From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
The read and write versions don't have anything in common except for the
call to iomap_dio_rw. So split this function, and merge each half into
its only caller.
Originally proposed by Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
---
fs/btrfs/ctree.h | 4 +-
fs/btrfs/file.c | 95 +++++++++++++++++++++++++++++++++++++++++++-----
fs/btrfs/inode.c | 82 +----------------------------------------
3 files changed, 90 insertions(+), 91 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 677f170434e3..1037969cda63 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -28,6 +28,7 @@
#include <linux/dynamic_debug.h>
#include <linux/refcount.h>
#include <linux/crc32c.h>
+#include <linux/iomap.h>
#include "extent-io-tree.h"
#include "extent_io.h"
#include "extent_map.h"
@@ -2935,7 +2936,8 @@ int btrfs_writepage_cow_fixup(struct page *page, u64 start, u64 end);
void btrfs_writepage_endio_finish_ordered(struct page *page, u64 start,
u64 end, int uptodate);
extern const struct dentry_operations btrfs_dentry_operations;
-ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter);
+extern const struct iomap_ops btrfs_dio_iomap_ops;
+extern const struct iomap_dio_ops btrfs_dops;
/* ioctl.c */
long btrfs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c
index 9d486350f1bf..8c738f8101c4 100644
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1825,21 +1825,65 @@ static noinline ssize_t btrfs_buffered_write(struct kiocb *iocb,
return num_written ? num_written : ret;
}
-static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
+static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
+ const struct iov_iter *iter, loff_t offset)
+{
+ const unsigned int blocksize_mask = fs_info->sectorsize - 1;
+
+ if (offset & blocksize_mask)
+ return -EINVAL;
+
+ if (iov_iter_alignment(iter) & blocksize_mask)
+ return -EINVAL;
+
+ return 0;
+}
+
+static ssize_t btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from)
{
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
- loff_t pos;
- ssize_t written;
+ struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
+ loff_t pos = iocb->ki_pos;
+ ssize_t written = 0;
ssize_t written_buffered;
loff_t endbyte;
int err;
+ size_t count = 0;
+ bool relock = false;
+ int flags = IOMAP_DIO_RWF_NO_STALE_PAGECACHE;
- written = btrfs_direct_IO(iocb, from);
+ if (check_direct_IO(fs_info, from, pos))
+ goto buffered;
+
+ count = iov_iter_count(from);
+ /*
+ * If the write DIO is beyond the EOF, we need update the isize, but it
+ * is protected by i_mutex. So we can not unlock the i_mutex at this
+ * case.
+ */
+ if (pos + count <= inode->i_size) {
+ inode_unlock(inode);
+ relock = true;
+ } else if (iocb->ki_flags & IOCB_NOWAIT) {
+ return -EAGAIN;
+ }
+
+ if (is_sync_kiocb(iocb))
+ flags |= IOMAP_DIO_RWF_SYNCIO;
+
+ down_read(&BTRFS_I(inode)->dio_sem);
+ written = iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dops,
+ flags);
+ up_read(&BTRFS_I(inode)->dio_sem);
+
+ if (relock)
+ inode_lock(inode);
if (written < 0 || !iov_iter_count(from))
return written;
+buffered:
pos = iocb->ki_pos;
written_buffered = btrfs_buffered_write(iocb, from);
if (written_buffered < 0) {
@@ -1990,7 +2034,7 @@ static ssize_t btrfs_file_write_iter(struct kiocb *iocb,
atomic_inc(&BTRFS_I(inode)->sync_writers);
if (iocb->ki_flags & IOCB_DIRECT) {
- num_written = __btrfs_direct_write(iocb, from);
+ num_written = btrfs_direct_write(iocb, from);
} else {
