diff options
Diffstat (limited to 'fs/nfs/direct.c')
| -rw-r--r-- | fs/nfs/direct.c | 54 |
1 files changed, 31 insertions, 23 deletions
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index df86e526702f..bcbc213b4033 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -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)) |