We check submounts before doing d_drop() on a non-empty directory dentry in
NFS (have_submounts()), but we do not exclude a racing mount.
Process A: have_submounts() -> returns false
Process B: mount() -> success
Process A: d_drop()
This patch prepares the ground for the fix by doing the following
operations all under the same rename lock:
have_submounts()
shrink_dcache_parent()
d_drop()
This is actually an optimization since have_submounts() and
shrink_dcache_parent() both traverse the same dentry tree separately.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
CC: David Howells <dhowells@redhat.com>
CC: Steven Whitehouse <swhiteho@redhat.com>
CC: Trond Myklebust <Trond.Myklebust@netapp.com>
CC: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This one replaces three instances open coded tree walking (have_submounts,
select_parent, d_genocide) with a common helper.
In addition to slightly reducing the kernel size, this simplifies the
callers and makes them less bug prone.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
It shouldn't matter when we decrement the refcount during the walk as long
as we do it exactly once.
Restructure d_genocide() to do the killing on entering the dentry instead
of when leaving it. This helps creating a common helper for tree walking.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull vfs pile 1 from Al Viro:
"Unfortunately, this merge window it'll have a be a lot of small piles -
my fault, actually, for not keeping #for-next in anything that would
resemble a sane shape ;-/
This pile: assorted fixes (the first 3 are -stable fodder, IMO) and
cleanups + %pd/%pD formats (dentry/file pathname, up to 4 last
components) + several long-standing patches from various folks.
There definitely will be a lot more (starting with Miklos'
check_submount_and_drop() series)"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (26 commits)
direct-io: Handle O_(D)SYNC AIO
direct-io: Implement generic deferred AIO completions
add formats for dentry/file pathnames
kvm eventfd: switch to fdget
powerpc kvm: use fdget
switch fchmod() to fdget
switch epoll_ctl() to fdget
switch copy_module_from_fd() to fdget
git simplify nilfs check for busy subtree
ibmasmfs: don't bother passing superblock when not needed
don't pass superblock to hypfs_{mkdir,create*}
don't pass superblock to hypfs_diag_create_files
don't pass superblock to hypfs_vm_create_files()
oprofile: get rid of pointless forward declarations of struct super_block
oprofilefs_create_...() do not need superblock argument
oprofilefs_mkdir() doesn't need superblock argument
don't bother with passing superblock to oprofile_create_stats_files()
oprofile: don't bother with passing superblock to ->create_files()
don't bother passing sb to oprofile_create_files()
coh901318: don't open-code simple_read_from_buffer()
...
up with PTR_ERR_OR_ZERO(), and replacing or fixing all the usages.
This has been sitting in linux-next for a whole cycle.
Thanks,
Rusty.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=LeaW
-----END PGP SIGNATURE-----
Merge tag 'PTR_RET-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux
Pull PTR_RET() removal patches from Rusty Russell:
"PTR_RET() is a weird name, and led to some confusing usage. We ended
up with PTR_ERR_OR_ZERO(), and replacing or fixing all the usages.
This has been sitting in linux-next for a whole cycle"
[ There are still some PTR_RET users scattered about, with some of them
possibly being new, but most of them existing in Rusty's tree too. We
have that
#define PTR_RET(p) PTR_ERR_OR_ZERO(p)
thing in <linux/err.h>, so they continue to work for now - Linus ]
* tag 'PTR_RET-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux:
GFS2: Replace PTR_RET with PTR_ERR_OR_ZERO
Btrfs: volume: Replace PTR_RET with PTR_ERR_OR_ZERO
drm/cma: Replace PTR_RET with PTR_ERR_OR_ZERO
sh_veu: Replace PTR_RET with PTR_ERR_OR_ZERO
dma-buf: Replace PTR_RET with PTR_ERR_OR_ZERO
drivers/rtc: Replace PTR_RET with PTR_ERR_OR_ZERO
mm/oom_kill: remove weird use of ERR_PTR()/PTR_ERR().
staging/zcache: don't use PTR_RET().
remoteproc: don't use PTR_RET().
pinctrl: don't use PTR_RET().
acpi: Replace weird use of PTR_RET.
s390: Replace weird use of PTR_RET.
