mirror of https://gitee.com/openkylin/linux.git
912 lines
24 KiB
C
912 lines
24 KiB
C
/*
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* linux/fs/nfs/file.c
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*
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* Copyright (C) 1992 Rick Sladkey
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*
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* Changes Copyright (C) 1994 by Florian La Roche
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* - Do not copy data too often around in the kernel.
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* - In nfs_file_read the return value of kmalloc wasn't checked.
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* - Put in a better version of read look-ahead buffering. Original idea
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* and implementation by Wai S Kok elekokws@ee.nus.sg.
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*
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* Expire cache on write to a file by Wai S Kok (Oct 1994).
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*
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* Total rewrite of read side for new NFS buffer cache.. Linus.
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*
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* nfs regular file handling functions
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*/
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#include <linux/module.h>
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#include <linux/time.h>
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#include <linux/kernel.h>
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#include <linux/errno.h>
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#include <linux/fcntl.h>
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#include <linux/stat.h>
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#include <linux/nfs_fs.h>
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#include <linux/nfs_mount.h>
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#include <linux/mm.h>
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#include <linux/pagemap.h>
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#include <linux/aio.h>
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#include <linux/gfp.h>
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#include <linux/swap.h>
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#include <asm/uaccess.h>
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#include "delegation.h"
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#include "internal.h"
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#include "iostat.h"
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#include "fscache.h"
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#define NFSDBG_FACILITY NFSDBG_FILE
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static const struct vm_operations_struct nfs_file_vm_ops;
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/* Hack for future NFS swap support */
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#ifndef IS_SWAPFILE
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# define IS_SWAPFILE(inode) (0)
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#endif
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int nfs_check_flags(int flags)
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{
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if ((flags & (O_APPEND | O_DIRECT)) == (O_APPEND | O_DIRECT))
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return -EINVAL;
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return 0;
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}
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EXPORT_SYMBOL_GPL(nfs_check_flags);
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/*
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* Open file
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*/
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static int
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nfs_file_open(struct inode *inode, struct file *filp)
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{
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int res;
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dprintk("NFS: open file(%s/%s)\n",
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filp->f_path.dentry->d_parent->d_name.name,
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filp->f_path.dentry->d_name.name);
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nfs_inc_stats(inode, NFSIOS_VFSOPEN);
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res = nfs_check_flags(filp->f_flags);
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if (res)
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return res;
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res = nfs_open(inode, filp);
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return res;
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}
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int
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nfs_file_release(struct inode *inode, struct file *filp)
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{
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dprintk("NFS: release(%s/%s)\n",
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filp->f_path.dentry->d_parent->d_name.name,
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filp->f_path.dentry->d_name.name);
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nfs_inc_stats(inode, NFSIOS_VFSRELEASE);
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return nfs_release(inode, filp);
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}
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EXPORT_SYMBOL_GPL(nfs_file_release);
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/**
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* nfs_revalidate_size - Revalidate the file size
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* @inode - pointer to inode struct
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* @file - pointer to struct file
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*
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* Revalidates the file length. This is basically a wrapper around
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* nfs_revalidate_inode() that takes into account the fact that we may
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* have cached writes (in which case we don't care about the server's
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* idea of what the file length is), or O_DIRECT (in which case we
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* shouldn't trust the cache).
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*/
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static int nfs_revalidate_file_size(struct inode *inode, struct file *filp)
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{
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struct nfs_server *server = NFS_SERVER(inode);
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struct nfs_inode *nfsi = NFS_I(inode);
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if (nfs_have_delegated_attributes(inode))
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goto out_noreval;
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if (filp->f_flags & O_DIRECT)
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goto force_reval;
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if (nfsi->cache_validity & NFS_INO_REVAL_PAGECACHE)
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goto force_reval;
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if (nfs_attribute_timeout(inode))
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goto force_reval;
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out_noreval:
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return 0;
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force_reval:
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return __nfs_revalidate_inode(server, inode);
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}
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loff_t nfs_file_llseek(struct file *filp, loff_t offset, int origin)
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{
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dprintk("NFS: llseek file(%s/%s, %lld, %d)\n",
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filp->f_path.dentry->d_parent->d_name.name,
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filp->f_path.dentry->d_name.name,
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offset, origin);
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/*
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* origin == SEEK_END || SEEK_DATA || SEEK_HOLE => we must revalidate
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* the cached file length
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*/
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if (origin != SEEK_SET && origin != SEEK_CUR) {
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struct inode *inode = filp->f_mapping->host;
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int retval = nfs_revalidate_file_size(inode, filp);
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if (retval < 0)
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return (loff_t)retval;
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}
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return generic_file_llseek(filp, offset, origin);
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}
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EXPORT_SYMBOL_GPL(nfs_file_llseek);
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/*
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* Flush all dirty pages, and check for write errors.
