30 Apr, 2008
40 commits
-
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__FUNCTION__ is gcc specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This patch adds partition management for Block RAM Device (BRD).
This patch is done to keep in sync BRD and loop device drivers.
This patch adds a parameter to the module, max_part, to specify
the maximum number of partitions per RAM device.Example:
# modprobe brd max_part=63
# ls -l /dev/ram*
brw-rw---- 1 root disk 1, 0 2008-04-03 13:39 /dev/ram0
brw-rw---- 1 root disk 1, 64 2008-04-03 13:39 /dev/ram1
brw-rw---- 1 root disk 1, 640 2008-04-03 13:39 /dev/ram10
brw-rw---- 1 root disk 1, 704 2008-04-03 13:39 /dev/ram11
brw-rw---- 1 root disk 1, 768 2008-04-03 13:39 /dev/ram12
brw-rw---- 1 root disk 1, 832 2008-04-03 13:39 /dev/ram13
brw-rw---- 1 root disk 1, 896 2008-04-03 13:39 /dev/ram14
brw-rw---- 1 root disk 1, 960 2008-04-03 13:39 /dev/ram15
brw-rw---- 1 root disk 1, 128 2008-04-03 13:39 /dev/ram2
brw-rw---- 1 root disk 1, 192 2008-04-03 13:39 /dev/ram3
brw-rw---- 1 root disk 1, 256 2008-04-03 13:39 /dev/ram4
brw-rw---- 1 root disk 1, 320 2008-04-03 13:39 /dev/ram5
brw-rw---- 1 root disk 1, 384 2008-04-03 13:39 /dev/ram6
brw-rw---- 1 root disk 1, 448 2008-04-03 13:39 /dev/ram7
brw-rw---- 1 root disk 1, 512 2008-04-03 13:39 /dev/ram8
brw-rw---- 1 root disk 1, 576 2008-04-03 13:39 /dev/ram9
# fdisk /dev/ram0
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): o
Building a new DOS disklabel. Changes will remain in memory only,
until you decide to write them. After that, of course, the previous
content won't be recoverable.Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-2, default 1): 1
Last cylinder or +size or +sizeM or +sizeK (1-2, default 2): 2Command (m for help): w
The partition table has been altered!Calling ioctl() to re-read partition table.
Syncing disks.
# ls -l /dev/ram0*
brw-rw---- 1 root disk 1, 0 2008-04-03 13:40 /dev/ram0
brw-rw---- 1 root disk 1, 1 2008-04-03 13:40 /dev/ram0p1
# mkfs /dev/ram0p1
mke2fs 1.40-WIP (14-Nov-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
4016 inodes, 16032 blocks
801 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=16515072
2 block groups
8192 blocks per group, 8192 fragments per group
2008 inodes per group
Superblock backups stored on blocks:
8193Writing inode tables: done
Writing superblocks and filesystem accounting information: doneThis filesystem will be automatically checked every 26 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
# mount /dev/ram0p1 /mnt
df /mnt
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/ram0p1 15521 138 14582 1% /mnt
# ls -l /mnt
total 12
drwx------ 2 root root 12288 2008-04-03 13:41 lost+found
# umount /mnt
# rmmod brdSigned-off-by: Laurent Vivier
Acked-by: Nick Piggin
Cc: Al Viro
Cc: Jens Axboe
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
hrtimers have now dynamic users in the network code. Put them under
debugobjects surveillance as well.Add calls to the generic object debugging infrastructure and provide fixup
functions which allow to keep the system alive when recoverable problems have
been detected by the object debugging core code.Signed-off-by: Thomas Gleixner
Cc: Greg KH
Cc: Randy Dunlap
Cc: Kay Sievers
Cc: Ingo Molnar
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add calls to the generic object debugging infrastructure and provide fixup
functions which allow to keep the system alive when recoverable problems have
been detected by the object debugging core code.Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Cc: Greg KH
Cc: Randy Dunlap
Cc: Kay Sievers
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a DocBook for debugobjects.
Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Cc: Greg KH
Cc: Randy Dunlap
Cc: Kay Sievers
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
We can see an ever repeating problem pattern with objects of any kind in the
kernel:1) freeing of active objects
2) reinitialization of active objectsBoth problems can be hard to debug because the crash happens at a point where
we have no chance to decode the root cause anymore. One problem spot are
kernel timers, where the detection of the problem often happens in interrupt
context and usually causes the machine to panic.While working on a timer related bug report I had to hack specialized code
into the timer subsystem to get a reasonable hint for the root cause. This
debug hack was fine for temporary use, but far from a mergeable solution due
to the intrusiveness into the timer code.The code further lacked the ability to detect and report the root cause
instantly and keep the system operational.Keeping the system operational is important to get hold of the debug
information without special debugging aids like serial consoles and special
knowledge of the bug reporter.The problems described above are not restricted to timers, but timers tend to
expose it usually in a full system crash. Other objects are less explosive,
but the symptoms caused by such mistakes can be even harder to debug.Instead of creating specialized debugging code for the timer subsystem a
generic infrastructure is created which allows developers to verify their code
and provides an easy to enable debug facility for users in case of trouble.The debugobjects core code keeps track of operations on static and dynamic
objects by inserting them into a hashed list and sanity checking them on
object operations and provides additional checks whenever kernel memory is
freed.The tracked object operations are:
- initializing an object
- adding an object to a subsystem list
- deleting an object from a subsystem listEach operation is sanity checked before the operation is executed and the
subsystem specific code can provide a fixup function which allows to prevent
the damage of the operation. When the sanity check triggers a warning message
and a stack trace is printed.The list of operations can be extended if the need arises. For now it's
limited to the requirements of the first user (timers).The core code enqueues the objects into hash buckets. The hash index is
generated from the address of the object to simplify the lookup for the check
on kfree/vfree. Each bucket has it's own spinlock to avoid contention on a
global lock.The debug code can be compiled in without being active. The runtime overhead
is minimal and could be optimized by asm alternatives. A kernel command line
option enables the debugging code.Thanks to Ingo Molnar for review, suggestions and cleanup patches.
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Cc: Greg KH
Cc: Randy Dunlap
Cc: Kay Sievers
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This is a preperatory patch for the debugobjects infrastructure. The flag
prevents debug_free checks on kmem_caches. This is necessary to avoid
resursive calls into a debug mechanism which uses a kmem_cache itself.Signed-off-by: Thomas Gleixner
Acked-by: Ingo Molnar
Cc: Pekka Enberg
Cc: Christoph Lameter
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
__FUNCTION__ is gcc-specific, use __func__
Signed-off-by: Harvey Harrison
Cc: Ben Dooks
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Also, change the variable names used in the min/max macros to avoid shadowed
variable warnings when min/max min_t/max_t are nested.Small formatting changes to make all the macros have a similar form.
[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix v4l build]
Signed-off-by: Harvey Harrison
Cc: Mauro Carvalho Chehab
Signed-off-by: Andrew Morton
Cc: Bartlomiej Zolnierkiewicz
Cc: Jeff Garzik
Cc: Tejun Heo
Cc: Michael Buesch
Cc: "John W. Linville"
Cc: Miklos Szeredi
Cc: Dmitry Torokhov
Cc: Jiri Kosina
Cc: Arnaldo Carvalho de Melo
Cc: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use kmem_cache_zalloc(), remove large amounts of initialisation code and
ifdeffery.Note: this assumes that memset(*atomic_t, 0) correctly initialises the
atomic_t. This is true for all present archtiectures and if it becomes false
for a future architecture then we'll need to make large changes all over the
place anyway.Acked-by: David Howells
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
fs/hfsplus/btree.c: In function 'hfsplus_bmap_alloc':
fs/hfsplus/btree.c:239: warning: comparison is always false due to limited range of data typeBut this might hide a real bug?
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
fs/hfs/btree.c: In function 'hfs_bmap_alloc':
fs/hfs/btree.c:263: warning: comparison is always false due to limited range of data typeThe patch makes the warning go away, but the code might actually be buggy?
