Commit Graph

70 Commits

Author SHA1 Message Date
Nick Piggin b74c79e993 fs: provide rcu-walk aware permission i_ops
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:29 +11:00
Nick Piggin fa0d7e3de6 fs: icache RCU free inodes
RCU free the struct inode. This will allow:

- Subsequent store-free path walking patch. The inode must be consulted for
  permissions when walking, so an RCU inode reference is a must.
- sb_inode_list_lock to be moved inside i_lock because sb list walkers who want
  to take i_lock no longer need to take sb_inode_list_lock to walk the list in
  the first place. This will simplify and optimize locking.
- Could remove some nested trylock loops in dcache code
- Could potentially simplify things a bit in VM land. Do not need to take the
  page lock to follow page->mapping.

The downsides of this is the performance cost of using RCU. In a simple
creat/unlink microbenchmark, performance drops by about 10% due to inability to
reuse cache-hot slab objects. As iterations increase and RCU freeing starts
kicking over, this increases to about 20%.

In cases where inode lifetimes are longer (ie. many inodes may be allocated
during the average life span of a single inode), a lot of this cache reuse is
not applicable, so the regression caused by this patch is smaller.

The cache-hot regression could largely be avoided by using SLAB_DESTROY_BY_RCU,
however this adds some complexity to list walking and store-free path walking,
so I prefer to implement this at a later date, if it is shown to be a win in
real situations. I haven't found a regression in any non-micro benchmark so I
doubt it will be a problem.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:26 +11:00
Prasad Joshi f06328d772 logfs: fix "Kernel BUG at readwrite.c:1193"
This happens when __logfs_create() tries to write a new inode to the disk
which is full.

__logfs_create() associates the transaction pointer with inode.  During
the logfs_write_inode() function call chain this transaction pointer is
moved from inode to page->private using function move_inode_to_page
(do_write_inode() -> inode_to_page() -> move_inode_to_page)

When the write inode fails, the transaction is aborted and iput is called
on the failed inode.  During delete_inode the same transaction pointer
associated with the page is getting used.  Thus causing kernel BUG.

The patch checks for error in write_inode() and restores the page->private
to NULL.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20162

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Joern Engel <joern@logfs.org>
Cc: Florian Mickler <florian@mickler.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-22 19:43:33 -08:00
Prasad Joshi eabb26cacd logfs: fix deadlock in logfs_get_wblocks, hold and wait on super->s_write_mutex
do_logfs_journal_wl_pass() should use GFP_NOFS for memory allocation GC
code calls btree_insert32 with GFP_KERNEL while holding a mutex
super->s_write_mutex.

The same mutex is used in address_space_operations->writepage(), and a
call to writepage() could be triggered as a result of memory allocation
in btree_insert32, causing a deadlock.

Addresses https://bugzilla.kernel.org/show_bug.cgi?id=20342

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Cc: Joern Engel <joern@logfs.org>
Cc: Florian Mickler <florian@mickler.org>
Cc: "Rafael J. Wysocki" <rjw@sisk.pl>
Cc: Maciej Rutecki <maciej.rutecki@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-12-22 19:43:33 -08:00
Paul Mundt e99d11d199 fs: logfs: Fix up MTD=y build.
Commit 7d945a3aa7 ("logfs get_sb, part 3") broke the logfs build when
CONFIG_MTD is set due to a mangled logfs_get_sb_mtd() definition.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-01 16:34:56 -04:00
Al Viro a1da9e8ab6 switch logfs to ->mount()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:51 -04:00
Al Viro e5a0726a95 logfs: fix a leak in get_sb
a) switch ->put_device() to logfs_super *
b) actually call it on early failures in logfs_get_sb_device()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:48 -04:00
Al Viro 7d945a3aa7 logfs get_sb, part 3
take logfs_get_sb_device() calls to logfs_get_sb() itself

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:46 -04:00
Al Viro 0d85c79962 logfs get_sb, part 2
take setting s_bdev/s_mtd/s_devops to callers of logfs_get_sb_device(),
don't bother passing them separately

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:43 -04:00
Al Viro 71a1c0125f logfs get_sb massage, part 1
move allocation of logfs_super to logfs_get_sb, pass it to
logfs_get_sb_...().

