Requiring userspace to close and re-open sysfs attributes has been the
policy since before 2.6.12. It allows userspace to get a consistent
snapshot of kernel state and consume it with incremental reads and seeks.
Now, if the file position is zero the kernel assumes userspace wants to see
the new value. The application for this change is to allow a userspace
RAID metadata handler to check the state of an array without causing any
memory allocations. Thus not causing writeback to a raid array that might
be blocked waiting for userspace to take action.
Cc: Neil Brown <neilb@suse.de>
Acked-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Mention how DMAPI affects default for noikeep.
Slightly modified since Josef's patch was based on
an old xfs.txt prior to Dave's (dgc) checkin which
missed going to oss.
Signed-off-by: Josef Sipek <jeffpc@josefsipek.net>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Update xfs docs for:
* In memory inode hashes has been removed.
* noikeep is now the default.
SGI-PV: 969561
SGI-Modid: 2.6.x-xfs-melb:linux:29481b
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Tim Shimmin <tes@sgi.com>
A couple of typos crept into the newly added document about the seq_file
interface. This patch corrects those typos and simultaneously deletes
unnecessary trailing spaces.
Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This file is nfs-related. (Maybe Documentation/filesystems/ would
benefit from a separate nfs/ directory at some point.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Documentation/ is a little large, and filesystems/ seems an obvious
place for this file.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
On Friday 2008-03-28 19:20, Jonathan Corbet wrote:
>commit 9756ccfda31b4c4544aa010aacf71b6672d668e8
>Date: Fri Mar 28 11:19:56 2008 -0600
>
> Add the seq_file documentation
patch on top:
- add const qualifiers
- remove void* casts
- use proper specifier (%Ld is not valid)
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Jan Engelhardt <jengelh@computergmbh.de>
Move laptop-mode.txt into the laptops/ sub-directory to consolidate
laptop doc files there.
Update references to the file's location.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Len Brown <len.brown@intel.com>
This series addresses the problem of showing mount options in
/proc/mounts.
Several filesystems which use mount options, have not implemented a
.show_options superblock operation. Several others have implemented
this callback, but have not kept it fully up to date with the parsed
options.
Q: Why do we need correct option showing in /proc/mounts?
A: We want /proc/mounts to fully replace /etc/mtab. The reasons for
this are:
- unprivileged mounters won't be able to update /etc/mtab
- /etc/mtab doesn't work with private mount namespaces
- /etc/mtab can become out-of-sync with reality
Q: Can't this be done, so that filesystems need not bother with
implementing a .show_mounts callback, and keeping it up to date?
A: Only in some cases. Certain filesystems allow modification of a
subset of options in their remount_fs method. It is not possible
to take this into account without knowing exactly how the
filesystem handles options.
For the simple case (no remount or remount resets all options) the
patchset introduces two helpers:
generic_show_options()
save_mount_options()
These can also be used to emulate the old /etc/mtab behavior, until
proper support is added. Even if this is not 100% correct, it's still
better than showing no options at all.
The following patches fix up most in-tree filesystems, some have been
compile tested only, some have been reviewed and acked by the
maintainer.
Table displaying status of all in-kernel filesystems:
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
legend:
none - fs has options, but doesn't define ->show_options()
some - fs defines ->show_options(), but some only options are shown
good - fs shows all options
noopt - fs does not have options
patch - a patch will be posted
merged - a patch has been merged by subsystem maintainer
9p good
adfs patch
affs patch
afs patch
autofs patch
autofs4 patch
befs patch
bfs noopt
cifs some
coda noopt
configfs noopt
cramfs noopt
debugfs noopt
devpts patch
ecryptfs good
efs noopt
ext2 patch
ext3 good
ext4 merged
fat patch
freevxfs noopt
fuse patch
fusectl noopt
gfs2 good
gfs2meta noopt
hfs good
hfsplus good
hostfs patch
hpfs patch
hppfs noopt
hugetlbfs patch
isofs patch
jffs2 noopt
jfs merged
minix noopt
msdos ->fat
ncpfs patch
nfs some
nfsd noopt
ntfs good
ocfs2 good
ocfs2/dlmfs noopt
openpromfs noopt
proc noopt
qnx4 noopt
ramfs noopt
reiserfs patch
romfs noopt
smbfs good
sysfs noopt
sysv noopt
udf patch
ufs good
vfat ->fat
xfs good
mm/shmem.c patch
drivers/oprofile/oprofilefs.c noopt
drivers/infiniband/hw/ipath/ipath_fs.c noopt
drivers/misc/ibmasm/ibmasmfs.c noopt
drivers/usb/core (usbfs) merged
drivers/usb/gadget (gadgetfs) noopt
drivers/isdn/capi/capifs.c patch
kernel/cpuset.c noopt
fs/binfmt_misc.c noopt
net/sunrpc/rpc_pipe.c noopt
arch/powerpc/platforms/cell/spufs patch
arch/s390/hypfs good
ipc/mqueue.c noopt
security (securityfs) noopt
security/selinux/selinuxfs.c noopt
kernel/cgroup.c good
security/smack/smackfs.c noopt
in -mm:
reiser4 some
unionfs good
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
This patch:
Document the rules for handling mount options in the .show_options
super operation.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Implement dmode option for iso9660 filesystem to allow setting of access
rights for directories on the filesystem.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: "Ilya N. Golubev" <gin@mo.msk.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Remove the old iget() call and the read_inode() superblock operation it uses
as these are really obsolete, and the use of read_inode() does not produce
proper error handling (no distinction between ENOMEM and EIO when marking an
inode bad).