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix update_console_cmdline() not to to read beyond the terminating zero of its
name argument.Signed-off-by: Markus Armbruster
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This adds a minimalistic braille screen reader support. This is meant to
be used by blind people e.g. on boot failures or when / cannot be mounted
etc and thus the userland screen readers can not work.[akpm@linux-foundation.org: fix exports]
Signed-off-by: Samuel Thibault
Cc: Jiri Kosina
Cc: Dmitry Torokhov
Acked-by: Alan Cox
Cc: Randy Dunlap
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Lots of asm-*/futex.h call pagefault_enable and pagefault_disable, which
are declared in linux/uaccess.h, without including linux/uaccess.h.They all include asm/uaccess.h, so this patch replaces asm/uaccess.h
with linux/uaccess.h.Signed-off-by: Jeff Dike
Cc: "Luck, Tony"
Cc: Ralf Baechle
Cc: Kyle McMartin
Cc: Paul Mackerras
Cc: Benjamin Herrenschmidt
Cc: Paul Mundt
Cc: "David S. Miller"
Cc: Ingo Molnar
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
replace all:
big/little_endian_variable = cpu_to_[bl]eX([bl]eX_to_cpu(big/little_endian_variable) +
expression_in_cpu_byteorder);
with:
[bl]eX_add_cpu(&big/little_endian_variable, expression_in_cpu_byteorder);
generated with semantic patchSigned-off-by: Marcin Slusarz
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
replace all:
little_endian_variable = cpu_to_leX(leX_to_cpu(little_endian_variable) +
expression_in_cpu_byteorder);
with:
leX_add_cpu(&little_endian_variable, expression_in_cpu_byteorder);
generated with semantic patchSigned-off-by: Marcin Slusarz
Acked-by: Jan Kara
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
replace all:
big_endian_variable = cpu_to_beX(beX_to_cpu(big_endian_variable) +
expression_in_cpu_byteorder);
with:
beX_add_cpu(&big_endian_variable, expression_in_cpu_byteorder);
generated with semantic patchSigned-off-by: Marcin Slusarz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
replace all:
big_endian_variable = cpu_to_beX(beX_to_cpu(big_endian_variable) +
expression_in_cpu_byteorder);
with:
beX_add_cpu(&big_endian_variable, expression_in_cpu_byteorder);
generated with semantic patchSigned-off-by: Marcin Slusarz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Use the proper helper to open a blockdevice by name for filesystem use,
this makes sure it's properly claimed (also added for open-by-number) and
gets rid of the struct file abuse.Tested by mounting a reiserfs filesystem with external journal.
Signed-off-by: Christoph Hellwig
Cc: Chris Mason
Cc: Jeff Mahoney
Acked-by: Edward Shishkin
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
fs/fuse/dev.c:306:2: warning: context imbalance in 'wait_answer_interruptible' - unexpected unlock
fs/fuse/dev.c:361:2: warning: context imbalance in 'request_wait_answer' - unexpected unlock
fs/fuse/dev.c:1002:4: warning: context imbalance in 'end_io_requests' - unexpected unlockSigned-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fuse doesn't use i_mutex to protect setting i_size, and so
generic_file_llseek() can be racy: it doesn't use i_size_read().So do a fuse specific llseek method, which does use i_size_read().
[akpm@linux-foundation.org: make `retval' loff_t]
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Node ID is 64bit but it is passed as unsigned long to some functions. This
breakage wasn't noticed, because libfuse uses unsigned long too.Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fix a bug that Werner Baumann reported: fuse can send a bigger write request
than the maximum specified. This only affected direct_io operation.In addition set a sane minimum for the max_read and max_write tunables, so I/O
always makes some progress.Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
If the READ request returned a short count, then either
- cached size is incorrect
- filesystem is buggy, as short reads are only allowed on EOFSo assume that the size is wrong and refresh it, so that cached read() doesn't
zero fill the missing chunk.Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Introduce fuse_perform_write. With fusexmp (a passthrough filesystem), large
(1MB) writes into a backing tmpfs filesystem are sped up by almost 4 times
(256MB/s vs 71MB/s).[mszeredi@suse.cz]:
- split into smaller functions
- testing
- duplicate generic_file_aio_write(), so that there's no need to add a
new ->perform_write() a_op. Comment from hch.Signed-off-by: Nick Piggin
Signed-off-by: Miklos Szeredi
Cc: Christoph Hellwig
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Extract common code for setting i_size in write functions into a common
helper.Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Quoting Linus (3 years ago, FUSE inclusion discussions):
"User-space filesystems are hard to get right. I'd claim that they
are almost impossible, unless you limit them somehow (shared
writable mappings are the nastiest part - if you don't have those,
you can reasonably limit your problems by limiting the number of
dirty pages you accept through normal "write()" calls)."Instead of attempting the impossible, I've just waited for the dirty page
accounting infrastructure to materialize (thanks to Peter Zijlstra and
others). This nicely solved the biggest problem: limiting the number of pages
used for write caching.Some small details remained, however, which this largish patch attempts to
address. It provides a page writeback implementation for fuse, which is
completely safe against VM related deadlocks. Performance may not be very
good for certain usage patterns, but generally it should be acceptable.It has been tested extensively with fsx-linux and bash-shared-mapping.
Fuse page writeback design
--------------------------fuse_writepage() allocates a new temporary page with GFP_NOFS|__GFP_HIGHMEM.
