Commit Graph

194 Commits

Author SHA1 Message Date
Steven Whitehouse
ff7f4cb461 GFS2: Consolidate free block searching functions
With the recently added block reservation code, an additional function
was added to search for free blocks. This had a restriction of only being
able to search for aligned extents of free blocks. As a result the
allocation patterns when reserving blocks were suboptimal when the
existing allocation of blocks for an inode was not aligned to the same
boundary.

This patch resolves that problem by adding the ability for gfs2_rbm_find
to search for extents of a particular minimum size. We can then use
gfs2_rbm_find for both looking for reservations, and also looking for
free blocks on an individual basis when we actually come to do the
allocation later on. As a result we only need a single set of code
to deal with both situations.

The function gfs2_rbm_from_block() is moved up rgrp.c so that it
occurs before all of its callers.

Many thanks are due to Bob for helping track down the final issue in
this patch. That fix to the rb_tree traversal and to not share
block reservations from a dirctory to its children is included here.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
2012-09-24 10:47:26 +01:00
Steven Whitehouse
71f890f7f7 GFS2: Remove rs_requested field from reservations
The rs_requested field is left over from the original allocation
code, however this should have been a parameter passed to the
various functions from gfs2_inplace_reserve() and not a member of the
reservation structure as the value is not required after the
initial allocation.

This also helps simplify the code since we no longer need to set
the rs_requested to zero. Also the gfs2_inplace_release()
function can also be simplified since the reservation structure
will always be defined when it is called, and the only remaining
task is to unlock the rgrp if required. It can also now be
called unconditionally too, resulting in a further simplification.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-24 10:46:54 +01:00
Steven Whitehouse
645b2ccc75 GFS2: Fix missing allocation data for set/remove xattr
These entry points were missed in the original patch to allocate
this data structure.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-09-13 10:30:34 +01:00
Linus Torvalds
801b03653f Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw
Pull GFS2 updates from Steven Whitehouse.

* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: Eliminate 64-bit divides
  GFS2: Reduce file fragmentation
  GFS2: kernel panic with small gfs2 filesystems - 1 RG
  GFS2: Fixing double brelse'ing bh allocated in gfs2_meta_read when EIO occurs
  GFS2: Combine functions get_local_rgrp and gfs2_inplace_reserve
  GFS2: Add kobject release method
  GFS2: Size seq_file buffer more carefully
  GFS2: Use seq_vprintf for glocks debugfs file
  seq_file: Add seq_vprintf function and export it
  GFS2: Use lvbs for storing rgrp information with mount option
  GFS2: Cache last hash bucket for glock seq_files
  GFS2: Increase buffer size for glocks and glstats debugfs files
  GFS2: Fix error handling when reading an invalid block from the journal
  GFS2: Add "top dir" flag support
  GFS2: Fold quota data into the reservations struct
  GFS2: Extend the life of the reservations
2012-07-24 17:57:05 -07:00
Bob Peterson
8e2e004735 GFS2: Reduce file fragmentation
This patch reduces GFS2 file fragmentation by pre-reserving blocks. The
resulting improved on disk layout greatly speeds up operations in cases
which would have resulted in interlaced allocation of blocks previously.
A typical example of this is 10 parallel dd processes, each writing to a
file in a common dirctory.

The implementation uses an rbtree of reservations attached to each
resource group (and each inode).

