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882 lines
22 KiB
882 lines
22 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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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 [email protected]. |
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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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|
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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/gfp.h> |
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#include <linux/swap.h> |
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|
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#include <linux/uaccess.h> |
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|
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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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#include "pnfs.h" |
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|
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#include "nfstrace.h" |
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|
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#define NFSDBG_FACILITY NFSDBG_FILE |
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|
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static const struct vm_operations_struct nfs_file_vm_ops; |
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|
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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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|
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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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/* |
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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(%pD2)\n", filp); |
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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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|
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res = nfs_open(inode, filp); |
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return res; |
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} |
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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(%pD2)\n", filp); |
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|
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nfs_inc_stats(inode, NFSIOS_VFSRELEASE); |
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nfs_file_clear_open_context(filp); |
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return 0; |
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} |
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EXPORT_SYMBOL_GPL(nfs_file_release); |
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|
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/** |
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* nfs_revalidate_file_size - Revalidate the file size |
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* @inode: pointer to inode struct |
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* @filp: 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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if (filp->f_flags & O_DIRECT) |
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goto force_reval; |
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if (nfs_check_cache_invalid(inode, NFS_INO_REVAL_PAGECACHE)) |
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goto force_reval; |
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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 whence) |
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{ |
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dprintk("NFS: llseek file(%pD2, %lld, %d)\n", |
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filp, offset, whence); |
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|
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/* |
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* whence == 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 (whence != SEEK_SET && whence != SEEK_CUR) { |
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struct inode *inode = filp->f_mapping->host; |
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|
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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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|
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return generic_file_llseek(filp, offset, whence); |
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} |
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EXPORT_SYMBOL_GPL(nfs_file_llseek); |
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|
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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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static int |
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nfs_file_flush(struct file *file, fl_owner_t id) |
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{ |
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struct inode *inode = file_inode(file); |
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errseq_t since; |
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dprintk("NFS: flush(%pD2)\n", file); |
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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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/* Flush writes to the server and return any errors */ |
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since = filemap_sample_wb_err(file->f_mapping); |
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nfs_wb_all(inode); |
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return filemap_check_wb_err(file->f_mapping, since); |
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} |
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ssize_t |
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nfs_file_read(struct kiocb *iocb, struct iov_iter *to) |
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{ |
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struct inode *inode = file_inode(iocb->ki_filp); |
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ssize_t result; |
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if (iocb->ki_flags & IOCB_DIRECT) |
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return nfs_file_direct_read(iocb, to); |
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dprintk("NFS: read(%pD2, %zu@%lu)\n", |
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iocb->ki_filp, |
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iov_iter_count(to), (unsigned long) iocb->ki_pos); |
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nfs_start_io_read(inode); |
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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_read_iter(iocb, to); |
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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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nfs_end_io_read(inode); |
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return result; |
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} |
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EXPORT_SYMBOL_GPL(nfs_file_read); |
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|
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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 inode *inode = file_inode(file); |
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int status; |
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dprintk("NFS: mmap(%pD2)\n", file); |