PTR_RET is now PTR_ERR_OR_ZERO(): Replace most.
PTR_RET is now PTR_ERR_OR_ZERO
This set includes a workqueue cleanup and the removal
of incorrect and unneeded signal blocking.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.13 (GNU/Linux)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=MaZw
-----END PGP SIGNATURE-----
Merge tag 'dlm-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm
Pull dlm updates from David Teigland:
"This set includes a workqueue cleanup and the removal of incorrect and
unneeded signal blocking"
* tag 'dlm-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm:
dlm: remove signal blocking
dlm: WQ_NON_REENTRANT is meaningless and going away
* Added aggressive extent caching using the extent status tree. This
can actually decrease memory usage in read-mostly workloads since
the information is much more compactly stored in the extent status
tree than if we had to keep the extent tree metadata blocks in the
buffer cache. This also improves Asynchronous I/O since it is it
makes much less likely that we need to do metadata I/O to lookup the
extent tree information.
* Improve the recovery after corrupted allocation bitmaps are found
when running in errors=ignore mode.
Also fixed some writeback vs. truncate races when using a blocksize
less than the page size.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.14 (GNU/Linux)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=tosu
-----END PGP SIGNATURE-----
Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:
"New features for 3.12:
- Added aggressive extent caching using the extent status tree. This
can actually decrease memory usage in read-mostly workloads since
the information is much more compactly stored in the extent status
tree than if we had to keep the extent tree metadata blocks in the
buffer cache. This also improves Asynchronous I/O since it is it
makes much less likely that we need to do metadata I/O to lookup
the extent tree information.
- Improve the recovery after corrupted allocation bitmaps are found
when running in errors=ignore mode.
Also fixed some writeback vs truncate races when using a blocksize
less than the page size"
* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (25 commits)
ext4: allow specifying external journal by pathname mount option
ext4: mark group corrupt on group descriptor checksum
ext4: mark block group as corrupt on inode bitmap error
ext4: mark block group as corrupt on block bitmap error
ext4: fix type declaration of ext4_validate_block_bitmap
ext4: error out if verifying the block bitmap fails
jbd2: Fix endian mixing problems in the checksumming code
ext4: isolate ext4_extents.h file
ext4: Fix misspellings using 'codespell' tool
ext4: convert write_begin methods to stable_page_writes semantics
ext4: fix use of potentially uninitialized variables in debugging code
ext4: fix lost truncate due to race with writeback
ext4: simplify truncation code in ext4_setattr()
ext4: fix ext4_writepages() in presence of truncate
ext4: move test whether extent to map can be extended to one place
ext4: fix warning in ext4_da_update_reserve_space()
quota: provide interface for readding allocated space into reserved space
ext4: avoid reusing recently deleted inodes in no journal mode
ext4: allocate delayed allocation blocks before rename
ext4: start handle at least possible moment when renaming files
...
Call generic_write_sync() from the deferred I/O completion handler if
O_DSYNC is set for a write request. Also make sure various callers
don't call generic_write_sync if the direct I/O code returns
-EIOCBQUEUED.
Based on an earlier patch from Jan Kara <jack@suse.cz> with updates from
Jeff Moyer <jmoyer@redhat.com> and Darrick J. Wong <darrick.wong@oracle.com>.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Add support to the core direct-io code to defer AIO completions to user
context using a workqueue. This replaces opencoded and less efficient
code in XFS and ext4 (we save a memory allocation for each direct IO)
and will be needed to properly support O_(D)SYNC for AIO.
The communication between the filesystem and the direct I/O code requires
a new buffer head flag, which is a bit ugly but not avoidable until the
direct I/O code stops abusing the buffer_head structure for communicating
with the filesystems.
