David Howells [Thu, 29 Jan 2015 12:02:35 +0000 (12:02 +0000)]
VFS: (Scripted) Convert S_ISLNK/DIR/REG(dentry->d_inode) to d_is_*(dentry)
Convert the following where appropriate:
(1) S_ISLNK(dentry->d_inode) to d_is_symlink(dentry).
(2) S_ISREG(dentry->d_inode) to d_is_reg(dentry).
(3) S_ISDIR(dentry->d_inode) to d_is_dir(dentry). This is actually more
complicated than it appears as some calls should be converted to
d_can_lookup() instead. The difference is whether the directory in
question is a real dir with a ->lookup op or whether it's a fake dir with
a ->d_automount op.
In some circumstances, we can subsume checks for dentry->d_inode not being
NULL into this, provided we the code isn't in a filesystem that expects
d_inode to be NULL if the dirent really *is* negative (ie. if we're going to
use d_inode() rather than d_backing_inode() to get the inode pointer).
Note that the dentry type field may be set to something other than
DCACHE_MISS_TYPE when d_inode is NULL in the case of unionmount, where the VFS
manages the fall-through from a negative dentry to a lower layer. In such a
case, the dentry type of the negative union dentry is set to the same as the
type of the lower dentry.
However, if you know d_inode is not NULL at the call site, then you can use
the d_is_xxx() functions even in a filesystem.
There is one further complication: a 0,0 chardev dentry may be labelled
DCACHE_WHITEOUT_TYPE rather than DCACHE_SPECIAL_TYPE. Strictly, this was
intended for special directory entry types that don't have attached inodes.
The following perl+coccinelle script was used:
use strict;
my @callers;
open($fd, 'git grep -l \'S_IS[A-Z].*->d_inode\' |') ||
die "Can't grep for S_ISDIR and co. callers";
@callers = <$fd>;
close($fd);
unless (@callers) {
print "No matches\n";
exit(0);
}
David Howells [Thu, 29 Jan 2015 12:02:31 +0000 (12:02 +0000)]
Apparmor: Use d_is_positive/negative() rather than testing dentry->d_inode
Use d_is_positive(dentry) or d_is_negative(dentry) rather than testing
dentry->d_inode as the dentry may cover another layer that has an inode when
the top layer doesn't or may hold a 0,0 chardev that's actually a whiteout.
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
David Howells [Thu, 29 Jan 2015 12:02:28 +0000 (12:02 +0000)]
VFS: Add a fallthrough flag for marking virtual dentries
Add a DCACHE_FALLTHRU flag to indicate that, in a layered filesystem, this is
a virtual dentry that covers another one in a lower layer that should be used
instead. This may be recorded on medium if directory integration is stored
there.
The flag can be set with d_set_fallthru() and tested with d_is_fallthru().
Original-author: Valerie Aurora <vaurora@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
David Howells [Thu, 29 Jan 2015 12:02:27 +0000 (12:02 +0000)]
VFS: Add a whiteout dentry type
Add DCACHE_WHITEOUT_TYPE and provide a d_is_whiteout() accessor function. A
d_is_miss() accessor is also added for ordinary cache misses and
d_is_negative() is modified to indicate either an ordinary miss or an enforced
miss (whiteout).
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
David Howells [Thu, 29 Jan 2015 12:02:27 +0000 (12:02 +0000)]
VFS: Introduce inode-getting helpers for layered/unioned fs environments
Introduce some function for getting the inode (and also the dentry) in an
environment where layered/unioned filesystems are in operation.
The problem is that we have places where we need *both* the union dentry and
the lower source or workspace inode or dentry available, but we can only have
a handle on one of them. Therefore we need to derive the handle to the other
from that.
The idea is to introduce an extra field in struct dentry that allows the union
dentry to refer to and pin the lower dentry.
Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Chris Mason [Fri, 20 Feb 2015 01:51:39 +0000 (17:51 -0800)]
Btrfs: fix allocation size calculations in alloc_btrfs_bio
Since commit 8e5cfb55d3f (Btrfs: Make raid_map array be inlined in
btrfs_bio structure), the raid map array is allocated along with the
btrfs bio in alloc_btrfs_bio. The calculation used to decide how much
we need to allocate was using the wrong parameter passed into the
allocation function.
The passed in real_stripes will be zero if a target replace operation
is not currently running. We want to use total_stripes instead.
Signed-off-by: Chris Mason <clm@fb.com> Reported-by: David Sterba <dsterba@suse.cz> Tested-by: David Sterba <dsterba@suse.cz>
(cherry picked from commit e57cf21e9787c081db4db6afa02e6e70112ee410)
Chris Mason [Fri, 20 Feb 2015 01:51:39 +0000 (17:51 -0800)]
Btrfs: fix allocation size calculations in alloc_btrfs_bio
Since commit 8e5cfb55d3f (Btrfs: Make raid_map array be inlined in
btrfs_bio structure), the raid map array is allocated along with the
btrfs bio in alloc_btrfs_bio. The calculation used to decide how much
we need to allocate was using the wrong parameter passed into the
allocation function.
The passed in real_stripes will be zero if a target replace operation
is not currently running. We want to use total_stripes instead.
Signed-off-by: Chris Mason <clm@fb.com> Reported-by: David Sterba <dsterba@suse.cz> Tested-by: David Sterba <dsterba@suse.cz>
Al Viro [Wed, 4 Feb 2015 21:02:09 +0000 (16:02 -0500)]
don't bother with most of the bad_file_ops methods
Only ->open() should be there (always failing, of course). We never
replace ->f_op of an already opened struct file, so there's no way
for any of those methods to be called.
