When we skip unrecognized options in xfs_fs_remount we should just break
out of the switch and not return because otherwise we may skip clearing
the xfs-internal read-only flag. This will only show up on some
operations like touch because most read-only checks are done by the VFS
which thinks this filesystem is r/w. Eventually we should replace the
XFS read-only flag with a helper that always checks the VFS flag to make
sure they can never get out of sync.
Bug reported and fix verified by Marcel Beister on #xfs.
Bug fix verified by updated xfstests/189.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Eric Sandeen <sandeen@sandeen.net>
Signed-off-by: Timothy Shimmin <tes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mfasheh/ocfs2: (56 commits)
ocfs2: Make cached block reads the common case.
ocfs2: Kill the last naked wait_on_buffer() for cached reads.
ocfs2: Move ocfs2_bread() into dir.c
ocfs2: Simplify ocfs2_read_block()
ocfs2: Require an inode for ocfs2_read_block(s)().
ocfs2: Separate out sync reads from ocfs2_read_blocks()
ocfs2: Refactor xattr list and remove ocfs2_xattr_handler().
ocfs2: Calculate EA hash only by its suffix.
ocfs2: Move trusted and user attribute support into xattr.c
ocfs2: Uninline ocfs2_xattr_name_hash()
ocfs2: Don't check for NULL before brelse()
ocfs2: use smaller counters in ocfs2_remove_xattr_clusters_from_cache
ocfs2: Documentation update for user_xattr / nouser_xattr mount options
ocfs2: make la_debug_mutex static
ocfs2: Remove pointless !!
ocfs2: Add empty bucket support in xattr.
ocfs2/xattr.c: Fix a bug when inserting xattr.
ocfs2: Add xattr mount option in ocfs2_show_options()
ocfs2: Switch over to JBD2.
ocfs2: Add the 'inode64' mount option.
...
The cache_change_attribute is used to decide whether or not a directory has
changed, in which case we may need to look it up again. Again, the use of
'jiffies' leads to an issue of resolution.
Once again, the fix is to change nfs_inode->cache_change_attribute, and
just make it a simple counter.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
It appears that 'jiffies' timestamps do not have high enough resolution for
nfs_inode_attrs_need_update(). One problem is that a GETATTR can be
launched within < 1 jiffy of the last operation that updated the attribute.
Another problem is that RPC calls can take < 1 jiffy to execute.
We can fix this by switching the variables to use a simple global counter
that gets incremented every time we start another GETATTR call.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux: (59 commits)
svcrdma: Fix IRD/ORD polarity
svcrdma: Update svc_rdma_send_error to use DMA LKEY
svcrdma: Modify the RPC reply path to use FRMR when available
svcrdma: Modify the RPC recv path to use FRMR when available
svcrdma: Add support to svc_rdma_send to handle chained WR
svcrdma: Modify post recv path to use local dma key
svcrdma: Add a service to register a Fast Reg MR with the device
svcrdma: Query device for Fast Reg support during connection setup
svcrdma: Add FRMR get/put services
NLM: Remove unused argument from svc_addsock() function
NLM: Remove "proto" argument from lockd_up()
NLM: Always start both UDP and TCP listeners
lockd: Remove unused fields in the nlm_reboot structure
lockd: Add helper to sanity check incoming NOTIFY requests
lockd: change nlmclnt_grant() to take a "struct sockaddr *"
lockd: Adjust nlmsvc_lookup_host() to accomodate AF_INET6 addresses
lockd: Adjust nlmclnt_lookup_host() signature to accomodate non-AF_INET
lockd: Support non-AF_INET addresses in nlm_lookup_host()
NLM: Convert nlm_lookup_host() to use a single argument
svcrdma: Add Fast Reg MR Data Types
...
ocfs2_read_blocks() currently requires the CACHED flag for cached I/O.
However, that's the common case. Let's flip it around and provide an
IGNORE_CACHE flag for the special users. This has the added benefit of
cleaning up the code some (ignore_cache takes on its special meaning
earlier in the loop).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2's cached buffer I/O goes through ocfs2_read_block(s)(). dir.c had
a naked wait_on_buffer() to wait for some readahead, but it should
use ocfs2_read_block() instead.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
dir.c is the only place using ocfs2_bread(), so let's make it static to
that file.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
More than 30 callers of ocfs2_read_block() pass exactly OCFS2_BH_CACHED.
Only six pass a different flag set. Rather than have every caller care,
let's make ocfs2_read_block() take no flags and always do a cached read.
The remaining six places can call ocfs2_read_blocks() directly.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Now that synchronous readers are using ocfs2_read_blocks_sync(), all
callers of ocfs2_read_blocks() are passing an inode. Use it
unconditionally. Since it's there, we don't need to pass the
ocfs2_super either.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The ocfs2_read_blocks() function currently handles sync reads, cached,
reads, and sometimes cached reads. We're going to add some
functionality to it, so first we should simplify it. The uncached,
synchronous reads are much easer to handle as a separate function, so we
instroduce ocfs2_read_blocks_sync().