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*/
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int
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nfs_file_flush(struct file *file, fl_owner_t id)
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{
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struct dentry *dentry = file->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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dprintk("NFS: flush(%s/%s)\n",
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dentry->d_parent->d_name.name,
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dentry->d_name.name);
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nfs_inc_stats(inode, NFSIOS_VFSFLUSH);
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if ((file->f_mode & FMODE_WRITE) == 0)
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return 0;
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/*
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* If we're holding a write delegation, then just start the i/o
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* but don't wait for completion (or send a commit).
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*/
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if (NFS_PROTO(inode)->have_delegation(inode, FMODE_WRITE))
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return filemap_fdatawrite(file->f_mapping);
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/* Flush writes to the server and return any errors */
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return vfs_fsync(file, 0);
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}
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EXPORT_SYMBOL_GPL(nfs_file_flush);
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ssize_t
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nfs_file_read(struct kiocb *iocb, const struct iovec *iov,
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unsigned long nr_segs, loff_t pos)
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{
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struct dentry * dentry = iocb->ki_filp->f_path.dentry;
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struct inode * inode = dentry->d_inode;
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ssize_t result;
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if (iocb->ki_filp->f_flags & O_DIRECT)
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return nfs_file_direct_read(iocb, iov, nr_segs, pos, true);
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dprintk("NFS: read(%s/%s, %lu@%lu)\n",
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dentry->d_parent->d_name.name, dentry->d_name.name,
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(unsigned long) iov_length(iov, nr_segs), (unsigned long) pos);
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result = nfs_revalidate_mapping(inode, iocb->ki_filp->f_mapping);
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if (!result) {
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result = generic_file_aio_read(iocb, iov, nr_segs, pos);
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if (result > 0)
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nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, result);
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}
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return result;
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}
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EXPORT_SYMBOL_GPL(nfs_file_read);
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ssize_t
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nfs_file_splice_read(struct file *filp, loff_t *ppos,
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struct pipe_inode_info *pipe, size_t count,
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unsigned int flags)
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{
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struct dentry *dentry = filp->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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ssize_t res;
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dprintk("NFS: splice_read(%s/%s, %lu@%Lu)\n",
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dentry->d_parent->d_name.name, dentry->d_name.name,
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(unsigned long) count, (unsigned long long) *ppos);
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res = nfs_revalidate_mapping(inode, filp->f_mapping);
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if (!res) {
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res = generic_file_splice_read(filp, ppos, pipe, count, flags);
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if (res > 0)
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nfs_add_stats(inode, NFSIOS_NORMALREADBYTES, res);
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}
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return res;
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}
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EXPORT_SYMBOL_GPL(nfs_file_splice_read);
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int
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nfs_file_mmap(struct file * file, struct vm_area_struct * vma)
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{
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struct dentry *dentry = file->f_path.dentry;
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struct inode *inode = dentry->d_inode;
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int status;
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dprintk("NFS: mmap(%s/%s)\n",
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dentry->d_parent->d_name.name, dentry->d_name.name);
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/* Note: generic_file_mmap() returns ENOSYS on nommu systems
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* so we call that before revalidating the mapping
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*/
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status = generic_file_mmap(file, vma);
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if (!status) {
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vma->vm_ops = &nfs_file_vm_ops;
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status = nfs_revalidate_mapping(inode, file->f_mapping);
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}
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return status;
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}
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EXPORT_SYMBOL_GPL(nfs_file_mmap);
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/*
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* Flush any dirty pages for this process, and check for write errors.
