When an xprt is created, it has a refcount of 1, and XPT_BUSY is set.
The refcount is *not* owned by the thread that created the xprt
(as is clear from the fact that creators never put the reference).
Rather, it is owned by the absence of XPT_DEAD. Once XPT_DEAD is set,
(And XPT_BUSY is clear) that initial reference is dropped and the xprt
can be freed.
So when a creator clears XPT_BUSY it is dropping its only reference and
so must not touch the xprt again.
However svc_recv, after calling ->xpo_accept (and so getting an XPT_BUSY
reference on a new xprt), calls svc_xprt_recieved. This clears
XPT_BUSY and then svc_xprt_enqueue - this last without owning a reference.
This is dangerous and has been seen to leave svc_xprt_enqueue working
with an xprt containing garbage.
So we need to hold an extra counted reference over that call to
svc_xprt_received.
For safety, any time we clear XPT_BUSY and then use the xprt again, we
first get a reference, and the put it again afterwards.
Note that svc_close_all does not need this extra protection as there are
no threads running, and the final free can only be called asynchronously
from such a thread.
Signed-off-by: NeilBrown <neilb@suse.de>
Cc: stable@kernel.org
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
If the rpcauth_refreshcred() call returns an error other than
EACCES, ENOMEM or ETIMEDOUT, we currently end up looping forever
between call_refresh and call_refreshresult.
The correct thing to do here is to exit on all errors except
EAGAIN and ETIMEDOUT, for which case we retry 3 times, then
return EACCES.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.
Remove this too as a cleanup.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Hi,
We can simplify net/sunrpc/stats.c::rpc_alloc_iostats() a bit by getting
rid of the unneeded local variable 'new'.
Please CC me on replies.
Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (52 commits)
split invalidate_inodes()
fs: skip I_FREEING inodes in writeback_sb_inodes
fs: fold invalidate_list into invalidate_inodes
fs: do not drop inode_lock in dispose_list
fs: inode split IO and LRU lists
fs: switch bdev inode bdi's correctly
fs: fix buffer invalidation in invalidate_list
fsnotify: use dget_parent
smbfs: use dget_parent
exportfs: use dget_parent
fs: use RCU read side protection in d_validate
fs: clean up dentry lru modification
fs: split __shrink_dcache_sb
fs: improve DCACHE_REFERENCED usage
fs: use percpu counter for nr_dentry and nr_dentry_unused
fs: simplify __d_free
fs: take dcache_lock inside __d_path
fs: do not assign default i_ino in new_inode
fs: introduce a per-cpu last_ino allocator
new helper: ihold()
...
* 'for-2.6.37' of git://linux-nfs.org/~bfields/linux: (99 commits)
svcrpc: svc_tcp_sendto XPT_DEAD check is redundant
svcrpc: no need for XPT_DEAD check in svc_xprt_enqueue
svcrpc: assume svc_delete_xprt() called only once
svcrpc: never clear XPT_BUSY on dead xprt
nfsd4: fix connection allocation in sequence()
nfsd4: only require krb5 principal for NFSv4.0 callbacks
nfsd4: move minorversion to client
nfsd4: delay session removal till free_client
nfsd4: separate callback change and callback probe
nfsd4: callback program number is per-session
nfsd4: track backchannel connections
nfsd4: confirm only on succesful create_session
nfsd4: make backchannel sequence number per-session
nfsd4: use client pointer to backchannel session
nfsd4: move callback setup into session init code
nfsd4: don't cache seq_misordered replies
SUNRPC: Properly initialize sock_xprt.srcaddr in all cases
SUNRPC: Use conventional switch statement when reclassifying sockets
sunrpc/xprtrdma: clean up workqueue usage
sunrpc: Turn list_for_each-s into the ..._entry-s
...
Fix up trivial conflicts (two different deprecation notices added in
separate branches) in Documentation/feature-removal-schedule.txt
* 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6:
net/sunrpc: Use static const char arrays
nfs4: fix channel attribute sanity-checks
NFSv4.1: Use more sensible names for 'initialize_mountpoint'
NFSv4.1: pnfs: filelayout: add driver's LAYOUTGET and GETDEVICEINFO infrastructure
NFSv4.1: pnfs: add LAYOUTGET and GETDEVICEINFO infrastructure
NFS: client needs to maintain list of inodes with active layouts
NFS: create and destroy inode's layout cache
NFSv4.1: pnfs: filelayout: introduce minimal file layout driver
NFSv4.1: pnfs: full mount/umount infrastructure
NFS: set layout driver
NFS: ask for layouttypes during v4 fsinfo call
NFS: change stateid to be a union
NFSv4.1: pnfsd, pnfs: protocol level pnfs constants
SUNRPC: define xdr_decode_opaque_fixed
NFSD: remove duplicate NFS4_STATEID_SIZE
Instead of always assigning an increasing inode number in new_inode
move the call to assign it into those callers that actually need it.
