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: Chuck Lever <cel@netapp.com> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
This commit is contained in:
Chuck Lever
Trond Myklebust
parent
9eafa8cc52
commit
88467055f7
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@ -7,11 +7,11 @@
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*
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* There are important applications whose performance or correctness
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* depends on uncached access to file data. Database clusters
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* (multiple copies of the same instance running on separate hosts)
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* (multiple copies of the same instance running on separate hosts)
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* implement their own cache coherency protocol that subsumes file
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* system cache protocols. Applications that process datasets
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* considerably larger than the client's memory do not always benefit
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* from a local cache. A streaming video server, for instance, has no
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* system cache protocols. Applications that process datasets
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* considerably larger than the client's memory do not always benefit
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* from a local cache. A streaming video server, for instance, has no
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* need to cache the contents of a file.
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*
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* When an application requests uncached I/O, all read and write requests
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@ -34,6 +34,7 @@
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* 08 Jun 2003 Port to 2.5 APIs --cel
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* 31 Mar 2004 Handle direct I/O without VFS support --cel
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* 15 Sep 2004 Parallel async reads --cel
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* 04 May 2005 support O_DIRECT with aio --cel
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*
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*/
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@ -67,11 +68,11 @@ static kmem_cache_t *nfs_direct_cachep;
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*/
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struct nfs_direct_req {
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struct kref kref; /* release manager */
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struct list_head list; /* nfs_read_data structs */
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struct list_head list; /* nfs_read/write_data structs */
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struct file * filp; /* file descriptor */
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struct kiocb * iocb; /* controlling i/o request */
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wait_queue_head_t wait; /* wait for i/o completion */
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struct inode * inode; /* target file of I/O */
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struct inode * inode; /* target file of i/o */
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struct page ** pages; /* pages in our buffer */
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unsigned int npages; /* count of pages */
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atomic_t complete, /* i/os we're waiting for */
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@ -110,7 +111,6 @@ static inline int nfs_get_user_pages(int rw, unsigned long user_addr, size_t siz
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size_t array_size;
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/* set an arbitrary limit to prevent type overflow */
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/* XXX: this can probably be as large as INT_MAX */
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if (size > MAX_DIRECTIO_SIZE) {
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*pages = NULL;
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return -EFBIG;
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@ -294,7 +294,7 @@ static const struct rpc_call_ops nfs_read_direct_ops = {
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* For each nfs_read_data struct that was allocated on the list, dispatch
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* an NFS READ operation
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*/
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static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t file_offset)
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static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
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{
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struct file *file = dreq->filp;
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struct inode *inode = file->f_mapping->host;
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@ -322,7 +322,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
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data->cred = ctx->cred;
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data->args.fh = NFS_FH(inode);
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data->args.context = ctx;
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data->args.offset = file_offset;
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data->args.offset = pos;
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data->args.pgbase = pgbase;
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data->args.pages = &pages[curpage];
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data->args.count = bytes;
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@ -347,7 +347,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
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bytes,
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(unsigned long long)data->args.offset);
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file_offset += bytes;
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pos += bytes;
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pgbase += bytes;
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curpage += pgbase >> PAGE_SHIFT;
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pgbase &= ~PAGE_MASK;
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@ -356,7 +356,7 @@ static void nfs_direct_read_schedule(struct nfs_direct_req *dreq, unsigned long
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} while (count != 0);
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}
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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)
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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)
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{
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ssize_t result;
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sigset_t oldset;
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@ -377,7 +377,7 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, unsigned long user_addr, size
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nfs_add_stats(inode, NFSIOS_DIRECTREADBYTES, count);
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rpc_clnt_sigmask(clnt, &oldset);
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nfs_direct_read_schedule(dreq, user_addr, count, file_offset);
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nfs_direct_read_schedule(dreq, user_addr, count, pos);
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result = nfs_direct_wait(dreq);
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rpc_clnt_sigunmask(clnt, &oldset);
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@ -459,7 +459,7 @@ static const struct rpc_call_ops nfs_write_direct_ops = {
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* XXX: For now, support only FILE_SYNC writes. Later we may add
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* support for UNSTABLE + COMMIT.
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*/
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static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t file_offset)
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static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long user_addr, size_t count, loff_t pos)
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{
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struct file *file = dreq->filp;
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struct inode *inode = file->f_mapping->host;
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@ -487,7 +487,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
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data->cred = ctx->cred;
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data->args.fh = NFS_FH(inode);
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data->args.context = ctx;
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data->args.offset = file_offset;
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data->args.offset = pos;
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data->args.pgbase = pgbase;
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data->args.pages = &pages[curpage];
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data->args.count = bytes;
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@ -513,7 +513,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
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bytes,
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(unsigned long long)data->args.offset);
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file_offset += bytes;
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pos += bytes;
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pgbase += bytes;
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curpage += pgbase >> PAGE_SHIFT;
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pgbase &= ~PAGE_MASK;
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@ -522,7 +522,7 @@ static void nfs_direct_write_schedule(struct nfs_direct_req *dreq, unsigned long
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} while (count != 0);
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}
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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)
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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)
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{
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ssize_t result;
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sigset_t oldset;
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@ -546,7 +546,7 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
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nfs_begin_data_update(inode);
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rpc_clnt_sigmask(clnt, &oldset);
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nfs_direct_write_schedule(dreq, user_addr, count, file_offset);
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nfs_direct_write_schedule(dreq, user_addr, count, pos);
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result = nfs_direct_wait(dreq);
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rpc_clnt_sigunmask(clnt, &oldset);
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@ -557,18 +557,18 @@ static ssize_t nfs_direct_write(struct kiocb *iocb, unsigned long user_addr, siz
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* nfs_file_direct_read - file direct read operation for NFS files
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* @iocb: target I/O control block
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* @buf: user's buffer into which to read data
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* count: number of bytes to read
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* pos: byte offset in file where reading starts
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* @count: number of bytes to read
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* @pos: byte offset in file where reading starts
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*
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* We use this function for direct reads instead of calling
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* generic_file_aio_read() in order to avoid gfar's check to see if
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* the request starts before the end of the file. For that check
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* to work, we must generate a GETATTR before each direct read, and
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* even then there is a window between the GETATTR and the subsequent
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* READ where the file size could change. So our preference is simply
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* READ where the file size could change. Our preference is simply
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* to do all reads the application wants, and the server will take
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* care of managing the end of file boundary.
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*
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*
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* This function also eliminates unnecessarily updating the file's
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* atime locally, as the NFS server sets the file's atime, and this
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* client must read the updated atime from the server back into its
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@ -621,8 +621,8 @@ out:
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* nfs_file_direct_write - file direct write operation for NFS files
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* @iocb: target I/O control block
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* @buf: user's buffer from which to write data
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* count: number of bytes to write
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* pos: byte offset in file where writing starts
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* @count: number of bytes to write
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* @pos: byte offset in file where writing starts
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*
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* We use this function for direct writes instead of calling
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* generic_file_aio_write() in order to avoid taking the inode
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@ -703,6 +703,10 @@ out:
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return retval;
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}
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/**
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* nfs_init_directcache - create a slab cache for nfs_direct_req structures
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*
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*/
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int nfs_init_directcache(void)
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{
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nfs_direct_cachep = kmem_cache_create("nfs_direct_cache",
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@ -715,6 +719,10 @@ int nfs_init_directcache(void)
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return 0;
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}
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/**
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* nfs_init_directcache - destroy the slab cache for nfs_direct_req structures
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*
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*/
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void nfs_destroy_directcache(void)
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{
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if (kmem_cache_destroy(nfs_direct_cachep))
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