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* The return status from this call provides a reliable indication of
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* whether any write errors occurred for this process.
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*
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* Notice that it clears the NFS_CONTEXT_ERROR_WRITE before synching to
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* disk, but it retrieves and clears ctx->error after synching, despite
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* the two being set at the same time in nfs_context_set_write_error().
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* This is because the former is used to notify the _next_ call to
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* nfs_file_write() that a write error occurred, and hence cause it to
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* fall back to doing a synchronous write.
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*/
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int
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nfs_file_fsync_commit(struct file *file, loff_t start, loff_t end, int datasync)
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{
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struct dentry *dentry = file->f_path.dentry;
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struct nfs_open_context *ctx = nfs_file_open_context(file);
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struct inode *inode = dentry->d_inode;
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int have_error, status;
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int ret = 0;
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dprintk("NFS: fsync file(%s/%s) datasync %d\n",
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dentry->d_parent->d_name.name, dentry->d_name.name,
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datasync);
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nfs_inc_stats(inode, NFSIOS_VFSFSYNC);
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have_error = test_and_clear_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
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status = nfs_commit_inode(inode, FLUSH_SYNC);
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if (status >= 0 && ret < 0)
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status = ret;
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have_error |= test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags);
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if (have_error)
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ret = xchg(&ctx->error, 0);
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if (!ret && status < 0)
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ret = status;
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return ret;
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}
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EXPORT_SYMBOL_GPL(nfs_file_fsync_commit);
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static int
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nfs_file_fsync(struct file *file, loff_t start, loff_t end, int datasync)
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{
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int ret;
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struct inode *inode = file->f_path.dentry->d_inode;
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ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
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if (ret != 0)
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goto out;
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mutex_lock(&inode->i_mutex);
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ret = nfs_file_fsync_commit(file, start, end, datasync);
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mutex_unlock(&inode->i_mutex);
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out:
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return ret;
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}
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/*
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* Decide whether a read/modify/write cycle may be more efficient
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* then a modify/write/read cycle when writing to a page in the
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* page cache.
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*
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* The modify/write/read cycle may occur if a page is read before
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* being completely filled by the writer. In this situation, the
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* page must be completely written to stable storage on the server
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* before it can be refilled by reading in the page from the server.
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* This can lead to expensive, small, FILE_SYNC mode writes being
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* done.
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*
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* It may be more efficient to read the page first if the file is
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* open for reading in addition to writing, the page is not marked
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* as Uptodate, it is not dirty or waiting to be committed,
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* indicating that it was previously allocated and then modified,
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* that there were valid bytes of data in that range of the file,
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* and that the new data won't completely replace the old data in
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* that range of the file.
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*/
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static int nfs_want_read_modify_write(struct file *file, struct page *page,
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loff_t pos, unsigned len)
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{
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unsigned int pglen = nfs_page_length(page);
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unsigned int offset = pos & (PAGE_CACHE_SIZE - 1);
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unsigned int end = offset + len;
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if ((file->f_mode & FMODE_READ) && /* open for read? */
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!PageUptodate(page) && /* Uptodate? */
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!PagePrivate(page) && /* i/o request already? */
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pglen && /* valid bytes of file? */
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(end < pglen || offset)) /* replace all valid bytes? */
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return 1;
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return 0;
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}
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/*
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* This does the "real" work of the write. We must allocate and lock the
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* page to be sent back to the generic routine, which then copies the
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* data from user space.
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*
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* If the writer ends up delaying the write, the writer needs to
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* increment the page use counts until he is done with the page.
