[Devel] [PATCH rh7] fs: Drop "pos" argument from {read, write}_iter() callbacks
Konstantin Khorenko
khorenko at virtuozzo.com
Wed Dec 23 13:16:39 MSK 2020
This syncs file_operations::read_iter()/write_iter() declarations with
mainstream versions.
We brought _iter() interface before it appeared in mainstream and
callbacks declarations are not in sync.
Usually this does not hurt, but zfs is a bit upset that we have
address_space_operations::direct_IO() which uses iters, but
file_operations::read_iter()/write_iter() are not implemented (they are
implemented in vz kernel, but have different declaration, thus not
detected correctly).
So, let's make zfs happy.
To_merge: eddb0e72476d ("fs/aio: kernel direct aio")
Signed-off-by: Konstantin Khorenko <khorenko at virtuozzo.com>
---
fs/aio.c | 4 ++--
fs/ext4/file.c | 29 +++++++++++++++--------------
include/linux/fs.h | 8 ++++----
mm/filemap.c | 24 ++++++++++++------------
4 files changed, 33 insertions(+), 32 deletions(-)
diff --git a/fs/aio.c b/fs/aio.c
index f1b27fc5defb..f0a9e1613529 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -1343,7 +1343,7 @@ static ssize_t aio_read_iter(struct kiocb *iocb)
if (!file->f_op->read_iter)
return -EINVAL;
- return file->f_op->read_iter(iocb, iocb->ki_iter, iocb->ki_pos);
+ return file->f_op->read_iter(iocb, iocb->ki_iter);
}
static ssize_t aio_write_iter(struct kiocb *iocb)
@@ -1365,7 +1365,7 @@ static ssize_t aio_write_iter(struct kiocb *iocb)
return -EINVAL;
file_start_write(file);
- ret = file->f_op->write_iter(iocb, iocb->ki_iter, iocb->ki_pos);
+ ret = file->f_op->write_iter(iocb, iocb->ki_iter);
file_end_write(file);
return ret;
}
diff --git a/fs/ext4/file.c b/fs/ext4/file.c
index 67a385e9f716..2b3a73f90163 100644
--- a/fs/ext4/file.c
+++ b/fs/ext4/file.c
@@ -318,26 +318,26 @@ ext4_file_dax_write(
#endif
static ssize_t
-ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+ext4_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct inode *inode = file_inode(iocb->ki_filp);
ssize_t ret;
int overwrite = 0;
- ret = ext4_write_checks(iocb, iter, &pos);
+ ret = ext4_write_checks(iocb, iter, &iocb->ki_pos);
if (ret <= 0)
return ret;
#ifdef CONFIG_FS_DAX
if (IS_DAX(inode))
- return ext4_file_dax_write(iocb, iter, pos);
+ return ext4_file_dax_write(iocb, iter, iocb->ki_pos);
#endif
iocb->private = &overwrite; /* RHEL7 only - prevent DIO race */
if (unlikely(io_is_direct(iocb->ki_filp)))
- ret = ext4_file_dio_write(iocb, iter, pos);
+ ret = ext4_file_dio_write(iocb, iter, iocb->ki_pos);
else
- ret = generic_file_write_iter(iocb, iter, pos);
+ ret = generic_file_write_iter(iocb, iter);
return ret;
}
@@ -350,7 +350,8 @@ ext4_file_write(struct kiocb *iocb, const struct iovec *iov,
iov_iter_init(&iter, iov, nr_segs, iov_length(iov, nr_segs), 0);
- return ext4_file_write_iter(iocb, &iter, pos);
+ BUG_ON(iocb->ki_pos != pos);
+ return ext4_file_write_iter(iocb, &iter);
}
#ifdef CONFIG_FS_DAX
@@ -585,8 +586,7 @@ loff_t ext4_llseek(struct file *file, loff_t offset, int whence)
static ssize_t
ext4_file_dax_read_iter(
struct kiocb *iocb,
- struct iov_iter *iter,
- loff_t pos)
+ struct iov_iter *iter)
{
size_t size = iov_iter_count(iter);
ssize_t ret = 0;
@@ -603,10 +603,10 @@ ext4_file_dax_read_iter(
if (!IS_DAX(inode)) {
inode_unlock(inode);
/* Fallback to buffered IO in case we cannot support DAX */
- return generic_file_read_iter(iocb, iter, pos);
+ return generic_file_read_iter(iocb, iter);
}
- ret = dax_iomap_rw(READ, iocb, iter, pos,
+ ret = dax_iomap_rw(READ, iocb, iter, iocb->ki_pos,
size, &ext4_iomap_ops);
inode_unlock(inode);
@@ -616,13 +616,13 @@ ext4_file_dax_read_iter(
#endif
ssize_t
-ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+ext4_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
#ifdef CONFIG_FS_DAX
if (IS_DAX(file_inode(iocb->ki_filp)))
- return ext4_file_dax_read_iter(iocb, iter, pos);
+ return ext4_file_dax_read_iter(iocb, iter);
#endif
- return generic_file_read_iter(iocb, iter, pos);
+ return generic_file_read_iter(iocb, iter);
}
static ssize_t
@@ -636,7 +636,8 @@ ext4_file_read(
struct iov_iter iter;
iov_iter_init(&iter, iovp, nr_segs, size, 0);
- return ext4_file_read_iter(iocb, &iter, pos);
+ BUG_ON(iocb->ki_pos != pos);
+ return ext4_file_read_iter(iocb, &iter);
}
const struct file_operations_extend ext4_file_operations = {
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 8398ec202a42..2f498238202a 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1969,9 +1969,9 @@ struct file_operations {
