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![Christoph Hellwig](/assets/img/avatar_default.png)
Allow the file system to keep state for all iterations. For now only wire it up for direct I/O as there is an immediate need for it there. Reviewed-by: Darrick J. Wong <djwong@kernel.org> Reviewed-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
943 lines
24 KiB
C
943 lines
24 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext4/file.c
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*
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* Copyright (C) 1992, 1993, 1994, 1995
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* Remy Card (card@masi.ibp.fr)
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* Laboratoire MASI - Institut Blaise Pascal
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* Universite Pierre et Marie Curie (Paris VI)
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*
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* from
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*
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* linux/fs/minix/file.c
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*
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* Copyright (C) 1991, 1992 Linus Torvalds
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*
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* ext4 fs regular file handling primitives
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*
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* 64-bit file support on 64-bit platforms by Jakub Jelinek
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* (jj@sunsite.ms.mff.cuni.cz)
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*/
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#include <linux/time.h>
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#include <linux/fs.h>
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#include <linux/iomap.h>
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#include <linux/mount.h>
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#include <linux/path.h>
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#include <linux/dax.h>
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#include <linux/quotaops.h>
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#include <linux/pagevec.h>
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#include <linux/uio.h>
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#include <linux/mman.h>
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#include <linux/backing-dev.h>
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#include "ext4.h"
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#include "ext4_jbd2.h"
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#include "xattr.h"
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#include "acl.h"
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#include "truncate.h"
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static bool ext4_dio_supported(struct kiocb *iocb, struct iov_iter *iter)
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{
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struct inode *inode = file_inode(iocb->ki_filp);
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if (!fscrypt_dio_supported(iocb, iter))
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return false;
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if (fsverity_active(inode))
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return false;
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if (ext4_should_journal_data(inode))
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return false;
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if (ext4_has_inline_data(inode))
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return false;
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return true;
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}
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static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
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{
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ssize_t ret;
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struct inode *inode = file_inode(iocb->ki_filp);
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if (iocb->ki_flags & IOCB_NOWAIT) {
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if (!inode_trylock_shared(inode))
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return -EAGAIN;
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} else {
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inode_lock_shared(inode);
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}
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if (!ext4_dio_supported(iocb, to)) {
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inode_unlock_shared(inode);
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/*
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* Fallback to buffered I/O if the operation being performed on
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* the inode is not supported by direct I/O. The IOCB_DIRECT
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* flag needs to be cleared here in order to ensure that the
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* direct I/O path within generic_file_read_iter() is not
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* taken.
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*/
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iocb->ki_flags &= ~IOCB_DIRECT;
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return generic_file_read_iter(iocb, to);
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}
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ret = iomap_dio_rw(iocb, to, &ext4_iomap_ops, NULL, 0, NULL, 0);
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inode_unlock_shared(inode);
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file_accessed(iocb->ki_filp);
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return ret;
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}
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#ifdef CONFIG_FS_DAX
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static ssize_t ext4_dax_read_iter(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 ret;
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if (iocb->ki_flags & IOCB_NOWAIT) {
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if (!inode_trylock_shared(inode))
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return -EAGAIN;
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} else {
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inode_lock_shared(inode);
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}
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/*
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* Recheck under inode lock - at this point we are sure it cannot
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* change anymore
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*/
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if (!IS_DAX(inode)) {
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inode_unlock_shared(inode);
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/* Fallback to buffered IO in case we cannot support DAX */
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return generic_file_read_iter(iocb, to);
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}
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ret = dax_iomap_rw(iocb, to, &ext4_iomap_ops);
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inode_unlock_shared(inode);
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file_accessed(iocb->ki_filp);
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return ret;
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}
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#endif
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static ssize_t ext4_file_read_iter(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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if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
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return -EIO;
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if (!iov_iter_count(to))
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return 0; /* skip atime */
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#ifdef CONFIG_FS_DAX
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if (IS_DAX(inode))
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return ext4_dax_read_iter(iocb, to);
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#endif
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if (iocb->ki_flags & IOCB_DIRECT)
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return ext4_dio_read_iter(iocb, to);
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return generic_file_read_iter(iocb, to);
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}
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/*
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* Called when an inode is released. Note that this is different
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* from ext4_file_open: open gets called at every open, but release
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* gets called only when /all/ the files are closed.