Furthermore, this removes the temptation to use iget() to find an inode by
number in a filesystem from code outside that filesystem.
iget_locked() should be used instead. A new function is added in an earlier
patch (iget_failed) that is to be called to mark an inode as bad, unlock it
and release it should the get routine fail. Mark iget() and read_inode() as
being obsolete and remove references to them from the documentation.
Typically a filesystem will be modified such that the read_inode function
becomes an internal iget function, for example the following:
void thingyfs_read_inode(struct inode *inode)
{
...
}
would be changed into something like:
struct inode *thingyfs_iget(struct super_block *sp, unsigned long ino)
{
struct inode *inode;
int ret;
inode = iget_locked(sb, ino);
if (!inode)
return ERR_PTR(-ENOMEM);
if (!(inode->i_state & I_NEW))
return inode;
...
unlock_new_inode(inode);
return inode;
error:
iget_failed(inode);
return ERR_PTR(ret);
}
and then thingyfs_iget() would be called rather than iget(), for example:
ret = -EINVAL;
inode = iget(sb, ino);
if (!inode || is_bad_inode(inode))
goto error;
becomes:
inode = thingyfs_iget(sb, ino);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
goto error;
}
Note that is_bad_inode() does not need to be called. The error returned by
thingyfs_iget() should render it unnecessary.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Introduce a function to register failure in an inode construction path. This
includes marking the inode under construction as bad, unlocking it and
releasing it.
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This documentation is also vfs-related.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
I'm inclined to think dnotify belongs in filesystems/.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
NR_OPEN (historically set to 1024*1024) actually forbids processes to open
more than 1024*1024 handles.
Unfortunatly some production servers hit the not so 'ridiculously high
value' of 1024*1024 file descriptors per process.
Changing NR_OPEN is not considered safe because of vmalloc space potential
exhaust.
This patch introduces a new sysctl (/proc/sys/fs/nr_open) wich defaults to
1024*1024, so that admins can decide to change this limit if their workload
needs it.
[akpm@linux-foundation.org: export it for sparc64]
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Richard Henderson <rth@twiddle.net>
Cc: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Though the lower_zone_protection was changed to lowmem_reserve_ratio, the
document has been not changed. The lowmem_reserve_ratio seems quite hard
to estimate, but there is no guidance. This patch is to change document
for it.
Signed-off-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Andrea Arcangeli <andrea@cpushare.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Add vm.highmem_is_dirtyable toggle
A 32 bit machine with HIGHMEM64 enabled running DCC has an MMAPed file of
approximately 2Gb size which contains a hash format that is written
randomly by the dbclean process. On 2.6.16 this process took a few
minutes. With lowmem only accounting of dirty ratios, this takes about 12
hours of 100% disk IO, all random writes.
Include a toggle in /proc/sys/vm/highmem_is_dirtyable which can be set to 1 to
add the highmem back to the total available memory count.
[akpm@linux-foundation.org: Fix the CONFIG_DETECT_SOFTLOCKUP=y build]
Signed-off-by: Bron Gondwana <brong@fastmail.fm>
Cc: Ethan Solomita <solo@google.com>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: WU Fengguang <wfg@mail.ustc.edu.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Use the normal, expected mountpoint in the relay(fs) example
for debugfs.