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
According to Christoph Hellwig's advice, we really don't need
a ->list to handle one xattr's list. Just a map from index to
xattr prefix is enough. And I also refactor the old list method
with the reference from fs/xfs/linux-2.6/xfs_xattr.c and the
xattr list method in btrfs.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
According to Christoph Hellwig's advice, the hash value of EA
is only calculated by its suffix.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Per Christoph Hellwig's suggestion - don't split these up. It's not like we
gained much by having the two tiny files around.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
i and b_len don't really need to be u64's. Xattr extent lengths should be
limited by the VFS, and then the size of our on-disk length field.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
As Mark mentioned, it may be time-consuming when we remove the
empty xattr bucket, so this patch try to let empty bucket exist
in xattr operation. The modification includes:
1. Remove the functin of bucket and extent record deletion during
xattr delete.
2. In xattr set:
1) Don't clean the last entry so that if the bucket is empty,
the hash value of the bucket is the hash value of the entry
which is deleted last.
2) During insert, if we meet with an empty bucket, just use the
1st entry.
3. In binary search of xattr bucket, use the bucket hash value(which
stored in the 1st xattr entry) to find the right place.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
During the process of xatt insertion, we use binary search
to find the right place and "low" is set to it. But when
there is one xattr which has the same name hash as the inserted
one, low is the wrong value. So set it to the right position.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Patch adds check for [no]user_xattr in ocfs2_show_options() that completes
the list of all mount options.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 wants JBD2 for many reasons, not the least of which is that JBD is
limiting our maximum filesystem size.
It's a pretty trivial change. Most functions are just renamed. The
only functional change is moving to Jan's inode-based ordered data mode.
It's better, too.
Because JBD2 reads and writes JBD journals, this is compatible with any
existing filesystem. It can even interact with JBD-based ocfs2 as long
as the journal is formated for JBD.
We provide a compatibility option so that paranoid people can still use
JBD for the time being. This will go away shortly.
[ Moved call of ocfs2_begin_ordered_truncate() from ocfs2_delete_inode() to
ocfs2_truncate_for_delete(). --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Now that ocfs2 limits inode numbers to 32bits, add a mount option to
disable the limit. This parallels XFS. 64bit systems can handle the
larger inode numbers.
[ Added description of inode64 mount option in ocfs2.txt. --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2 inode numbers are block numbers. For any filesystem with less
than 2^32 blocks, this is not a problem. However, when ocfs2 starts
using JDB2, it will be able to support filesystems with more than 2^32
blocks. This would result in inode numbers higher than 2^32.
The problem is that stat(2) can't handle those numbers on 32bit
machines. The simple solution is to have ocfs2 allocate all inodes
below that boundary.
The suballoc code is changed to honor an optional block limit. Only the
inode suballocator sets that limit - all other allocations stay unlimited.
The biggest trick is to grow the inode suballocator beneath that limit.
There's no point in allocating block groups that are above the limit,
then rejecting their elements later on. We want to prevent the inode
allocator from ever having block groups above the limit. This involves
a little gyration with the local alloc code. If the local alloc window
is above the limit, it signals the caller to try the global bitmap but
does not disable the local alloc file (which can be used for other
allocations).
[ Minor cleanup - removed an ML_NOTICE comment. --Mark ]
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In ocfs2_xattr_free_block, we take a cluster lock on xb_alloc_inode while we
have a transaction open. This will deadlock the downconvert thread, so fix
it.
We can clean up how xattr blocks are removed while here - this patch also
moves the mechanism of releasing xattr block (including both value, xattr
tree and xattr block) into this function.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In ocfs2_extend_trans, when we can't extend the current
transaction, it will commit current transaction and restart
a new one. So if the previous credits we have allocated aren't
used(the block isn't dirtied before our extend), we will not
have enough credits for any future operation(it will cause jbd
complain and bug out). So check this and re-extend it.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The original get/put_extent_tree() functions held a reference on
et_root_bh. However, every single caller already has a safe reference,
making the get/put cycle irrelevant.
We change ocfs2_get_*_extent_tree() to ocfs2_init_*_extent_tree(). It
no longer gets a reference on et_root_bh. ocfs2_put_extent_tree() is
removed. Callers now have a simpler init+use pattern.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
struct ocfs2_extent_tree_operations provides methods for the different
on-disk btrees in ocfs2. Describing what those methods do is probably a
good idea.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
We now have three different kinds of extent trees in ocfs2: inode data
(dinode), extended attributes (xattr_tree), and extended attribute
values (xattr_value). There is a nice abstraction for them,
ocfs2_extent_tree, but it is hidden in alloc.c. All the calling
functions have to pick amongst a varied API and pass in type bits and
often extraneous pointers.
A better way is to make ocfs2_extent_tree a first-class object.
Everyone converts their object to an ocfs2_extent_tree() via the
ocfs2_get_*_extent_tree() calls, then uses the ocfs2_extent_tree for all
tree calls to alloc.c.