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*/
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static int ext4_release_file(struct inode *inode, struct file *filp)
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{
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if (ext4_test_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE)) {
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ext4_alloc_da_blocks(inode);
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ext4_clear_inode_state(inode, EXT4_STATE_DA_ALLOC_CLOSE);
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}
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/* if we are the last writer on the inode, drop the block reservation */
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if ((filp->f_mode & FMODE_WRITE) &&
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(atomic_read(&inode->i_writecount) == 1) &&
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!EXT4_I(inode)->i_reserved_data_blocks) {
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down_write(&EXT4_I(inode)->i_data_sem);
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ext4_discard_preallocations(inode, 0);
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up_write(&EXT4_I(inode)->i_data_sem);
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}
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if (is_dx(inode) && filp->private_data)
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ext4_htree_free_dir_info(filp->private_data);
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return 0;
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}
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/*
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* This tests whether the IO in question is block-aligned or not.
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* Ext4 utilizes unwritten extents when hole-filling during direct IO, and they
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* are converted to written only after the IO is complete. Until they are
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* mapped, these blocks appear as holes, so dio_zero_block() will assume that
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* it needs to zero out portions of the start and/or end block. If 2 AIO
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* threads are at work on the same unwritten block, they must be synchronized
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* or one thread will zero the other's data, causing corruption.
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*/
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static bool
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ext4_unaligned_io(struct inode *inode, struct iov_iter *from, loff_t pos)
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{
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struct super_block *sb = inode->i_sb;
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unsigned long blockmask = sb->s_blocksize - 1;
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if ((pos | iov_iter_alignment(from)) & blockmask)
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return true;
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return false;
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}
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static bool
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ext4_extending_io(struct inode *inode, loff_t offset, size_t len)
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{
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if (offset + len > i_size_read(inode) ||
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offset + len > EXT4_I(inode)->i_disksize)
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return true;
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return false;
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}
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/* Is IO overwriting allocated and initialized blocks? */
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static bool ext4_overwrite_io(struct inode *inode, loff_t pos, loff_t len)
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{
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struct ext4_map_blocks map;
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unsigned int blkbits = inode->i_blkbits;
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int err, blklen;
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if (pos + len > i_size_read(inode))
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return false;
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map.m_lblk = pos >> blkbits;
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map.m_len = EXT4_MAX_BLOCKS(len, pos, blkbits);
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blklen = map.m_len;
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err = ext4_map_blocks(NULL, inode, &map, 0);
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/*
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* 'err==len' means that all of the blocks have been preallocated,
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* regardless of whether they have been initialized or not. To exclude
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* unwritten extents, we need to check m_flags.
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*/
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return err == blklen && (map.m_flags & EXT4_MAP_MAPPED);
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}
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static ssize_t ext4_generic_write_checks(struct kiocb *iocb,
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struct iov_iter *from)
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{
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struct inode *inode = file_inode(iocb->ki_filp);
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ssize_t ret;
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if (unlikely(IS_IMMUTABLE(inode)))
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return -EPERM;
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ret = generic_write_checks(iocb, from);
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if (ret <= 0)
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return ret;
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/*
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* If we have encountered a bitmap-format file, the size limit
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* is smaller than s_maxbytes, which is for extent-mapped files.