575849e Btrfs: fix scheduler warning when syncing log f55985f Btrfs: scrub, fix sleep in atomic context 13212b5 btrfs: Fix out-of-space bug 3e05bde Btrfs: only adjust outstanding_extents when we do a short write 3266789 Btrfs: don't set and clear delalloc for O_DIRECT writes dcab6a3 Btrfs: account for large extents with enospc 3d84be7 Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group 1a4bcf4 Btrfs: fix fsync data loss after adding hard link to inode a742994 Btrfs: don't remove extents and xattrs when logging new names
Excluded commits:
b4caecd fs: introduce f_op->mmap_capabilities for nommu mmap support de1414a fs: export inode_to_bdi and use it in favor of mapping->backing_dev_info b83ae6d fs: remove mapping->backing_dev_info df0ce26 fs: remove default_backing_dev_info 8d38633 page_writeback: put account_page_redirty() after set_page_dirty()
Filipe Manana [Fri, 13 Feb 2015 16:56:14 +0000 (16:56 +0000)]
Btrfs: don't remove extents and xattrs when logging new names
If we are recording in the tree log that an inode has new names (new hard
links were added), we would drop items, belonging to the inode, that we
shouldn't:
1) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime
flags, we ended up dropping all the extent and xattr items that were
previously logged. This was done only in memory, since logging a new
name doesn't imply syncing the log;
2) When the flag BTRFS_INODE_COPY_EVERYTHING is set in the inode's runtime
flags, we ended up dropping all the xattr items that were previously
logged. Like the case before, this was done only in memory because
logging a new name doesn't imply syncing the log.
This led to some surprises in scenarios such as the following:
1) write some extents to an inode;
2) fsync the inode;
3) truncate the inode or delete/modify some of its xattrs
4) add a new hard link for that inode
5) fsync some other file, to force the log tree to be durably persisted
6) power failure happens
The next time the fs is mounted, the fsync log replay code is executed,
and the resulting file doesn't have the content it had when the last fsync
against it was performed, instead if has a content matching what it had
when the last transaction commit happened.
So change the behaviour such that when a new name is logged, only the inode
item and reference items are processed.
This is easy to reproduce with the test I just made for xfstests, whose
main body is:
# Create our test file with some data.
$XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Make sure the file is durably persisted.
sync
# Append some data to our file, to increase its size.
$XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Fsync the file, so from this point on if a crash/power failure happens, our
# new data is guaranteed to be there next time the fs is mounted.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo
# Now shrink our file to 5000 bytes.
$XFS_IO_PROG -c "truncate 5000" $SCRATCH_MNT/foo
# Now do an expanding truncate to a size larger than what we had when we last
# fsync'ed our file. This is just to verify that after power failure and
# replaying the fsync log, our file matches what it was when we last fsync'ed
# it - 12Kb size, first 8Kb of data had a value of 0xaa and the last 4Kb of
# data had a value of 0xcc.
$XFS_IO_PROG -c "truncate 32K" $SCRATCH_MNT/foo
# Add one hard link to our file. This made btrfs drop all of our file's
# metadata from the fsync log, including the metadata relative to the
# extent we just wrote and fsync'ed. This change was made only to the fsync
# log in memory, so adding the hard link alone doesn't change the persisted
# fsync log. This happened because the previous truncates set the runtime
# flag BTRFS_INODE_NEEDS_FULL_SYNC in the btrfs inode structure.
ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link
# Now make sure the in memory fsync log is durably persisted.
# Creating and fsync'ing another file will do it.
# After this our persisted fsync log will no longer have metadata for our file
# foo that points to the extent we wrote and fsync'ed before.
touch $SCRATCH_MNT/bar
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar
# As expected, before the crash/power failure, we should be able to see a file
# with a size of 32Kb, with its first 5000 bytes having the value 0xaa and all
# the remaining bytes with value 0x00.
echo "File content before:"
od -t x1 $SCRATCH_MNT/foo
# Simulate a crash/power loss.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey
# After mounting the fs again, the fsync log was replayed.
# The expected result is to see a file with a size of 12Kb, with its first 8Kb
# of data having the value 0xaa and its last 4Kb of data having a value of 0xcc.
# The btrfs bug used to leave the file as it used te be as of the last
# transaction commit - that is, with a size of 8Kb with all bytes having a
# value of 0xaa.
echo "File content after:"
od -t x1 $SCRATCH_MNT/foo
Filipe Manana [Fri, 13 Feb 2015 12:30:56 +0000 (12:30 +0000)]
Btrfs: fix fsync data loss after adding hard link to inode
We have a scenario where after the fsync log replay we can lose file data
that had been previously fsync'ed if we added an hard link for our inode
and after that we sync'ed the fsync log (for example by fsync'ing some
other file or directory).
This is because when adding an hard link we updated the inode item in the
log tree with an i_size value of 0. At that point the new inode item was
in memory only and a subsequent fsync log replay would not make us lose
the file data. However if after adding the hard link we sync the log tree
to disk, by fsync'ing some other file or directory for example, we ended
up losing the file data after log replay, because the inode item in the
persisted log tree had an an i_size of zero.