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-07-19 14:51:08 +01:00
Al Viro
ebfc3b49a7 don't pass nameidata to ->create()
boolean "does it have to be exclusive?" flag is passed instead;
Local filesystem should just ignore it - the object is guaranteed
not to be there yet.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:47 +04:00
Al Viro
00cd8dd3bf stop passing nameidata to ->lookup()
Just the flags; only NFS cares even about that, but there are
legitimate uses for such argument.  And getting rid of that
completely would require splitting ->lookup() into a couple
of methods (at least), so let's leave that alone for now...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-14 16:34:32 +04:00
Bob Peterson
5407e24229 GFS2: Fold quota data into the reservations struct
This patch moves the ancillary quota data structures into the
block reservations structure. This saves GFS2 some time and
effort in allocating and deallocating the qadata structure.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06 11:20:22 +01:00
Bob Peterson
0a305e4960 GFS2: Extend the life of the reservations
This patch lengthens the lifespan of the reservations structure for
inodes. Before, they were allocated and deallocated for every write
operation. With this patch, they are allocated when the first write
occurs, and deallocated when the last process closes the file.
It's more efficient to do it this way because it saves GFS2 a lot of
unnecessary allocates and frees. It also gives us more flexibility
for the future: (1) we can now fold the qadata structure back into
the structure and save those alloc/frees, (2) we can use this for
multi-block reservations.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-06-06 11:17:59 +01:00
Bob Peterson
5e2f7d617b GFS2: Make sure rindex is uptodate before starting transactions
This patch removes the call from gfs2_blk2rgrd to function
gfs2_rindex_update and replaces it with individual calls.
The former way turned out to be too problematic.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-04-05 10:20:10 +01:00
Steven Whitehouse
66fc061bda GFS2: FITRIM ioctl support
The FITRIM ioctl provides an alternative way to send discard requests to
the underlying device. Using the discard mount option results in every
freed block generating a discard request to the block device. This can
be slow, since many block devices can only process discard requests of
larger sizes, and also such operations can be time consuming.

Rather than using the discard mount option, FITRIM allows a sweep of the
filesystem on an occasional basis, and also to optionally avoid sending
down discard requests for smaller regions.

In GFS2 FITRIM will work at resource group granularity. There is a flag
for each resource group which keeps track of which resource groups have
been trimmed. This flag is reset whenever a deallocation occurs in the
resource group, and set whenever a successful FITRIM of that resource
group has taken place. This helps to reduce repeated discard requests
for the same block ranges, again improving performance.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 17:10:21 +00:00
Steven Whitehouse
a365fbf354 GFS2: Read resource groups on mount
This makes mount take slightly longer, but at the same time, the first
write to the filesystem will be faster too. It also means that if there
is a problem in the resource index, then we can refuse to mount rather
than having to try and report that when the first write occurs.

In addition, to avoid recursive locking, we hvae to take account of
instances when the rindex glock may already be held when we are
trying to update the rbtree of resource groups.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 09:52:39 +00:00
Bob Peterson
718b97bd6b GFS2: Read in rindex if necessary during unlink
This patch fixes a problem whereby you were unable to delete
files until other file system operations were done (such as
statfs, touch, writes, etc.) that caused the rindex to be
read in.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-02-28 09:48:02 +00:00
Steven Whitehouse
66ad863b41 GFS2: Fix nlink setting on inode creation
Since the nlink count will be 0, we need to use set_nlink rather
than inc_nlink in order to avoid triggering the inc_nlink warning
which was added recently.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2012-01-11 12:35:05 +00:00
Linus Torvalds
1619ed8f60 Merge git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-3.0-nmw:
  GFS2: local functions should be static
  GFS2: We only need one ACL getting function
  GFS2: Fix multi-block allocation
  GFS2: decouple quota allocations from block allocations
  GFS2: split function rgblk_search
  GFS2: Fix up "off by one" in the previous patch
  GFS2: move toward a generic multi-block allocator
  GFS2: O_(D)SYNC support for fallocate
  GFS2: remove vestigial al_alloced
  GFS2: combine gfs2_alloc_block and gfs2_alloc_di
  GFS2: Add non-try locks back to get_local_rgrp
  GFS2: f_ra is always valid in dir readahead function
  GFS2: Fix very unlikley memory leak in ACL xattr code
  GFS2: More automated code analysis fixes
  GFS2: Add readahead to sequential directory traversal
  GFS2: Fix up REQ flags
2012-01-08 13:07:54 -08:00
Al Viro
175a4eb7ea fs: propagate umode_t, misc bits
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:55:10 -05:00
Al Viro
1a67aafb5f switch ->mknod() to umode_t
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:54 -05:00
Al Viro
4acdaf27eb switch ->create() to umode_t
vfs_create() ignores everything outside of 16bit subset of its
mode argument; switching it to umode_t is obviously equivalent
and it's the only caller of the method

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:53 -05:00
Al Viro
18bb1db3e7 switch vfs_mkdir() and ->mkdir() to umode_t
vfs_mkdir() gets int, but immediately drops everything that might not
fit into umode_t and that's the only caller of ->mkdir()...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:53 -05:00
H Hartley Sweeten
46cc1e5fce GFS2: local functions should be static
Quiets the sparse noise:

warning: symbol 'gfs2_initxattrs' was not declared. Should it be static?

