From 14a3ec79437252d922bae574ecbf0c0584c330f3 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Thu, 14 Nov 2013 08:50:31 -0800 Subject: [PATCH] nfs: merge nfs_direct_read into nfs_file_direct_read Simple code cleanup to prepare for later fixes. Signed-off-by: Christoph Hellwig Signed-off-by: Trond Myklebust --- fs/nfs/direct.c | 107 ++++++++++++++++++++++++++------------------------------ 1 file changed, 49 insertions(+), 58 deletions(-) diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c index 6c23210..f8b0a81 100644 --- a/fs/nfs/direct.c +++ b/fs/nfs/direct.c @@ -458,14 +458,55 @@ static ssize_t nfs_direct_read_schedule_iovec(struct nfs_direct_req *dreq, return 0; } -static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos, bool uio) +/** + * nfs_file_direct_read - file direct read operation for NFS files + * @iocb: target I/O control block + * @iov: vector of user buffers into which to read data + * @nr_segs: size of iov vector + * @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. 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 + * cache. + */ +ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos, bool uio) { - ssize_t result = -ENOMEM; - struct inode *inode = iocb->ki_filp->f_mapping->host; + struct file *file = iocb->ki_filp; + struct address_space *mapping = file->f_mapping; + struct inode *inode = mapping->host; struct nfs_direct_req *dreq; struct nfs_lock_context *l_ctx; + ssize_t result = -EINVAL; + size_t count; + + count = iov_length(iov, nr_segs); + nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); + + dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n", + file, count, (long long) pos); + + result = 0; + if (!count) + goto out; + + result = nfs_sync_mapping(mapping); + if (result) + goto out; + + task_io_account_read(count); + result = -ENOMEM; dreq = nfs_direct_req_alloc(); if (dreq == NULL) goto out; @@ -484,8 +525,11 @@ static ssize_t nfs_direct_read(struct kiocb *iocb, const struct iovec *iov, NFS_I(inode)->read_io += iov_length(iov, nr_segs); result = nfs_direct_read_schedule_iovec(dreq, iov, nr_segs, pos, uio); - if (!result) + if (!result) { result = nfs_direct_wait(dreq); + if (result > 0) + iocb->ki_pos = pos + result; + } out_release: nfs_direct_req_release(dreq); out: @@ -889,59 +933,6 @@ out: } /** - * nfs_file_direct_read - file direct read operation for NFS files - * @iocb: target I/O control block - * @iov: vector of user buffers into which to read data - * @nr_segs: size of iov vector - * @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. 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 - * cache. - */ -ssize_t nfs_file_direct_read(struct kiocb *iocb, const struct iovec *iov, - unsigned long nr_segs, loff_t pos, bool uio) -{ - ssize_t retval = -EINVAL; - struct file *file = iocb->ki_filp; - struct address_space *mapping = file->f_mapping; - size_t count; - - count = iov_length(iov, nr_segs); - nfs_add_stats(mapping->host, NFSIOS_DIRECTREADBYTES, count); - - dfprintk(FILE, "NFS: direct read(%pD2, %zd@%Ld)\n", - file, count, (long long) pos); - - retval = 0; - if (!count) - goto out; - - retval = nfs_sync_mapping(mapping); - if (retval) - goto out; - - task_io_account_read(count); - - retval = nfs_direct_read(iocb, iov, nr_segs, pos, uio); - if (retval > 0) - iocb->ki_pos = pos + retval; - -out: - return retval; -} - -/** * nfs_file_direct_write - file direct write operation for NFS files * @iocb: target I/O control block * @iov: vector of user buffers from which to write data -- 2.7.4