This is easy to reproduce, and the following excerpt from my test for
xfstests shows this:
# Create one file with data and fsync it.
# This made the btrfs fsync log persist the data and the inode metadata with
# a correct inode->i_size (4096 bytes).
$XFS_IO_PROG -f -c "pwrite -S 0xaa -b 4K 0 4K" -c "fsync" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Now add one hard link to our file. This made the btrfs code update the fsync
# log, in memory only, with an inode metadata having a size of 0.
ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link
# Now force persistence of the fsync log to disk, for example, by fsyncing some
# other file.
touch $SCRATCH_MNT/bar
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar
# Before a power loss or crash, we could read the 4Kb of data from our file as
# expected.
echo "File content before:"
od -t x1 $SCRATCH_MNT/foo
# Simulate a crash/power loss.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey
# After the fsync log replay, because the fsync log had a value of 0 for our
# inode's i_size, we couldn't read anymore the 4Kb of data that we previously
# wrote and fsync'ed. The size of the file became 0 after the fsync log replay.
echo "File content after:"
od -t x1 $SCRATCH_MNT/foo
Another alternative test, that doesn't need to fsync an inode in the same
transaction it was created, is:
# Create our test file with some data.
$XFS_IO_PROG -f -c "pwrite -S 0xaa -b 8K 0 8K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Make sure the file is durably persisted.
sync
# Append some data to our file, to increase its size.
$XFS_IO_PROG -f -c "pwrite -S 0xcc -b 4K 8K 4K" \
$SCRATCH_MNT/foo | _filter_xfs_io
# Fsync the file, so from this point on if a crash/power failure happens, our
# new data is guaranteed to be there next time the fs is mounted.
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/foo
# Add one hard link to our file. This made btrfs write into the in memory fsync
# log a special inode with generation 0 and an i_size of 0 too. Note that this
# didn't update the inode in the fsync log on disk.
ln $SCRATCH_MNT/foo $SCRATCH_MNT/foo_link
# Now make sure the in memory fsync log is durably persisted.
# Creating and fsync'ing another file will do it.
touch $SCRATCH_MNT/bar
$XFS_IO_PROG -c "fsync" $SCRATCH_MNT/bar
# As expected, before the crash/power failure, we should be able to read the
# 12Kb of file data.
echo "File content before:"
od -t x1 $SCRATCH_MNT/foo
# Simulate a crash/power loss.
_load_flakey_table $FLAKEY_DROP_WRITES
_unmount_flakey
# After mounting the fs again, the fsync log was replayed.
# The btrfs fsync log replay code didn't update the i_size of the persisted
# inode because the inode item in the log had a special generation with a
# value of 0 (and it couldn't know the correct i_size, since that inode item
# had a 0 i_size too). This made the last 4Kb of file data inaccessible and
# effectively lost.
echo "File content after:"
od -t x1 $SCRATCH_MNT/foo
This isn't a new issue/regression. This problem has been around since the
log tree code was added in 2008:
CC: <stable@vger.kernel.org> Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 1a4bcf470c886b955adf36486f4c86f2441d85cb)
Forrest Liu [Wed, 11 Feb 2015 06:24:12 +0000 (14:24 +0800)]
Btrfs: fix BUG_ON in btrfs_orphan_add() when delete unused block group
Removing large amount of block group in a transaction may encounters
BUG_ON() in btrfs_orphan_add(). That is because btrfs_orphan_reserve_metadata()
will grab metadata reservation from transaction handle, and
btrfs_delete_unused_bgs() didn't reserve metadata for trnasaction handle when
delete unused block group.
Josef Bacik [Wed, 11 Feb 2015 20:08:59 +0000 (15:08 -0500)]
Btrfs: account for large extents with enospc
On our gluster boxes we stream large tar balls of backups onto our fses. With
160gb of ram this means we get really large contiguous ranges of dirty data, but
the way our ENOSPC stuff works is that as long as it's contiguous we only hold
metadata reservation for one extent. The problem is we limit our extents to
128mb, so we'll end up with at least 800 extents so our enospc accounting is
quite a bit lower than what we need. To keep track of this make sure we
increase outstanding_extents for every multiple of the max extent size so we can
be sure to have enough reserved metadata space. Thanks,
Josef Bacik [Wed, 11 Feb 2015 20:08:58 +0000 (15:08 -0500)]
Btrfs: don't set and clear delalloc for O_DIRECT writes
We do this to get the space accounting, but this is just needless churn on the
io_tree, so just drop setting/clearing delalloc and just drop the reserved data
space when we have a successfull allocation. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 3266789f9d08b27275bae5ab1dcd27d1bbf15e79)
Josef Bacik [Wed, 11 Feb 2015 20:08:57 +0000 (15:08 -0500)]
Btrfs: only adjust outstanding_extents when we do a short write
We have this weird dance where we always inc outstanding_extents when we do a
O_DIRECT write, even if we allocate the entire range. To get around this we
also drop the metadata space if we successfully write. This is an unnecessary
dance, we only need to jack up outstanding_extents if we don't satisfy the
entire range request in get_blocks_direct, otherwise we are good using our
original reservation. So drop the unconditional inc and the drop of the
metadata space that we have for the unconditional inc. Thanks,
Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 3e05bde8c3c2dd761da4d52944a087907955a53c)
Zhao Lei [Thu, 12 Feb 2015 06:18:17 +0000 (14:18 +0800)]
btrfs: Fix out-of-space bug
Btrfs will report NO_SPACE when we create and remove files for several times,
and we can't write to filesystem until mount it again.