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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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/* |
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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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static int |
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nfs_file_fsync_commit(struct file *file, int datasync) |
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{ |
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struct inode *inode = file_inode(file); |
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int ret; |
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dprintk("NFS: fsync file(%pD2) datasync %d\n", file, datasync); |
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nfs_inc_stats(inode, NFSIOS_VFSFSYNC); |
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ret = nfs_commit_inode(inode, FLUSH_SYNC); |
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if (ret < 0) |
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return ret; |
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return file_check_and_advance_wb_err(file); |
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} |
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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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struct nfs_open_context *ctx = nfs_file_open_context(file); |
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struct inode *inode = file_inode(file); |
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int ret; |
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trace_nfs_fsync_enter(inode); |
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for (;;) { |
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ret = file_write_and_wait_range(file, start, end); |
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if (ret != 0) |
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break; |
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ret = nfs_file_fsync_commit(file, datasync); |
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if (ret != 0) |
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break; |
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ret = pnfs_sync_inode(inode, !!datasync); |
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if (ret != 0) |
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break; |
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if (!test_and_clear_bit(NFS_CONTEXT_RESEND_WRITES, &ctx->flags)) |
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break; |
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/* |
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* If nfs_file_fsync_commit detected a server reboot, then |
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* resend all dirty pages that might have been covered by |
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* the NFS_CONTEXT_RESEND_WRITES flag |
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*/ |
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start = 0; |
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end = LLONG_MAX; |
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} |
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trace_nfs_fsync_exit(inode, ret); |
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return ret; |
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} |
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EXPORT_SYMBOL_GPL(nfs_file_fsync); |
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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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* Some pNFS layout drivers can only read/write at a certain block |
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* granularity like all block devices and therefore we must perform |
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* read/modify/write whenever a page hasn't read yet and the data |
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* to be written there is not aligned to a block boundary and/or |
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* smaller than the block size. |
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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 bool nfs_full_page_write(struct page *page, loff_t pos, unsigned int 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_SIZE - 1); |
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unsigned int end = offset + len; |
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return !pglen || (end >= pglen && !offset); |
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} |
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static bool nfs_want_read_modify_write(struct file *file, struct page *page, |
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loff_t pos, unsigned int len) |
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{ |
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/* |
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* Up-to-date pages, those with ongoing or full-page write |
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* don't need read/modify/write |
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*/ |
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if (PageUptodate(page) || PagePrivate(page) || |
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nfs_full_page_write(page, pos, len)) |
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return false; |
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if (pnfs_ld_read_whole_page(file->f_mapping->host)) |
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return true; |
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/* Open for reading too? */ |
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if (file->f_mode & FMODE_READ) |
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return true; |
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return false; |
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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_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(%pD2(%lu), %u@%lld)\n", |
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file, mapping->host->i_ino, len, (long long) pos); |
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start: |
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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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put_page(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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put_page(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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|
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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_SIZE - 1); |
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struct nfs_open_context *ctx = nfs_file_open_context(file); |
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int status; |
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dfprintk(PAGECACHE, "NFS: write_end(%pD2(%lu), %u@%lld)\n", |
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file, 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 + copied; |
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if (pglen == 0) { |
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zero_user_segments(page, 0, offset, |
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end, PAGE_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_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_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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put_page(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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if (nfs_ctx_key_to_expire(ctx, mapping->host)) { |
