Performance enhancement reducing the number of copies in the data and
stat paths.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
v9fs_create doesn't manage correctly the fids when it is called to create a
directory.. The fid created by the create 9P call (newfid) and the one
created by walking to already created file (wfidno) are not used
consistently.
This patch cleans up the usage of newfid and wfidno.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
New multiplexer implementation. Decreases the number of kernel threads
required. Better handling when the user process receives a signal.
Signed-off-by: Latchesar Ionkov <lucho@ionkov.net>
Cc: Eric Van Hensbergen <ericvh@ericvh.myip.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If a 9pfs server crashes, v9fs_fd_close() is called. Subsequently, in
cleaning up by performing a umount() on the FS that was provided by this
server v9fs_fd_close() is called again, and uses the old, freed valus of
trans->priv. This patch ensures that trans->priv can be freed only once,
otherwise this function bails early.
Signed-off-by: Michal Ostrowski <mostrows@watson.ibm.com>
Signed-off-by: Eric Van Hensbergen <ericvh@gmail.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch fixes a data corruption in smb_proc_setattr_unix()
(smb_filetype_from_mode() returns an u32, and there are only four bytes
reserved for it in data.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Function prototypes belong into header files.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove various things which were checking for gcc-1.x and gcc-2.x compilers.
From: Adrian Bunk <bunk@stusta.de>
Some documentation updates and removes some code paths for gcc < 3.2.
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
"extern inline" doesn't make much sense.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch inlines the single user of struct super_block field
s_old_blocksize and removes the field.
Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
mmap() returns -EINVAL if given a zero length, and thus elf_map() in
binfmt_elf.c does likewise if it attempts to map a (page-aligned) ELF
segment with zero filesize. Such a situation never arises with the default
linker scripts, but there's nothing inherently wrong with zero-filesize
(but non-zero memsize) ELF segments. Custom linker scripts can generate
them, and the kernel should be able to map them; this patch makes it so.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Some long time ago, dentry struct was carefully tuned so that on 32 bits
UP, sizeof(struct dentry) was exactly 128, ie a power of 2, and a multiple
of memory cache lines.
Then RCU was added and dentry struct enlarged by two pointers, with nice
results for SMP, but not so good on UP, because breaking the above tuning
(128 + 8 = 136 bytes)
This patch reverts this unwanted side effect, by using an union (d_u),
where d_rcu and d_child are placed so that these two fields can share their
memory needs.
At the time d_free() is called (and d_rcu is really used), d_child is known
to be empty and not touched by the dentry freeing.
Lockless lookups only access d_name, d_parent, d_lock, d_op, d_flags (so
the previous content of d_child is not needed if said dentry was unhashed
but still accessed by a CPU because of RCU constraints)
As dentry cache easily contains millions of entries, a size reduction is
worth the extra complexity of the ugly C union.
Signed-off-by: Eric Dumazet <dada1@cosmosbay.com>
Cc: Dipankar Sarma <dipankar@in.ibm.com>
Cc: Maneesh Soni <maneesh@in.ibm.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Cc: Ian Kent <raven@themaw.net>
Cc: Paul Jackson <pj@sgi.com>
Cc: Al Viro <viro@ftp.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@epoch.ncsc.mil>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It would be helpful if the kernel did not silently stop parsing
nfs options, but instead warned about any he does not recognize. The
attached patch adds one printk to do just that.
It took me a couple of hours to find my configuration mistake.
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The only user of send_sigio_to_task() already holds tasklist_lock, so it is
better not to send the signal via send_group_sig_info() (which takes
tasklist recursively) but use group_send_sig_info().
The same change in send_sigurg()->send_sigurg_to_task().
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
There are places in the resize code in which EXT3_SB() macro is used after
an statement like sbi = EXT3_SB(sb) is done. Inside the same function,
both sbi and EXT3_SB() are used to reference the super block Altough it is
not wrong, keeping it coherent increases legibility, IMHO.
Signed-off-by: Glauber de Oliveira Costa <glommer@br.ibm.com>
Cc: "Stephen C. Tweedie" <sct@redhat.com>
Cc: Andreas Dilger <adilger@clusterfs.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Remove the trailing newlines in calls to ext3_warning(). This function
already adds a trailing newline to the end of messages.