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:41 -04:00
Al Viro 7de9c6ee3e new helper: ihold()
Clones an existing reference to inode; caller must already hold one.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-25 21:26:11 -04:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Arnd Bergmann 02d6d685fc logfs: kill BKL
logfs does not need the BKL, so use ->unlocked_ioctl instead
of ->ioctl in file operations.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Joern Engel <joern@logfs.org>
[ fixed trivial conflict ]
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-08-14 00:24:24 +02:00
Al Viro 45321ac543 Make ->drop_inode() just return whether inode needs to be dropped
... and let iput_final() do the actual eviction or retention

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:35 -04:00
Al Viro 7da08fd17a convert logfs to ->evict_inode()
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:28 -04:00
Al Viro 8e22c1a4e4 logfs: get rid of magical inodes
ordering problems at ->kill_sb() time are solved by doing iput()
of these suckers in ->put_super()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:48:26 -04:00
Christoph Hellwig db78b877f7 always call inode_change_ok early in ->setattr
Make sure we call inode_change_ok before doing any changes in ->setattr,
and make sure to call it even if our fs wants to ignore normal UNIX
permissions, but use the ATTR_FORCE to skip those.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:38 -04:00
Christoph Hellwig 1025774ce4 remove inode_setattr
Replace inode_setattr with opencoded variants of it in all callers.  This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.

In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:

 spufs: explicitly checks for ATTR_SIZE earlier
 btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
 ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above

In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:37 -04:00
Al Viro 256249584b fix leak in __logfs_create()
if kmalloc fails, we still need to drop the inode, as we do
on other failure exits.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-09 16:47:28 -04:00
Christoph Hellwig 7ea8085910 drop unused dentry argument to ->fsync
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-27 22:05:02 -04:00
Al Viro ab9a79b966 logfs: replace inode uid,gid,mode initialization with helper function
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-21 18:31:27 -04:00
Linus Torvalds f39d01be4c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (44 commits)
  vlynq: make whole Kconfig-menu dependant on architecture
  add descriptive comment for TIF_MEMDIE task flag declaration.
  EEPROM: max6875: Header file cleanup
  EEPROM: 93cx6: Header file cleanup
  EEPROM: Header file cleanup
  agp: use NULL instead of 0 when pointer is needed
  rtc-v3020: make bitfield unsigned
  PCI: make bitfield unsigned
  jbd2: use NULL instead of 0 when pointer is needed
  cciss: fix shadows sparse warning
  doc: inode uses a mutex instead of a semaphore.
  uml: i386: Avoid redefinition of NR_syscalls
  fix "seperate" typos in comments
  cocbalt_lcdfb: correct sections
  doc: Change urls for sparse
  Powerpc: wii: Fix typo in comment
  i2o: cleanup some exit paths
  Documentation/: it's -> its where appropriate
  UML: Fix compiler warning due to missing task_struct declaration
  UML: add kernel.h include to signal.c
  ...
2010-05-20 09:20:59 -07:00
Linus Torvalds 7d32c0aca4 Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
  logfs: handle powerfail on NAND flash
  logfs: handle errors from get_mtd_device()
  logfs: remove unused variable
  logfs: fix sync
  logfs: fix compile failure
  logfs: initialize li->li_refcount
  logfs: commit reservations under space pressure
  logfs: survive logfs_buf_recover read errors
  logfs: Close i_ino reuse race
  logfs: fix logfs_seek_hole()
  logfs: Return -EINVAL if filesystem image doesn't match
  LogFS: Fix typo in b6349ac8
  logfs: testing the wrong variable
2010-05-17 13:53:35 -07:00
Al Viro 265624495f Fix double-free in logfs
iput() is needed *until* we'd done successful d_alloc_root()

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-05-15 07:16:33 -04:00
Anand Gadiyar a8cd4561ea fix "seperate" typos in comments
s/seperate/separate

Signed-off-by: Anand Gadiyar <gadiyar@ti.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-05-10 11:56:30 +02:00
Joern Engel 6f485b4187 logfs: handle powerfail on NAND flash
The write buffer may not have been written and may no longer be written
due to an interrupted write in the affected page.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-07 19:38:40 +02:00
Dan Carpenter ccf31c10f1 logfs: handle errors from get_mtd_device()
The get_mtd_device() function returns error pointers on failure and if we
don't handle it, it leads to a crash.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-07 14:16:09 +02:00
Joern Engel 58e323cf5e logfs: remove unused variable
Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-07 14:15:04 +02:00
Joern Engel c0c79c31c9 logfs: fix sync
Rather self-explanatory.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-05 22:33:36 +02:00
Joern Engel bba0b5c2c2 logfs: fix compile failure
When CONFIG_BLOCK is not enabled:

fs/logfs/super.c:142: error: implicit declaration of function 'bdev_get_queue'
fs/logfs/super.c:142: error: invalid type argument of '->' (have 'int')

