff811d2998>] cleanup_mnt+0x58/0x80
[<ffffffff811d2a12>] __cleanup_mnt+0x12/0x20
[<ffffffff8108c87d>] task_work_run+0x7d/0xa0
[<ffffffff8106d7d9>] exit_to_usermode_loop+0x73/0x98
[<ffffffff81003961>] syscall_return_slowpath+0x41/0x50
[<ffffffff815a594c>] int_ret_from_sys_call+0x25/0x8f
[<ffffffffffffffff>] 0xffffffffffffffff

Signed-off-by: Tim Smith <tim.smith@citrix.com>
Signed-off-by: Mark Syms <mark.syms@citrix.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:23:25 +01:00
Borislav Petkov
27647dde30 proc/vmcore: Fix i386 build error of missing copy_oldmem_page_encrypted()
[ Upstream commit cf089611f4c446285046fcd426d90c18f37d2905 ]

Lianbo reported a build error with a particular 32-bit config, see Link
below for details.

Provide a weak copy_oldmem_page_encrypted() function which architectures
can override, in the same manner other functionality in that file is
supplied.

Reported-by: Lianbo Jiang <lijiang@redhat.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
CC: x86@kernel.org
Link: http://lkml.kernel.org/r/710b9d95-2f70-eadf-c4a1-c3dc80ee4ebb@redhat.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:23:23 +01:00
Olga Kornievskaia
d9871d9c52 NFSv4.x: fix lock recovery during delegation recall
[ Upstream commit 44f411c353bf6d98d5a34f8f1b8605d43b2e50b8 ]

Running "./nfstest_delegation --runtest recall26" uncovers that
client doesn't recover the lock when we have an appending open,
where the initial open got a write delegation.

Instead of checking for the passed in open context against
the file lock's open context. Check that the state is the same.

Signed-off-by: Olga Kornievskaia <kolga@netapp.com>
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:23:12 +01:00
Gabriel Krisman Bertazi
3610daee86 ext4: fix build error when DX_DEBUG is defined
[ Upstream commit 799578ab16e86b074c184ec5abbda0bc698c7b0b ]

Enabling DX_DEBUG triggers the build error below.  info is an attribute
of  the dxroot structure.

linux/fs/ext4/namei.c:2264:12: error: ‘info’
undeclared (first use in this function); did you mean ‘insl’?
	   	  info->indirect_levels));

Fixes: e08ac99fa2a2 ("ext4: add largedir feature")
Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.co.uk>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Lukas Czerner <lczerner@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:22:58 +01:00
Jaegeuk Kim
715119d3f1 f2fs: return correct errno in f2fs_gc
[ Upstream commit 61f7725aa148ee870436a29d3a24d5c00ab7e9af ]

This fixes overriding error number in f2fs_gc.

Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-24 08:22:50 +01:00
Kirill Tkhai
2b149bb378 fuse: use READ_ONCE on congestion_threshold and max_background
[ Upstream commit 2a23f2b8adbe4bd584f936f7ac17a99750eed9d7 ]

Since they are of unsigned int type, it's allowed to read them
unlocked during reporting to userspace. Let's underline this fact
with READ_ONCE() macroses.

Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:00:52 +01:00
Chao Yu
34ef137386 f2fs: mark inode dirty explicitly in recover_inode()
[ Upstream commit 4a1728cad6340bfbe17bd17fd158b2165cd99508 ]

Mark inode dirty explicitly in the end of recover_inode() to make sure
that all recoverable fields can be persisted later.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:00:45 +01:00
Chao Yu
471d39b9f0 f2fs: fix to recover inode's project id during POR
[ Upstream commit f4474aa6e5e901ee4af21f39f1b9115aaaaec503 ]

Testcase to reproduce this bug:
1. mkfs.f2fs -O extra_attr -O project_quota /dev/sdd
2. mount -t f2fs /dev/sdd /mnt/f2fs
3. touch /mnt/f2fs/file
4. sync
5. chattr -p 1 /mnt/f2fs/file
6. xfs_io -f /mnt/f2fs/file -c "fsync"
7. godown /mnt/f2fs
8. umount /mnt/f2fs
9. mount -t f2fs /dev/sdd /mnt/f2fs
10. lsattr -p /mnt/f2fs/file

    0 -----------------N- /mnt/f2fs/file

But actually, we expect the correct result is:

    1 -----------------N- /mnt/f2fs/file

The reason is we didn't recover inode.i_projid field during mount,
fix it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:00:44 +01:00
Chao Yu
47df751764 f2fs: fix to recover inode's uid/gid during POR
[ Upstream commit dc4cd1257c86451cec3e8e352cc376348e4f4af4 ]