This simplifies a lot of callers, making for readability. It also
provides an easy way to add additional extent tree types, as they only
need to be defined in alloc.c with a ocfs2_get_<new>_extent_tree()
function.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
A couple places check an extent_tree for a valid inode. We move that
out to add an eo_insert_check() operation. It can be called from
ocfs2_insert_extent() and elsewhere.
We also have the wrapper calls ocfs2_et_insert_check() and
ocfs2_et_sanity_check() ignore NULL ops. That way we don't have to
provide useless operations for xattr types.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
A caller knows what kind of extent tree they have. There's no reason
they have to call ocfs2_get_extent_tree() with a NULL when they could
just as easily call a specific function to their type of extent tree.
Introduce ocfs2_dinode_get_extent_tree(),
ocfs2_xattr_tree_get_extent_tree(), and
ocfs2_xattr_value_get_extent_tree(). They only take the necessary
arguments, calling into the underlying __ocfs2_get_extent_tree() to do
the real work.
__ocfs2_get_extent_tree() is the old ocfs2_get_extent_tree(), but
without needing any switch-by-type logic.
ocfs2_get_extent_tree() is now a wrapper around the specific calls. It
exists because a couple alloc.c functions can take et_type. This will
go later.
Another benefit is that ocfs2_xattr_value_get_extent_tree() can take a
struct ocfs2_xattr_value_root* instead of void*. This gives us
typechecking where we didn't have it before.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Provide an optional extent_tree_operation to specify the
max_leaf_clusters of an ocfs2_extent_tree. If not provided, the value
is 0 (unlimited).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2_num_free_extents() re-implements the logic of
ocfs2_get_extent_tree(). Now that ocfs2_get_extent_tree() does not
allocate, let's use it in ocfs2_num_free_extents() to simplify the code.
The inode validation code in ocfs2_num_free_extents() is not needed.
All callers are passing in pre-validated inodes.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The root_el of an ocfs2_extent_tree needs to be calculated from
et->et_object. Make it an operation on et->et_ops.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The 'private' pointer was a way to store off xattr values, which don't
live at a set place in the bh. But the concept of "the object
containing the extent tree" is much more generic. For an inode it's the
struct ocfs2_dinode, for an xattr value its the value. Let's save off
the 'object' at all times. If NULL is passed to
ocfs2_get_extent_tree(), 'object' is set to bh->b_data;
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Rather than allocating a struct ocfs2_extent_tree, just put it on the
stack. Fill it with ocfs2_get_extent_tree() and drop it with
ocfs2_put_extent_tree(). Now the callers don't have to ENOMEM, yet
still safely ref the root_bh.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The members of the ocfs2_extent_tree structure gain a prefix of 'et_'.
All users are updated.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The ocfs2_extent_tree_operations structure gains a field prefix on its
members. The ->eo_sanity_check() operation gains a wrapper function for
completeness. All of the extent tree operation wrappers gain a
consistent name (ocfs2_et_*()).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch fixes the following build warnings:
fs/ocfs2/xattr.c: In function 'ocfs2_half_xattr_bucket':
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 7 has type 'long int'
fs/ocfs2/xattr.c:3282: warning: format '%d' expects type 'int', but argument 8 has type 'long int'
fs/ocfs2/xattr.c: In function 'ocfs2_xattr_set_entry_in_bucket':
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
fs/ocfs2/xattr.c:4092: warning: format '%d' expects type 'int', but argument 6 has type 'size_t'
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch adds the s_incompat flag for extended attribute support. This
helps us ensure that older versions of Ocfs2 or ocfs2-tools will not be able
to mount a volume with xattr support.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In inode removal, we need to iterate all the buckets, remove any
externally-stored EA values and delete the xattr buckets.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Where the previous patches added the ability of list/get xattr in buckets
for ocfs2, this patch enables ocfs2 to store large numbers of EAs.
The original design doc is written by Mark Fasheh, and it can be found in
http://oss.oracle.com/osswiki/OCFS2/DesignDocs/IndexedEATrees. I only had to
make small modifications to it.
First, because the bucket size is 4K, a new field named xh_free_start is added
in ocfs2_xattr_header to indicate the next valid name/value offset in a bucket.
It is used when we store new EA name/value. With this field, we can find the
place more quickly and what's more, we don't need to sort the name/value every
time to let the last entry indicate the next unused space. This makes the
insert operation more efficient for blocksizes smaller than 4k.
Because of the new xh_free_start, another field named as xh_name_value_len is
also added in ocfs2_xattr_header. It records the total length of all the
name/values in the bucket. We need this so that we can check it and defragment
the bucket if there is not enough contiguous free space.
An xattr insertion looks like this:
1. xattr_index_block_find: find the right bucket by the name_hash, say bucketA.
2. check whether there is enough space in bucketA. If yes, insert it directly
and modify xh_free_start and xh_name_value_len accordingly. If not, check
xh_name_value_len to see whether we can store this by defragment the bucket.