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*/
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static int nfs_write_begin(struct file *file, struct address_space *mapping,
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loff_t pos, unsigned len, unsigned flags,
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struct page **pagep, void **fsdata)
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{
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int ret;
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pgoff_t index = pos >> PAGE_CACHE_SHIFT;
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struct page *page;
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int once_thru = 0;
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dfprintk(PAGECACHE, "NFS: write_begin(%s/%s(%ld), %u@%lld)\n",
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file->f_path.dentry->d_parent->d_name.name,
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file->f_path.dentry->d_name.name,
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mapping->host->i_ino, len, (long long) pos);
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start:
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/*
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* Prevent starvation issues if someone is doing a consistency
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* sync-to-disk
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*/
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ret = wait_on_bit(&NFS_I(mapping->host)->flags, NFS_INO_FLUSHING,
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nfs_wait_bit_killable, TASK_KILLABLE);
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if (ret)
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return ret;
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page = grab_cache_page_write_begin(mapping, index, flags);
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if (!page)
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return -ENOMEM;
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*pagep = page;
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ret = nfs_flush_incompatible(file, page);
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if (ret) {
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unlock_page(page);
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page_cache_release(page);
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} else if (!once_thru &&
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nfs_want_read_modify_write(file, page, pos, len)) {
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once_thru = 1;
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ret = nfs_readpage(file, page);
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page_cache_release(page);
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if (!ret)
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goto start;
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}
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return ret;
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}
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static int nfs_write_end(struct file *file, struct address_space *mapping,
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loff_t pos, unsigned len, unsigned copied,
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struct page *page, void *fsdata)
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{
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unsigned offset = pos & (PAGE_CACHE_SIZE - 1);
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int status;
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dfprintk(PAGECACHE, "NFS: write_end(%s/%s(%ld), %u@%lld)\n",
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file->f_path.dentry->d_parent->d_name.name,
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file->f_path.dentry->d_name.name,
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mapping->host->i_ino, len, (long long) pos);
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/*
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* Zero any uninitialised parts of the page, and then mark the page
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* as up to date if it turns out that we're extending the file.
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*/
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if (!PageUptodate(page)) {
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unsigned pglen = nfs_page_length(page);
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unsigned end = offset + len;
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if (pglen == 0) {
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zero_user_segments(page, 0, offset,
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end, PAGE_CACHE_SIZE);
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SetPageUptodate(page);
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} else if (end >= pglen) {
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zero_user_segment(page, end, PAGE_CACHE_SIZE);
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if (offset == 0)
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SetPageUptodate(page);
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} else
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zero_user_segment(page, pglen, PAGE_CACHE_SIZE);
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}
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status = nfs_updatepage(file, page, offset, copied);
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unlock_page(page);
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page_cache_release(page);
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if (status < 0)
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return status;
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NFS_I(mapping->host)->write_io += copied;
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return copied;
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}
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/*
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* Partially or wholly invalidate a page
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* - Release the private state associated with a page if undergoing complete
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* page invalidation
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* - Called if either PG_private or PG_fscache is set on the page
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* - Caller holds page lock
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*/
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static void nfs_invalidate_page(struct page *page, unsigned long offset)
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{
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dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %lu)\n", page, offset);
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if (offset != 0)
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return;
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/* Cancel any unstarted writes on this page */
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nfs_wb_page_cancel(page_file_mapping(page)->host, page);
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nfs_fscache_invalidate_page(page, page->mapping->host);
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}
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/*
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* Attempt to release the private state associated with a page
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* - Called if either PG_private or PG_fscache is set on the page
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* - Caller holds page lock
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* - Return true (may release page) or false (may not)
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*/
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static int nfs_release_page(struct page *page, gfp_t gfp)
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{
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struct address_space *mapping = page->mapping;
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dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page);
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/* Only do I/O if gfp is a superset of GFP_KERNEL, and we're not
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* doing this memory reclaim for a fs-related allocation.