Found by Randy Dunlap <randy.dunlap@oracle.com>

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-05 22:32:52 +02:00
Prasad Joshi 24797535e1 logfs: initialize li->li_refcount
li_refcount was not re-initialized in function logfs_init_inode(), small
patch that will fix the problem

Signed-off-by: Prasad Joshi <prasadjoshi124@gmail.com>
Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-04 22:17:08 +02:00
Joern Engel 05ebad8529 logfs: commit reservations under space pressure
Ensures we only return -ENOSPC when there really is no space.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-04 19:41:09 +02:00
Joern Engel 20503664b0 logfs: survive logfs_buf_recover read errors
Refusing to mount beats a kernel crash.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-04 19:37:04 +02:00
Joern Engel ccc0197b02 logfs: Close i_ino reuse race
logfs_seek_hole() may return the same offset it is passed as argument.
Found by Prasad Joshi <prasadjoshi124@gmail.com>

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-01 18:02:34 +02:00
Joern Engel bd2b3f2959 logfs: fix logfs_seek_hole()
logfs_seek_hole(inode, 0x200) would crap itself if the inode contained
just 0x1ff (or fewer) blocks.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-01 18:02:30 +02:00
Joern Engel ad342631f1 logfs: Return -EINVAL if filesystem image doesn't match
Signed-off-by: Joern Engel <joern@logfs.org>
2010-05-01 18:02:20 +02:00
Joern Engel 2e531fa0d0 LogFS: Fix typo in b6349ac8
Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-29 15:19:28 +02:00
Dan Carpenter 3272c8a57b logfs: testing the wrong variable
There is a typo here.  We should test "last" instead of "first".

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-29 15:19:27 +02:00
Linus Torvalds 255f41c595 Merge git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs
* git://git.kernel.org/pub/scm/linux/kernel/git/joern/logfs:
  [LogFS] Split large truncated into smaller chunks
  [LogFS] Set s_bdi
  [LogFS] Prevent mempool_destroy NULL pointer dereference
  [LogFS] Move assertion
  [LogFS] Plug 8 byte information leak
  [LogFS] Prevent memory corruption on large deletes
  [LogFS] Remove unused method

Fix trivial conflict with added header includes in fs/logfs/super.c
2010-04-21 12:31:12 -07:00
Joern Engel b6349ac89e [LogFS] Split large truncated into smaller chunks
Truncate would do an almost limitless amount of work without invoking
the garbage collector in between.  Split it up into more manageable,
though still large, chunks.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-20 21:44:10 +02:00
Joern Engel b8639077ab [LogFS] Set s_bdi
Since 32a88aa1 sync() was turned into a NOP for logfs.  Worse, sync()
would not return an error, giving the illusion that writeout had
actually happened.

Afaics jffs2 was broken as well.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-17 19:54:27 +02:00
Joern Engel 1f1b0008e8 [LogFS] Prevent mempool_destroy NULL pointer dereference
It would probably be better to just accept NULL pointers in
mempool_destroy().  But for the current -rc series let's keep things
simple.

This patch was lost in the cracks for a while.
Kevin Cernekee <cernekee@gmail.com> had to rediscover the problem and
send a similar patch because of it. :(

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-15 08:03:57 +02:00
Joern Engel ead88af5f5 [LogFS] Move assertion
The assertion is valid independently of the condition.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13 17:57:21 +02:00
Joern Engel d3a03f8031 [LogFS] Plug 8 byte information leak
Within each journal segment, 8 bytes at offset 24 would remain
uninitialized.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13 17:54:27 +02:00
Joern Engel 032d8f7268 [LogFS] Prevent memory corruption on large deletes
Removing sufficiently large files would create aliases for a large
number of segments.  This in turn results in a large number of journal
entries and an overflow of s_je_array.

Cheap fix is to add a BUG_ON, turning memory corruption into something
annoying, but less dangerous.  Real fix is to count the number of
affected segments and prevent the problem completely.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-04-13 17:46:37 +02:00
Tejun Heo 336f5899d2 Merge branch 'master' into export-slabh 2010-04-05 11:37:28 +09:00
Joern Engel e05c378f49 [LogFS] Remove unused method
All callers are long gone.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-30 18:25:17 +02:00
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00
Joern Engel 6be7fa06eb [LogFS] Erase new journal segments
If the device contains on old logfs image and the journal is moved to
segment that have never been used by the current logfs and not all
journal segments are erased before the next mount, the old content can
confuse mount code.  To prevent this, always erase the new journal
segments.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-29 21:14:52 +02:00
Joern Engel 0943846ae0 [LogFS] Move reserved segments with journal
Fixes a GC livelock.

Signed-off-by: Joern Engel <joern@logfs.org>
2010-03-29 21:13:28 +02:00