For now callers that need it is estimated conservatively, that is
the call is added to all filesystems that do not assign an i_ino
by themselves. For a few more filesystems we can avoid assigning
any inode number given that they aren't user visible, and for others
it could be done lazily when an inode number is actually needed,
but that's left for later patches.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
If any xprt marked DEAD is also left BUSY for the rest of its life, then
the XPT_DEAD check here is superfluous--we'll get the same result from
the XPT_BUSY check just after.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
As long as DEAD exports are left BUSY, and svc_delete_xprt is called
only with BUSY held, then svc_delete_xprt() will never be called on an
xprt that is already DEAD.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Once an xprt has been deleted, there's no reason to allow it to be
enqueued--at worst, that might cause the xprt to be re-added to some
global list, resulting in later corruption.
Also, note this leaves us with no need for the reference-count
manipulation here.
Reviewed-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* 'nfs-for-2.6.37' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: (67 commits)
SUNRPC: Cleanup duplicate assignment in rpcauth_refreshcred
nfs: fix unchecked value
Ask for time_delta during fsinfo probe
Revalidate caches on lock
SUNRPC: After calling xprt_release(), we must restart from call_reserve
NFSv4: Fix up the 'dircount' hint in encode_readdir
NFSv4: Clean up nfs4_decode_dirent
NFSv4: nfs4_decode_dirent must clear entry->fattr->valid
NFSv4: Fix a regression in decode_getfattr
NFSv4: Fix up decode_attr_filehandle() to handle the case of empty fh pointer
NFS: Ensure we check all allocation return values in new readdir code
NFS: Readdir plus in v4
NFS: introduce generic decode_getattr function
NFS: check xdr_decode for errors
NFS: nfs_readdir_filler catch all errors
NFS: readdir with vmapped pages
NFS: remove page size checking code
NFS: decode_dirent should use an xdr_stream
SUNRPC: Add a helper function xdr_inline_peek
NFS: remove readdir plus limit
...
We sometimes need to be able to read ahead in an xdr_stream without
incrementing the current pointer position.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1699 commits)
bnx2/bnx2x: Unsupported Ethtool operations should return -EINVAL.
vlan: Calling vlan_hwaccel_do_receive() is always valid.
tproxy: use the interface primary IP address as a default value for --on-ip
tproxy: added IPv6 support to the socket match
cxgb3: function namespace cleanup
tproxy: added IPv6 support to the TPROXY target
tproxy: added IPv6 socket lookup function to nf_tproxy_core
be2net: Changes to use only priority codes allowed by f/w
tproxy: allow non-local binds of IPv6 sockets if IP_TRANSPARENT is enabled
tproxy: added tproxy sockopt interface in the IPV6 layer
tproxy: added udp6_lib_lookup function
tproxy: added const specifiers to udp lookup functions
tproxy: split off ipv6 defragmentation to a separate module
l2tp: small cleanup
nf_nat: restrict ICMP translation for embedded header
can: mcp251x: fix generation of error frames
can: mcp251x: fix endless loop in interrupt handler if CANINTF_MERRF is set
can-raw: add msg_flags to distinguish local traffic
9p: client code cleanup
rds: make local functions/variables static
...
Fix up conflicts in net/core/dev.c, drivers/net/pcmcia/smc91c92_cs.c and
drivers/net/wireless/ath/ath9k/debug.c as per David
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
vfs: make no_llseek the default
vfs: don't use BKL in default_llseek
llseek: automatically add .llseek fop
libfs: use generic_file_llseek for simple_attr
mac80211: disallow seeks in minstrel debug code
lirc: make chardev nonseekable
viotape: use noop_llseek
raw: use explicit llseek file operations
ibmasmfs: use generic_file_llseek
spufs: use llseek in all file operations
arm/omap: use generic_file_llseek in iommu_debug
lkdtm: use generic_file_llseek in debugfs
net/wireless: use generic_file_llseek in debugfs
drm: use noop_llseek
* 'config' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
BKL: introduce CONFIG_BKL.
dabusb: remove the BKL
sunrpc: remove the big kernel lock
init/main.c: remove BKL notations
blktrace: remove the big kernel lock
rtmutex-tester: make it build without BKL
dvb-core: kill the big kernel lock
dvb/bt8xx: kill the big kernel lock
tlclk: remove big kernel lock
fix rawctl compat ioctls breakage on amd64 and itanic
uml: kill big kernel lock
parisc: remove big kernel lock
cris: autoconvert trivial BKL users
alpha: kill big kernel lock
isapnp: BKL removal
s390/block: kill the big kernel lock
hpet: kill BKL, add compat_ioctl
The source address field in the transport's sock_xprt is initialized
ONLY IF the RPC application passed a pointer to a source address
during the call to rpc_create(). However, xs_bind() subsequently uses
the value of this field without regard to whether the source address
was initialized during transport creation or not.
So far we've been lucky: the uninitialized value of this field is
zeroes. xs_bind(), until recently, used only the sin[6]_addr field in
this sockaddr, and all zeroes is a valid value for this: it means
ANYADDR. This is a happy coincidence.
However, xs_bind() now wants to use the sa_family field as well, and
expects it to be initialized to something other than zero.
Therefore, the source address sockaddr field should be fully
initialized at transport create time in _every_ case, not just when
the RPC application wants to use a specific bind address.