Step to reproduce this bug:
1. logon as root
2. mount -t f2fs /dev/sdd /mnt;
3. touch /mnt/file;
4. chown system /mnt/file; chgrp system /mnt/file;
5. xfs_io -f /mnt/file -c "fsync";
6. godown /mnt;
7. umount /mnt;
8. mount -t f2fs /dev/sdd /mnt;

After step 8) we will expect file's uid/gid are all system, but during
recovery, these two fields were not been recovered, fix it.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:00:21 +01:00
Bernd Edlinger
e32819f088 kernfs: Fix range checks in kernfs_get_target_path
[ Upstream commit a75e78f21f9ad4b810868c89dbbabcc3931591ca ]

The terminating NUL byte is only there because the buffer is
allocated with kzalloc(PAGE_SIZE, GFP_KERNEL), but since the
range-check is off-by-one, and PAGE_SIZE==PATH_MAX, the
returned string may not be zero-terminated if it is exactly
PATH_MAX characters long.  Furthermore also the initial loop
may theoretically exceed PATH_MAX and cause a fault.

Signed-off-by: Bernd Edlinger <bernd.edlinger@hotmail.de>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 18:00:02 +01:00
Arnd Bergmann
cd5bedea5e media: dvb: fix compat ioctl translation
[ Upstream commit 1ccbeeb888ac33627d91f1ccf0b84ef3bcadef24 ]

The VIDEO_GET_EVENT and VIDEO_STILLPICTURE was added back in 2005 but
it never worked because the command number is wrong.

Using the right command number means we have a better chance of them
actually doing the right thing, though clearly nobody has ever tried
it successfully.

I noticed these while auditing the remaining users of compat_time_t
for y2038 bugs. This one is fine in that regard, it just never did
anything.

Fixes: 6e87abd0b8cb ("[DVB]: Add compat ioctl handling.")

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 17:59:57 +01:00
Chao Yu
2afdbe7020 f2fs: fix memory leak of percpu counter in fill_super()
[ Upstream commit 4a70e255449c9a13eed7a6eeecc85a1ea63cef76 ]

In fill_super -> init_percpu_info, we should destroy percpu counter
in error path, otherwise memory allcoated for percpu counter will
leak.

Signed-off-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 17:59:52 +01:00
Bob Peterson
caf450580c gfs2: Don't set GFS2_RDF_UPTODATE when the lvb is updated
[ Upstream commit 4f36cb36c9d14340bb200d2ad9117b03ce992cfe ]

The GFS2_RDF_UPTODATE flag in the rgrp is used to determine when
a rgrp buffer is valid. It's cleared when the glock is invalidated,
signifying that the buffer data is now invalid. But before this
patch, function update_rgrp_lvb was setting the flag when it
determined it had a valid lvb. But that's an invalid assumption:
just because you have a valid lvb doesn't mean you have valid
buffers. After all, another node may have made the lvb valid,
and this node just fetched it from the glock via dlm.

Consider this scenario:
1. The file system is mounted with RGRPLVB option.
2. In gfs2_inplace_reserve it locks the rgrp glock EX, but thanks
   to GL_SKIP, it skips the gfs2_rgrp_bh_get.
3. Since loops == 0 and the allocation target (ap->target) is
   bigger than the largest known chunk of blocks in the rgrp
   (rs->rs_rbm.rgd->rd_extfail_pt) it skips that rgrp and bypasses
   the call to gfs2_rgrp_bh_get there as well.
4. update_rgrp_lvb sees the lvb MAGIC number is valid, so bypasses
   gfs2_rgrp_bh_get, but it still sets sets GFS2_RDF_UPTODATE due
   to this invalid assumption.
5. The next time update_rgrp_lvb is called, it sees the bit is set
   and just returns 0, assuming both the lvb and rgrp are both
   uptodate. But since this is a smaller allocation, or space has
   been freed by another node, thus adjusting the lvb values,
   it decides to use the rgrp for allocations, with invalid rd_free
   due to the fact it was never updated.

This patch changes update_rgrp_lvb so it doesn't set the UPTODATE
flag anymore. That way, it has no choice but to fetch the latest
values.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-20 17:59:42 +01:00
Al Viro
d47135249f ecryptfs_lookup_interpose(): lower_dentry->d_parent is not stable either
commit 762c69685ff7ad5ad7fee0656671e20a0c9c864d upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20 17:59:32 +01:00
Al Viro
dc39d4f7ec ecryptfs_lookup_interpose(): lower_dentry->d_inode is not stable
commit e72b9dd6a5f17d0fb51f16f8685f3004361e83d0 upstream.

