[RFC PATCH v2 17/21] ocfs2: add support for read_iter, write_iter, and direct_IO_bvec

From: Dave Kleikamp
Date: Fri Mar 30 2012 - 11:45:52 EST


From: Zach Brown <zab@xxxxxxxxx>

ocfs2's .aio_read and .aio_write methods are changed to take
iov_iter and pass it to generic functions. Wrappers are made to pack
the iovecs into iters and call these new functions.

Signed-off-by: Dave Kleikamp <dave.kleikamp@xxxxxxxxxx>
Cc: Zach Brown <zab@xxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: ocfs2-devel@xxxxxxxxxxxxxx
---
fs/ocfs2/file.c | 82 ++++++++++++++++++++++++++++++++++--------------
fs/ocfs2/ocfs2_trace.h | 6 +++-
2 files changed, 63 insertions(+), 25 deletions(-)

diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 061591a..f636813 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -2233,15 +2233,13 @@ out:
return ret;
}

-static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
- const struct iovec *iov,
- unsigned long nr_segs,
- loff_t pos)
+static ssize_t ocfs2_file_write_iter(struct kiocb *iocb,
+ struct iov_iter *iter,
+ loff_t pos)
{
int ret, direct_io, appending, rw_level, have_alloc_sem = 0;
int can_do_direct, has_refcount = 0;
ssize_t written = 0;
- size_t ocount; /* original count */
size_t count; /* after file limit checks */
loff_t old_size, *ppos = &iocb->ki_pos;
u32 old_clusters;
@@ -2252,11 +2250,11 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
OCFS2_MOUNT_COHERENCY_BUFFERED);
int unaligned_dio = 0;

- trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry,
+ trace_ocfs2_file_write_iter(inode, file, file->f_path.dentry,
(unsigned long long)OCFS2_I(inode)->ip_blkno,
file->f_path.dentry->d_name.len,
file->f_path.dentry->d_name.name,
- (unsigned int)nr_segs);
+ (unsigned long long)pos);

if (iocb->ki_left == 0)
return 0;
@@ -2358,28 +2356,24 @@ relock:
/* communicate with ocfs2_dio_end_io */
ocfs2_iocb_set_rw_locked(iocb, rw_level);

- ret = generic_segment_checks(iov, &nr_segs, &ocount,
- VERIFY_READ);
- if (ret)
- goto out_dio;

- count = ocount;
+ count = iov_iter_count(iter);
ret = generic_write_checks(file, ppos, &count,
S_ISBLK(inode->i_mode));
if (ret)
goto out_dio;

if (direct_io) {
- written = generic_file_direct_write(iocb, iov, &nr_segs, *ppos,
- ppos, count, ocount);
+ written = generic_file_direct_write_iter(iocb, iter, *ppos,
+ ppos, count);
if (written < 0) {
ret = written;
goto out_dio;
}
} else {
current->backing_dev_info = file->f_mapping->backing_dev_info;
- written = generic_file_buffered_write(iocb, iov, nr_segs, *ppos,
- ppos, count, 0);
+ written = generic_file_buffered_write_iter(iocb, iter, *ppos,
+ ppos, 0);
current->backing_dev_info = NULL;
}

@@ -2440,6 +2434,25 @@ out_sems:
return ret;
}

+static ssize_t ocfs2_file_aio_write(struct kiocb *iocb,
+ const struct iovec *iov,
+ unsigned long nr_segs,
+ loff_t pos)
+{
+ struct iov_iter iter;
+ size_t count;
+ int ret;
+
+ count = 0;
+ ret = generic_segment_checks(iov, &nr_segs, &count, VERIFY_READ);
+ if (ret)
+ return ret;
+
+ iov_iter_init(&iter, iov, nr_segs, count, 0);
+
+ return ocfs2_file_write_iter(iocb, &iter, pos);
+}
+
static int ocfs2_splice_to_file(struct pipe_inode_info *pipe,
struct file *out,
struct splice_desc *sd)
@@ -2553,19 +2566,18 @@ bail:
return ret;
}

-static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
- const struct iovec *iov,
- unsigned long nr_segs,
+static ssize_t ocfs2_file_read_iter(struct kiocb *iocb,
+ struct iov_iter *iter,
loff_t pos)
{
int ret = 0, rw_level = -1, have_alloc_sem = 0, lock_level = 0;
struct file *filp = iocb->ki_filp;
struct inode *inode = filp->f_path.dentry->d_inode;