Currently this creates a per-superblock unbound workqueue for these
completions, which is taken from an earlier patch by Jan Kara. I'm
not really convinced about this use and would prefer a "normal" global
workqueue with a high concurrency limit, but this needs further discussion.
JK: Fixed ext4 part, dynamic allocation of the workqueue.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
generic pstore layer so that all backends can use the
pitiful amounts of storage they control more effectively.
Three other small fixes/cleanups too.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.12 (GNU/Linux)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=6H8r
-----END PGP SIGNATURE-----
Merge tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux
Pull pstore changes from Tony Luck:
"A big part of this is the addition of compression to the generic
pstore layer so that all backends can use the pitiful amounts of
storage they control more effectively. Three other small
fixes/cleanups too.
* tag 'please-pull-pstore' of git://git.kernel.org/pub/scm/linux/kernel/git/aegl/linux:
pstore/ram: (really) fix undefined usage of rounddown_pow_of_two
pstore/ram: Read and write to the 'compressed' flag of pstore
efi-pstore: Read and write to the 'compressed' flag of pstore
erst: Read and write to the 'compressed' flag of pstore
powerpc/pseries: Read and write to the 'compressed' flag of pstore
pstore: Add file extension to pstore file if compressed
pstore: Add decompression support to pstore
pstore: Introduce new argument 'compressed' in the read callback
pstore: Add compression support to pstore
pstore/Kconfig: Select ZLIB_DEFLATE and ZLIB_INFLATE when PSTORE is selected
pstore: Add new argument 'compressed' in pstore write callback
powerpc/pseries: Remove (de)compression in nvram with pstore enabled
pstore: d_alloc_name() doesn't return an ERR_PTR
acpi/apei/erst: Add missing iounmap() on error in erst_exec_move_data()
Christopher reported a regression where he was unable to unmount a NFS
filesystem where the root had gone stale. The problem is that
d_revalidate handles the root of the filesystem differently from other
dentries, but d_weak_revalidate does not. We could simply fix this by
making d_weak_revalidate return success on IS_ROOT dentries, but there
are cases where we do want to revalidate the root of the fs.
A umount is really a special case. We generally aren't interested in
anything but the dentry and vfsmount that's attached at that point. If
the inode turns out to be stale we just don't care since the intent is
to stop using it anyway.
Try to handle this situation better by treating umount as a special
case in the lookup code. Have it resolve the parent using normal
means, and then do a lookup of the final dentry without revalidating
it. In most cases, the final lookup will come out of the dcache, but
the case where there's a trailing symlink or !LAST_NORM entry on the
end complicates things a bit.
Cc: Neil Brown <neilb@suse.de>
Reported-by: Christopher T Vogan <cvogan@us.ibm.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The d_prune dentry operation is used to notify filesystem when VFS
about to prune a hashed dentry from the dcache. There are three
code paths that prune dentries: shrink_dcache_for_umount_subtree(),
prune_dcache_sb() and d_prune_aliases(). For the d_prune_aliases()
case, VFS unhashes the dentry first, then call the d_prune dentry
operation. This confuses ceph_d_prune() (ceph uses the d_prune
dentry operation to maintain a flag indicating whether the complete
contents of a directory are in the dcache, pruning unhashed dentry
does not affect dir's completeness)
This patch fixes the issue by calling the d_prune dentry operation
in d_prune_aliases(), before unhashing the dentry. Also make VFS
only call the d_prune dentry operation for hashed dentry, to avoid
calling the d_prune dentry operation twice when dentry is pruned
by d_prune_aliases().
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull cgroup updates from Tejun Heo:
"A lot of activities on the cgroup front. Most changes aren't visible
to userland at all at this point and are laying foundation for the
planned unified hierarchy.
- The biggest change is decoupling the lifetime management of css
(cgroup_subsys_state) from that of cgroup's. Because controllers
(cpu, memory, block and so on) will need to be dynamically enabled
and disabled, css which is the association point between a cgroup
and a controller may come and go dynamically across the lifetime of
a cgroup. Till now, css's were created when the associated cgroup
was created and stayed till the cgroup got destroyed.