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*/
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if (mapping && (gfp & GFP_KERNEL) == GFP_KERNEL &&
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!(current->flags & PF_FSTRANS)) {
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int how = FLUSH_SYNC;
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/* Don't let kswapd deadlock waiting for OOM RPC calls */
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if (current_is_kswapd())
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how = 0;
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nfs_commit_inode(mapping->host, how);
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}
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/* If PagePrivate() is set, then the page is not freeable */
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if (PagePrivate(page))
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return 0;
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return nfs_fscache_release_page(page, gfp);
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}
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/*
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* Attempt to clear the private state associated with a page when an error
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* occurs that requires the cached contents of an inode to be written back or
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* destroyed
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* - Called if either PG_private or fscache is set on the page
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* - Caller holds page lock
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|
* - Return 0 if successful, -error otherwise
|
|
*/
|
|
static int nfs_launder_page(struct page *page)
|
|
{
|
|
struct inode *inode = page_file_mapping(page)->host;
|
|
struct nfs_inode *nfsi = NFS_I(inode);
|
|
|
|
dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n",
|
|
inode->i_ino, (long long)page_offset(page));
|
|
|
|
nfs_fscache_wait_on_page_write(nfsi, page);
|
|
return nfs_wb_page(inode, page);
|
|
}
|
|
|
|
#ifdef CONFIG_NFS_SWAP
|
|
static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file,
|
|
sector_t *span)
|
|
{
|
|
*span = sis->pages;
|
|
return xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 1);
|
|
}
|
|
|
|
static void nfs_swap_deactivate(struct file *file)
|
|
{
|
|
xs_swapper(NFS_CLIENT(file->f_mapping->host)->cl_xprt, 0);
|
|
}
|
|
#endif
|
|
|
|
const struct address_space_operations nfs_file_aops = {
|
|
.readpage = nfs_readpage,
|
|
.readpages = nfs_readpages,
|
|
.set_page_dirty = __set_page_dirty_nobuffers,
|
|
.writepage = nfs_writepage,
|
|
.writepages = nfs_writepages,
|
|
.write_begin = nfs_write_begin,
|
|
.write_end = nfs_write_end,
|
|
.invalidatepage = nfs_invalidate_page,
|
|
.releasepage = nfs_release_page,
|
|
.direct_IO = nfs_direct_IO,
|
|
.migratepage = nfs_migrate_page,
|
|
.launder_page = nfs_launder_page,
|
|
.error_remove_page = generic_error_remove_page,
|
|
#ifdef CONFIG_NFS_SWAP
|
|
.swap_activate = nfs_swap_activate,
|
|
.swap_deactivate = nfs_swap_deactivate,
|
|
#endif
|
|
};
|
|
|
|
/*
|
|
* Notification that a PTE pointing to an NFS page is about to be made
|
|
* writable, implying that someone is about to modify the page through a
|
|
* shared-writable mapping
|
|
*/
|
|
static int nfs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
|
|
{
|
|
struct page *page = vmf->page;
|
|
struct file *filp = vma->vm_file;
|
|
struct dentry *dentry = filp->f_path.dentry;
|
|
unsigned pagelen;
|
|
int ret = VM_FAULT_NOPAGE;
|
|
struct address_space *mapping;
|
|
|
|
dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%s/%s(%ld), offset %lld)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
filp->f_mapping->host->i_ino,
|
|
(long long)page_offset(page));
|
|
|
|
/* make sure the cache has finished storing the page */
|
|
nfs_fscache_wait_on_page_write(NFS_I(dentry->d_inode), page);
|
|
|
|
lock_page(page);
|
|
mapping = page_file_mapping(page);
|
|
if (mapping != dentry->d_inode->i_mapping)
|
|
goto out_unlock;
|
|
|
|
wait_on_page_writeback(page);
|
|
|
|
pagelen = nfs_page_length(page);
|
|
if (pagelen == 0)
|
|
goto out_unlock;
|
|
|
|
ret = VM_FAULT_LOCKED;
|
|
if (nfs_flush_incompatible(filp, page) == 0 &&
|
|
nfs_updatepage(filp, page, 0, pagelen) == 0)
|
|
goto out;
|
|
|
|
ret = VM_FAULT_SIGBUS;
|
|
out_unlock:
|
|
unlock_page(page);
|
|
out:
|
|
return ret;
|
|
}
|
|
|
|
static const struct vm_operations_struct nfs_file_vm_ops = {
|
|
.fault = filemap_fault,
|
|
.page_mkwrite = nfs_vm_page_mkwrite,
|
|
};
|
|
|
|
static int nfs_need_sync_write(struct file *filp, struct inode *inode)
|
|
{
|
|
struct nfs_open_context *ctx;
|
|
|
|
if (IS_SYNC(inode) || (filp->f_flags & O_DSYNC))
|
|
return 1;
|
|
ctx = nfs_file_open_context(filp);
|
|
if (test_bit(NFS_CONTEXT_ERROR_WRITE, &ctx->flags))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
ssize_t nfs_file_write(struct kiocb *iocb, const struct iovec *iov,
|
|
unsigned long nr_segs, loff_t pos)
|
|
{
|
|
struct dentry * dentry = iocb->ki_filp->f_path.dentry;
|
|
struct inode * inode = dentry->d_inode;
|
|
unsigned long written = 0;
|
|
ssize_t result;
|
|
size_t count = iov_length(iov, nr_segs);
|
|
|
|
if (iocb->ki_filp->f_flags & O_DIRECT)
|
|
return nfs_file_direct_write(iocb, iov, nr_segs, pos, true);
|
|
|
|
dprintk("NFS: write(%s/%s, %lu@%Ld)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
(unsigned long) count, (long long) pos);
|
|
|
|
result = -EBUSY;
|
|
if (IS_SWAPFILE(inode))
|
|
goto out_swapfile;
|
|
/*
|
|
* O_APPEND implies that we must revalidate the file length.