Signed-off-by: Glauber de Oliveira Costa <glommer@br.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The patch below adds a new mount option to allow the external journal
device to be specified.
The syntax is as follows:
# mount -t ext3 -o journal_dev=0x0820 ...
where 0x0820 means major=8 and minor=32.
Signed-off-by: Johann Lombardi <johann.lombardi@bull.net>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
__group_complete_signal() sets ->group_stop_count in sig_kernel_coredump()
path and marks the target thread as ->group_exit_task. So any thread
except group_exit_task will go to handle_group_stop()->finish_stop().
However, when group_exit_task actually starts do_coredump(), it sets
SIGNAL_GROUP_EXIT, but does not reset ->group_stop_count while killing
other threads. If we have not yet stopped threads in the same thread
group, they all will spin in kernel mode until group_exit_task sends them
SIGKILL, because ->group_stop_count > 0 means:
recalc_sigpending_tsk() never clears TIF_SIGPENDING
get_signal_to_deliver() goes to handle_group_stop()
handle_group_stop() returns when SIGNAL_GROUP_EXIT set
syscall_exit/resume_userspace notice TIF_SIGPENDING,
call get_signal_to_deliver() again.
So we are wasting cpu cycles, and if one of these threads is rt_task() this
may be a serious problem.
NOTE: do_coredump() holds ->mmap_sem, so not stopped threads can't escape
coredumping after clearing ->group_stop_count.
See also this thread: http://marc.theaimsgroup.com/?t=112739139900002
Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We've had two instances recently of overflows when doing
64_bit_value = (32_bit_value << PAGE_CACHE_SHIFT)
I did a tree-wide grep of `<<.*PAGE_CACHE_SHIFT' and this is the result.
- afs_rxfs_fetch_descriptor.offset is of type off_t, which seems broken.
- jfs and jffs are limited to 4GB anyway.
- reiserfs map_block_for_writepage() takes an unsigned long for the block -
it should take sector_t. (It'll fail for huge filesystems with
blocksize<PAGE_CACHE_SIZE)
- cramfs_read() needs to use sector_t (I think cramsfs is busted on large
filesystems anyway)
- affs is limited in file size anyway.
- I generally didn't fix 32-bit overflows in directory operations.
- arm's __flush_dcache_page() is peculiar. What if the page lies beyond 4G?
- gss_wrap_req_priv() needs checking (snd_buf->page_base)
Cc: Oleg Drokin <green@linuxhacker.ru>
Cc: David Howells <dhowells@redhat.com>
Cc: David Woodhouse <dwmw2@infradead.org>
Cc: <reiserfs-dev@namesys.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Anton Altaparmakov <aia21@cantab.net>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Cc: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
When making an fctl locking call through compat_sys_fcntl64 (i.e. a 32bit
app on a 64bit kernel), the syscall can return a locking range that is in
conflict with the queried lock.
If some aspect of this range does not fit in the 32bit structure, something
needs to be done.
The current code is wrong in several respects:
- It returns data to userspace even if no conflict was found
i.e. it should check l_type for F_UNLCK
- It returns -EOVERFLOW too agressively. A lock range covering
the last possible byte of the file (start = COMPAT_OFF_T_MAX,
len = 1) should be possible, but is rejected with the current test.
- A extra-long 'len' should not be a problem. If only that part
of the conflicting lock that would be visible to the 32bit
app needs to be reported to the 32bit app anyway.
This patch addresses those three issues and adds a comment to (hopefully)
record it for posterity.
Note: this patch mainly affects test-cases. Real applications rarely is
ever see the problems.
This patch has been tested (LSB test suite), and works.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Matthew Wilcox <willy@debian.org>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
SUS requires that when truncating a file to the size that it currently
is:
truncate and ftruncate should NOT modify ctime or mtime
O_TRUNC SHOULD modify ctime and mtime.
Currently mtime and ctime are always modified on most local
filesystems (side effect of ->truncate) or never modified (on NFS).
With this patch:
ATTR_CTIME|ATTR_MTIME are sent with ATTR_SIZE precisely when
an update of these times is required whether size changes or not
(via a new argument to do_truncate). This allows NFS to do
the right thing for O_TRUNC.
inode_setattr nolonger forces ATTR_MTIME|ATTR_CTIME when the ATTR_SIZE
sets the size to it's current value. This allows local filesystems
to do the right thing for f?truncate.