Assumptions around this tight coupling permeated through cgroup
core and controllers. These assumptions are gradually removed,
which consists bulk of patches, and css destruction path is
completely decoupled from cgroup destruction path. Note that
decoupling of creation path is relatively easy on top of these
changes and the patchset is pending for the next window.
- cgroup has its own event mechanism cgroup.event_control, which is
only used by memcg. It is overly complex trying to achieve high
flexibility whose benefits seem dubious at best. Going forward,
new events will simply generate file modified event and the
existing mechanism is being made specific to memcg. This pull
request contains prepatory patches for such change.
- Various fixes and cleanups"
Fixed up conflict in kernel/cgroup.c as per Tejun.
* 'for-3.12' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup: (69 commits)
cgroup: fix cgroup_css() invocation in css_from_id()
cgroup: make cgroup_write_event_control() use css_from_dir() instead of __d_cgrp()
cgroup: make cgroup_event hold onto cgroup_subsys_state instead of cgroup
cgroup: implement CFTYPE_NO_PREFIX
cgroup: make cgroup_css() take cgroup_subsys * instead and allow NULL subsys
cgroup: rename cgroup_css_from_dir() to css_from_dir() and update its syntax
cgroup: fix cgroup_write_event_control()
cgroup: fix subsystem file accesses on the root cgroup
cgroup: change cgroup_from_id() to css_from_id()
cgroup: use css_get() in cgroup_create() to check CSS_ROOT
cpuset: remove an unncessary forward declaration
cgroup: RCU protect each cgroup_subsys_state release
cgroup: move subsys file removal to kill_css()
cgroup: factor out kill_css()
cgroup: decouple cgroup_subsys_state destruction from cgroup destruction
cgroup: replace cgroup->css_kill_cnt with ->nr_css
cgroup: bounce cgroup_subsys_state ref kill confirmation to a work item
cgroup: move cgroup->subsys[] assignment to online_css()
cgroup: reorganize css init / exit paths
cgroup: add __rcu modifier to cgroup->subsys[]
...
Here's the big driver core pull request for 3.12-rc1.
Lots of tiny changes here fixing up the way sysfs attributes are
created, to try to make drivers simpler, and fix a whole class race
conditions with creations of device attributes after the device was
announced to userspace.
All the various pieces are acked by the different subsystem maintainers.
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.21 (GNU/Linux)
iEYEABECAAYFAlIlIPcACgkQMUfUDdst+ynUMwCaAnITsxyDXYQ4DqEsz8EcOtMk
718AoLrgnUZs3B+70AT34DVktg4HSThk
=USl9
-----END PGP SIGNATURE-----
Merge tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core
Pull driver core patches from Greg KH:
"Here's the big driver core pull request for 3.12-rc1.
Lots of tiny changes here fixing up the way sysfs attributes are
created, to try to make drivers simpler, and fix a whole class race
conditions with creations of device attributes after the device was
announced to userspace.
All the various pieces are acked by the different subsystem
maintainers"
* tag 'driver-core-3.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: (119 commits)
firmware loader: fix pending_fw_head list corruption
drivers/base/memory.c: introduce help macro to_memory_block
dynamic debug: line queries failing due to uninitialized local variable
sysfs: sysfs_create_groups returns a value.
debugfs: provide debugfs_create_x64() when disabled
rbd: convert bus code to use bus_groups
firmware: dcdbas: use binary attribute groups
sysfs: add sysfs_create/remove_groups for when SYSFS is not enabled
driver core: add #include <linux/sysfs.h> to core files.
HID: convert bus code to use dev_groups
Input: serio: convert bus code to use drv_groups
Input: gameport: convert bus code to use drv_groups
driver core: firmware: use __ATTR_RW()
driver core: core: use DEVICE_ATTR_RO
driver core: bus: use DRIVER_ATTR_WO()
driver core: create write-only attribute macros for devices and drivers
sysfs: create __ATTR_WO()
driver-core: platform: convert bus code to use dev_groups
workqueue: convert bus code to use dev_groups
MEI: convert bus code to use dev_groups
...