It copies the contents of the original page, and queues a WRITE request to the
userspace filesystem using this temp page.The writeback is finished instantly from the MM's point of view: the page is
removed from the radix trees, and the PageDirty and PageWriteback flags are
cleared.For the duration of the actual write, the NR_WRITEBACK_TEMP counter is
incremented. The per-bdi writeback count is not decremented until the actual
write completes.On dirtying the page, fuse waits for a previous write to finish before
proceeding. This makes sure, there can only be one temporary page used at a
time for one cached page.This approach is wasteful in both memory and CPU bandwidth, so why is this
complication needed?The basic problem is that there can be no guarantee about the time in which
the userspace filesystem will complete a write. It may be buggy or even
malicious, and fail to complete WRITE requests. We don't want unrelated parts
of the system to grind to a halt in such cases.Also a filesystem may need additional resources (particularly memory) to
complete a WRITE request. There's a great danger of a deadlock if that
allocation may wait for the writepage to finish.Currently there are several cases where the kernel can block on page
writeback:- allocation order is larger than PAGE_ALLOC_COSTLY_ORDER
- page migration
- throttle_vm_writeout (through NR_WRITEBACK)
- sync(2)Of course in some cases (fsync, msync) we explicitly want to allow blocking.
So for these cases new code has to be added to fuse, since the VM is not
tracking writeback pages for us any more.As an extra safetly measure, the maximum dirty ratio allocated to a single
fuse filesystem is set to 1% by default. This way one (or several) buggy or
malicious fuse filesystems cannot slow down the rest of the system by hogging
dirty memory.With appropriate privileges, this limit can be raised through
'/sys/class/bdi//max_ratio'.Signed-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
A few fields in /proc/meminfo were not documented. Fix.
Signed-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fuse will use temporary buffers to write back dirty data from memory mappings
(normal writes are done synchronously). This is needed, because there cannot
be any guarantee about the time in which a write will complete.By using temporary buffers, from the MM's point if view the page is written
back immediately. If the writeout was due to memory pressure, this
effectively migrates data from a full zone to a less full zone.This patch adds a new counter (NR_WRITEBACK_TEMP) for the number of pages used
as temporary buffers.[Lee.Schermerhorn@hp.com: add vmstat_text for NR_WRITEBACK_TEMP]
Signed-off-by: Miklos Szeredi
Cc: Christoph Lameter
Signed-off-by: Lee Schermerhorn
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Fuse needs this for writable mmap support.
Signed-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add a new BDI capability flag: BDI_CAP_NO_ACCT_WB. If this flag is
set, then don't update the per-bdi writeback stats from
test_set_page_writeback() and test_clear_page_writeback().Misc cleanups:
- convert bdi_cap_writeback_dirty() and friends to static inline functions
- create a flag that includes all three dirty/writeback related flags,
since almst all users will want to have them toghetherSigned-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Move BDI statistics to debugfs:
/sys/kernel/debug/bdi//stats
Use postcore_initcall() to initialize the sysfs class and debugfs,
because debugfs is initialized in core_initcall().Update descriptions in ABI documentation.
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Add "max_ratio" to /sys/class/bdi. This indicates the maximum percentage of
the global dirty threshold allocated to this bdi.[mszeredi@suse.cz]
- fix parsing in max_ratio_store().
- export bdi_set_max_ratio() to modules
- limit bdi_dirty with bdi->max_ratio
- document new sysfs attributeSigned-off-by: Peter Zijlstra
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Under normal circumstances each device is given a part of the total write-back
cache that relates to its current avg writeout speed in relation to the other
devices.min_ratio - allows one to assign a minimum portion of the write-back cache to
a particular device. This is useful in situations where you might want to
provide a minimum QoS. (One request for this feature came from flash based
storage people who wanted to avoid writing out at all costs - they of course
needed some pdflush hacks as well)max_ratio - allows one to assign a maximum portion of the dirty limit to a
particular device. This is useful in situations where you want to avoid one
device taking all or most of the write-back cache. Eg. an NFS mount that is
prone to get stuck, or a FUSE mount which you don't trust to play fair.Add "min_ratio" to /sys/class/bdi. This indicates the minimum percentage of
the global dirty threshold allocated to this bdi.[mszeredi@suse.cz]
- fix parsing in min_ratio_store()
- document new sysfs attributeSigned-off-by: Peter Zijlstra
Signed-off-by: Miklos Szeredi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
Register FUSE's backing_dev_info under sysfs with the name "fuse-MAJOR:MINOR"
Make the fuse control filesystem use s_dev instead of a fuse specific ID.
This makes it easier to match directories under /sys/fs/fuse/connections/ with
directories under /sys/class/bdi, and with actual mounts.Signed-off-by: Miklos Szeredi
Cc: Peter Zijlstra
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