|
|
*/
|
|
if (iocb->ki_filp->f_flags & O_APPEND) {
|
|
result = nfs_revalidate_file_size(inode, iocb->ki_filp);
|
|
if (result)
|
|
goto out;
|
|
}
|
|
|
|
result = count;
|
|
if (!count)
|
|
goto out;
|
|
|
|
result = generic_file_aio_write(iocb, iov, nr_segs, pos);
|
|
if (result > 0)
|
|
written = result;
|
|
|
|
/* Return error values for O_DSYNC and IS_SYNC() */
|
|
if (result >= 0 && nfs_need_sync_write(iocb->ki_filp, inode)) {
|
|
int err = vfs_fsync(iocb->ki_filp, 0);
|
|
if (err < 0)
|
|
result = err;
|
|
}
|
|
if (result > 0)
|
|
nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
|
|
out:
|
|
return result;
|
|
|
|
out_swapfile:
|
|
printk(KERN_INFO "NFS: attempt to write to active swap file!\n");
|
|
goto out;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_file_write);
|
|
|
|
ssize_t nfs_file_splice_write(struct pipe_inode_info *pipe,
|
|
struct file *filp, loff_t *ppos,
|
|
size_t count, unsigned int flags)
|
|
{
|
|
struct dentry *dentry = filp->f_path.dentry;
|
|
struct inode *inode = dentry->d_inode;
|
|
unsigned long written = 0;
|
|
ssize_t ret;
|
|
|
|
dprintk("NFS splice_write(%s/%s, %lu@%llu)\n",
|
|
dentry->d_parent->d_name.name, dentry->d_name.name,
|
|
(unsigned long) count, (unsigned long long) *ppos);
|
|
|
|
/*
|
|
* The combination of splice and an O_APPEND destination is disallowed.
|
|
*/
|
|
|
|
ret = generic_file_splice_write(pipe, filp, ppos, count, flags);
|
|
if (ret > 0)
|
|
written = ret;
|
|
|
|
if (ret >= 0 && nfs_need_sync_write(filp, inode)) {
|
|
int err = vfs_fsync(filp, 0);
|
|
if (err < 0)
|
|
ret = err;
|
|
}
|
|
if (ret > 0)
|
|
nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written);
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_file_splice_write);
|
|
|
|
static int
|
|
do_getlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
|
|
{
|
|
struct inode *inode = filp->f_mapping->host;
|
|
int status = 0;
|
|
unsigned int saved_type = fl->fl_type;
|
|
|
|
/* Try local locking first */
|
|
posix_test_lock(filp, fl);
|
|
if (fl->fl_type != F_UNLCK) {
|
|
/* found a conflict */
|
|
goto out;
|
|
}
|
|
fl->fl_type = saved_type;
|
|
|
|
if (NFS_PROTO(inode)->have_delegation(inode, FMODE_READ))
|
|
goto out_noconflict;
|
|
|
|
if (is_local)
|
|
goto out_noconflict;
|
|
|
|
status = NFS_PROTO(inode)->lock(filp, cmd, fl);
|
|
out:
|
|
return status;
|
|
out_noconflict:
|
|
fl->fl_type = F_UNLCK;
|
|
goto out;
|
|
}
|
|
|
|
static int do_vfs_lock(struct file *file, struct file_lock *fl)
|
|
{
|
|
int res = 0;
|
|
switch (fl->fl_flags & (FL_POSIX|FL_FLOCK)) {
|
|
case FL_POSIX:
|
|
res = posix_lock_file_wait(file, fl);
|
|
break;
|
|
case FL_FLOCK:
|
|
res = flock_lock_file_wait(file, fl);
|
|
break;
|
|
default:
|
|
BUG();
|
|
}
|
|
return res;
|
|
}
|
|
|
|
static int
|
|
do_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
|
|
{
|
|
struct inode *inode = filp->f_mapping->host;
|
|
int status;
|
|
|
|
/*
|
|
* Flush all pending writes before doing anything
|
|
* with locks..