Merge lockref infrastructure code by me and Waiman Long.
I already merged some of the preparatory patches that didn't actually do
any semantic changes earlier, but this merges the actual _reason_ for
those preparatory patches.
The "lockref" structure is a combination "spinlock and reference count"
that allows optimized reference count accesses. In particular, it
guarantees that the reference count will be updated AS IF the spinlock
was held, but using atomic accesses that cover both the reference count
and the spinlock words, we can often do the update without actually
having to take the lock.
This allows us to avoid the nastiest cases of spinlock contention on
large machines under heavy pathname lookup loads. When updating the
dentry reference counts on a large system, we'll still end up with the
cache line bouncing around, but that's much less noticeable than
actually having to spin waiting for the lock.
* lockref:
lockref: implement lockless reference count updates using cmpxchg()
lockref: uninline lockref helper functions
vfs: reimplement d_rcu_to_refcount() using lockref_get_or_lock()
vfs: use lockref_get_not_zero() for optimistic lockless dget_parent()
lockref: add 'lockref_get_or_lock() helper
This moves __d_rcu_to_refcount() from <linux/dcache.h> into fs/namei.c
and re-implements it using the lockref infrastructure instead. It also
adds a lot of comments about what is actually going on, because turning
a dentry that was looked up using RCU into a long-lived reference
counted entry is one of the more subtle parts of the rcu walk.
We also used to be _particularly_ subtle in unlazy_walk() where we
re-validate both the dentry and its parent using the same sequence
count. We used to do it by nesting the locks and then verifying the
sequence count just once.
That was silly, because nested locking is expensive, but the sequence
count check is not. So this just re-validates the dentry and the parent
separately, avoiding the nested locking, and making the lockref lookup
possible.
Acked-by: Waiman Long <waiman.long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
A valid parent pointer is always going to have a non-zero reference
count, but if we look up the parent optimistically without locking, we
have to protect against the (very unlikely) race against renaming
changing the parent from under us.
We do that by using lockref_get_not_zero(), and then re-checking the
parent pointer after getting a valid reference.
[ This is a re-implementation of a chunk from the original patch by
Waiman Long: "dcache: Enable lockless update of dentry's refcount".
I've completely rewritten the patch-series and split it up, but I'm
attributing this part to Waiman as it's close enough to his earlier
patch - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Previous attempt to fix was b042e47491
Suggested use of is_power_of_2() was bogus because is_power_of_2(0) is
false (documented behaviour).
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Merge fixes from Andrew Morton:
"Five fixes.
err, make that six. let me try again"
* emailed patches from Andrew Morton <akpm@linux-foundation.org>:
fs/ocfs2/super.c: Use bigger nodestr to accomodate 32-bit node numbers
memcg: check that kmem_cache has memcg_params before accessing it
drivers/base/memory.c: fix show_mem_removable() to handle missing sections
IPC: bugfix for msgrcv with msgtyp < 0
Omnikey Cardman 4000: pull in ioctl.h in user header
timer_list: correct the iterator for timer_list
While using pacemaker/corosync, the node numbers are generated using IP
address as opposed to serial node number generation. This may not fit
in a 8-byte string. Use a bigger string to print the complete node
number.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This just replaces the dentry count/lock combination with the lockref
structure that contains both a count and a spinlock, and does the
mechanical conversion to use the lockref infrastructure.
There are no semantic changes here, it's purely syntactic. The
reference lockref implementation uses the spinlock exactly the same way
that the old dcache code did, and the bulk of this patch is just
expanding the internal "d_count" use in the dcache code to use
"d_lockref.count" instead.
This is purely preparation for the real change to make the reference
count updates be lockless during the 3.12 merge window.
[ As with the previous commit, this is a rewritten version of a concept
originally from Waiman, so credit goes to him, blame for any errors
goes to me.