Bruce added a workaround for this missing initialization by adjusting
commit 6bc9638a, but the "right" way to do this is to ensure that the
source address sockaddr is always correctly initialized from the
get-go.
This patch doesn't introduce a behavior change. It's simply a
clean-up of Bruce's fix, to prevent future problems of this kind. It
may look like overkill, but
a) it clearly documents the default initial value of this field,
b) it doesn't assume that the sockaddr_storage memory is first
initialized to any particular value, and
c) it will fail verbosely if some unknown address family is passed
in
Originally introduced by commit d3bc9a1d.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Clean up.
Defensive coding: If "family" is ever something that is neither
AF_INET nor AF_INET6, xs_reclassify_socket6() is not the appropriate
default action. Choose to do nothing in that case.
Introduced by commit 6bc9638a.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
* Create and use svc_rdma_wq instead of using the system workqueue and
flush_scheduled_work(). This workqueue is necessary to serve as
flushing domain for rdma->sc_work which is used to destroy itself
and thus can't be flushed explicitly.
* Replace cancel_delayed_work() + flush_scheduled_work() with
cancel_delayed_work_sync().
* Implement synchronous connect in xprt_rdma_connect() using
flush_delayed_work() on the rdma_connect work instead of using
flush_scheduled_work().
This is to prepare for the deprecation and removal of
flush_scheduled_work().
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Saves some lines of code and some branticks when reading one.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Since the xprt in question is forcibly set to be bound the else
branch of this check is unneeded.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> The reason for this is in the future, we may want to support additional
> address family types. We should, therefore, ensure that every piece of
> code that is sensitive to address families fail in some orderly manner
> to let developers know where a change is needed.
Makes sense. I was under impression, that AF-s other than INET are not
cared about at all :(
Here's a fixed version of the patch.
Log:
Its callers check for ERR_PTR.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The task in question is dereferenced above (and is actually never NULL).
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Same for UDP sockets creation paths.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The v4 and the v6 wrappers only pass the respective family
to the xs_tcp_setup_socket. This family can be taken from the
xprt's sockaddr.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Now we have a single socket creation routine and can call it
directly from the setup_socket routines.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
After xs_bind is merged it's easy to merge its callers.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
[bfields@redhat.com: fix address family initialization]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There's the only difference betseen the xs_bind4 and the
xs_bind6 - the size of sockaddr structure they use.
Fortunatelly its size can be indirectly get from the transport.
Change since v1:
* use sockaddr_storage instead of sockaddr
* use rpc_set_port instead of manual port assigning
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
[bfields@redhat.com: fix address family initialization]
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Remove now unneeded wrappers that just add type and protocol
to socket creation callback.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Same patch for v6 protocols.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The UDPv4 and TCPv4 socket creation callbacks now look very similar.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Make it look like the TCP sockets creation.
Unfortunately the git diff made the patch look messy :(
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The xs_tcp_reuse_connection takes the xprt only to pass it down
to the xs_abort_connection. The later one can get it from the given
transport itself.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The sunrpc cache_ioctl function does not need the big kernel lock
because it uses its own queue_lock already.
rpc_pipe_ioctl apparently should be using i_lock like the other
operations on the pipe file descriptor do.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
There are several error paths in the code that do not unmap DMA. This
patch adds calls to svc_rdma_unmap_dma to free these DMA contexts.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
There was logic in the send path that assumed that a page containing data
to send to the client has a KVA. This is not always the case and can result
in data corruption when page_address returns zero and we end up DMA mapping
zero.
This patch changes the bus mapping logic to avoid page_address() where
necessary and converts all calls from ib_dma_map_single to ib_dma_map_page
in order to keep the map/unmap calls symmetric.
Signed-off-by: Tom Tucker <tom@ogc.us>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
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>
We limit the number of 'defer' requests to DFR_MAX.
The imposition of this limit is spread about a bit - sometime we don't
add new things to the list, sometimes we remove old things.
Also it is currently applied to requests which we are 'waiting' for
rather than 'deferring'. This doesn't seem ideal as 'waiting'
requests are naturally limited by the number of threads.
So gather the DFR_MAX handling code to one place and only apply it to
requests that are actually being deferred.
This means that not all 'cache_deferred_req' structures go on the
'cache_defer_list, so we need to be careful when adding and removing
things.
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
The return value from cache_defer_req is somewhat confusing.
Various different error codes are returned, but the single caller is
only interested in success or failure.
In fact it can measure this success or failure itself by checking
CACHE_PENDING, which makes the point of the code more explicit.
So change cache_defer_req to return 'void' and test CACHE_PENDING
after it completes, to see if the request was actually deferred or
not.
Similarly setup_deferral and cache_wait_req don't need a return value,
so make them void and remove some code.
The call to cache_revisit_request (to guard against a race) is only
needed for the second call to setup_deferral, so move it out of
setup_deferral to after that second call. With the first call the
race is handled differently (by explicitly calling
'wait_for_completion').
Signed-off-by: NeilBrown <neilb@suse.de>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