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*/
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if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))) {
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struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
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if (iocb->ki_pos >= sbi->s_bitmap_maxbytes)
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return -EFBIG;
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iov_iter_truncate(from, sbi->s_bitmap_maxbytes - iocb->ki_pos);
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}
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return iov_iter_count(from);
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}
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static ssize_t ext4_write_checks(struct kiocb *iocb, struct iov_iter *from)
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{
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ssize_t ret, count;
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count = ext4_generic_write_checks(iocb, from);
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if (count <= 0)
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return count;
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ret = file_modified(iocb->ki_filp);
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if (ret)
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return ret;
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return count;
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}
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static ssize_t ext4_buffered_write_iter(struct kiocb *iocb,
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struct iov_iter *from)
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{
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ssize_t ret;
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struct inode *inode = file_inode(iocb->ki_filp);
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if (iocb->ki_flags & IOCB_NOWAIT)
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return -EOPNOTSUPP;
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inode_lock(inode);
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ret = ext4_write_checks(iocb, from);
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if (ret <= 0)
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goto out;
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current->backing_dev_info = inode_to_bdi(inode);
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ret = generic_perform_write(iocb, from);
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current->backing_dev_info = NULL;
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out:
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inode_unlock(inode);
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if (likely(ret > 0)) {
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iocb->ki_pos += ret;
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ret = generic_write_sync(iocb, ret);
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}
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return ret;
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}
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static ssize_t ext4_handle_inode_extension(struct inode *inode, loff_t offset,
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ssize_t written, size_t count)
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{
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handle_t *handle;
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bool truncate = false;
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u8 blkbits = inode->i_blkbits;
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ext4_lblk_t written_blk, end_blk;
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int ret;
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/*
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* Note that EXT4_I(inode)->i_disksize can get extended up to
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* inode->i_size while the I/O was running due to writeback of delalloc
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* blocks. But, the code in ext4_iomap_alloc() is careful to use
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* zeroed/unwritten extents if this is possible; thus we won't leave
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* uninitialized blocks in a file even if we didn't succeed in writing
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* as much as we intended.
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*/
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WARN_ON_ONCE(i_size_read(inode) < EXT4_I(inode)->i_disksize);
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if (offset + count <= EXT4_I(inode)->i_disksize) {
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/*
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* We need to ensure that the inode is removed from the orphan
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* list if it has been added prematurely, due to writeback of
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* delalloc blocks.
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*/
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if (!list_empty(&EXT4_I(inode)->i_orphan) && inode->i_nlink) {
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handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
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if (IS_ERR(handle)) {
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ext4_orphan_del(NULL, inode);
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return PTR_ERR(handle);
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}
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ext4_orphan_del(handle, inode);
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ext4_journal_stop(handle);
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}
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return written;
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}
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if (written < 0)
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goto truncate;
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handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
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if (IS_ERR(handle)) {
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written = PTR_ERR(handle);
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goto truncate;
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}
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if (ext4_update_inode_size(inode, offset + written)) {
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ret = ext4_mark_inode_dirty(handle, inode);
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if (unlikely(ret)) {
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written = ret;
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ext4_journal_stop(handle);
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goto truncate;
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}
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}
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|
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/*
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* We may need to truncate allocated but not written blocks beyond EOF.
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*/
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written_blk = ALIGN(offset + written, 1 << blkbits);
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end_blk = ALIGN(offset + count, 1 << blkbits);
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if (written_blk < end_blk && ext4_can_truncate(inode))
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truncate = true;
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/*
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* Remove the inode from the orphan list if it has been extended and
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* everything went OK.
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*/
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if (!truncate && inode->i_nlink)
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ext4_orphan_del(handle, inode);
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ext4_journal_stop(handle);
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if (truncate) {
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truncate:
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ext4_truncate_failed_write(inode);
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/*
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* If the truncate operation failed early, then the inode may
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* still be on the orphan list. In that case, we need to try
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* remove the inode from the in-memory linked list.
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*/
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if (inode->i_nlink)
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ext4_orphan_del(NULL, inode);
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}
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|
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return written;
|
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}
|
|
|
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static int ext4_dio_write_end_io(struct kiocb *iocb, ssize_t size,
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int error, unsigned int flags)
|
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{
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loff_t pos = iocb->ki_pos;
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struct inode *inode = file_inode(iocb->ki_filp);
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|
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if (error)
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return error;
|
|
|
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if (size && flags & IOMAP_DIO_UNWRITTEN) {
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error = ext4_convert_unwritten_extents(NULL, inode, pos, size);
|
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if (error < 0)
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return error;
|
|
}
|
|
/*
|
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* If we are extending the file, we have to update i_size here before
|
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* page cache gets invalidated in iomap_dio_rw(). Otherwise racing
|
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* buffered reads could zero out too much from page cache pages. Update
|
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* of on-disk size will happen later in ext4_dio_write_iter() where
|
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* we have enough information to also perform orphan list handling etc.
|
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* Note that we perform all extending writes synchronously under
|
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* i_rwsem held exclusively so i_size update is safe here in that case.