Waiman's patch had some semantic differences for taking advantage of
the lockless update in dget_parent(), while this patch is
intentionally a pure search-and-replace change with no semantic
changes. - Linus ]
Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
It's always been a hassle that if an external journal's
device number changes, the filesystem won't mount.
And since boot-time enumeration can change, device number
changes aren't unusual.
The current mechanism to update the journal location is by
passing in a mount option w/ a new devnum, but that's a hassle;
it's a manual approach, fixing things after the fact.
Adding a mount option, "-o journal_path=/dev/$DEVICE" would
help, since then we can do i.e.
# mount -o journal_path=/dev/disk/by-label/$JOURNAL_LABEL ...
and it'll mount even if the devnum has changed, as shown here:
# losetup /dev/loop0 journalfile
# mke2fs -L mylabel-journal -O journal_dev /dev/loop0
# mkfs.ext4 -L mylabel -J device=/dev/loop0 /dev/sdb1
Change the journal device number:
# losetup -d /dev/loop0
# losetup /dev/loop1 journalfile
And today it will fail:
# mount /dev/sdb1 /mnt/test
mount: wrong fs type, bad option, bad superblock on /dev/sdb1,
missing codepage or helper program, or other error
In some cases useful info is found in syslog - try
dmesg | tail or so
# dmesg | tail -n 1
[17343.240702] EXT4-fs (sdb1): error: couldn't read superblock of external journal
But with this new mount option, we can specify the new path:
# mount -o journal_path=/dev/loop1 /dev/sdb1 /mnt/test
#
(which does update the encoded device number, incidentally):
# umount /dev/sdb1
# dumpe2fs -h /dev/sdb1 | grep "Journal device"
dumpe2fs 1.41.12 (17-May-2010)
Journal device: 0x0701
But best of all we can just always mount by journal-path, and
it'll always work:
# mount -o journal_path=/dev/disk/by-label/mylabel-journal /dev/sdb1 /mnt/test
#
So the journal_path option can be specified in fstab, and as long as
the disk is available somewhere, and findable by label (or by UUID),
we can mount.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
If the group descriptor fails validation, mark the whole blockgroup
corrupt so that the inode/block allocators skip this group. The
previous approach takes the risk of writing to a damaged group
descriptor; hopefully it was never the case that the [ib]bitmap fields
pointed to another valid block and got dirtied, since the memset would
fill the page with 1s.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
If we detect either a discrepancy between the inode bitmap and the
inode counts or the inode bitmap fails to pass validation checks, mark
the block group corrupt and refuse to allocate or deallocate inodes
from the group.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
When we notice a block-bitmap corruption (because of device failure or
something else), we should mark this group as corrupt and prevent
further block allocations/deallocations from it. Currently, we end up
generating one error message for every block in the bitmap. This
potentially could make the system unstable as noticed in some
bugs. With this patch, the error will be printed only the first time
and mark the entire block group as corrupted. This prevents future
access allocations/deallocations from it.
Also tested by corrupting the block
bitmap and forcefully introducing the mb_free_blocks error:
(1) create a largefile (2Gb)
$ dd if=/dev/zero of=largefile oflag=direct bs=10485760 count=200
(2) umount filesystem. use dumpe2fs to see which block-bitmaps
are in use by largefile and note their block numbers
(3) use dd to zero-out the used block bitmaps
$ dd if=/dev/zero of=/dev/hdc4 bs=4096 seek=14 count=8 oflag=direct
(4) mount the FS and delete the largefile.
(5) recreate the largefile. verify that the new largefile does not
get any blocks from the groups marked as bad.
Without the patch, we will see mb_free_blocks error for each bit in
each zero'ed out bitmap at (4). With the patch, we only see the error
once per blockgroup:
[ 309.706803] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 15: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.720824] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 14: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.732858] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.748321] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 13: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.760331] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.769695] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 12: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.781721] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.798166] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 11: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
[ 309.810184] EXT4-fs error (device sdb4) in ext4_free_blocks:4802: IO failure
[ 309.819532] EXT4-fs error (device sdb4): ext4_mb_generate_buddy:735: group 10: 32768 clusters in bitmap, 0 in gd. blk grp corrupted.