Steps to reproduce:
1: Create a single-dev btrfs fs with default option
2: Write a file into it to take up most fs space
3: Delete above file
4: Wait about 100s to let chunk removed
5: goto 2
Script is like following:
#!/bin/bash
# Recommend 1.2G space, too large disk will make test slow
DEV="/dev/sda16"
MNT="/mnt/tmp"
for ((i = 0; i < 10; i++)); do
df "$MNT" | tail -1
sleep 10
done
done
Reason:
It is triggered by commit: 47ab2a6c689913db23ccae38349714edf8365e0a
which is used to remove empty block groups automatically, but the
reason is not in that patch. Code before works well because btrfs
don't need to create and delete chunks so many times with high
complexity.
Above bug is caused by many reason, any of them can trigger it.
Reason1:
When we remove some continuous chunks but leave other chunks after,
these disk space should be used by chunk-recreating, but in current
code, only first create will successed.
Fixed by Forrest Liu <forrestl@synology.com> in:
Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
Reason2:
contains_pending_extent() return wrong value in calculation.
Fixed by Forrest Liu <forrestl@synology.com> in:
Btrfs: fix find_free_dev_extent() malfunction in case device tree has hole
Reason3:
btrfs_check_data_free_space() try to commit transaction and retry
allocating chunk when the first allocating failed, but space_info->full
is set in first allocating, and prevent second allocating in retry.
Fixed in this patch by clear space_info->full in commit transaction.
Tested for severial times by above script.
Changelog v3->v4:
use light weight int instead of atomic_t to record have_remove_bgs in
transaction, suggested by:
Josef Bacik <jbacik@fb.com>
Changelog v2->v3:
v2 fixed the bug by adding more commit-transaction, but we
only need to reclaim space when we are really have no space for
new chunk, noticed by:
Filipe David Manana <fdmanana@gmail.com>
Actually, our code already have this type of commit-and-retry,
we only need to make it working with removed-bgs.
v3 fixed the bug with above way.
Changelog v1->v2:
v1 will introduce a new bug when delete and create chunk in same disk
space in same transaction, noticed by:
Filipe David Manana <fdmanana@gmail.com>
V2 fix this bug by commit transaction after remove block grops.
Reported-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Suggested-by: Filipe David Manana <fdmanana@gmail.com> Suggested-by: Josef Bacik <jbacik@fb.com> Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 13212b54d18d5235fb97fbdcba8ae453fd2a3a51)
Filipe Manana [Mon, 9 Feb 2015 21:14:24 +0000 (21:14 +0000)]
Btrfs: scrub, fix sleep in atomic context
My previous patch "Btrfs: fix scrub race leading to use-after-free"
introduced the possibility to sleep in an atomic context, which happens
when the scrub_lock mutex is held at the time scrub_pending_bio_dec()
is called - this function can be called under an atomic context.
Chris ran into this in a debug kernel which gave the following trace:
Fix this my acquiring the mutex after calling finish_wait(), which sets the
task's state to TASK_RUNNING.
Signed-off-by: Filipe Manana <fdmanana@suse.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: Chris Mason <clm@fb.com>
(cherry picked from commit 575849ecf5d103ca9bbf0a6b9e89eba335d4e750)
Al Viro [Mon, 19 Jan 2015 04:31:19 +0000 (23:31 -0500)]
switch ll_lookup_finish_locks() and ll_revalidate_it_finish() to inode
Note that ll_prep_inode() in the latter does *not* modify ->d_inode;
it expects non-negative dentry, and in such cases ll_prep_inode() doesn't
modify *inode - it only uses the value.
1) Missing netlink attribute validation in nft_lookup, from Patrick
McHardy.
2) Restrict ipv6 partial checksum handling to UDP, since that's the
only case it works for. From Vlad Yasevich.
3) Clear out silly device table sentinal macros used by SSB and BCMA
drivers. From Joe Perches.
4) Make sure the remote checksum code never creates a situation where
the remote checksum is applied yet the tunneling metadata describing
the remote checksum transformation is still present. Otherwise an
external entity might see this and apply the checksum again. From
Tom Herbert.
5) Use msecs_to_jiffies() where applicable, from Nicholas Mc Guire.
6) Don't explicitly initialize timer struct fields, use setup_timer()
and mod_timer() instead. From Vaishali Thakkar.
7) Don't invoke tg3_halt() without the tp->lock held, from Jun'ichi
Nomura.
8) Missing __percpu annotation in ipvlan driver, from Eric Dumazet.
9) Don't potentially perform skb_get() on shared skbs, also from Eric
Dumazet.
10) Fix COW'ing of metrics for non-DST_HOST routes in ipv6, from Martin
KaFai Lau.
11) Fix merge resolution error between the iov_iter changes in vhost and
some bug fixes that occurred at the same time. From Jason Wang.
12) If rtnl_configure_link() fails we have to perform a call to
->dellink() before unregistering the device. From WANG Cong.
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (39 commits)
net: dsa: Set valid phy interface type
rtnetlink: call ->dellink on failure when ->newlink exists
com20020-pci: add support for eae single card
vhost_net: fix wrong iter offset when setting number of buffers
net: spelling fixes
net/core: Fix warning while make xmldocs caused by dev.c
net: phy: micrel: disable NAND-tree for KSZ8021, KSZ8031, KSZ8051, KSZ8081
ipv6: fix ipv6_cow_metrics for non DST_HOST case
openvswitch: Fix key serialization.
r8152: restore hw settings
hso: fix rx parsing logic when skb allocation fails
tcp: make sure skb is not shared before using skb_get()
bridge: netfilter: Move sysctl-specific error code inside #ifdef
ipv6: fix possible deadlock in ip6_fl_purge / ip6_fl_gc
ipvlan: add a missing __percpu pcpu_stats
tg3: Hold tp->lock before calling tg3_halt() from tg3_init_one()
bgmac: fix device initialization on Northstar SoCs (condition typo)
qlcnic: Delete existing multicast MAC list before adding new
net/mlx5_core: Fix configuration of log_uar_page_sz
sunvnet: don't change gso data on clones
...