|
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* If the write was not extending, we cannot see pos > i_size here
|
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* because operations reducing i_size like truncate wait for all
|
|
* outstanding DIO before updating i_size.
|
|
*/
|
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pos += size;
|
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if (pos > i_size_read(inode))
|
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i_size_write(inode, pos);
|
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|
|
return 0;
|
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}
|
|
|
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static const struct iomap_dio_ops ext4_dio_write_ops = {
|
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.end_io = ext4_dio_write_end_io,
|
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};
|
|
|
|
/*
|
|
* The intention here is to start with shared lock acquired then see if any
|
|
* condition requires an exclusive inode lock. If yes, then we restart the
|
|
* whole operation by releasing the shared lock and acquiring exclusive lock.
|
|
*
|
|
* - For unaligned_io we never take shared lock as it may cause data corruption
|
|
* when two unaligned IO tries to modify the same block e.g. while zeroing.
|
|
*
|
|
* - For extending writes case we don't take the shared lock, since it requires
|
|
* updating inode i_disksize and/or orphan handling with exclusive lock.
|
|
*
|
|
* - shared locking will only be true mostly with overwrites. Otherwise we will
|
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* switch to exclusive i_rwsem lock.
|
|
*/
|
|
static ssize_t ext4_dio_write_checks(struct kiocb *iocb, struct iov_iter *from,
|
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bool *ilock_shared, bool *extend)
|
|
{
|
|
struct file *file = iocb->ki_filp;
|
|
struct inode *inode = file_inode(file);
|
|
loff_t offset;
|
|
size_t count;
|
|
ssize_t ret;
|
|
|
|
restart:
|
|
ret = ext4_generic_write_checks(iocb, from);
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
offset = iocb->ki_pos;
|
|
count = ret;
|
|
if (ext4_extending_io(inode, offset, count))
|
|
*extend = true;
|
|
/*
|
|
* Determine whether the IO operation will overwrite allocated
|
|
* and initialized blocks.
|
|
* We need exclusive i_rwsem for changing security info
|
|
* in file_modified().
|
|
*/
|
|
if (*ilock_shared && (!IS_NOSEC(inode) || *extend ||
|
|
!ext4_overwrite_io(inode, offset, count))) {
|
|
if (iocb->ki_flags & IOCB_NOWAIT) {
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
inode_unlock_shared(inode);
|
|
*ilock_shared = false;
|
|
inode_lock(inode);
|
|
goto restart;
|
|
}
|
|
|
|
ret = file_modified(file);
|
|
if (ret < 0)
|
|
goto out;
|
|
|
|
return count;
|
|
out:
|
|
if (*ilock_shared)
|
|
inode_unlock_shared(inode);
|
|
else
|
|
inode_unlock(inode);
|
|
return ret;
|
|
}
|
|
|
|
static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
ssize_t ret;
|
|
handle_t *handle;
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
loff_t offset = iocb->ki_pos;
|
|
size_t count = iov_iter_count(from);
|
|
const struct iomap_ops *iomap_ops = &ext4_iomap_ops;
|
|
bool extend = false, unaligned_io = false;
|
|
bool ilock_shared = true;
|
|
|
|
/*
|
|
* We initially start with shared inode lock unless it is
|
|
* unaligned IO which needs exclusive lock anyways.
|
|
*/
|
|
if (ext4_unaligned_io(inode, from, offset)) {
|
|
unaligned_io = true;
|
|
ilock_shared = false;
|
|
}
|
|
/*
|
|
* Quick check here without any i_rwsem lock to see if it is extending
|
|
* IO. A more reliable check is done in ext4_dio_write_checks() with
|
|
* proper locking in place.