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Steven Whitehouse <swhiteho@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-12-06 09:46:41 +00:00
Steven Whitehouse
6a8099ed56 GFS2: Fix multi-block allocation
Clean up gfs2_alloc_blocks so that it takes the full extent length
rather than just the number of non-inode blocks as an argument. That
will only make a difference in the inode allocation case for now.

Also, this fixes the extent length handling around gfs2_alloc_extent() so
that multi block allocations will work again.

The rd_last_alloc block is set to the final block in the allocated
extent (as per the update to i_goal, but referenced to a different
start point).

This also removes the dinode argument to rgblk_search() which is no
longer used.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-22 12:18:51 +00:00
Bob Peterson
564e12b115 GFS2: decouple quota allocations from block allocations
This patch separates the code pertaining to allocations into two
parts: quota-related information and block reservations.
This patch also moves all the block reservation structure allocations to
function gfs2_inplace_reserve to simplify the code, and moves
the frees to function gfs2_inplace_release.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-22 10:25:21 +00:00
Bob Peterson
6e87ed0fc9 GFS2: move toward a generic multi-block allocator
This patch is a revision of the one I previously posted.
I tried to integrate all the suggestions Steve gave.
The purpose of the patch is to change function gfs2_alloc_block
(allocate either a dinode block or an extent of data blocks)
to a more generic gfs2_alloc_blocks function that can
allocate both a dinode _and_ an extent of data blocks in the
same call. This will ultimately help us create a multi-block
reservation scheme to reduce file fragmentation.

This patch moves more toward a generic multi-block allocator that
takes a pointer to the number of data blocks to allocate, plus whether
or not to allocate a dinode. In theory, it could be called to allocate
(1) a single dinode block, (2) a group of one or more data blocks, or
(3) a dinode plus several data blocks.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-21 10:04:09 +00:00
Bob Peterson
3c5d785acf GFS2: combine gfs2_alloc_block and gfs2_alloc_di
GFS2 functions gfs2_alloc_block and gfs2_alloc_di do basically
the same things, with a few exceptions. This patch combines
the two functions into a slightly more generic gfs2_alloc_block.
Having one centralized block allocation function will reduce
code redundancy and make it easier to implement multi-block
reservations to reduce file fragmentation in the future.

Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-15 15:25:03 +00:00
Steven Whitehouse
87654896ca GFS2: More automated code analysis fixes
A potentially uninitialised variable, some unreachable code,
and the main part of this, fixing the error path in the
unlink function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-11-08 14:04:20 +00:00
Linus Torvalds
f793f29611 Merge http://sucs.org/~rohan/git/gfs2-3.0-nmw
* http://sucs.org/~rohan/git/gfs2-3.0-nmw: (24 commits)
  GFS2: Move readahead of metadata during deallocation into its own function
  GFS2: Remove two unused variables
  GFS2: Misc fixes
  GFS2: rewrite fallocate code to write blocks directly
  GFS2: speed up delete/unlink performance for large files
  GFS2: Fix off-by-one in gfs2_blk2rgrpd
  GFS2: Clean up ->page_mkwrite
  GFS2: Correctly set goal block after allocation
  GFS2: Fix AIL flush issue during fsync
  GFS2: Use cached rgrp in gfs2_rlist_add()
  GFS2: Call do_strip() directly from recursive_scan()
  GFS2: Remove obsolete assert
  GFS2: Cache the most recently used resource group in the inode
  GFS2: Make resource groups "append only" during life of fs
  GFS2: Use rbtree for resource groups and clean up bitmap buffer ref count scheme
  GFS2: Fix lseek after SEEK_DATA, SEEK_HOLE have been added
  GFS2: Clean up gfs2_create
  GFS2: Use ->dirty_inode()
  GFS2: Fix bug trap and journaled data fsync
  GFS2: Fix inode allocation error path
  ...
2011-10-28 10:44:50 -07:00
Steven Whitehouse
54335b1fca GFS2: Cache the most recently used resource group in the inode
This means that after the initial allocation for any inode, the
last used resource group is cached in the inode for future use.
This drastically reduces the number of lookups of resource
groups in the common case, and this the contention on that
data structure.