Linus Torvalds [Wed, 18 Feb 2015 01:34:21 +0000 (17:34 -0800)]
Merge tag 'md/3.20-fixes' of git://neil.brown.name/md
Pull md bugfixes from Neil Brown:
"Three bug md fixes for 3.20
yet-another-livelock in raid5, and a problem with write errors to
4K-block devices"
* tag 'md/3.20-fixes' of git://neil.brown.name/md:
md/raid5: Fix livelock when array is both resyncing and degraded.
md/raid10: round up to bdev_logical_block_size in narrow_write_error.
md/raid1: round up to bdev_logical_block_size in narrow_write_error
Linus Torvalds [Wed, 18 Feb 2015 01:03:07 +0000 (17:03 -0800)]
Merge tag 'please-pull-fixmcelog' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras
Pull mcelog regression fix from Tony Luck:
"Fix regression - functions on the mce notifier chain should not be
able to decide that an event should not be logged"
* tag 'please-pull-fixmcelog' of git://git.kernel.org/pub/scm/linux/kernel/git/ras/ras:
x86/mce: Fix regression. All error records should report via /dev/mcelog
Causes an RCW cycle to be forced even when the array is degraded.
A degraded array cannot support RCW as that requires reading all data
blocks, and one may be missing.
Forcing an RCW when it is not possible causes a live-lock and the code
spins, repeatedly deciding to do something that cannot succeed.
So change the condition to only force RCW on non-degraded arrays.
Linus Torvalds [Wed, 18 Feb 2015 00:12:34 +0000 (16:12 -0800)]
Merge branch 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull lazytime mount option support from Al Viro:
"Lazytime stuff from tytso"
* 'lazytime' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
ext4: add optimization for the lazytime mount option
vfs: add find_inode_nowait() function
vfs: add support for a lazytime mount option
Linus Torvalds [Tue, 17 Feb 2015 23:48:33 +0000 (15:48 -0800)]
Merge branch 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull iov_iter updates from Al Viro:
"More iov_iter work - missing counterpart of iov_iter_init() for
bvec-backed ones and vfs_read_iter()/vfs_write_iter() - wrappers for
sync calls of ->read_iter()/->write_iter()"
* 'iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fs: add vfs_iter_{read,write} helpers
new helper: iov_iter_bvec()
Linus Torvalds [Tue, 17 Feb 2015 23:27:47 +0000 (15:27 -0800)]
Merge branch 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull getname/putname updates from Al Viro:
"Rework of getname/getname_kernel/etc., mostly from Paul Moore. Gets
rid of quite a pile of kludges between namei and audit..."
* 'getname2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
audit: replace getname()/putname() hacks with reference counters
audit: fix filename matching in __audit_inode() and __audit_inode_child()
audit: enable filename recording via getname_kernel()
simpler calling conventions for filename_mountpoint()
fs: create proper filename objects using getname_kernel()
fs: rework getname_kernel to handle up to PATH_MAX sized filenames
cut down the number of do_path_lookup() callers
Linus Torvalds [Tue, 17 Feb 2015 23:18:19 +0000 (15:18 -0800)]
Merge branch 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull debugfs patches from Al Viro:
"debugfs patches, mostly to make it possible for something like tracefs
to be transparently automounted on given directory in debugfs.
New primitive in there is debugfs_create_automount(name, parent, func,
arg), which creates a directory and makes its ->d_automount() return
func(arg). Another missing primitive was debugfs_create_file_size() -
open-coded in quite a few places. Dave's patch adds it and converts
the open-code instances to calling it"
* 'debugfs_automount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
debugfs: Provide a file creation function that also takes an initial size
new primitive: debugfs_create_automount()
debugfs: split end_creating() into success and failure cases
debugfs: take mode-dependent parts of debugfs_get_inode() into callers
fold debugfs_mknod() into callers
fold debugfs_create() into caller
fold debugfs_mkdir() into caller
debugfs_mknod(): get rid useless arguments
fold debugfs_link() into caller
debugfs: kill __create_file()
debugfs: split the beginning and the end of __create_file() off
debugfs_{mkdir,create,link}(): get rid of redundant argument
Linus Torvalds [Tue, 17 Feb 2015 22:56:45 +0000 (14:56 -0800)]
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull misc VFS updates from Al Viro:
"This cycle a lot of stuff sits on topical branches, so I'll be sending
more or less one pull request per branch.