If yes, defragment it and go on insertion.
3. If defragement doesn't work, check whether there is new empty bucket in
the clusters within this extent record. If yes, init the new bucket and move
all the buckets after bucketA one by one to the next bucket. Move half of the
entries in bucketA to the next bucket and go on insertion.
4. If there is no new bucket, grow the extent tree.
As for xattr deletion, we will delete an xattr bucket when all it's xattrs
are removed and move all the buckets after it to the previous one. When all
the xattr buckets in an extend record are freed, free this extend records
from ocfs2_xattr_tree.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In xattr bucket, we want to limit the maximum size of a btree leaf,
otherwise we'll lose the benefits of hashing because we'll have to search
large leaves.
So add a new field in ocfs2_extent_tree which indicates the maximum leaf cluster
size we want so that we can prevent ocfs2_insert_extent() from merging the leaf
record even if it is contiguous with an adjacent record.
Other btree types are not affected by this change.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add code to lookup a given extended attribute in the xattr btree. Lookup
follows this general scheme:
1. Use ocfs2_xattr_get_rec to find the xattr extent record
2. Find the xattr bucket within the extent which may contain this xattr
3. Iterate the bucket to find the xattr. In ocfs2_xattr_block_get(), we need
to recalcuate the block offset and name offset for the right position of
name/value.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Ocfs2 breaks up xattr index tree leaves into 4k regions, called buckets.
Attributes are stored within a given bucket, depending on hash value.
After a discussion with Mark, we decided that the per-bucket index
(xe_entry[]) would only exist in the 1st block of a bucket. Likewise,
name/value pairs will not straddle more than one block. This allows the
majority of operations to work directly on the buffer heads in a leaf block.
This patch adds code to iterate the buckets in an EA. A new abstration of
ocfs2_xattr_bucket is added. It records the bhs in this bucket and
ocfs2_xattr_header. This keeps the code neat, improving readibility.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
When necessary, an ocfs2_xattr_block will embed an ocfs2_extent_list to
store large numbers of EAs. This patch adds a new type in
ocfs2_extent_tree_type and adds the implementation so that we can re-use the
b-tree code to handle the storage of many EAs.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This patch implements storing extended attributes both in inode or a single
external block. We only store EA's in-inode when blocksize > 512 or that
inode block has free space for it. When an EA's value is larger than 80
bytes, we will store the value via b-tree outside inode or block.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add the structures and helper functions we want for handling inline extended
attributes. We also update the inline-data handlers so that they properly
function in the event that we have both inline data and inline attributes
sharing an inode block.
Signed-off-by: Tiger Yang <tiger.yang@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add some thin wrappers around ocfs2_insert_extent() for each of the 3
different btree types, ocfs2_inode_insert_extent(),
ocfs2_xattr_value_insert_extent() and ocfs2_xattr_tree_insert_extent(). The
last is for the xattr index btree, which will be used in a followup patch.
All the old callers in file.c etc will call ocfs2_dinode_insert_extent(),
while the other two handle the xattr issue. And the init of extent tree are
handled by these functions.
When storing xattr value which is too large, we will allocate some clusters
for it and here ocfs2_extent_list and ocfs2_extent_rec will also be used. In
order to re-use the b-tree operation code, a new parameter named "private"
is added into ocfs2_extent_tree and it is used to indicate the root of
ocfs2_exent_list. The reason is that we can't deduce the root from the
buffer_head now. It may be in an inode, an ocfs2_xattr_block or even worse,
in any place in an ocfs2_xattr_bucket.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
The old uptodate only handles the issue of removing one buffer_head from
ocfs2 inode's buffer cache. With xattr clusters, we may need to remove
multiple buffer_head's at a time.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Ocfs2 uses a very flexible structure for storing extended attributes on
disk. Small amount of attributes are stored directly in the inode block - up
to 256 bytes worth. If that fills up, attributes are also stored in an
external block, linked to from the inode block. That block can in turn
expand to a btree, capable of storing large numbers of attributes.
Individual attribute values are stored inline if they're small enough
(currently about 80 bytes, this can be changed though), and otherwise are
expanded to a btree. The theoretical limit to the size of an individual
attribute is about the same as an inode, though the kernel's upper bound on
the size of an attributes data is far smaller.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Factor out the non-inode specifics of ocfs2_do_extend_allocation() into a more generic
function, ocfs2_do_cluster_allocation(). ocfs2_do_extend_allocation calls
ocfs2_do_cluster_allocation() now, but the latter can be used for other
btree types as well.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In the old extent tree operation, we take the hypothesis that we
are using the ocfs2_extent_list in ocfs2_dinode as the tree root.
As xattr will also use ocfs2_extent_list to store large value
for a xattr entry, we refactor the tree operation so that xattr
can use it directly.
The refactoring includes 4 steps:
1. Abstract set/get of last_eb_blk and update_clusters since they may
be stored in different location for dinode and xattr.