The allocation algorithm is the same as previously, except that we
always check to see if the goal block is within the cached rgrp
first before going to the rbtree to look one up.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:34 +01:00
Steven Whitehouse
8339ee543e GFS2: Make resource groups "append only" during life of fs
Since we have ruled out supporting online filesystem shrink,
it is possible to make the resource group list append only
during the life of a super block. This gives several benefits:

Firstly, we only need to read new rindex elements as they are added
rather than needing to reread the whole rindex file each time one
element is added.

Secondly, the rindex glock can be held for much shorter periods of
time, and is completely removed from the fast path for allocations.
The lock is taken in shared mode only when updating the resource
groups when the first allocation occurs, and after a grow has
taken place.

Thirdly, this results in a reduction in code size, and everything
gets a lot simpler to understand in this area.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:33 +01:00
Steven Whitehouse
9a63edd12b GFS2: Clean up gfs2_create
If we pass through knowledge of whether the creation is intended to be
exclusive or not, then we can deal with that in gfs2_create_inode
and remove one set of locking. Also this removes the loop in
gfs2_create and simplifies the code a bit.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:28 +01:00
Steven Whitehouse
ab9bbda020 GFS2: Use ->dirty_inode()
The aim of this patch is to use the newly enhanced ->dirty_inode()
super block operation to deal with atime updates, rather than
piggy backing that code into ->write_inode() as is currently
done.

The net result is a simplification of the code in various places
and a reduction of the number of gfs2_dinode_out() calls since
this is now implied by ->dirty_inode().

Some of the mark_inode_dirty() calls have been moved under glocks
in order to take advantage of then being able to avoid locking in
->dirty_inode() when we already have suitable locks.

One consequence is that generic_write_end() now correctly deals
with file size updates, so that we do not need a separate check
for that afterwards. This also, indirectly, means that fdatasync
should work correctly on GFS2 - the current code always syncs the
metadata whether it needs to or not.

Has survived testing with postmark (with and without atime) and
also fsx.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:26 +01:00
Steven Whitehouse
40ac218f52 GFS2: Fix inode allocation error path
If we have got far enough through the inode allocation code
path that an inode has already been allocated, then we must
call iput to dispose of it, if an error occurs during a
later part of the process. This will always be the final iput
since there will be no other references to the inode.

Unlike when the inode has been unlinked, its block state will
be GFS2_BLKST_INODE rather than GFS2_BLKST_UNLINKED so we need
to skip the test in ->evict_inode() for this one case in order
to ensure that it will be deallocated correctly. This patch adds
a new flag in order to ensure that this will happen correctly.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-10-21 12:39:23 +01:00
James Morris
5a2f3a02ae Merge branch 'next-evm' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/ima-2.6 into next
Conflicts:
	fs/attr.c

Resolve conflict manually.

Signed-off-by: James Morris <jmorris@namei.org>
2011-08-09 10:31:03 +10:00
Christoph Hellwig
4e34e719e4 fs: take the ACL checks to common code
Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-25 14:30:23 -04:00
Al Viro
6c673ab393 simplify gfs2_lookup()
d_splice_alias() will DTRT when given NULL or ERR_PTR

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 20:48:02 -04:00
Al Viro
10556cb21a ->permission() sanitizing: don't pass flags to ->permission()
not used by the instances anymore.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:24 -04:00
Al Viro
2830ba7f34 ->permission() sanitizing: don't pass flags to generic_permission()
redundant; all callers get it duplicated in mask & MAY_NOT_BLOCK and none of
them removes that bit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:22 -04:00
Al Viro
178ea73521 kill check_acl callback of generic_permission()
its value depends only on inode and does not change; we might as
well store it in ->i_op->check_acl and be done with that.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:16 -04:00
Mimi Zohar
9d8f13ba3f security: new security_inode_init_security API adds function callback
This patch changes the security_inode_init_security API by adding a
filesystem specific callback to write security extended attributes.
This change is in preparation for supporting the initialization of
multiple LSM xattrs and the EVM xattr.  Initially the callback function
walks an array of xattrs, writing each xattr separately, but could be
optimized to write multiple xattrs at once.

