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153 lines
3.6 KiB
153 lines
3.6 KiB
// SPDX-License-Identifier: GPL-2.0+ |
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/* |
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* file.c - NILFS regular file handling primitives including fsync(). |
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* |
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* Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. |
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* |
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* Written by Amagai Yoshiji and Ryusuke Konishi. |
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*/ |
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#include <linux/fs.h> |
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#include <linux/mm.h> |
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#include <linux/writeback.h> |
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#include "nilfs.h" |
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#include "segment.h" |
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int nilfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) |
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{ |
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/* |
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* Called from fsync() system call |
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* This is the only entry point that can catch write and synch |
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* timing for both data blocks and intermediate blocks. |
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* |
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* This function should be implemented when the writeback function |
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* will be implemented. |
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*/ |
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struct the_nilfs *nilfs; |
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struct inode *inode = file->f_mapping->host; |
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int err = 0; |
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if (nilfs_inode_dirty(inode)) { |
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if (datasync) |
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err = nilfs_construct_dsync_segment(inode->i_sb, inode, |
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start, end); |
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else |
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err = nilfs_construct_segment(inode->i_sb); |
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} |
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nilfs = inode->i_sb->s_fs_info; |
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if (!err) |
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err = nilfs_flush_device(nilfs); |
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return err; |
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} |
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static vm_fault_t nilfs_page_mkwrite(struct vm_fault *vmf) |
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{ |
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struct vm_area_struct *vma = vmf->vma; |
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struct page *page = vmf->page; |
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struct inode *inode = file_inode(vma->vm_file); |
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struct nilfs_transaction_info ti; |
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int ret = 0; |
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if (unlikely(nilfs_near_disk_full(inode->i_sb->s_fs_info))) |
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return VM_FAULT_SIGBUS; /* -ENOSPC */ |
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sb_start_pagefault(inode->i_sb); |
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lock_page(page); |
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if (page->mapping != inode->i_mapping || |
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page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) { |
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unlock_page(page); |
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ret = -EFAULT; /* make the VM retry the fault */ |
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goto out; |
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} |
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/* |
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* check to see if the page is mapped already (no holes) |
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*/ |
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if (PageMappedToDisk(page)) |
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goto mapped; |
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if (page_has_buffers(page)) { |
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struct buffer_head *bh, *head; |
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int fully_mapped = 1; |
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bh = head = page_buffers(page); |
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do { |
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if (!buffer_mapped(bh)) { |
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fully_mapped = 0; |
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break; |
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} |
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} while (bh = bh->b_this_page, bh != head); |
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if (fully_mapped) { |
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SetPageMappedToDisk(page); |
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goto mapped; |
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} |
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} |
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unlock_page(page); |
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/* |
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* fill hole blocks |
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*/ |
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ret = nilfs_transaction_begin(inode->i_sb, &ti, 1); |
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/* never returns -ENOMEM, but may return -ENOSPC */ |
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if (unlikely(ret)) |
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goto out; |
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file_update_time(vma->vm_file); |
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ret = block_page_mkwrite(vma, vmf, nilfs_get_block); |
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if (ret) { |
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nilfs_transaction_abort(inode->i_sb); |
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goto out; |
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} |
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nilfs_set_file_dirty(inode, 1 << (PAGE_SHIFT - inode->i_blkbits)); |
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nilfs_transaction_commit(inode->i_sb); |
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mapped: |
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wait_for_stable_page(page); |
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out: |
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sb_end_pagefault(inode->i_sb); |
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return block_page_mkwrite_return(ret); |
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} |
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static const struct vm_operations_struct nilfs_file_vm_ops = { |
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.fault = filemap_fault, |
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.map_pages = filemap_map_pages, |
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.page_mkwrite = nilfs_page_mkwrite, |
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}; |
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static int nilfs_file_mmap(struct file *file, struct vm_area_struct *vma) |
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{ |
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file_accessed(file); |
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vma->vm_ops = &nilfs_file_vm_ops; |
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return 0; |
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} |
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/* |
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* We have mostly NULL's here: the current defaults are ok for |
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* the nilfs filesystem. |
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*/ |
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const struct file_operations nilfs_file_operations = { |
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.llseek = generic_file_llseek, |
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.read_iter = generic_file_read_iter, |
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.write_iter = generic_file_write_iter, |
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.unlocked_ioctl = nilfs_ioctl, |
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#ifdef CONFIG_COMPAT |
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.compat_ioctl = nilfs_compat_ioctl, |
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#endif /* CONFIG_COMPAT */ |
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.mmap = nilfs_file_mmap, |
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.open = generic_file_open, |
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/* .release = nilfs_release_file, */ |
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.fsync = nilfs_sync_file, |
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.splice_read = generic_file_splice_read, |
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.splice_write = iter_file_splice_write, |
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}; |
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const struct inode_operations nilfs_file_inode_operations = { |
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.setattr = nilfs_setattr, |
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.permission = nilfs_permission, |
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.fiemap = nilfs_fiemap, |
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}; |
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/* end of file */
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