This is the first pile; more to follow in a few. In this one are
several misc commits from early in the cycle (before I went for
separate branches), plus the rework of mntput/dput ordering on umount,
switching to use of fs_pin instead of convoluted games in
namespace_unlock()"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
switch the IO-triggering parts of umount to fs_pin
new fs_pin killing logics
allow attaching fs_pin to a group not associated with some superblock
get rid of the second argument of acct_kill()
take count and rcu_head out of fs_pin
dcache: let the dentry count go down to zero without taking d_lock
pull bumping refcount into ->kill()
kill pin_put()
mode_t whack-a-mole: chelsio
file->f_path.dentry is pinned down for as long as the file is open...
get rid of lustre_dump_dentry()
gut proc_register() a bit
kill d_validate()
ncpfs: get rid of d_validate() nonsense
selinuxfs: don't open-code d_genocide()
Linus Torvalds [Tue, 17 Feb 2015 22:35:02 +0000 (14:35 -0800)]
Merge branch 'akpm' (patches from Andrew)
Merge yet more updates from Andrew Morton:
- a pile of minor fs fixes and cleanups
- kexec updates
- random misc fixes in various places: vmcore, rbtree, eventfd, ipc, seccomp.
- a series of python-based kgdb helper scripts
* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO
samples/seccomp: improve label helper
ipc,sem: use current->state helpers
scripts/gdb: disable pagination while printing from breakpoint handler
scripts/gdb: define maintainer
scripts/gdb: convert CpuList to generator function
scripts/gdb: convert ModuleList to generator function
scripts/gdb: use a generator instead of iterator for task list
scripts/gdb: ignore byte-compiled python files
scripts/gdb: port to python3 / gdb7.7
scripts/gdb: add basic documentation
scripts/gdb: add lx-lsmod command
scripts/gdb: add class to iterate over CPU masks
scripts/gdb: add lx_current convenience function
scripts/gdb: add internal helper and convenience function for per-cpu lookup
scripts/gdb: add get_gdbserver_type helper
scripts/gdb: add internal helper and convenience function to retrieve thread_info
scripts/gdb: add is_target_arch helper
scripts/gdb: add helper and convenience function to look up tasks
scripts/gdb: add task iteration class
...
Kees Cook [Tue, 17 Feb 2015 21:48:00 +0000 (13:48 -0800)]
seccomp: cap SECCOMP_RET_ERRNO data to MAX_ERRNO
The value resulting from the SECCOMP_RET_DATA mask could exceed MAX_ERRNO
when setting errno during a SECCOMP_RET_ERRNO filter action. This makes
sure we have a reliable value being set, so that an invalid errno will not
be ignored by userspace.
Signed-off-by: Kees Cook <keescook@chromium.org> Reported-by: Dmitry V. Levin <ldv@altlinux.org> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Will Drewry <wad@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Davidlohr Bueso [Tue, 17 Feb 2015 21:47:55 +0000 (13:47 -0800)]
ipc,sem: use current->state helpers
Call __set_current_state() instead of assigning the new state directly.
These interfaces also aid CONFIG_DEBUG_ATOMIC_SLEEP environments, keeping
track of who changed the state.
Jan Kiszka [Tue, 17 Feb 2015 21:47:52 +0000 (13:47 -0800)]
scripts/gdb: disable pagination while printing from breakpoint handler
While reporting the (refreshed) list of modules on automatic updates we
may hit the page boundary of the output console and cause a stop if
pagination is enabled. However, gdb does not accept user input while
running over the breakpoint handler. So we get stuck, and the user is
forced to interrupt gdb.
Resolve this by disabling pagination during automatic symbol updates. We
restore the user's configuration once done.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Wagner [Tue, 17 Feb 2015 21:47:41 +0000 (13:47 -0800)]
scripts/gdb: use a generator instead of iterator for task list
The iterator does not return any task_struct from the thread_group list
because the first condition in the 'if not t or ...' will only be the
first time None.
Instead of keeping track of the state ourself in the next() function, we
fall back using Python's generator.
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Daniel Thompson [Tue, 17 Feb 2015 21:47:38 +0000 (13:47 -0800)]
scripts/gdb: ignore byte-compiled python files
Using the gdb scripts leaves byte-compiled python files in the scripts/
directory. These should be ignored by git.
[jan.kiszka@siemens.com: drop redundant mrproper rule as suggested by Michal] Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Michal Marek <mmarek@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I tried to use these scripts in an ubuntu 14.04 host (gdb 7.7 compiled
against python 3.3) but there were several errors.
I believe this patch fixes these issues so that the commands now work (I
tested lx-symbols, lx-dmesg, lx-lsmod).
Main issues that needed to be resolved:
* In python 2 iterators have a "next()" method. In python 3 it is
__next__() instead (so let's just add both).
* In older python versions there was an implicit conversion
in object.__format__() (used when an object is in string.format())
where it was converting the object to str first and then
calling str's __format__(). This has now been removed so
we must explicitly convert to str the objects for which
we need to keep this behavior.
* In dmesg.py: in python 3 log_buf is now a "memoryview" object
which needs to be converted to a string in order to use string
methods like "splitlines()". Luckily memoryview exists in
python 2.7.6 as well, so we can convert log_buf to memoryview
and use the same code in both python 2 and python 3.
This version of the patch has now been tested with gdb 7.7 and both python
3.4 and python 2.7.6 (I think asking for at least python 2.7.6 is a
reasonable requirement instead of complicating the code with version
checks etc).
Signed-off-by: Pantelis Koukousoulas <pktoss@gmail.com> Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:47:18 +0000 (13:47 -0800)]
scripts/gdb: add get_gdbserver_type helper
This helper probes the type of the gdb server. Supported are QEMU and
KGDB so far. Knowledge about the gdb server is required e.g. to
retrieve the current CPU or current task.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:47:15 +0000 (13:47 -0800)]
scripts/gdb: add internal helper and convenience function to retrieve thread_info
Add the internal helper get_thread_info that calculates the thread_info
from a given task variable. Also export this service as a convenience
function.