Google-Bug-Id: 7258357
[darrick.wong@oracle.com]
Further modifications (by Darrick) to make more obvious that this corruption
bit applies to blocks only. Set the corruption flag if the block group bitmap
verification fails.
Original-author: Aditya Kali <adityakali@google.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The block_group parameter to ext4_validate_block_bitmap is both used
as a ext4_group_t inside the function and the same type is passed in
by all callers. We might as well use the typedef consistently instead
of open-coding the 'unsigned int'.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
The block bitmap verification code assumes that calling ext4_error()
either panics the system or makes the fs readonly. However, this is
not always true: when 'errors=continue' is specified, an error is
printed but we don't return any indication of error to the caller,
which is (probably) the block allocator, which pretends that the crud
we read in off the disk is a usable bitmap. Yuck.
A block bitmap that fails the check should at least return no bitmap
to the caller. The block allocator should be told to go look in a
different group, but that's a separate issue.
The easiest way to reproduce this is to modify bg_block_bitmap (on a
^flex_bg fs) to point to a block outside the block group; or you can
create a metadata_csum filesystem and zero out the block bitmaps.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
In the jbd2 checksumming code, explicitly declare separate variables with
endianness information so that we don't get confused and screw things up again.
Also fixes sparse warnings.
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
After applied the commit (4a092d73), we have reduced the number of
source files that need to #include ext4_extents.h. But we can do
better.
This commit defines ext4_zeroout_es() in extents.c and move
EXT_MAX_BLOCKS into ext4.h in order not to include ext4_extents.h in
indirect.c and ioctl.c. Meanwhile we just need to include this file in
extent_status.c when ES_AGGRESSIVE_TEST is defined. Otherwise, this
commit removes a duplicated declaration in trace/events/ext4.h.
After applied this patch, we just need to include ext4_extents.h file
in {super,migrate,move_extents,extents}.c, and it is easy for us to
define a new extent disk layout.
Signed-off-by: Zheng Liu <wenqing.lz@taobao.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Use wait_for_stable_page() instead of wait_on_page_writeback()
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
If ext_debugging is enabled and path[depth].p_ext is NULL, len
and lblock are printed non initialized
Signed-off-by: Andi Shyti <andi@etezian.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This reverts commit bb2314b479.
It wasn't necessarily wrong per se, but we're still busily discussing
the exact details of this all, so I'm going to revert it for now.
It's true that you can already do flink() through /proc and that flink()
isn't new. But as Brad Spengler points out, some secure environments do
not mount proc, and flink adds a new interface that can avoid path
lookup of the source for those kinds of environments.
We may re-do this (and even mark it for stable backporting back in 3.11
and possibly earlier) once the whole discussion about the interface is done.
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
client reporting a readdir loop.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.21 (GNU/Linux)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=+aYs
-----END PGP SIGNATURE-----
Merge tag 'jfs-3.11-rc8' of git://github.com/kleikamp/linux-shaggy
Pull jfs fix from Dave Kleikamp:
"One JFS patch to fix an incompatibility with NFSv4 resulting in the
nfs client reporting a readdir loop"
* tag 'jfs-3.11-rc8' of git://github.com/kleikamp/linux-shaggy:
jfs: fix readdir cookie incompatibility with NFSv4
Pull vfs fixes from Al Viro:
"Assorted fixes from the last week or so"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
VFS: collect_mounts() should return an ERR_PTR
bfs: iget_locked() doesn't return an ERR_PTR
efs: iget_locked() doesn't return an ERR_PTR()
proc: kill the extra proc_readfd_common()->dir_emit_dots()
cope with potentially long ->d_dname() output for shmem/hugetlb
This is a set of small bug fixes for lpfc and zfcp and a fix for a fairly
nasty bug in sg where a process which cancels I/O completes in a kernel thread
which would then try to write back to the now gone userspace and end up
writing to a random kernel address instead.