- trace_ocfs2_file_aio_read(inode, filp, filp->f_path.dentry,
+ trace_ocfs2_file_read_iter(inode, filp, filp->f_path.dentry,
(unsigned long long)OCFS2_I(inode)->ip_blkno,
filp->f_path.dentry->d_name.len,
- filp->f_path.dentry->d_name.name, nr_segs);
+ filp->f_path.dentry->d_name.name, pos);


if (!inode) {
@@ -2601,7 +2613,7 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
*
* Take and drop the meta data lock to update inode fields
* like i_size. This allows the checks down below
- * generic_file_aio_read() a chance of actually working.
+ * generic_file_read_iter() a chance of actually working.
*/
ret = ocfs2_inode_lock_atime(inode, filp->f_vfsmnt, &lock_level);
if (ret < 0) {
@@ -2610,8 +2622,8 @@ static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
}
ocfs2_inode_unlock(inode, lock_level);

- ret = generic_file_aio_read(iocb, iov, nr_segs, iocb->ki_pos);
- trace_generic_file_aio_read_ret(ret);
+ ret = generic_file_read_iter(iocb, iter, iocb->ki_pos);
+ trace_generic_file_read_iter_ret(ret);

/* buffered aio wouldn't have proper lock coverage today */
BUG_ON(ret == -EIOCBQUEUED && !(filp->f_flags & O_DIRECT));
@@ -2683,6 +2695,24 @@ out:
return offset;
}

+static ssize_t ocfs2_file_aio_read(struct kiocb *iocb,
+ const struct iovec *iov,
+ unsigned long nr_segs,
+ loff_t pos)
+{
+ struct iov_iter iter;
+ size_t count;
+ int ret;
+
+ ret = generic_segment_checks(iov, &nr_segs, &count, VERIFY_WRITE);
+ if (ret)
+ return ret;
+
+ iov_iter_init(&iter, iov, nr_segs, count, 0);
+
+ return ocfs2_file_read_iter(iocb, &iter, pos);
+}
+
const struct inode_operations ocfs2_file_iops = {
.setattr = ocfs2_setattr,
.getattr = ocfs2_getattr,
@@ -2716,6 +2746,8 @@ const struct file_operations ocfs2_fops = {
.open = ocfs2_file_open,
.aio_read = ocfs2_file_aio_read,
.aio_write = ocfs2_file_aio_write,
+ .read_iter = ocfs2_file_read_iter,
+ .write_iter = ocfs2_file_write_iter,
.unlocked_ioctl = ocfs2_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ocfs2_compat_ioctl,
@@ -2764,6 +2796,8 @@ const struct file_operations ocfs2_fops_no_plocks = {
.open = ocfs2_file_open,
.aio_read = ocfs2_file_aio_read,
.aio_write = ocfs2_file_aio_write,
+ .read_iter = ocfs2_file_read_iter,
+ .write_iter = ocfs2_file_write_iter,
.unlocked_ioctl = ocfs2_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = ocfs2_compat_ioctl,
diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h
index 3b481f4..8409f00 100644
--- a/fs/ocfs2/ocfs2_trace.h
+++ b/fs/ocfs2/ocfs2_trace.h
@@ -1312,12 +1312,16 @@ DEFINE_OCFS2_FILE_OPS(ocfs2_sync_file);

DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_write);

+DEFINE_OCFS2_FILE_OPS(ocfs2_file_write_iter);
+
DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_write);

DEFINE_OCFS2_FILE_OPS(ocfs2_file_splice_read);

DEFINE_OCFS2_FILE_OPS(ocfs2_file_aio_read);

+DEFINE_OCFS2_FILE_OPS(ocfs2_file_read_iter);
+
DEFINE_OCFS2_ULL_ULL_ULL_EVENT(ocfs2_truncate_file);

DEFINE_OCFS2_ULL_ULL_EVENT(ocfs2_truncate_file_error);
@@ -1474,7 +1478,7 @@ TRACE_EVENT(ocfs2_prepare_inode_for_write,
__entry->direct_io, __entry->has_refcount)
);

-DEFINE_OCFS2_INT_EVENT(generic_file_aio_read_ret);
+DEFINE_OCFS2_INT_EVENT(generic_file_read_iter_ret);

/* End of trace events for fs/ocfs2/file.c. */

--
1.7.9.5

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