Note: ia64 version is untested.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:47:04 +0000 (13:47 -0800)]
scripts/gdb: add lx-dmesg command
This pokes into the log buffer of the debugged kernel, dumping it to the
gdb console. Helping in case the target should or can no longer execute
dmesg itself.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Kay Sievers <kay@vrfy.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:47:01 +0000 (13:47 -0800)]
scripts/gdb: add read_u16/32/64 helpers
Add helpers for reading integers from target memory buffers. Required
when caching the memory access is more efficient than reading individual
values via gdb.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:58 +0000 (13:46 -0800)]
scripts/gdb: add get_target_endianness helper
Parse the target endianness from the output of "show endian" and cache the
result to return it via the new helper get_target_endiannes. We will need
it for reading integers from buffers that contain target memory.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:55 +0000 (13:46 -0800)]
scripts/gdb: add internal helper and convenience function to look up a module
Add the internal helper get_module_by_name to obtain the module structure
corresponding to the given name. Also export this service as a
convenience function.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:52 +0000 (13:46 -0800)]
scripts/gdb: add automatic symbol reloading on module insertion
This installs a silent breakpoint on the do_init_module function. The
breakpoint handler will try to load symbols from the module files found
during lx-symbols execution. This way, breakpoints can be set to module
initialization functions, and there is no need to explicitly call
lx-symbols after (re-)loading a module.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:47 +0000 (13:46 -0800)]
scripts/gdb: add lx-symbols command
This is probably the most useful helper when debugging kernel modules:
lx-symbols first reloads vmlinux. Then it searches recursively for *.ko
files in the specified paths and the current directory. Finally it walks
the kernel's module list, issuing the necessary add-symbol-file command
for each loaded module so that gdb knows which module symbol corresponds
to which address. It also looks up variable sections (bss, data, rodata)
and appends their address to the add-symbole-file command line. This
allows to access global module variables just like any other variable.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:41 +0000 (13:46 -0800)]
scripts/gdb: add container_of helper and convenience function
Provide an internal helper with container_of semantics. As type lookups
are very slow in gdb-python and we need a type "long" for this, cache the
reference to this type object. Then export the helper also as a
convenience function form use at the gdb command line.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:38 +0000 (13:46 -0800)]
scripts/gdb: add cache for type objects
Type lookups are very slow in gdb-python which is often noticeable when
iterating over a number of objects. Introduce the helper class CachedType
that keeps a reference to a gdb.Type object but also refreshes it after an
object file has been loaded.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Jan Kiszka [Tue, 17 Feb 2015 21:46:36 +0000 (13:46 -0800)]
scripts/gdb: add infrastructure
This provides the basic infrastructure to load kernel-specific python
helper scripts when debugging the kernel in gdb.
The loading mechanism is based on gdb loading for <objfile>-gdb.py when
opening <objfile>. Therefore, this places a corresponding link to the
main helper script into the output directory that contains vmlinux.
The main scripts will pull in submodules containing Linux specific gdb
commands and functions. To avoid polluting the source directory with
compiled python modules, we link to them from the object directory.
Due to gdb.parse_and_eval and string redirection for gdb.execute, we
depend on gdb >= 7.2.
This feature is enabled via CONFIG_GDB_SCRIPTS.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com> Acked-by: Michal Marek <mmarek@suse.cz> [kbuild stuff] Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Ben Widawsky <ben@bwidawsk.net> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Tue, 17 Feb 2015 21:46:17 +0000 (13:46 -0800)]
fs/affs/super.c: destroy sbi mutex in affs_kill_sb()
Call mutex_destroy() on superblock mutex in affs_kill_sb() otherwise mutex
debugging code isn't able to detect that mutex is used after being freed.
(thanks to Jan Kara for complete definition).
Signed-off-by: Fabian Frederick <fabf@skynet.be> Cc: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fabian Frederick [Tue, 17 Feb 2015 21:46:15 +0000 (13:46 -0800)]
fs/affs/file.c: fix direct IO writes beyond EOF
Use the same fallback to normal IO in case of write
operations beyond EOF as fat direct IO. This patch fixes
fsx file -d -Z -r 4096 -w 4096
Report:
129(129 mod 256): TRUNCATE DOWN from 0x3ff01 to 0xb3f6
130(130 mod 256): WRITE 0x22000 thru 0x2dfff (0xc000 bytes) HOLE
Thanks to Jan for helping me on this problem.
The ideal solution suggested by Jan Kara would be to use
cont_write_begin() but affs direct_IO shouldn't be used a lot anyway...
Signed-off-by: Fabian Frederick <fabf@skynet.be> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
- "inode.i_ino" is "unsigned long",
- "loff_t" is always "unsigned long long",
- "sector_t" should be cast to "unsigned long long" for printing,
- "u32" should not be cast to "unsigned int" for printing.
Chris Mason [Tue, 17 Feb 2015 21:46:07 +0000 (13:46 -0800)]
eventfd: don't take the spinlock in eventfd_poll
The spinlock in eventfd_poll is trying to protect the count of events so
it can decide if it should return POLLIN, POLLERR, or POLLOUT. But,
because of the way we drop the lock after calling poll_wait, and drop it
again before returning, we have the same pile of races with the lock as
we do with a single read of ctx->count().
This replaces the lock with a read barrier and single read.
eventfd_write does a single bump of ctx->count, so this should not add
new races with adding events. eventfd_read is similar, it will do a
single decrement with the lock held, and so we're making the race with
concurrent readers slightly larger.