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.19 (GNU/Linux)
iQEcBAABAgAGBQJSGIaHAAoJEDeqqVYsXL0MbPUH/3UXceHlgYRrwYZ0C10Ao5XB
WA8RWsDsX9UJxG68zEd8ED1aRHhmkfm4pEdMQ8DHW7+B7mvNhpb6mF0wxvmS5aIj
OVI0G+3KmghA3aDWbTtg8ED0wJ4q3ftcyzl4Fhpat+yA4g/BW7iJNDCv17nvZ90f
hNmdGm23wuYCid7JWNDO79spSp0q6wPJhG6ynJYOtzX1GvpEliZiGB0IOR3K44nW
cF6+Uigs3+6RGXX9UHOMrk9Ug3YFHfok224vvydcbRXVh8uneB8RQ6tziJVFI8tE
WPgAv2oDzly8l+ku71CqrjzG7fSwCr9Urlog9cEugE1iUmFCIQm6xJcSSnGJqaY=
=jKT6
-----END PGP SIGNATURE-----
Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
Pull SCSI fixes from James Bottomley:
"This is a set of small bug fixes for lpfc and zfcp and a fix for a
fairly nasty bug in sg where a process which cancels I/O completes in
a kernel thread which would then try to write back to the now gone
userspace and end up writing to a random kernel address instead"
* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
[SCSI] zfcp: remove access control tables interface (keep sysfs files)
[SCSI] zfcp: fix schedule-inside-lock in scsi_device list loops
[SCSI] zfcp: fix lock imbalance by reworking request queue locking
[SCSI] sg: Fix user memory corruption when SG_IO is interrupted by a signal
[SCSI] lpfc: Don't force CONFIG_GENERIC_CSUM on
This should actually be returning an ERR_PTR on error instead of NULL.
That was how it was designed and all the callers expect it.
[AV: actually, that's what "VFS: Make clone_mnt()/copy_tree()/collect_mounts()
return errors" missed - originally collect_mounts() was expected to return
NULL on failure]
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
iget_locked() returns a NULL on error, it doesn't return an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
The iget_locked() function returns NULL on error and never an ERR_PTR.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
proc_readfd_common() does dir_emit_dots() twice in a row,
we need to do this only once.
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
dynamic_dname() is both too much and too little for those - the
output may be well in excess of 64 bytes dynamic_dname() assumes
to be enough (thanks to ashmem feeding really long names to
shmem_file_setup()) and vsnprintf() is an overkill for those
guys.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Fix the issue with improper counting number of flying bio requests for
BIO_EOPNOTSUPP error detection case.
The sb_nbio must be incremented exactly the same number of times as
complete() function was called (or will be called) because
nilfs_segbuf_wait() will call wail_for_completion() for the number of
times set to sb_nbio:
do {
wait_for_completion(&segbuf->sb_bio_event);
} while (--segbuf->sb_nbio > 0);
Two functions complete() and wait_for_completion() must be called the
same number of times for the same sb_bio_event. Otherwise,
wait_for_completion() will hang or leak.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Cc: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove double call of bio_put() in nilfs_end_bio_write() for the case of
BIO_EOPNOTSUPP error detection. The issue was found by Dan Carpenter
and he suggests first version of the fix too.
Signed-off-by: Vyacheslav Dubeyko <slava@dubeyko.com>
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Tested-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix up the wording of sysfs_create/remove_groups() a bit.
Reported-by: Anthony Foiani <tkil@scrye.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Miklos Szeredi
Linus Torvalds
Christoph Hellwig
Al Viro
Jeff Layton
Yan, Zheng
Waiman Long
Maxime Bizon
Goldwyn Rodrigues
Eric Sandeen
Darrick J. Wong
Zheng Liu
Anatol Pomozov
Dmitry Monakhov
Andi Shyti
Dan Carpenter
Oleg Nesterov
Vyacheslav Dubeyko
Greg Kroah-Hartman