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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-20 17:59:31 +01:00
Tejun Heo
d527ab46d1 cgroup,writeback: don't switch wbs immediately on dead wbs if the memcg is dead
commit 65de03e251382306a4575b1779c57c87889eee49 upstream.

cgroup writeback tries to refresh the associated wb immediately if the
current wb is dead.  This is to avoid keeping issuing IOs on the stale
wb after memcg - blkcg association has changed (ie. when blkcg got
disabled / enabled higher up in the hierarchy).

Unfortunately, the logic gets triggered spuriously on inodes which are
associated with dead cgroups.  When the logic is triggered on dead
cgroups, the attempt fails only after doing quite a bit of work
allocating and initializing a new wb.

While c3aab9a0bd91 ("mm/filemap.c: don't initiate writeback if mapping
has no dirty pages") alleviated the issue significantly as it now only
triggers when the inode has dirty pages.  However, the condition can
still be triggered before the inode is switched to a different cgroup
and the logic simply doesn't make sense.

Skip the immediate switching if the associated memcg is dying.

This is a simplified version of the following two patches:

 * https://lore.kernel.org/linux-mm/20190513183053.GA73423@dennisz-mbp/
 * http://lkml.kernel.org/r/156355839560.2063.5265687291430814589.stgit@buzz

Cc: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Fixes: e8a7abf5a5bd ("writeback: disassociate inodes from dying bdi_writebacks")
Acked-by: Dennis Zhou <dennis@kernel.org>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:47 +01:00
Trond Myklebust
640b29e018 NFSv4: Don't allow a cached open with a revoked delegation
[ Upstream commit be3df3dd4c70ee020587a943a31b98a0fb4b6424 ]

If the delegation is marked as being revoked, we must not use it
for cached opens.

Fixes: 869f9dfa4d6d ("NFSv4: Fix races between nfs_remove_bad_delegation() and delegation return")
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
2019-11-12 19:18:43 +01:00
Al Viro
e49b85dd3c configfs: fix a deadlock in configfs_symlink()
commit 351e5d869e5ac10cb40c78b5f2d7dfc816ad4587 upstream.

Configfs abuses symlink(2).  Unlike the normal filesystems, it
wants the target resolved at symlink(2) time, like link(2) would've
done.  The problem is that ->symlink() is called with the parent
directory locked exclusive, so resolving the target inside the
->symlink() is easily deadlocked.

Short of really ugly games in sys_symlink() itself, all we can
do is to unlock the parent before resolving the target and
relock it after.  However, that invalidates the checks done
by the caller of ->symlink(), so we have to
	* check that dentry is still where it used to be
(it couldn't have been moved, but it could've been unhashed)
	* recheck that it's still negative (somebody else
might've successfully created a symlink with the same name
while we were looking the target up)
	* recheck the permissions on the parent directory.

Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:18 +01:00
Al Viro
09e21253d1 configfs: provide exclusion between IO and removals
commit b0841eefd9693827afb9888235e26ddd098f9cef upstream.

Make sure that attribute methods are not called after the item
has been removed from the tree.  To do so, we
	* at the point of no return in removals, grab ->frag_sem
exclusive and mark the fragment dead.
	* call the methods of attributes with ->frag_sem taken
shared and only after having verified that the fragment is still
alive.

	The main benefit is for method instances - they are
guaranteed that the objects they are accessing *and* all ancestors
are still there.  Another win is that we don't need to bother
with extra refcount on config_item when opening a file -
the item will be alive for as long as it stays in the tree, and
we won't touch it/attributes/any associated data after it's
been removed from the tree.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:17 +01:00
Al Viro
2f41c26ed4 configfs: new object reprsenting tree fragments
commit 47320fbe11a6059ae502c9c16b668022fdb4cf76 upstream.

Refcounted, hangs of configfs_dirent, created by operations that add
fragments to configfs tree (mkdir and configfs_register_{subsystem,group}).
Will be used in the next commit to provide exclusion between fragment
removal and ->show/->store calls.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:17 +01:00
Al Viro
5f7f9c7cde configfs_register_group() shouldn't be (and isn't) called in rmdirable parts
commit f19e4ed1e1edbfa3c9ccb9fed17759b7d6db24c6 upstream.

revert cc57c07343bd "configfs: fix registered group removal"
It was an attempt to handle something that fundamentally doesn't
work - configfs_register_group() should never be done in a part
of tree that can be rmdir'ed.  And in mainline it never had been,
so let's not borrow trouble; the fix was racy anyway, it would take
a lot more to make that work and desired semantics is not clear.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:16 +01:00
Al Viro
3e651dd602 configfs: stash the data we need into configfs_buffer at open time
commit ff4dd081977da56566a848f071aed8fa92d604a1 upstream.

simplifies the ->read()/->write()/->release() instances nicely

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-11-12 19:18:15 +01:00