|
|
*/
|
|
nfs_sync_mapping(filp->f_mapping);
|
|
|
|
/* NOTE: special case
|
|
* If we're signalled while cleaning up locks on process exit, we
|
|
* still need to complete the unlock.
|
|
*/
|
|
/*
|
|
* Use local locking if mounted with "-onolock" or with appropriate
|
|
* "-olocal_lock="
|
|
*/
|
|
if (!is_local)
|
|
status = NFS_PROTO(inode)->lock(filp, cmd, fl);
|
|
else
|
|
status = do_vfs_lock(filp, fl);
|
|
return status;
|
|
}
|
|
|
|
static int
|
|
is_time_granular(struct timespec *ts) {
|
|
return ((ts->tv_sec == 0) && (ts->tv_nsec <= 1000));
|
|
}
|
|
|
|
static int
|
|
do_setlk(struct file *filp, int cmd, struct file_lock *fl, int is_local)
|
|
{
|
|
struct inode *inode = filp->f_mapping->host;
|
|
int status;
|
|
|
|
/*
|
|
* Flush all pending writes before doing anything
|
|
* with locks..
|
|
*/
|
|
status = nfs_sync_mapping(filp->f_mapping);
|
|
if (status != 0)
|
|
goto out;
|
|
|
|
/*
|
|
* Use local locking if mounted with "-onolock" or with appropriate
|
|
* "-olocal_lock="
|
|
*/
|
|
if (!is_local)
|
|
status = NFS_PROTO(inode)->lock(filp, cmd, fl);
|
|
else
|
|
status = do_vfs_lock(filp, fl);
|
|
if (status < 0)
|
|
goto out;
|
|
|
|
/*
|
|
* Revalidate the cache if the server has time stamps granular
|
|
* enough to detect subsecond changes. Otherwise, clear the
|
|
* cache to prevent missing any changes.
|
|
*
|
|
* This makes locking act as a cache coherency point.