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status = nfs_wb_all(mapping->host); |
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if (status < 0) |
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return status; |
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} |
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return copied; |
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} |
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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 int offset, |
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unsigned int length) |
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{ |
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dfprintk(PAGECACHE, "NFS: invalidate_page(%p, %u, %u)\n", |
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page, offset, length); |
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if (offset != 0 || length < PAGE_SIZE) |
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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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dfprintk(PAGECACHE, "NFS: release_page(%p)\n", page); |
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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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static void nfs_check_dirty_writeback(struct page *page, |
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bool *dirty, bool *writeback) |
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{ |
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struct nfs_inode *nfsi; |
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struct address_space *mapping = page_file_mapping(page); |
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|
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if (!mapping || PageSwapCache(page)) |
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return; |
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/* |
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* Check if an unstable page is currently being committed and |
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* if so, have the VM treat it as if the page is under writeback |
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* so it will not block due to pages that will shortly be freeable. |
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*/ |
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nfsi = NFS_I(mapping->host); |
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if (atomic_read(&nfsi->commit_info.rpcs_out)) { |
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*writeback = true; |
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return; |
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} |
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|
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/* |
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* If PagePrivate() is set, then the page is not freeable and as the |
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* inode is not being committed, it's not going to be cleaned in the |
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* near future so treat it as dirty |
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*/ |
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if (PagePrivate(page)) |
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*dirty = true; |
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} |
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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 |
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*/ |
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static int nfs_launder_page(struct page *page) |
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{ |
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struct inode *inode = page_file_mapping(page)->host; |
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struct nfs_inode *nfsi = NFS_I(inode); |
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dfprintk(PAGECACHE, "NFS: launder_page(%ld, %llu)\n", |
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inode->i_ino, (long long)page_offset(page)); |
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nfs_fscache_wait_on_page_write(nfsi, page); |
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return nfs_wb_page(inode, page); |
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} |
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|
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static int nfs_swap_activate(struct swap_info_struct *sis, struct file *file, |
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sector_t *span) |
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{ |
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unsigned long blocks; |
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long long isize; |
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struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); |
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struct inode *inode = file->f_mapping->host; |
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|
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spin_lock(&inode->i_lock); |
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blocks = inode->i_blocks; |
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isize = inode->i_size; |
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spin_unlock(&inode->i_lock); |
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if (blocks*512 < isize) { |
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pr_warn("swap activate: swapfile has holes\n"); |
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return -EINVAL; |
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} |
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|
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*span = sis->pages; |
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|
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return rpc_clnt_swap_activate(clnt); |
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} |
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|
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static void nfs_swap_deactivate(struct file *file) |
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{ |
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struct rpc_clnt *clnt = NFS_CLIENT(file->f_mapping->host); |
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|
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rpc_clnt_swap_deactivate(clnt); |
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} |
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|
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const struct address_space_operations nfs_file_aops = { |
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.readpage = nfs_readpage, |
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.readpages = nfs_readpages, |
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.set_page_dirty = __set_page_dirty_nobuffers, |
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.writepage = nfs_writepage, |
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.writepages = nfs_writepages, |
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.write_begin = nfs_write_begin, |
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.write_end = nfs_write_end, |
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.invalidatepage = nfs_invalidate_page, |
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.releasepage = nfs_release_page, |
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.direct_IO = nfs_direct_IO, |
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#ifdef CONFIG_MIGRATION |
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.migratepage = nfs_migrate_page, |