2. Add a new structure named ocfs2_extent_tree to indicate the
extent tree the operation will work on.
3. Remove all the use of fe_bh and di, use root_bh and root_el in
extent tree instead. So now all the fe_bh is replaced with
et->root_bh, el with root_el accordingly.
4. Make ocfs2_lock_allocators generic. Now it is limited to be only used
in file extend allocation. But the whole function is useful when we want
to store large EAs.
Note: This patch doesn't touch ocfs2_commit_truncate() since it is not used
for anything other than truncate inode data btrees.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2_extend_meta_needed(), ocfs2_calc_extend_credits() and
ocfs2_reserve_new_metadata() are all useful for extent tree operations. But
they are all limited to an inode btree because they use a struct
ocfs2_dinode parameter. Change their parameter to struct ocfs2_extent_list
(the part of an ocfs2_dinode they actually use) so that the xattr btree code
can use these functions.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
ocfs2_num_free_extents() is used to find the number of free extent records
in an inode btree. Hence, it takes an "ocfs2_dinode" parameter. We want to
use this for extended attribute trees in the future, so genericize the
interface the take a buffer head. A future patch will allow that buffer_head
to contain any structure rooting an ocfs2 btree.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
A per-mount debugfs file, "local_alloc" is created which when read will
expose live state of the nodes local alloc file. Performance impact is
minimal, only a bit of memory overhead per mount point. Still, the code is
hidden behind CONFIG_OCFS2_FS_STATS. This feature will help us debug
local alloc performance problems on a live system.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Ocfs2's local allocator disables itself for the duration of a mount point
when it has trouble allocating a large enough area from the primary bitmap.
That can cause performance problems, especially for disks which were only
temporarily full or fragmented. This patch allows for the allocator to
shrink it's window first, before being disabled. Later, it can also be
re-enabled so that any performance drop is minimized.
To do this, we allow the value of osb->local_alloc_bits to be shrunk when
needed. The default value is recorded in a mostly read-only variable so that
we can re-initialize when required.
Locking had to be updated so that we could protect changes to
local_alloc_bits. Mostly this involves protecting various local alloc values
with the osb spinlock. A new state is also added, OCFS2_LA_THROTTLED, which
is used when the local allocator is has shrunk, but is not disabled. If the
available space dips below 1 megabyte, the local alloc file is disabled. In
either case, local alloc is re-enabled 30 seconds after the event, or when
an appropriate amount of bits is seen in the primary bitmap.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Do this instead of tracking absolute local alloc size. This avoids
needless re-calculatiion of bits from bytes in localalloc.c. Additionally,
the value is now in a more natural unit for internal file system bitmap
work.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This is actually pretty easy since fs/dlm already handles the bulk of the
work. The Ocfs2 userspace cluster stack module already uses fs/dlm as the
underlying lock manager, so I only had to add the right calls.
Cluster-aware POSIX locks ("plocks") can be turned off by the same means at
UNIX locks - mount with 'noflocks', or create a local-only Ocfs2 volume.
Internally, the file system uses two sets of file_operations, depending on
whether cluster aware plocks is required. This turns out to be easier than
implementing local-only versions of ->lock.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.
This was posted for review some time ago and I believe its been in -mm
since then.
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'proc' of git://git.kernel.org/pub/scm/linux/kernel/git/adobriyan/proc:
proc: remove kernel.maps_protect
proc: remove now unneeded ADDBUF macro
[PATCH] proc: show personality via /proc/pid/personality
[PATCH] signal, procfs: some lock_task_sighand() users do not need rcu_read_lock()
proc: move PROC_PAGE_MONITOR to fs/proc/Kconfig
proc: make grab_header() static
proc: remove unused get_dma_list()
proc: remove dummy vmcore_open()
proc: proc_sys_root tweak
proc: fix return value of proc_reg_open() in "too late" case
Fixed up trivial conflict in removed file arch/sparc/include/asm/dma_32.h
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (24 commits)
integrity: special fs magic
As pointed out by Jonathan Corbet, the timer must be deleted before
ERROR: code indent should use tabs where possible
The tpm_dev_release function is only called for platform devices, not pnp
Protect tpm_chip_list when transversing it.
Renames num_open to is_open, as only one process can open the file at a time.
Remove the BKL calls from the TPM driver, which were added in the overall
netlabel: Add configuration support for local labeling
cipso: Add support for native local labeling and fixup mapping names
netlabel: Changes to the NetLabel security attributes to allow LSMs to pass full contexts
selinux: Cache NetLabel secattrs in the socket's security struct
selinux: Set socket NetLabel based on connection endpoint
netlabel: Add functionality to set the security attributes of a packet
netlabel: Add network address selectors to the NetLabel/LSM domain mapping
netlabel: Add a generic way to create ordered linked lists of network addrs
netlabel: Replace protocol/NetLabel linking with refrerence counts
smack: Fix missing calls to netlbl_skbuff_err()
selinux: Fix missing calls to netlbl_skbuff_err()
selinux: Fix a problem in security_netlbl_sid_to_secattr()
selinux: Better local/forward check in selinux_ip_postroute()
...