|
|
*/
|
|
nfs_sync_mapping(filp->f_mapping);
|
|
if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) {
|
|
if (is_time_granular(&NFS_SERVER(inode)->time_delta))
|
|
__nfs_revalidate_inode(NFS_SERVER(inode), inode);
|
|
else
|
|
nfs_zap_caches(inode);
|
|
}
|
|
out:
|
|
return status;
|
|
}
|
|
|
|
/*
|
|
* Lock a (portion of) a file
|
|
*/
|
|
int nfs_lock(struct file *filp, int cmd, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = filp->f_mapping->host;
|
|
int ret = -ENOLCK;
|
|
int is_local = 0;
|
|
|
|
dprintk("NFS: lock(%s/%s, t=%x, fl=%x, r=%lld:%lld)\n",
|
|
filp->f_path.dentry->d_parent->d_name.name,
|
|
filp->f_path.dentry->d_name.name,
|
|
fl->fl_type, fl->fl_flags,
|
|
(long long)fl->fl_start, (long long)fl->fl_end);
|
|
|
|
nfs_inc_stats(inode, NFSIOS_VFSLOCK);
|
|
|
|
/* No mandatory locks over NFS */
|
|
if (__mandatory_lock(inode) && fl->fl_type != F_UNLCK)
|
|
goto out_err;
|
|
|
|
if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FCNTL)
|
|
is_local = 1;
|
|
|
|
if (NFS_PROTO(inode)->lock_check_bounds != NULL) {
|
|
ret = NFS_PROTO(inode)->lock_check_bounds(fl);
|
|
if (ret < 0)
|
|
goto out_err;
|
|
}
|
|
|
|
if (IS_GETLK(cmd))
|
|
ret = do_getlk(filp, cmd, fl, is_local);
|
|
else if (fl->fl_type == F_UNLCK)
|
|
ret = do_unlk(filp, cmd, fl, is_local);
|
|
else
|
|
ret = do_setlk(filp, cmd, fl, is_local);
|
|
out_err:
|
|
return ret;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_lock);
|
|
|
|
/*
|
|
* Lock a (portion of) a file
|
|
*/
|
|
int nfs_flock(struct file *filp, int cmd, struct file_lock *fl)
|
|
{
|
|
struct inode *inode = filp->f_mapping->host;
|
|
int is_local = 0;
|
|
|
|
dprintk("NFS: flock(%s/%s, t=%x, fl=%x)\n",
|
|
filp->f_path.dentry->d_parent->d_name.name,
|
|
filp->f_path.dentry->d_name.name,
|
|
fl->fl_type, fl->fl_flags);
|
|
|
|
if (!(fl->fl_flags & FL_FLOCK))
|
|
return -ENOLCK;
|
|
|
|
/*
|
|
* The NFSv4 protocol doesn't support LOCK_MAND, which is not part of
|
|
* any standard. In principle we might be able to support LOCK_MAND
|
|
* on NFSv2/3 since NLMv3/4 support DOS share modes, but for now the
|
|
* NFS code is not set up for it.
|
|
*/
|
|
if (fl->fl_type & LOCK_MAND)
|
|
return -EINVAL;
|
|
|
|
if (NFS_SERVER(inode)->flags & NFS_MOUNT_LOCAL_FLOCK)
|
|
is_local = 1;
|
|
|
|
/* We're simulating flock() locks using posix locks on the server */
|
|
fl->fl_owner = (fl_owner_t)filp;
|
|
fl->fl_start = 0;
|
|
fl->fl_end = OFFSET_MAX;
|
|
|
|
if (fl->fl_type == F_UNLCK)
|
|
return do_unlk(filp, cmd, fl, is_local);
|
|
return do_setlk(filp, cmd, fl, is_local);
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_flock);
|
|
|
|
/*
|
|
* There is no protocol support for leases, so we have no way to implement
|
|
* them correctly in the face of opens by other clients.
|
|
*/
|
|
int nfs_setlease(struct file *file, long arg, struct file_lock **fl)
|
|
{
|
|
dprintk("NFS: setlease(%s/%s, arg=%ld)\n",
|
|
file->f_path.dentry->d_parent->d_name.name,
|
|
file->f_path.dentry->d_name.name, arg);
|
|
return -EINVAL;
|
|
}
|
|
EXPORT_SYMBOL_GPL(nfs_setlease);
|
|
|
|
const struct file_operations nfs_file_operations = {
|
|
.llseek = nfs_file_llseek,
|
|
.read = do_sync_read,
|
|
.write = do_sync_write,
|
|
.aio_read = nfs_file_read,
|
|
.aio_write = nfs_file_write,
|
|
.mmap = nfs_file_mmap,
|
|
.open = nfs_file_open,
|
|
.flush = nfs_file_flush,
|
|
.release = nfs_file_release,
|
|
.fsync = nfs_file_fsync,
|
|
.lock = nfs_lock,
|
|
.flock = nfs_flock,
|
|
.splice_read = nfs_file_splice_read,
|
|
.splice_write = nfs_file_splice_write,
|
|
.check_flags = nfs_check_flags,
|
|
.setlease = nfs_setlease,
|
|
};
|
|
EXPORT_SYMBOL_GPL(nfs_file_operations);
|