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#endif |
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.launder_page = nfs_launder_page, |
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.is_dirty_writeback = nfs_check_dirty_writeback, |
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.error_remove_page = generic_error_remove_page, |
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.swap_activate = nfs_swap_activate, |
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.swap_deactivate = nfs_swap_deactivate, |
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}; |
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|
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/* |
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* Notification that a PTE pointing to an NFS page is about to be made |
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* writable, implying that someone is about to modify the page through a |
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* shared-writable mapping |
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*/ |
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static vm_fault_t nfs_vm_page_mkwrite(struct vm_fault *vmf) |
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{ |
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struct page *page = vmf->page; |
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struct file *filp = vmf->vma->vm_file; |
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struct inode *inode = file_inode(filp); |
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unsigned pagelen; |
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vm_fault_t ret = VM_FAULT_NOPAGE; |
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struct address_space *mapping; |
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|
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dfprintk(PAGECACHE, "NFS: vm_page_mkwrite(%pD2(%lu), offset %lld)\n", |
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filp, filp->f_mapping->host->i_ino, |
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(long long)page_offset(page)); |
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|
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sb_start_pagefault(inode->i_sb); |
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|
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/* make sure the cache has finished storing the page */ |
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nfs_fscache_wait_on_page_write(NFS_I(inode), page); |
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|
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wait_on_bit_action(&NFS_I(inode)->flags, NFS_INO_INVALIDATING, |
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nfs_wait_bit_killable, TASK_KILLABLE); |
|
|
|
lock_page(page); |
|
mapping = page_file_mapping(page); |
|
if (mapping != 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: |
|
sb_end_pagefault(inode->i_sb); |
|
return ret; |
|
} |
|
|
|
static const struct vm_operations_struct nfs_file_vm_ops = { |
|
.fault = filemap_fault, |
|
.map_pages = filemap_map_pages, |
|
.page_mkwrite = nfs_vm_page_mkwrite, |
|
}; |
|
|
|
static int nfs_need_check_write(struct file *filp, struct inode *inode, |
|
int error) |
|
{ |
|
struct nfs_open_context *ctx; |
|
|
|
ctx = nfs_file_open_context(filp); |
|
if (nfs_error_is_fatal_on_server(error) || |
|
nfs_ctx_key_to_expire(ctx, inode)) |
|
return 1; |
|
return 0; |
|
} |
|
|
|
ssize_t nfs_file_write(struct kiocb *iocb, struct iov_iter *from) |
|
{ |
|
struct file *file = iocb->ki_filp; |
|
struct inode *inode = file_inode(file); |
|
unsigned int mntflags = NFS_SERVER(inode)->flags; |
|
ssize_t result, written; |
|
errseq_t since; |
|
int error; |
|
|
|
result = nfs_key_timeout_notify(file, inode); |
|
if (result) |
|
return result; |
|
|
|
if (iocb->ki_flags & IOCB_DIRECT) |
|
return nfs_file_direct_write(iocb, from); |
|
|
|
dprintk("NFS: write(%pD2, %zu@%Ld)\n", |
|
file, iov_iter_count(from), (long long) iocb->ki_pos); |
|
|
|
if (IS_SWAPFILE(inode)) |
|
goto out_swapfile; |
|
/* |
|
* O_APPEND implies that we must revalidate the file length. |
|
*/ |
|
if (iocb->ki_flags & IOCB_APPEND || iocb->ki_pos > i_size_read(inode)) { |
|
result = nfs_revalidate_file_size(inode, file); |
|
if (result) |
|
goto out; |
|
} |
|
|
|
nfs_clear_invalid_mapping(file->f_mapping); |
|
|
|
since = filemap_sample_wb_err(file->f_mapping); |
|
nfs_start_io_write(inode); |
|
result = generic_write_checks(iocb, from); |
|
if (result > 0) { |
|
current->backing_dev_info = inode_to_bdi(inode); |
|
result = generic_perform_write(file, from, iocb->ki_pos); |
|
current->backing_dev_info = NULL; |
|
} |
|
nfs_end_io_write(inode); |
|
if (result <= 0) |
|
goto out; |
|
|
|
written = result; |
|
iocb->ki_pos += written; |
|
|
|
if (mntflags & NFS_MOUNT_WRITE_EAGER) { |
|
result = filemap_fdatawrite_range(file->f_mapping, |
|
iocb->ki_pos - written, |
|
iocb->ki_pos - 1); |
|
if (result < 0) |
|
goto out; |
|
} |
|
if (mntflags & NFS_MOUNT_WRITE_WAIT) { |
|
result = filemap_fdatawait_range(file->f_mapping, |
|
iocb->ki_pos - written, |
|
iocb->ki_pos - 1); |
|
if (result < 0) |
|
goto out; |
|
} |
|
result = generic_write_sync(iocb, written); |
|
if (result < 0) |
|
goto out; |
|
|
|
/* Return error values */ |
|
error = filemap_check_wb_err(file->f_mapping, since); |
|
if (nfs_need_check_write(file, inode, error)) { |
|
int err = nfs_wb_all(inode); |
|
if (err < 0) |
|
result = err; |
|
} |
|
nfs_add_stats(inode, NFSIOS_NORMALWRITTENBYTES, written); |
|
out: |
|
return result; |
|
|
|
out_swapfile: |
|
printk(KERN_INFO "NFS: attempt to write to active swap file!\n"); |
|
return -ETXTBSY; |
|
} |
|
EXPORT_SYMBOL_GPL(nfs_file_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_unlk(struct file *filp, int cmd, struct file_lock *fl, int is_local) |
|
{ |
|
struct inode *inode = filp->f_mapping->host; |
|
struct nfs_lock_context *l_ctx; |
|
int status; |
|
|
|
/* |
|
* Flush all pending writes before doing anything |
|
* with locks.. |
|
*/ |
|
nfs_wb_all(inode); |
|
|
|
l_ctx = nfs_get_lock_context(nfs_file_open_context(filp)); |
|
if (!IS_ERR(l_ctx)) { |
|
status = nfs_iocounter_wait(l_ctx); |
|
nfs_put_lock_context(l_ctx); |
|
/* NOTE: special case |
|
* If we're signalled while cleaning up locks on process exit, we |
|
* still need to complete the unlock. |
|
*/ |
|
if (status < 0 && !(fl->fl_flags & FL_CLOSE)) |
|
return status; |
|
} |
|
|
|
/* |
|
* 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 = locks_lock_file_wait(filp, fl); |
|
return status; |
|
} |
|
|
|
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 = locks_lock_file_wait(filp, fl); |
|
if (status < 0) |
|
goto out; |
|
|
|
/* |
|
* Invalidate cache to prevent missing any changes. If |
|
* the file is mapped, clear the page cache as well so |
|
* those mappings will be loaded. |
|
* |
|
* This makes locking act as a cache coherency point. |
|
*/ |
|
nfs_sync_mapping(filp->f_mapping); |
|
if (!NFS_PROTO(inode)->have_delegation(inode, FMODE_READ)) { |
|
nfs_zap_caches(inode); |
|
if (mapping_mapped(filp->f_mapping)) |
|
nfs_revalidate_mapping(inode, filp->f_mapping); |
|
} |
|
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(%pD2, t=%x, fl=%x, r=%lld:%lld)\n", |
|
filp, 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(%pD2, t=%x, fl=%x)\n", |
|
filp, 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 */ |
|
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); |
|
|
|
const struct file_operations nfs_file_operations = { |
|
.llseek = nfs_file_llseek, |
|
.read_iter = nfs_file_read, |
|
.write_iter = 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 = generic_file_splice_read, |
|
.splice_write = iter_file_splice_write, |
|
.check_flags = nfs_check_flags, |
|
.setlease = simple_nosetlease, |
|
}; |
|
EXPORT_SYMBOL_GPL(nfs_file_operations);
|
|
|