* git://git.infradead.org/users/dwmw2/random-2.6:
Fix autoloading of MacBook Pro backlight driver.
Automatic MODULE_ALIAS() for DMI match tables.
Remove asm/a.out.h files for all architectures without a.out support.
Introduce HAVE_AOUT symbol to remove hard-coded arch list for BINFMT_AOUT
Remove redundant CONFIG_ARCH_SUPPORTS_AOUT
S390: Update comments about why we don't use <asm-generic/statfs.h>
SPARC: Use <asm-generic/statfs.h>
PowerPC: Use <asm-generic/statfs.h>
PARISC: Use <asm-generic/statfs.h>
x86_64: Use <asm-generic/statfs.h>
IA64: Use <asm-generic/statfs.h>
ARM: Use <asm-generic/statfs.h>
Make <asm-generic/statfs.h> suitable for 64-bit platforms.
Define and use PCI_DEVICE_ID_MARVELL_88ALP01_CCIC for CAFÉ camera driver
[MTD] [NAND] Define and use PCI_DEVICE_ID_MARVELL_88ALP01_NAND for CAFÉ
Use PCI_DEVICE_ID_88ALP01 for CAFÉ chip, rather than PCI_DEVICE_ID_CAFE.
EFS: Don't set f_fsid in statfs().
When creating a new pty, save the pty's inode in the tty->driver_data.
Use this inode in pty_kill() to identify the devpts instance. Since
we now have the inode for the pty, we can skip get_node() lookup and
remove the unused get_node().
TODO:
- check if the mutex_lock is needed in pty_kill().
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
devpts_pty_new() is called when setting up a new pty and would not
will not have an existing dentry or inode for the pty. So don't bother
looking for an existing dentry - just create a new one.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
As pointed out by H. Peter Anvin, since the inode for the pty is known,
we don't need to look it up.
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pass-in 'inode' or 'tty' parameter to devpts interfaces. With multiple
devpts instances, these parameters will be used in subsequent patches
to identify the instance of devpts mounted. The parameters also help
simplify devpts implementation.
Changelog[v3]:
- minor changes due to merge with ttydev updates
- rename parameters to emphasize they are ptmx or pts inodes
- pass-in tty_struct * to devpts_pty_kill() (this will help
cleanup the get_node() call in a subsequent patch)
Signed-off-by: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Currently it is sometimes locked by the tty mutex and sometimes by the
sighand lock. The latter is in fact correct and now we can hand back referenced
objects we can fix this up without problems around sleeping functions.
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We now have the infrastructure to sort this out but rather than teaching
the syscall tty lock rules we move the hard work into a tty helper
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We now return a kref covered tty reference. That ensures the tty structure
doesn't go away when you have a return from get_current_tty. This is not
enough to protect you from most of the resources being freed behind your
back - yet.
[Updated to include fixes for SELinux problems found by Andrew Morton and
an s390 leak found while debugging the former]
Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix kconfig typo and extra whitespace
ext4: fix build failure without procfs
ext4: add an option to control error handling on file data
jbd2: don't dirty original metadata buffer on abort
ext4: add checks for errors from jbd2
jbd2: fix error handling for checkpoint io
jbd2: abort when failed to log metadata buffers
Discussion on the mailing list questioned the use of these
magic values in userspace, concluding these values are already
exported to userspace via statfs and their correct/incorrect
usage is left up to the userspace application.
- Move special fs magic number definitions to magic.h
- Add magic.h include
Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Reviewed-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
fs/ext4/super.c: In function 'ext4_fill_super':
fs/ext4/super.c:2226: error: 'ext4_ui_proc_fops' undeclared (first use
in this function)
fs/ext4/super.c:2226: error: (Each undeclared identifier is reported
only once
fs/ext4/super.c:2226: error: for each function it appears in.)
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This fixes the following compile error with CONFIG_BLOCK=n caused by
commit 68c9d702bb ("generic block based
fiemap implementation"):
CC fs/ioctl.o
fs/ioctl.c: In function 'generic_block_fiemap':
fs/ioctl.c:249: error: storage size of 'tmp' isn't known
fs/ioctl.c:272: error: invalid application of 'sizeof' to incomplete type 'struct buffer_head'
fs/ioctl.c:280: error: implicit declaration of function 'buffer_mapped'
fs/ioctl.c:249: warning: unused variable 'tmp'
make[2]: *** [fs/ioctl.o] Error 1
Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Josef Bacik <jbacik@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
We lock GlobalMid_Lock in header_assemble and then immediately unlock it
again without doing anything. Not sure what this was intended to do, but
remove it.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (43 commits)
ext4: Rename ext4dev to ext4
ext4: Avoid double dirtying of super block in ext4_put_super()
Update ext4 MAINTAINERS file
Hook ext4 to the vfs fiemap interface.