ssize_t (*read) (struct file *, char __user *, size_t, loff_t *);
ssize_t (*write) (struct file *, const char __user *, size_t, loff_t *);
ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
- ssize_t (*read_iter) (struct kiocb *, struct iov_iter *, loff_t);
+ ssize_t (*read_iter) (struct kiocb *, struct iov_iter *);
ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t);
- ssize_t (*write_iter) (struct kiocb *, struct iov_iter *, loff_t);
+ ssize_t (*write_iter) (struct kiocb *, struct iov_iter *);
int (*readdir) (struct file *, void *, filldir_t);
unsigned int (*poll) (struct file *, struct poll_table_struct *);
long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long);
@@ -3239,12 +3239,12 @@ extern int generic_file_readonly_mmap(struct file *, struct vm_area_struct *);
extern int file_read_actor(read_descriptor_t * desc, struct page *page, unsigned long offset, unsigned long size);
int generic_write_checks(struct file *file, loff_t *pos, size_t *count, int isblk);
extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsigned long, loff_t);
-extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *, loff_t);
+extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *);
extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long,
loff_t *);
extern ssize_t __generic_file_write_iter(struct kiocb *, struct iov_iter *, loff_t *);
extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t);
-extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *, loff_t);
+extern ssize_t generic_file_write_iter(struct kiocb *, struct iov_iter *);
extern ssize_t generic_file_direct_write(struct kiocb *iocb, struct iov_iter *iter,
loff_t pos, loff_t *ppos, size_t count);
extern ssize_t generic_file_direct_write_iter(struct kiocb *, struct iov_iter *,
diff --git a/mm/filemap.c b/mm/filemap.c
index 950d92b6059b..e0f7e5c73f80 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -2006,16 +2006,14 @@ static int file_read_iter_actor(read_descriptor_t *desc, struct page *page,
* generic_file_read_iter - generic filesystem read routine
* @iocb: kernel I/O control block
* @iov_iter: memory vector
- * @pos: current file position
*/
ssize_t
-generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
+generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *filp = iocb->ki_filp;
read_descriptor_t desc;
ssize_t retval = 0;
size_t count = iov_iter_count(iter);
- loff_t *ppos = &iocb->ki_pos;
if (io_is_direct(filp)) {
loff_t size;
@@ -2027,14 +2025,15 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
if (!count)
goto out; /* skip atime */
size = i_size_read(inode);
- retval = filemap_write_and_wait_range(mapping, pos,
- pos + count - 1);
+ retval = filemap_write_and_wait_range(mapping, iocb->ki_pos,
+ iocb->ki_pos + count - 1);
if (!retval) {
struct iov_iter data = *iter;
- retval = mapping->a_ops->direct_IO(READ, iocb, &data, pos);
+ retval = mapping->a_ops->direct_IO(READ, iocb, &data,
+ iocb->ki_pos);
}
if (retval > 0) {
- *ppos = pos + retval;
+ iocb->ki_pos += retval;
count -= retval;
}
@@ -2046,7 +2045,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
* and return. Otherwise fallthrough to buffered io for
* the rest of the read.
*/
- if (retval < 0 || !count || *ppos >= size) {
+ if (retval < 0 || !count || iocb->ki_pos >= size) {
file_accessed(filp);
goto out;
}
@@ -2067,7 +2066,7 @@ generic_file_read_iter(struct kiocb *iocb, struct iov_iter *iter, loff_t pos)
desc.arg.data = iter;
desc.count = count;
desc.error = 0;
- do_generic_file_read(filp, ppos, &desc, file_read_iter_actor);
+ do_generic_file_read(filp, &iocb->ki_pos, &desc, file_read_iter_actor);
retval += desc.written;
if (desc.error && !retval)
@@ -2096,7 +2095,8 @@ generic_file_aio_read(struct kiocb *iocb, const struct iovec *iov,
iov_iter_init(&iter, iov, nr_segs, count, 0);
- return generic_file_read_iter(iocb, &iter, pos);
+ BUG_ON(iocb->ki_pos != pos);
+ return generic_file_read_iter(iocb, &iter);
}
EXPORT_SYMBOL(generic_file_aio_read);
@@ -3097,12 +3097,12 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
}
EXPORT_SYMBOL(__generic_file_write_iter);
-ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter,
- loff_t pos)
+ssize_t generic_file_write_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file->f_mapping->host;
ssize_t ret;
+ loff_t pos = iocb->ki_pos;
mutex_lock(&inode->i_mutex);
ret = __generic_file_write_iter(iocb, iter, &iocb->ki_pos);
--
2.24.3
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