This spinlock is the top CPU user in kernel code during one of our
workloads. Removing it gives us a ~2% boost.
[arnd@arndb.de: avoid unused variable warning]
[dan.carpenter@oracle.com: type bug in eventfd_poll()] Signed-off-by: Chris Mason <clm@fb.com> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
John de la Garza [Tue, 17 Feb 2015 21:46:04 +0000 (13:46 -0800)]
lib/rbtree.c: fix typo in comment
Signed-off-by: John de la Garza <john@jjdev.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
When updating PT_NOTE header size (ie. p_memsz), an overflow issue
happens with the following bogus note entry:
n_namesz = 0xFFFFFFFF
n_descsz = 0x0
n_type = 0x0
This kind of note entry should be dropped during updating p_memsz. But
because n_namesz is 32bit, after (n_namesz + 3) & (~3), it's overflow to
0x0, the note entry size looks sane and reserved.
When userspace (eg. crash utility) is trying to access such bogus note,
it could lead to an unexpected behavior (eg. crash utility segment fault
because it's reading bogus address).
The source of bogus note hasn't been identified yet. At least we could
drop the bogus note so user space wouldn't be surprised.
Signed-off-by: WANG Chao <chaowang@redhat.com> Cc: Dave Anderson <anderson@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Randy Wright <rwright@hp.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Fabian Frederick <fabf@skynet.be> Cc: Vitaly Kuznetsov <vkuznets@redhat.com> Cc: Rashika Kheria <rashika.kheria@gmail.com> Cc: Greg Pearson <greg.pearson@hp.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geoff Levand [Tue, 17 Feb 2015 21:45:58 +0000 (13:45 -0800)]
kexec: add IND_FLAGS macro
Add a new kexec preprocessor macro IND_FLAGS, which is the bitwise OR of
all the possible kexec IND_ kimage_entry indirection flags. Having this
macro allows for simplified code in the prosessing of the kexec
kimage_entry items. Also, remove the local powerpc definition and use the
generic one.
Signed-off-by: Geoff Levand <geoff@infradead.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Maximilian Attems <max@stro.at> Cc: Michal Marek <mmarek@suse.cz> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geoff Levand [Tue, 17 Feb 2015 21:45:56 +0000 (13:45 -0800)]
kexec: add bit definitions for kimage entry flags
Define new kexec preprocessor macros IND_*_BIT that define the bit
position of the kimage entry flags. Change the existing IND_* flag macros
to be defined as bit shifts of the corresponding IND_*_BIT macros. Also
wrap all C language code in kexec.h with #if !defined(__ASSEMBLY__) so
assembly files can include kexec.h to get the IND_* and IND_*_BIT macros.
Some CPU instruction sets have tests for bit position which are convenient
in implementing routines that operate on the kimage entry list. The
addition of these bit position macros in a common location will avoid
duplicate definitions and the chance that changes to the IND_* flags will
not be propagated to assembly files.
Signed-off-by: Geoff Levand <geoff@infradead.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Maximilian Attems <max@stro.at> Cc: Michal Marek <mmarek@suse.cz> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geoff Levand [Tue, 17 Feb 2015 21:45:53 +0000 (13:45 -0800)]
kexec: simplify conditional
Simplify the code around one of the conditionals in the kexec_load syscall
routine.
The original code was confusing with a redundant check on KEXEC_ON_CRASH
and comments outside of the conditional block. This change switches the
order of the conditional check, and cleans up the comments for the
conditional. There is no functional change to the code.
Signed-off-by: Geoff Levand <geoff@infradead.org> Acked-by: Vivek Goyal <vgoyal@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Maximilian Attems <max@stro.at> Cc: Michal Marek <mmarek@suse.cz> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Geoff Levand [Tue, 17 Feb 2015 21:45:50 +0000 (13:45 -0800)]
kexec: Fix make headers_check
Remove the unneded declaration for a kexec_load() routine.
Fixes errors like these when running 'make headers_check':
include/uapi/linux/kexec.h: userspace cannot reference function or variable defined in the kernel
Paul said:
: The kexec_load declaration isn't very useful for userspace, see the patch
: I submitted in http://lkml.kernel.org/r/1389791824.17407.9.camel@x220 .
: And After my attempt the export of that declaration has also been
: discussed in
: http://lkml.kernel.org/r/115373b6ac68ee7a305975896e1c4971e8e51d4c.1408731991.git.geoff@infradead.org
:
: In that last discussion no one has been able to point to an actual user of
: it. So, as far as I can tell, no one actually uses it. Which makes
: sense, because including this header by itself doesn't give one access to
: a useful definition of kexec_load. So why bother with the declaration?
Signed-off-by: Geoff Levand <geoff@infradead.org> Acked-by: Paul Bolle <pebolle@tiscali.nl> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Maximilian Attems <max@stro.at> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Baoquan He [Tue, 17 Feb 2015 21:45:44 +0000 (13:45 -0800)]
kexec: remove never used member destination in kimage
struct kimage has a member destination which is used to store the real
destination address of each page when load segment from user space buffer
to kernel. But we never retrieve the value stored in kimage->destination,
so this member variable in kimage and its assignment operation are
redundent code.
I guess for_each_kimage_entry just does the work that kimage->destination
is expected to do.
So in this patch just make a cleanup to remove it.
Signed-off-by: Baoquan He <bhe@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
projects / linux / log