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
execve arguments can be quite large. There is no limit on the number of
arguments and a 4G limit on the size of an argument.
this patch prints those aruguments in bite sized pieces. a userspace size
limitation of 8k was discovered so this keeps messages around 7.5k
single arguments larger than 7.5k in length are split into multiple records
and can be identified as aX[Y]=
Signed-off-by: Eric Paris <eparis@redhat.com>
Current ip route cache implementation is not suited to large caches.
We can consume a lot of CPU when cache must be invalidated, since we
currently need to evict all cache entries, and this eviction is
sometimes asynchronous. min_delay & max_delay can somewhat control this
asynchronism behavior, but whole thing is a kludge, regularly triggering
infamous soft lockup messages. When entries are still in use, this also
consumes a lot of ram, filling dst_garbage.list.
A better scheme is to use a generation identifier on each entry,
so that cache invalidation can be performed by changing the table
identifier, without having to scan all entries.
No more delayed flushing, no more stalling when secret_interval expires.
Invalidated entries will then be freed at GC time (controled by
ip_rt_gc_timeout or stress), or when an invalidated entry is found
in a chain when an insert is done.
Thus we keep a normal equilibrium.
This patch :
- renames rt_hash_rnd to rt_genid (and makes it an atomic_t)
- Adds a new rt_genid field to 'struct rtable' (filling a hole on 64bit)
- Checks entry->rt_genid at appropriate places :
The journal checksum feature adds two new flags i.e
JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT and JBD2_FEATURE_COMPAT_CHECKSUM.
JBD2_FEATURE_CHECKSUM flag indicates that the commit block contains the
checksum for the blocks described by the descriptor blocks.
Due to checksums, writing of the commit record no longer needs to be
synchronous. Now commit record can be sent to disk without waiting for
descriptor blocks to be written to disk. This behavior is controlled
using JBD2_FEATURE_ASYNC_COMMIT flag. Older kernels/e2fsck should not be
able to recover the journal with _ASYNC_COMMIT hence it is made
incompat.
The commit header has been extended to hold the checksum along with the
type of the checksum.
For recovery in pass scan checksums are verified to ensure the sanity
and completeness(in case of _ASYNC_COMMIT) of every transaction.
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Girish Shilamkar <girish@clusterfs.com>
Signed-off-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Hook up ocfs2_flock(), using the new flock lock type in dlmglue.c. A new
mount option, "localflocks" is added so that users can revert to old
functionality as need be.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Local alloc is a performance optimization in ocfs2 in which a node
takes a window of bits from the global bitmap and then uses that for
all small local allocations. This window size is fixed to 8MB currently.
This patch allows users to specify the window size in MB including
disabling it by passing in 0. If the number specified is too large,
the fs will use the default value of 8MB.
mount -o localalloc=X /dev/sdX /mntpoint
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Mostly taken from ext3. This allows the user to set the jbd commit interval,
in seconds. The default of 5 seconds stays the same, but now users can
easily increase the commit interval. Typically, this would be increased in
order to benefit performance at the expense of data-safety.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Remove 'readpages' from the list in ocfs2.txt. Instead of having two
identical lists, I just removed the list in the OCFS2 section of fs/Kconfig
and added a pointer to Documentation/filesystems/ocfs2.txt.
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
This adds a transport to 9p for communicating between guests and a host
using a virtio based transport.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Update documentation to the current state of affairs. Remove duplicated
method descruptions in exportfs.h and point to Documentation/filesystems/
Exporting instead. Add a little file header comment in expfs.c describing
what's going on and mentioning Neils and my copyright [1].
Signed-off-by: Christoph Hellwig <hch@lst.de>
Cc: Neil Brown <neilb@suse.de>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: <linux-ext4@vger.kernel.org>
Cc: Dave Kleikamp <shaggy@austin.ibm.com>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: David Chinner <dgc@sgi.com>
Cc: Timothy Shimmin <tes@sgi.com>
Cc: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Hugh Dickins <hugh@veritas.com>
Cc: Chris Mason <mason@suse.com>
Cc: Jeff Mahoney <jeffm@suse.com>
Cc: "Vladimir V. Saveliev" <vs@namesys.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Fix some grammar in the explanation of the Journal Block Device layer.
Signed-off-by: Shaun Zinck <shaun.zinck@gmail.com>
Acked-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
rcuref_inc_lf() is not used anymore. Replace it by atomic_inc_not_zero()
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Most of these fixes were already submitted for old kernel versions, and were
approved, but for some reason they never made it into the releases.
Because this is a consolidation of a couple old missed patches, it touches both
Kconfigs and documentation texts.
Signed-off-by: Matt LaPlante <kernel1@cyberdogtech.com>
Acked-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Fix the various misspellings of "system", controller", "interrupt" and
"[un]necessary".
