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convert ext4 to ->write_iter() 

unfortunately, Ted's changes to ext4_file_write() are *still* an
incomplete fix - playing with rlimits can let you smuggle an
unaligned request past the checks.  So there almost certainly
will be more merge PITA around that place...

[fix from Peter Ujfalusi <peter.ujfalusi@ti.com> folded]

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2014-04-17 16:09:22 -04:00
parent a832475488
commit 9b884164d5
1 changed files with 11 additions and 18 deletions
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29
fs/ext4/file.c
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@ -74,26 +74,22 @@ void ext4_unwritten_wait(struct inode *inode)
* or one thread will zero the other's data, causing corruption.
*/
static int
ext4_unaligned_aio(struct inode *inode, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
ext4_unaligned_aio(struct inode *inode, struct iov_iter *from, loff_t pos)
{
struct super_block *sb = inode->i_sb;
int blockmask = sb->s_blocksize - 1;
size_t count = iov_length(iov, nr_segs);
loff_t final_size = pos + count;
if (pos >= i_size_read(inode))
return 0;
if ((pos & blockmask) || (final_size & blockmask))
if ((pos | iov_iter_alignment(from)) & blockmask)
return 1;
return 0;
}
static ssize_t
ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
unsigned long nr_segs, loff_t pos)
ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(iocb->ki_filp);
@ -101,10 +97,9 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
struct blk_plug plug;
int o_direct = file->f_flags & O_DIRECT;
int overwrite = 0;
size_t length = iov_length(iov, nr_segs);
size_t length = iov_iter_count(from);
ssize_t ret;
BUG_ON(iocb->ki_pos != pos);
loff_t pos = iocb->ki_pos;
/*
* Unaligned direct AIO must be serialized; see comment above
@ -114,7 +109,7 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS) &&
!is_sync_kiocb(iocb) &&
(file->f_flags & O_APPEND ||
ext4_unaligned_aio(inode, iov, nr_segs, pos))) {
ext4_unaligned_aio(inode, from, pos))) {
aio_mutex = ext4_aio_mutex(inode);
mutex_lock(aio_mutex);
ext4_unwritten_wait(inode);
@ -138,10 +133,8 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
goto errout;
}
if (pos + length > sbi->s_bitmap_maxbytes) {
nr_segs = iov_shorten((struct iovec *)iov, nr_segs,
sbi->s_bitmap_maxbytes - pos);
}
if (pos + length > sbi->s_bitmap_maxbytes)
iov_iter_truncate(from, sbi->s_bitmap_maxbytes - pos);
}
if (o_direct) {
@ -179,7 +172,7 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
}
}
ret = __generic_file_aio_write(iocb, iov, nr_segs);
ret = __generic_file_write_iter(iocb, from);
mutex_unlock(&inode->i_mutex);
if (ret > 0) {
@ -594,9 +587,9 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
const struct file_operations ext4_file_operations = {
.llseek = ext4_llseek,
.read = new_sync_read,
.write = do_sync_write,
.write = new_sync_write,
.read_iter = generic_file_read_iter,
.aio_write = ext4_file_write,
.write_iter = ext4_file_write_iter,
.unlocked_ioctl = ext4_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ext4_compat_ioctl,