|
|
*/
|
|
if (offset + count > i_size_read(inode))
|
|
ilock_shared = false;
|
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) {
|
|
if (ilock_shared) {
|
|
if (!inode_trylock_shared(inode))
|
|
return -EAGAIN;
|
|
} else {
|
|
if (!inode_trylock(inode))
|
|
return -EAGAIN;
|
|
}
|
|
} else {
|
|
if (ilock_shared)
|
|
inode_lock_shared(inode);
|
|
else
|
|
inode_lock(inode);
|
|
}
|
|
|
|
/* Fallback to buffered I/O if the inode does not support direct I/O. */
|
|
if (!ext4_dio_supported(iocb, from)) {
|
|
if (ilock_shared)
|
|
inode_unlock_shared(inode);
|
|
else
|
|
inode_unlock(inode);
|
|
return ext4_buffered_write_iter(iocb, from);
|
|
}
|
|
|
|
ret = ext4_dio_write_checks(iocb, from, &ilock_shared, &extend);
|
|
if (ret <= 0)
|
|
return ret;
|
|
|
|
/* if we're going to block and IOCB_NOWAIT is set, return -EAGAIN */
|
|
if ((iocb->ki_flags & IOCB_NOWAIT) && (unaligned_io || extend)) {
|
|
ret = -EAGAIN;
|
|
goto out;
|
|
}
|
|
|
|
offset = iocb->ki_pos;
|
|
count = ret;
|
|
|
|
/*
|
|
* Unaligned direct IO must be serialized among each other as zeroing
|
|
* of partial blocks of two competing unaligned IOs can result in data
|
|
* corruption.
|
|
*
|
|
* So we make sure we don't allow any unaligned IO in flight.
|
|
* For IOs where we need not wait (like unaligned non-AIO DIO),
|
|
* below inode_dio_wait() may anyway become a no-op, since we start
|
|
* with exclusive lock.
|
|
*/
|
|
if (unaligned_io)
|
|
inode_dio_wait(inode);
|
|
|
|
if (extend) {
|
|
handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
|
|
if (IS_ERR(handle)) {
|
|
ret = PTR_ERR(handle);
|
|
goto out;
|
|
}
|
|
|
|
ret = ext4_orphan_add(handle, inode);
|
|
if (ret) {
|
|
ext4_journal_stop(handle);
|
|
goto out;
|
|
}
|
|
|
|
ext4_journal_stop(handle);
|
|
}
|
|
|
|
if (ilock_shared)
|
|
iomap_ops = &ext4_iomap_overwrite_ops;
|
|
ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
|
|
(unaligned_io || extend) ? IOMAP_DIO_FORCE_WAIT : 0,
|
|
NULL, 0);
|
|
if (ret == -ENOTBLK)
|
|
ret = 0;
|
|
|
|
if (extend)
|
|
ret = ext4_handle_inode_extension(inode, offset, ret, count);
|
|
|
|
out:
|
|
if (ilock_shared)
|
|
inode_unlock_shared(inode);
|
|
else
|
|
inode_unlock(inode);
|
|
|
|
if (ret >= 0 && iov_iter_count(from)) {
|
|
ssize_t err;
|
|
loff_t endbyte;
|
|
|
|
offset = iocb->ki_pos;
|
|
err = ext4_buffered_write_iter(iocb, from);
|
|
if (err < 0)
|
|
return err;
|
|
|
|
/*
|
|
* We need to ensure that the pages within the page cache for
|
|
* the range covered by this I/O are written to disk and
|
|
* invalidated. This is in attempt to preserve the expected
|
|
* direct I/O semantics in the case we fallback to buffered I/O
|
|
* to complete off the I/O request.