For existing security_inode_init_security() calls, which have not yet
been converted to use the new callback function, such as those in
reiserfs and ocfs2, this patch defines security_old_inode_init_security().

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
2011-07-18 12:29:38 -04:00
Steven Whitehouse
f2741d9898 GFS2: Move all locking inside the inode creation function
Now that there are no longer any exceptions to the normal inode
creation code path, we can move the parts of the locking code
which were duplicated in mkdir/mknod/create/symlink into the
inode create function.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-13 12:11:17 +01:00
Steven Whitehouse
160b4026dc GFS2: Clean up symlink creation
This moves the symlink specific parts of inode creation
into the function where we initialise the rest of the
dinode. As a result we have one less place where we need
to look up the inode's buffer.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-13 10:34:59 +01:00
Steven Whitehouse
e2d0a13bba GFS2: Clean up mkdir
This moves the initialisation of the directory into the inode
creation functions to avoid having to duplicate the lookup
of the inode's buffer.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-13 09:55:55 +01:00
Steven Whitehouse
2ab9cd1c63 GFS2: Rename ops_inode.c to inode.c
This is the final part of the ops_inode.c/inode.c reordering. We
are left with a single file called inode.c which now contains
all the inode operations, as expected.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-10 13:12:49 +01:00
Steven Whitehouse
64ea540258 GFS2: Inode.c is empty now, remove it
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-10 13:09:53 +01:00
Steven Whitehouse
9eed04cd99 GFS2: Move final part of inode.c into super.c
Now inode.c is empty.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-09 16:45:38 +01:00
Steven Whitehouse
194c011fc4 GFS2: Move most of the remaining inode.c into ops_inode.c
This is in preparation to remove inode.c and rename ops_inode.c
to inode.c. Also most of the functions which were left in inode.c
relate to the creation and lookup of inodes. I'm intending to work
on consolidating some of that code, and its easier when its all in
one place.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-09 16:45:14 +01:00
Steven Whitehouse
d4b2cf1b05 GFS2: Move gfs2_refresh_inode() and friends into glops.c
Eventually there will only be a single caller of this code, so lets
move it where it can be made static at some future date.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-09 16:44:49 +01:00
Steven Whitehouse
94fb763b1a GFS2: Remove gfs2_dinode_print() function
This function was intended for debugging purposes, but it is not very
useful. If we want to know what is on disk then all we need is a
block number and gfs2_edit can give us much better information about
what is there. Otherwise, if we are interested in what is stored in
the in-core inode, it doesn't help us out there either.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-09 16:44:29 +01:00
Steven Whitehouse
3d6ecb7d16 GFS2: When adding a new dir entry, inc link count if it is a subdir
This adds an increment of the link count when we add a new directory
entry, if that entry is itself a directory. This means that we no
longer need separate code to perform this operation.

Now that both adding and removing directory entries automatically
update the parent directory's link count if required, that makes
the code shorter and simpler than before.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-09 16:43:53 +01:00
Steven Whitehouse
d192a8e5c6 GFS2: Double check link count under glock
To avoid any possible races relating to the link count, we need to
recheck it under the inode's glock in all cases where it matters.
Also to ensure we never get any nasty surprises, this patch also
ensures that once the link count has hit zero it can never be
elevated by rereading in data from disk.

The only place we cannot provide a proper solution is in rename
in the case where we are removing a target inode and we discover
that the target inode has been already unlinked on another node.
The race window is very small, and we return EAGAIN in this case
to indicate what has happened. The proper solution would be to move
the lookup parts of rename from the vfs into library calls which
the fs could call directly, but that is potentially a very big job
and this fix should cover most cases for now.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-05-05 12:35:40 +01:00
Steven Whitehouse
4667a0ec32 GFS2: Make writeback more responsive to system conditions
This patch adds writeback_control to writing back the AIL
list. This means that we can then take advantage of the
information we get in ->write_inode() in order to set off
some pre-emptive writeback.

In addition, the AIL code is cleaned up a bit to make it
a bit simpler to understand.

There is still more which can usefully be done in this area,
but this is a good start at least.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
2011-04-20 09:01:37 +01:00