generic block based fiemap implementation
ocfs2: fiemap support
vfs: vfs-level fiemap interface
ext4: fix xattr deadlock
jbd2: Fix buffer head leak when writing the commit block
ext4: Add debugging markers that can be used by systemtap
jbd2: abort instead of waiting for nonexistent transaction
ext4: fix initialization of UNINIT bitmap blocks
ext4: Remove old legacy block allocator
ext4: Use readahead when reading an inode from the inode table
ext4: Improve the documentation for ext4's /proc tunables
ext4: Combine proc file handling into a single set of functions
ext4: move /proc setup and teardown out of mballoc.c
ext4: Don't use 'struct dentry' for internal lookups
ext4/jbd2: Avoid WARN() messages when failing to write to the superblock
ext4: use percpu data structures for lg_prealloc_list
...
* git://git.kernel.org/pub/scm/linux/kernel/git/sfrench/cifs-2.6:
[CIFS] Check that last search entry resume key is valid
[CIFS] make sure we have the right resume info before calling CIFSFindNext
[CIFS] clean up error handling in cifs_unlink
[CIFS] fix some settings of cifsAttrs after calling SetFileInfo and SetPathInfo
cifs: explicitly revoke SPNEGO key after session setup
cifs: Convert cifs to new aops.
[CIFS] update DOS attributes in cifsInode if we successfully changed them
cifs: remove NULL termination from rename target in CIFSSMBRenameOpenFIle
cifs: work around samba returning -ENOENT on SetFileDisposition call
cifs: fix inverted NULL check after kmalloc
[CIFS] clean up upcall handling for dns_resolver keys
[CIFS] fix busy-file renames and refactor cifs_rename logic
cifs: add function to set file disposition
[CIFS] add constants for string lengths of keynames in SPNEGO upcall string
cifs: move rename and delete-on-close logic into helper function
cifs: have find_writeable_file prefer filehandles opened by same task
cifs: don't use GFP_KERNEL with GFP_NOFS
[CIFS] use common code for turning off ATTR_READONLY in cifs_unlink
cifs: clean up variables in cifs_unlink
If the journal doesn't abort when it gets an IO error in file data
blocks, the file data corruption will spread silently. Because
most of applications and commands do buffered writes without fsync(),
they don't notice the IO error. It's scary for mission critical
systems. On the other hand, if the journal aborts whenever it gets
an IO error in file data blocks, the system will easily become
inoperable. So this patch introduces a filesystem option to
determine whether it aborts the journal or just call printk() when
it gets an IO error in file data.
If you mount an ext4 fs with data_err=abort option, it aborts on file
data write error. If you mount it with data_err=ignore, it doesn't
abort, just call printk(). data_err=ignore is the default.
Here is the corresponding patch of the ext3 version:
http://kerneltrap.org/mailarchive/linux-kernel/2008/9/9/3239374
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Currently, original metadata buffers are dirtied when they are
unfiled whether the journal has aborted or not. Eventually these
buffers will be written-back to the filesystem by pdflush. This
means some metadata buffers are written to the filesystem without
journaling if the journal aborts. So if both journal abort and
system crash happen at the same time, the filesystem would become
inconsistent state. Additionally, replaying journaled metadata
can overwrite the latest metadata on the filesystem partly.
Because, if the journal gets aborted, journaled metadata are
preserved and replayed during the next mount not to lose
uncheckpointed metadata. This would also break the consistency
of the filesystem.
This patch prevents original metadata buffers from being dirtied
on abort by clearing BH_JBDDirty flag from those buffers. Thus,
no metadata buffers are written to the filesystem without journaling.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If the journal has aborted due to a checkpointing failure, we
have to keep the contents of the journal space. Otherwise, the
filesystem will lose uncheckpointed metadata completely and
become inconsistent. To avoid this, we need to keep needs_recovery
flag if checkpoint has failed.
With this patch, ext4_put_super() detects a checkpointing failure
from the return value of journal_destroy(), then it invokes
ext4_abort() to make the filesystem read only and keep
needs_recovery flag. Errors from jbd2_journal_flush() are also
handled by this patch in some places.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
When a checkpointing IO fails, current JBD2 code doesn't check the
error and continue journaling. This means latest metadata can be
lost from both the journal and filesystem.
This patch leaves the failed metadata blocks in the journal space
and aborts journaling in the case of jbd2_log_do_checkpoint().
To achieve this, we need to do:
1. don't remove the failed buffer from the checkpoint list where in
the case of __try_to_free_cp_buf() because it may be released or
overwritten by a later transaction
2. jbd2_log_do_checkpoint() is the last chance, remove the failed
buffer from the checkpoint list and abort the journal
3. when checkpointing fails, don't update the journal super block to
prevent the journaled contents from being cleaned. For safety,
don't update j_tail and j_tail_sequence either
4. when checkpointing fails, notify this error to the ext4 layer so
that ext4 don't clear the needs_recovery flag, otherwise the
journaled contents are ignored and cleaned in the recovery phase
5. if the recovery fails, keep the needs_recovery flag
6. prevent jbd2_cleanup_journal_tail() from being called between
__jbd2_journal_drop_transaction() and jbd2_journal_abort()
(a possible race issue between jbd2_log_do_checkpoint()s called by
jbd2_journal_flush() and __jbd2_log_wait_for_space())
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
If we failed to write metadata buffers to the journal space and
succeeded to write the commit record, stale data can be written
back to the filesystem as metadata in the recovery phase.