|
|
*/
|
|
ret += err;
|
|
endbyte = offset + err - 1;
|
|
err = filemap_write_and_wait_range(iocb->ki_filp->f_mapping,
|
|
offset, endbyte);
|
|
if (!err)
|
|
invalidate_mapping_pages(iocb->ki_filp->f_mapping,
|
|
offset >> PAGE_SHIFT,
|
|
endbyte >> PAGE_SHIFT);
|
|
}
|
|
|
|
return ret;
|
|
}
|
|
|
|
#ifdef CONFIG_FS_DAX
|
|
static ssize_t
|
|
ext4_dax_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
ssize_t ret;
|
|
size_t count;
|
|
loff_t offset;
|
|
handle_t *handle;
|
|
bool extend = false;
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
|
|
if (iocb->ki_flags & IOCB_NOWAIT) {
|
|
if (!inode_trylock(inode))
|
|
return -EAGAIN;
|
|
} else {
|
|
inode_lock(inode);
|
|
}
|
|
|
|
ret = ext4_write_checks(iocb, from);
|
|
if (ret <= 0)
|
|
goto out;
|
|
|
|
offset = iocb->ki_pos;
|
|
count = iov_iter_count(from);
|
|
|
|
if (offset + count > EXT4_I(inode)->i_disksize) {
|
|
handle = ext4_journal_start(inode, EXT4_HT_INODE, 2);
|
|
if (IS_ERR(handle)) {
|
|
ret = PTR_ERR(handle);
|
|
goto out;
|
|
}
|
|
|
|
ret = ext4_orphan_add(handle, inode);
|
|
if (ret) {
|
|
ext4_journal_stop(handle);
|
|
goto out;
|
|
}
|
|
|
|
extend = true;
|
|
ext4_journal_stop(handle);
|
|
}
|
|
|
|
ret = dax_iomap_rw(iocb, from, &ext4_iomap_ops);
|
|
|
|
if (extend)
|
|
ret = ext4_handle_inode_extension(inode, offset, ret, count);
|
|
out:
|
|
inode_unlock(inode);
|
|
if (ret > 0)
|
|
ret = generic_write_sync(iocb, ret);
|
|
return ret;
|
|
}
|
|
#endif
|
|
|
|
static ssize_t
|
|
ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
|
|
{
|
|
struct inode *inode = file_inode(iocb->ki_filp);
|
|
|
|
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
|
|
return -EIO;
|
|
|
|
#ifdef CONFIG_FS_DAX
|
|
if (IS_DAX(inode))
|
|
return ext4_dax_write_iter(iocb, from);
|
|
#endif
|
|
if (iocb->ki_flags & IOCB_DIRECT)
|
|
return ext4_dio_write_iter(iocb, from);
|
|
else
|
|
return ext4_buffered_write_iter(iocb, from);
|
|
}
|
|
|
|
#ifdef CONFIG_FS_DAX
|
|
static vm_fault_t ext4_dax_huge_fault(struct vm_fault *vmf,
|
|
enum page_entry_size pe_size)
|
|
{
|
|
int error = 0;
|
|
vm_fault_t result;
|
|
int retries = 0;
|
|
handle_t *handle = NULL;
|
|
struct inode *inode = file_inode(vmf->vma->vm_file);
|
|
struct super_block *sb = inode->i_sb;
|
|
|
|
/*
|
|
* We have to distinguish real writes from writes which will result in a
|
|
* COW page; COW writes should *not* poke the journal (the file will not
|
|
* be changed). Doing so would cause unintended failures when mounted
|
|
* read-only.
|
|
*
|
|
* We check for VM_SHARED rather than vmf->cow_page since the latter is
|
|
* unset for pe_size != PE_SIZE_PTE (i.e. only in do_cow_fault); for
|
|
* other sizes, dax_iomap_fault will handle splitting / fallback so that
|
|
* we eventually come back with a COW page.
|
|
*/
|
|
bool write = (vmf->flags & FAULT_FLAG_WRITE) &&
|
|
(vmf->vma->vm_flags & VM_SHARED);
|
|
struct address_space *mapping = vmf->vma->vm_file->f_mapping;