Signed-off-by: Robert P. J. Day <rpjday@mindspring.com>
Signed-off-by: Adrian Bunk <bunk@kernel.org>
The 9P2000 protocol requires the authentication and permission checks to be
done in the file server. For that reason every user that accesses the file
server tree has to authenticate and attach to the server separately.
Multiple users can share the same connection to the server.
Currently v9fs does a single attach and executes all I/O operations as a
single user. This makes using v9fs in multiuser environment unsafe as it
depends on the client doing the permission checking.
This patch improves the 9P2000 support by allowing every user to attach
separately. The patch defines three modes of access (new mount option
'access'):
- attach-per-user (access=user) (default mode for 9P2000.u)
If a user tries to access a file served by v9fs for the first time, v9fs
sends an attach command to the server (Tattach) specifying the user. If
the attach succeeds, the user can access the v9fs tree.
As there is no uname->uid (string->integer) mapping yet, this mode works
only with the 9P2000.u dialect.
- allow only one user to access the tree (access=<uid>)
Only the user with uid can access the v9fs tree. Other users that attempt
to access it will get EPERM error.
- do all operations as a single user (access=any) (default for 9P2000)
V9fs does a single attach and all operations are done as a single user.
If this mode is selected, the v9fs behavior is identical with the current
one.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Change the names of 'uid' and 'gid' parameters to the more appropriate
'dfltuid' and 'dfltgid'. This also sets the default uid/gid to -2
(aka nfsnobody)
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
This patch abstracts out the interfaces to underlying transports so that
new transports can be added as modules. This should also allow kernel
configuration of transports without ifdef-hell.
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Add missing IRQs and IRQ descriptions to /proc/interrupts.
/proc/interrupts is most useful when it displays every IRQ vector in use by
the system, not just those somebody thought would be interesting.
This patch inserts the following vector displays to the i386 and x86_64
platforms, as appropriate:
rescheduling interrupts
TLB flush interrupts
function call interrupts
thermal event interrupts
threshold interrupts
spurious interrupts
A threshold interrupt occurs when ECC memory correction is occuring at too
high a frequency. Thresholds are used by the ECC hardware as occasional
ECC failures are part of normal operation, but long sequences of ECC
failures usually indicate a memory chip that is about to fail.
Thermal event interrupts occur when a temperature threshold has been
exceeded for some CPU chip. IIRC, a thermal interrupt is also generated
when the temperature drops back to a normal level.
A spurious interrupt is an interrupt that was raised then lowered by the
device before it could be fully processed by the APIC. Hence the apic sees
the interrupt but does not know what device it came from. For this case
the APIC hardware will assume a vector of 0xff.
Rescheduling, call, and TLB flush interrupts are sent from one CPU to
another per the needs of the OS. Typically, their statistics would be used
to discover if an interrupt flood of the given type has been occuring.
AK: merged v2 and v4 which had some more tweaks
AK: replace Local interrupts with Local timer interrupts
AK: Fixed description of interrupt types.
[ tglx: arch/x86 adaptation ]
[ mingo: small cleanup ]
Signed-off-by: Joe Korty <joe.korty@ccur.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Tim Hockin <thockin@hockin.org>
Cc: Andi Kleen <ak@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Implement sending of quota messages via netlink interface. The advantage
is that in userspace we can better decide what to do with the message - for
example display a dialogue in your X session or just write the message to
the console. As a bonus, we can get rid of problems with console locking
deep inside filesystem code once we remove the old printing mechanism.
Signed-off-by: Jan Kara <jack@suse.cz>
Cc: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
prepare/commit_write no longer returns AOP_TRUNCATED_PAGE since OCFS2 and
GFS2 were converted to the new aops, so we can make some simplifications
for that.
[michal.k.k.piotrowski@gmail.com: fix warning]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: Michael Halcrow <mhalcrow@us.ibm.com>
Cc: Mark Fasheh <mark.fasheh@oracle.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Michal Piotrowski <michal.k.k.piotrowski@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
These are intended to replace prepare_write and commit_write with more
flexible alternatives that are also able to avoid the buffered write
deadlock problems efficiently (which prepare_write is unable to do).
[mark.fasheh@oracle.com: API design contributions, code review and fixes]
[akpm@linux-foundation.org: various fixes]
[dmonakhov@sw.ru: new aop block_write_begin fix]
Signed-off-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>
Signed-off-by: Dmitriy Monakhov <dmonakhov@openvz.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