To avoid this, when we failed to write out metadata buffers,
abort the journal before writing the commit record.
We can also avoid this kind of corruption by using the journal
checksum feature because it can detect invalid metadata blocks in the
journal and avoid them from being replayed. So we don't need to care
about asynchronous commit record writeout with a checksum.
Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
The ext4 filesystem is getting stable enough that it's time to drop
the "dev" prefix. Also remove the requirement for the TEST_FILESYS
flag.
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Bruce observed that nfs_parse_ip_address() will successfully parse an
IPv6 address that looks like this:
"::1%"
A scope delimiter is present, but there is no scope ID following it.
This is harmless, as it would simply set the scope ID to zero. However,
in some cases we would like to flag this as an improperly formed
address.
We are now also careful to reject addresses where garbage follows the
address (up to the length of the string), instead of ignoring the
non-address characters; and where the scope ID is nonsense (not a valid
device name, but also not numeric). Before, both of these cases would
result in a harmless zero scope ID.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Currently we disable barriers as soon as we get a buffer in xlog_iodone
that has the XBF_ORDERED flag cleared. But this can be the case not only
for buffers where the barrier failed, but also the first buffer of a
split log write in case of a log wraparound. Due to the disabled
barriers we can easily get directory corruption on unclean shutdowns.
So instead of using this check add a new buffer flag for failed barrier
writes.
This is a regression vs 2.6.26 caused by patch to use the right macro
to check for the ORDERED flag, as we previously got true returned for
every buffer.
Thanks to Toei Rei for reporting the bug.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Eric Sandeen <sandeen@sandeen.net>
Reviewed-by: David Chinner <david@fromorbit.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* git://git.kernel.org/pub/scm/linux/kernel/git/steve/gfs2-2.6-nmw:
GFS2: Support for I/O barriers
GFS2: Add UUID to GFS2 sb
GFS2: high time to take some time over atime
GFS2: The war on bloat
GFS2: GFS2 will panic if you misspell any mount options
GFS2: Direct IO write at end of file error
GFS2: Use an IS_ERR test rather than a NULL test
GFS2: Fix race relating to glock min-hold time
GFS2: Fix & clean up GFS2 rename
GFS2: rm on multiple nodes causes panic
GFS2: Fix metafs mounts
GFS2: Fix debugfs glock file iterator
* 'for-2.6.28' of git://git.kernel.dk/linux-2.6-block: (132 commits)
doc/cdrom: Trvial documentation error, file not present
block_dev: fix kernel-doc in new functions
block: add some comments around the bio read-write flags
block: mark bio_split_pool static
block: Find bio sector offset given idx and offset
block: gendisk integrity wrapper
block: Switch blk_integrity_compare from bdev to gendisk
block: Fix double put in blk_integrity_unregister
block: Introduce integrity data ownership flag
block: revert part of d7533ad0e132f92e75c1b2eb7c26387b25a583c1
bio.h: Remove unused conditional code
block: remove end_{queued|dequeued}_request()
block: change elevator to use __blk_end_request()
gdrom: change to use __blk_end_request()
memstick: change to use __blk_end_request()
virtio_blk: change to use __blk_end_request()
blktrace: use BLKTRACE_BDEV_SIZE as the name size for setup structure
block: add lld busy state exporting interface
block: Fix blk_start_queueing() to not kick a stopped queue
include blktrace_api.h in headers_install
...
After commit 831830b5a2 aka
"restrict reading from /proc/<pid>/maps to those who share ->mm or can ptrace"
sysctl stopped being relevant because commit moved security checks from ->show
time to ->start time (mm_for_maps()).
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: Kees Cook <kees.cook@canonical.com>
Make process personality flags visible in /proc. Since a process's
personality is potentially sensitive (e.g. READ_IMPLIES_EXEC), make this
file only readable by the process owner.
Signed-off-by: Kees Cook <kees.cook@canonical.com>
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
lock_task_sighand() make sure task->sighand is being protected,
so we do not need rcu_read_lock().
[ exec() will get task->sighand->siglock before change task->sighand! ]
But code using rcu_read_lock() _just_ to protect lock_task_sighand()
only appear in procfs. (and some code in procfs use lock_task_sighand()
without such redundant protection.)
Other subsystem may put lock_task_sighand() into rcu_read_lock()
critical region, but these rcu_read_lock() are used for protecting
"for_each_process()", "find_task_by_vpid()" etc. , not for protecting
lock_task_sighand().
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
[ok from Oleg]
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Christoph Hellwig