|
|
pfn_t pfn;
|
|
|
|
if (write) {
|
|
sb_start_pagefault(sb);
|
|
file_update_time(vmf->vma->vm_file);
|
|
filemap_invalidate_lock_shared(mapping);
|
|
retry:
|
|
handle = ext4_journal_start_sb(sb, EXT4_HT_WRITE_PAGE,
|
|
EXT4_DATA_TRANS_BLOCKS(sb));
|
|
if (IS_ERR(handle)) {
|
|
filemap_invalidate_unlock_shared(mapping);
|
|
sb_end_pagefault(sb);
|
|
return VM_FAULT_SIGBUS;
|
|
}
|
|
} else {
|
|
filemap_invalidate_lock_shared(mapping);
|
|
}
|
|
result = dax_iomap_fault(vmf, pe_size, &pfn, &error, &ext4_iomap_ops);
|
|
if (write) {
|
|
ext4_journal_stop(handle);
|
|
|
|
if ((result & VM_FAULT_ERROR) && error == -ENOSPC &&
|
|
ext4_should_retry_alloc(sb, &retries))
|
|
goto retry;
|
|
/* Handling synchronous page fault? */
|
|
if (result & VM_FAULT_NEEDDSYNC)
|
|
result = dax_finish_sync_fault(vmf, pe_size, pfn);
|
|
filemap_invalidate_unlock_shared(mapping);
|
|
sb_end_pagefault(sb);
|
|
} else {
|
|
filemap_invalidate_unlock_shared(mapping);
|
|
}
|
|
|
|
return result;
|
|
}
|
|
|
|
static vm_fault_t ext4_dax_fault(struct vm_fault *vmf)
|
|
{
|
|
return ext4_dax_huge_fault(vmf, PE_SIZE_PTE);
|
|
}
|
|
|
|
static const struct vm_operations_struct ext4_dax_vm_ops = {
|
|
.fault = ext4_dax_fault,
|
|
.huge_fault = ext4_dax_huge_fault,
|
|
.page_mkwrite = ext4_dax_fault,
|
|
.pfn_mkwrite = ext4_dax_fault,
|
|
};
|
|
#else
|
|
#define ext4_dax_vm_ops ext4_file_vm_ops
|
|
#endif
|
|
|
|
static const struct vm_operations_struct ext4_file_vm_ops = {
|
|
.fault = filemap_fault,
|
|
.map_pages = filemap_map_pages,
|
|
.page_mkwrite = ext4_page_mkwrite,
|
|
};
|
|
|
|
static int ext4_file_mmap(struct file *file, struct vm_area_struct *vma)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
|
|
struct dax_device *dax_dev = sbi->s_daxdev;
|
|
|
|
if (unlikely(ext4_forced_shutdown(sbi)))
|
|
return -EIO;
|
|
|
|
/*
|
|
* We don't support synchronous mappings for non-DAX files and
|
|
* for DAX files if underneath dax_device is not synchronous.
|
|
*/
|
|
if (!daxdev_mapping_supported(vma, dax_dev))
|
|
return -EOPNOTSUPP;
|
|
|
|
file_accessed(file);
|
|
if (IS_DAX(file_inode(file))) {
|
|
vma->vm_ops = &ext4_dax_vm_ops;
|
|
vma->vm_flags |= VM_HUGEPAGE;
|
|
} else {
|
|
vma->vm_ops = &ext4_file_vm_ops;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int ext4_sample_last_mounted(struct super_block *sb,
|
|
struct vfsmount *mnt)
|
|
{
|
|
struct ext4_sb_info *sbi = EXT4_SB(sb);
|
|
struct path path;
|
|
char buf[64], *cp;
|
|
handle_t *handle;
|
|
int err;
|
|
|
|
if (likely(ext4_test_mount_flag(sb, EXT4_MF_MNTDIR_SAMPLED)))
|
|
return 0;
|
|
|
|
if (sb_rdonly(sb) || !sb_start_intwrite_trylock(sb))
|
|
return 0;
|
|
|
|
ext4_set_mount_flag(sb, EXT4_MF_MNTDIR_SAMPLED);
|
|
/*
|
|
* Sample where the filesystem has been mounted and
|
|
* store it in the superblock for sysadmin convenience
|
|
* when trying to sort through large numbers of block
|
|
* devices or filesystem images.