Also, the logic in inode_setattr is changed a bit so there are two return
points. One returns the error from vmtruncate if it failed, the other
returns 0 (there can be no other failure).
Finally, if vmtruncate succeeds, and ATTR_SIZE is the only change
requested, we now fall-through and mark_inode_dirty. If a filesystem did
not have a ->truncate function, then vmtruncate will have changed i_size,
without marking the inode as 'dirty', and I think this is wrong.
Signed-off-by: Neil Brown <neilb@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
inode can never be NULL when calling this function.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch renames relayfs_file_operations to relay_file_operations, and the
file operations themselves from relayfs_XXX to relay_file_XXX, to make it more
clear that they refer to relay files.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds the optional is_global outparam to the create_buf_file()
callback. This can be used by clients to create a single global relayfs
buffer instead of the default per-cpu buffers. This was suggested as being
useful for certain debugging applications where it's more convenient to be
able to get all the data from a single channel without having to go to the
bother of dealing with per-cpu files.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a couple of callback functions that allow a client to hook
into relay_open()/close() and supply the files that will be used to represent
the channel buffers; the default implementation if no callbacks are defined is
to create the files in relayfs. This is to support the creation and use of
relay files in other filesystems such as debugfs, as implied by the fact that
relayfs_file_operations are exported.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Since we're no longer using relayfs_inode_info, remove relayfs_alloc_inode()
and relayfs_destroy_inode() along with the relayfs inode cache.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use inode->u.generic_ip instead of relayfs_inode_info to store pointer to user
data. Clients using relayfs_file_create() to create their own files would
probably more expect their data to be stored in generic_ip; we also intend in
the next set of patches to get rid of relayfs-specific stuff in the file
operations, so we might as well do it here.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds and exports relayfs_remove_file(), for API symmetry (with
relayfs_create_file()).
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch adds a mandatory fileops param to relayfs_create_file() and exports
that function so that clients can use it to create files defined by their own
set of file operations, in relayfs. The purpose is to allow relayfs
applications to create their own set of 'control' files alongside their relay
files in relayfs rather than having to create them in /proc or debugfs for
instance. relayfs_create_file() is also used by relay_open_buf() to create
the relay files for a channel. In this case, a pointer to
relayfs_file_operations is passed in, along with a pointer to the buffer
associated with the file.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
The patch series implementa or fixes 3 things that were specifically requested
or suggested by relayfs users:
- support for non-relay files (patches 1-6)
Currently, the relayfs API only supports the creation of directories
(relayfs_create_dir()) and relay files (relay_open()). These patches adds
support for non-relay files (relayfs_create_file()). This is so relayfs
applications can create 'control files' in relayfs itself rather than in /proc
or via a netlink channel, as is currently done in the relay-app examples.
Basically what this amounts to is exporting relayfs_create_file() with an
additional file_ops param that clients can use to supply file operations for
their own special-purpose files in relayfs.
- make exported relay file ops useful (patches 7-8)
The relayfs relay_file_operations have always been exported, the intent being
to make it possible to create relay files in other filesystems such as
debugfs. The problem, though, is that currently the file operations are too
tightly coupled to relayfs to actually be used for this purpose. This patch
fixes that by adding a couple of callback functions that allow a client to
hook into relay_open()/close() and supply the files that will be used to
represent the channel buffers; the default implementation if no callbacks are
defined is to create the files in relayfs.
- add an option to create global relay buffer (patches 9-10) The file creation
callback also supplies an optional param, is_global, that can be used by
clients to create a single global relayfs buffer instead of the default
per-cpu buffers. This was suggested as being useful for certain debugging
applications where it's more convenient to be able to get all the data from a
single channel without having to go to the bother of dealing with per-cpu
files.
- cleanup, some renaming and Documentation updates (patches 11-12)
There were several comments that the use of netlink in the example code was
non-intuitive and in fact the whole relay-app business was needlessly
confusing. Based on that feedback, the example code has been completely
converted over to relayfs control files as supported by this patch, and have
also been made completely self-contained.
The converted examples along with a couple of new examples that demonstrate
using exported relay files can be found in relay-apps tarball:
http://prdownloads.sourceforge.net/relayfs/relay-apps-0.9.tar.gz?download
This patch:
Separate buffer create/destroy from inode create/destroy. We want to be able
to associate other data and not just relay buffers with inodes. Buffer
create/destroy is moved out of inode.c and into relayfs core code.
