Commit 88467055 authored by Chuck Lever's avatar Chuck Lever Committed by Trond Myklebust
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NFS: clean up comments and tab damage in direct.c



Clean up tab damage and comments.  Replace "file_offset" with more commonly
used "pos".

Test plan:
Compile with CONFIG_NFS and CONFIG_NFS_DIRECTIO enabled.
Signed-off-by: default avatarChuck Lever <cel@netapp.com>
Signed-off-by: default avatarTrond Myklebust <Trond.Myklebust@netapp.com>
parent 9eafa8cc
......@@ -7,11 +7,11 @@
*
* There are important applications whose performance or correctness
* depends on uncached access to file data. Database clusters
* (multiple copies of the same instance running on separate hosts)
* (multiple copies of the same instance running on separate hosts)
* implement their own cache coherency protocol that subsumes file
* system cache protocols. Applications that process datasets
* considerably larger than the client's memory do not always benefit
* from a local cache. A streaming video server, for instance, has no
* system cache protocols. Applications that process datasets
* considerably larger than the client's memory do not always benefit
* from a local cache. A streaming video server, for instance, has no
* need to cache the contents of a file.
*
* When an application requests uncached I/O, all read and write requests
......@@ -34,6 +34,7 @@
* 08 Jun 2003 Port to 2.5 APIs --cel
* 31 Mar 2004 Handle direct I/O without VFS support --cel
* 15 Sep 2004 Parallel async reads --cel
* 04 May 2005 support O_DIRECT with aio --cel
*
*/
......@@ -67,11 +68,11 @@ static kmem_cache_t *nfs_direct_cachep;
*/
struct nfs_direct_req {
struct kref kref; /* release manager */
struct list_head list; /* nfs_read_data structs */
struct list_head list; /* nfs_read/write_data structs */
struct file * filp; /* file descriptor */
struct kiocb * iocb; /* controlling i/o request */
wait_queue_head_t wait; /* wait for i/o completion */
struct inode * inode; /* target file of I/O */
struct inode * inode; /* target file of i/o */
struct page ** pages; /* pages in our buffer */
unsigned int npages; /* count of pages */
atomic_t complete, /* i/os we're waiting for */
......@@ -110,7 +111,6 @@ static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t siz
size_t array_size;
/* set an arbitrary limit to prevent type overflow */
/* XXX: this can probably be as large as INT_MAX */
if (size > MAX_DIRECTIO_SIZE) {
*pages = NULL;
return -EFBIG;
......@@ -294,7 +294,7 @@ static const struct rpc_call_ops nfs_read_direct_ops = {
* For each nfs_read_data struct that was allocated on the list, dispatch
* an NFS READ operation
*/
static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t file_offset)
static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
{
struct file *file = dreq->filp;
struct inode *inode = file->f_mapping->host;
......@@ -322,7 +322,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
data->cred = ctx->cred;
data->args.fh = NFS_FH(inode);
data->args.context = ctx;
data->args.offset = file_offset;
data->args.offset = pos;
data->args.pgbase = pgbase;
data->args.pages = &pages[curpage];
data->args.count = bytes;
......@@ -347,7 +347,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
bytes,
(unsigned long long)data->args.offset);
file_offset += bytes;
pos += bytes;
pgbase += bytes;
curpage += pgbase >> PAGE_SHIFT;
pgbase &= ~PAGE_MASK;
......@@ -356,7 +356,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
} while (count != 0);
}
static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t file_offset, struct page **pages, unsigned int nr_pages)
static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, unsigned int nr_pages)
{
ssize_t result;
sigset_t oldset;
......@@ -377,7 +377,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size
nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
rpc_clnt_sigmask(clnt, &oldset);
nfs_direct_read_schedule(dreq, user_addr, count, file_offset);
nfs_direct_read_schedule(dreq, user_addr, count, pos);
result = nfs_direct_wait(dreq);
rpc_clnt_sigunmask(clnt, &oldset);
......@@ -459,7 +459,7 @@ static const struct rpc_call_ops nfs_write_direct_ops = {
* XXX: For now, support only FILE_SYNC writes. Later we may add
* support for UNSTABLE + COMMIT.
*/
static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t file_offset)
static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
{
struct file *file = dreq->filp;
struct inode *inode = file->f_mapping->host;
......@@ -487,7 +487,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
data->cred = ctx->cred;
data->args.fh = NFS_FH(inode);
data->args.context = ctx;
data->args.offset = file_offset;
data->args.offset = pos;
data->args.pgbase = pgbase;
data->args.pages = &pages[curpage];
data->args.count = bytes;
......@@ -513,7 +513,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
bytes,
(unsigned long long)data->args.offset);
file_offset += bytes;
pos += bytes;
pgbase += bytes;
curpage += pgbase >> PAGE_SHIFT;
pgbase &= ~PAGE_MASK;
......@@ -522,7 +522,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
} while (count != 0);
}
static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t file_offset, struct page **pages, int nr_pages)
static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, size_t count, loff_t pos, struct page **pages, int nr_pages)
{
ssize_t result;
sigset_t oldset;
......@@ -546,7 +546,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
nfs_begin_data_update(inode);
rpc_clnt_sigmask(clnt, &oldset);
nfs_direct_write_schedule(dreq, user_addr, count, file_offset);
nfs_direct_write_schedule(dreq, user_addr, count, pos);
result = nfs_direct_wait(dreq);
rpc_clnt_sigunmask(clnt, &oldset);
......@@ -557,18 +557,18 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
* nfs_file_direct_read - file direct read operation for NFS files
* @iocb: target I/O control block
* @buf: user's buffer into which to read data
* count: number of bytes to read
* pos: byte offset in file where reading starts
* @count: number of bytes to read
* @pos: byte offset in file where reading starts
*
* We use this function for direct reads instead of calling
* generic_file_aio_read() in order to avoid gfar's check to see if
* the request starts before the end of the file. For that check
* to work, we must generate a GETATTR before each direct read, and
* even then there is a window between the GETATTR and the subsequent
* READ where the file size could change. So our preference is simply
* READ where the file size could change. Our preference is simply
* to do all reads the application wants, and the server will take
* care of managing the end of file boundary.
*
*
* This function also eliminates unnecessarily updating the file's
* atime locally, as the NFS server sets the file's atime, and this
* client must read the updated atime from the server back into its
......@@ -621,8 +621,8 @@ out:
* nfs_file_direct_write - file direct write operation for NFS files
* @iocb: target I/O control block
* @buf: user's buffer from which to write data
* count: number of bytes to write
* pos: byte offset in file where writing starts
* @count: number of bytes to write
* @pos: byte offset in file where writing starts
*
* We use this function for direct writes instead of calling
* generic_file_aio_write() in order to avoid taking the inode
......@@ -703,6 +703,10 @@ out:
return retval;
}
/**
* nfs_init_directcache - create a slab cache for nfs_direct_req structures
*
*/
int nfs_init_directcache(void)
{
nfs_direct_cachep = kmem_cache_create("nfs_direct_cache",
......@@ -715,6 +719,10 @@ int nfs_init_directcache(void)
return 0;
}
/**
* nfs_init_directcache - destroy the slab cache for nfs_direct_req structures
*
*/
void nfs_destroy_directcache(void)
{
if (kmem_cache_destroy(nfs_direct_cachep))
......
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