|
|
*/
|
|
memset(buf, 0, sizeof(buf));
|
|
path.mnt = mnt;
|
|
path.dentry = mnt->mnt_root;
|
|
cp = d_path(&path, buf, sizeof(buf));
|
|
err = 0;
|
|
if (IS_ERR(cp))
|
|
goto out;
|
|
|
|
handle = ext4_journal_start_sb(sb, EXT4_HT_MISC, 1);
|
|
err = PTR_ERR(handle);
|
|
if (IS_ERR(handle))
|
|
goto out;
|
|
BUFFER_TRACE(sbi->s_sbh, "get_write_access");
|
|
err = ext4_journal_get_write_access(handle, sb, sbi->s_sbh,
|
|
EXT4_JTR_NONE);
|
|
if (err)
|
|
goto out_journal;
|
|
lock_buffer(sbi->s_sbh);
|
|
strncpy(sbi->s_es->s_last_mounted, cp,
|
|
sizeof(sbi->s_es->s_last_mounted));
|
|
ext4_superblock_csum_set(sb);
|
|
unlock_buffer(sbi->s_sbh);
|
|
ext4_handle_dirty_metadata(handle, NULL, sbi->s_sbh);
|
|
out_journal:
|
|
ext4_journal_stop(handle);
|
|
out:
|
|
sb_end_intwrite(sb);
|
|
return err;
|
|
}
|
|
|
|
static int ext4_file_open(struct inode *inode, struct file *filp)
|
|
{
|
|
int ret;
|
|
|
|
if (unlikely(ext4_forced_shutdown(EXT4_SB(inode->i_sb))))
|
|
return -EIO;
|
|
|
|
ret = ext4_sample_last_mounted(inode->i_sb, filp->f_path.mnt);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = fscrypt_file_open(inode, filp);
|
|
if (ret)
|
|
return ret;
|
|
|
|
ret = fsverity_file_open(inode, filp);
|
|
if (ret)
|
|
return ret;
|
|
|
|
/*
|
|
* Set up the jbd2_inode if we are opening the inode for
|
|
* writing and the journal is present
|
|
*/
|
|
if (filp->f_mode & FMODE_WRITE) {
|
|
ret = ext4_inode_attach_jinode(inode);
|
|
if (ret < 0)
|
|
return ret;
|
|
}
|
|
|
|
filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
|
|
return dquot_file_open(inode, filp);
|
|
}
|
|
|
|
/*
|
|
* ext4_llseek() handles both block-mapped and extent-mapped maxbytes values
|
|
* by calling generic_file_llseek_size() with the appropriate maxbytes
|
|
* value for each.
|
|
*/
|
|
loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
|
|
{
|
|
struct inode *inode = file->f_mapping->host;
|
|
loff_t maxbytes;
|
|
|
|
if (!(ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)))
|
|
maxbytes = EXT4_SB(inode->i_sb)->s_bitmap_maxbytes;
|
|
else
|
|
maxbytes = inode->i_sb->s_maxbytes;
|
|
|
|
switch (whence) {
|
|
default:
|
|
return generic_file_llseek_size(file, offset, whence,
|
|
maxbytes, i_size_read(inode));
|
|
case SEEK_HOLE:
|
|
inode_lock_shared(inode);
|
|
offset = iomap_seek_hole(inode, offset,
|
|
&ext4_iomap_report_ops);
|
|
inode_unlock_shared(inode);
|
|
break;
|
|
case SEEK_DATA:
|
|
inode_lock_shared(inode);
|
|
offset = iomap_seek_data(inode, offset,
|
|
&ext4_iomap_report_ops);
|
|
inode_unlock_shared(inode);
|
|
break;
|
|
}
|
|
|
|
if (offset < 0)
|
|
return offset;
|
|
return vfs_setpos(file, offset, maxbytes);
|
|
}
|
|
|
|
const struct file_operations ext4_file_operations = {
|
|
.llseek = ext4_llseek,
|
|
.read_iter = ext4_file_read_iter,
|
|
.write_iter = ext4_file_write_iter,
|
|
.iopoll = iocb_bio_iopoll,
|
|
.unlocked_ioctl = ext4_ioctl,
|
|
#ifdef CONFIG_COMPAT
|
|
.compat_ioctl = ext4_compat_ioctl,
|
|
#endif
|
|
.mmap = ext4_file_mmap,
|
|
.mmap_supported_flags = MAP_SYNC,
|
|
.open = ext4_file_open,
|
|
.release = ext4_release_file,
|
|
.fsync = ext4_sync_file,
|
|
.get_unmapped_area = thp_get_unmapped_area,
|
|
.splice_read = generic_file_splice_read,
|
|
.splice_write = iter_file_splice_write,
|
|
.fallocate = ext4_fallocate,
|
|
};
|
|
|
|
const struct inode_operations ext4_file_inode_operations = {
|
|
.setattr = ext4_setattr,
|
|
.getattr = ext4_file_getattr,
|
|
.listxattr = ext4_listxattr,
|
|
.get_acl = ext4_get_acl,
|
|
.set_acl = ext4_set_acl,
|
|
.fiemap = ext4_fiemap,
|
|
.fileattr_get = ext4_fileattr_get,
|
|
.fileattr_set = ext4_fileattr_set,
|
|
};
|
|
|