Signed-off-by: Tom Zanussi <zanussi@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Use atomic_inc_not_zero for rcu files instead of special case rcuref.
Signed-off-by: Nick Piggin <npiggin@suse.de>
Cc: "Paul E. McKenney" <paulmck@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch add EXPORT_SYMBOL(filemap_write_and_wait) and use it.
See mm/filemap.c:
And changes the filemap_write_and_wait() and filemap_write_and_wait_range().
Current filemap_write_and_wait() doesn't wait if filemap_fdatawrite()
returns error. However, even if filemap_fdatawrite() returned an
error, it may have submitted the partially data pages to the device.
(e.g. in the case of -ENOSPC)
<quotation>
Andrew Morton writes,
If filemap_fdatawrite() returns an error, this might be due to some
I/O problem: dead disk, unplugged cable, etc. Given the generally
crappy quality of the kernel's handling of such exceptions, there's a
good chance that the filemap_fdatawait() will get stuck in D state
forever.
</quotation>
So, this patch doesn't wait if filemap_fdatawrite() returns the -EIO.
Trond, could you please review the nfs part? Especially I'm not sure,
nfs must use the "filemap_fdatawrite(inode->i_mapping) == 0", or not.
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch changes generic_cont_expand(), in order to share the code
with fatfs.
- Use vmtruncate() if ->prepare_write() returns a error.
Even if ->prepare_write() returns an error, it may already have added some
blocks. So, this truncates blocks outside of ->i_size by vmtruncate().
- Add generic_cont_expand_simple().
The generic_cont_expand_simple() assumes that ->prepare_write() can handle
the block boundary. With this, we don't need to care the extra byte.
And for expanding a file size by truncate(), fatfs uses the
added generic_cont_expand_simple().
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch add to support of ->direct_IO() for mostly read.
The user of this seems to want to use for streaming read. So, current direct
I/O has limitation, it can only overwrite. (For write operation, mainly we
need to handle the hole etc..)
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
All EXPORT_SYMBOL of fatfs is only for vfat/msdos. _GPL would be proper.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
We don't need to allocate buffer for checking the buffer is uptodate. This
use sb_find_get_block() instead, and if it returns NULL it's not uptodate.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
It is overkill to update the FS_INFO whenever modifying
prev_free/free_clusters, because those are just a hint.
So, this patch uses ->write_super() for updating FS_INFO instead.
Signed-off-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
RCU tasklist_lock and RCU signal handling: send signals RCU-read-locked
instead of tasklist_lock read-locked. This is a scalability improvement on
SMP and a preemption-latency improvement under PREEMPT_RCU.
Signed-off-by: Paul E. McKenney <paulmck@us.ibm.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Acked-by: William Irwin <wli@holomorphy.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Suppress configuration of certain features for the FRV arch as they can't be
built for FRV at the moment:
(*) RTC
(*) HISAX_*
(*) PARPORT_PC
(*) VGA_CONSOLE
(*) BINFMT_ELF
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
First discussed at http://marc.theaimsgroup.com/?t=113149255100001&r=1&w=2
- Use the check_range() in mempolicy.c to gather statistics.
- Improve the numa_maps code in general and fix some comments.
Signed-off-by: Christoph Lameter <clameter@sgi.com>
Cc: Andi Kleen <ak@muc.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Add /proc/sys/vm/drop_caches. When written to, this will cause the kernel to
discard as much pagecache and/or reclaimable slab objects as it can. THis
operation requires root permissions.
It won't drop dirty data, so the user should run `sync' first.
Caveats:
a) Holds inode_lock for exorbitant amounts of time.
b) Needs to be taught about NUMA nodes: propagate these all the way through
so the discarding can be controlled on a per-node basis.
This is a debugging feature: useful for getting consistent results between
filesystem benchmarks. We could possibly put it under a config option, but
it's less than 300 bytes.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
This patch should fix compilation failure of fs/ufs/dir.c with defined UFS_DIR_DEBUG
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
If someone changes the uid/gid mapping in userland, then we do eventually
want those changes to be propagated to the kernel. Currently the kernel
assumes that it may cache entries forever.
Add an expiration time + garbage collector for idmap entries.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Latchesar Ionkov