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5693486bad
ocfs2's allocation unit is the cluster. This can be larger than a block or even a memory page. This means that a file may have many blocks in its last extent that are beyond the block containing i_size. There also may be more unwritten extents after that. When ocfs2 grows a file, it zeros the entire cluster in order to ensure future i_size growth will see cleared blocks. Unfortunately, block_write_full_page() drops the pages past i_size. This means that ocfs2 is actually leaking garbage data into the tail end of that last cluster. This is a bug. We adjust ocfs2_write_begin_nolock() and ocfs2_extend_file() to detect when a write or truncate is past i_size. They will use ocfs2_zero_extend() to ensure the data is properly zeroed. Older versions of ocfs2_zero_extend() simply zeroed every block between i_size and the zeroing position. This presumes three things: 1) There is allocation for all of these blocks. 2) The extents are not unwritten. 3) The extents are not refcounted. (1) and (2) hold true for non-sparse filesystems, which used to be the only users of ocfs2_zero_extend(). (3) is another bug. Since we're now using ocfs2_zero_extend() for sparse filesystems as well, we teach ocfs2_zero_extend() to check every extent between i_size and the zeroing position. If the extent is unwritten, it is ignored. If it is refcounted, it is CoWed. Then it is zeroed. Signed-off-by: Joel Becker <joel.becker@oracle.com> Cc: stable@kernel.org
77 lines
2.6 KiB
C
77 lines
2.6 KiB
C
/* -*- mode: c; c-basic-offset: 8; -*-
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* vim: noexpandtab sw=8 ts=8 sts=0:
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*
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* file.h
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*
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* Function prototypes
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*
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* Copyright (C) 2002, 2004 Oracle. All rights reserved.
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* General Public License for more details.
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*
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* You should have received a copy of the GNU General Public
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* License along with this program; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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* Boston, MA 021110-1307, USA.
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*/
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#ifndef OCFS2_FILE_H
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#define OCFS2_FILE_H
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extern const struct file_operations ocfs2_fops;
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extern const struct file_operations ocfs2_dops;
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extern const struct file_operations ocfs2_fops_no_plocks;
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extern const struct file_operations ocfs2_dops_no_plocks;
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extern const struct inode_operations ocfs2_file_iops;
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extern const struct inode_operations ocfs2_special_file_iops;
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struct ocfs2_alloc_context;
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enum ocfs2_alloc_restarted;
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struct ocfs2_file_private {
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struct file *fp_file;
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struct mutex fp_mutex;
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struct ocfs2_lock_res fp_flock;
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};
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int ocfs2_add_inode_data(struct ocfs2_super *osb,
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struct inode *inode,
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u32 *logical_offset,
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u32 clusters_to_add,
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int mark_unwritten,
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struct buffer_head *fe_bh,
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handle_t *handle,
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struct ocfs2_alloc_context *data_ac,
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struct ocfs2_alloc_context *meta_ac,
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enum ocfs2_alloc_restarted *reason_ret);
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int ocfs2_simple_size_update(struct inode *inode,
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struct buffer_head *di_bh,
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u64 new_i_size);
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int ocfs2_extend_no_holes(struct inode *inode, struct buffer_head *di_bh,
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u64 new_i_size, u64 zero_to);
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int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh,
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loff_t zero_to);
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int ocfs2_setattr(struct dentry *dentry, struct iattr *attr);
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int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
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struct kstat *stat);
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int ocfs2_permission(struct inode *inode, int mask);
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int ocfs2_should_update_atime(struct inode *inode,
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struct vfsmount *vfsmnt);
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int ocfs2_update_inode_atime(struct inode *inode,
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struct buffer_head *bh);
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int ocfs2_change_file_space(struct file *file, unsigned int cmd,
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struct ocfs2_space_resv *sr);
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int ocfs2_check_range_for_refcount(struct inode *inode, loff_t pos,
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size_t count);
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#endif /* OCFS2_FILE_H */
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