num_written = btrfs_buffered_write(iocb, from);
if (num_written > 0)
@@ -3504,16 +3548,47 @@ static int btrfs_file_open(struct inode *inode, struct file *filp)
return generic_file_open(inode, filp);
}
+static int check_direct_read(struct btrfs_fs_info *fs_info,
+ const struct iov_iter *iter, loff_t offset)
+{
+ int ret;
+ int i, seg;
+
+ ret = check_direct_IO(fs_info, iter, offset);
+ if (ret < 0)
+ return ret;
+
+ for (seg = 0; seg < iter->nr_segs; seg++)
+ for (i = seg + 1; i < iter->nr_segs; i++)
+ if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
+ return -EINVAL;
+ return 0;
+}
+
+static ssize_t btrfs_direct_read(struct kiocb *iocb, struct iov_iter *to)
+{
+ struct inode *inode = file_inode(iocb->ki_filp);
+ ssize_t ret;
+ int flags = IOMAP_DIO_RWF_NO_STALE_PAGECACHE;
+
+ if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
+ return 0;
+
+ if (is_sync_kiocb(iocb))
+ flags |= IOMAP_DIO_RWF_SYNCIO;
+
+ inode_lock_shared(inode);
+ ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dops, flags);
+ inode_unlock_shared(inode);
+ return ret;
+}
+
static ssize_t btrfs_file_read_iter(struct kiocb *iocb, struct iov_iter *to)
{
ssize_t ret = 0;
if (iocb->ki_flags & IOCB_DIRECT) {
- struct inode *inode = file_inode(iocb->ki_filp);
-
- inode_lock_shared(inode);
- ret = btrfs_direct_IO(iocb, to);
- inode_unlock_shared(inode);
+ ret = btrfs_direct_read(iocb, to);
if (ret < 0)
return ret;
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 264b676ebf29..864415a17b1f 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -29,7 +29,6 @@
#include <linux/swap.h>
#include <linux/migrate.h>
#include <linux/sched/mm.h>
-#include <linux/iomap.h>
#include <asm/unaligned.h>
#include "misc.h"
#include "ctree.h"
@@ -7844,92 +7843,15 @@ static blk_qc_t btrfs_submit_direct(struct inode *inode, struct iomap *iomap,
return BLK_QC_T_NONE;
}
-static ssize_t check_direct_IO(struct btrfs_fs_info *fs_info,
- const struct iov_iter *iter, loff_t offset)
-{
- int seg;
- int i;
- unsigned int blocksize_mask = fs_info->sectorsize - 1;
- ssize_t retval = -EINVAL;
-
- if (offset & blocksize_mask)
- goto out;
-
- if (iov_iter_alignment(iter) & blocksize_mask)
- goto out;
-
- /* If this is a write we don't need to check anymore */
- if (iov_iter_rw(iter) != READ || !iter_is_iovec(iter))
- return 0;
- /*
- * Check to make sure we don't have duplicate iov_base's in this
- * iovec, if so return EINVAL, otherwise we'll get csum errors
- * when reading back.
- */
- for (seg = 0; seg < iter->nr_segs; seg++) {
- for (i = seg + 1; i < iter->nr_segs; i++) {
- if (iter->iov[seg].iov_base == iter->iov[i].iov_base)
- goto out;
- }
- }
- retval = 0;
-out:
- return retval;
-}
-
-static const struct iomap_ops btrfs_dio_iomap_ops = {
+const struct iomap_ops btrfs_dio_iomap_ops = {
.iomap_begin = btrfs_dio_iomap_begin,
.iomap_end = btrfs_dio_iomap_end,
};
-static const struct iomap_dio_ops btrfs_dops = {
+const struct iomap_dio_ops btrfs_dops = {
.submit_io = btrfs_submit_direct,
};
-ssize_t btrfs_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
-{
- struct file *file = iocb->ki_filp;
- struct inode *inode = file->f_mapping->host;
- struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
- struct extent_changeset *data_reserved = NULL;
- loff_t offset = iocb->ki_pos;
- size_t count = 0;
- bool relock = false;
- ssize_t ret;
- int flags = IOMAP_DIO_RWF_NO_STALE_PAGECACHE;
-
- if (check_direct_IO(fs_info, iter, offset))
- return 0;
-
- count = iov_iter_count(iter);
- if (iov_iter_rw(iter) == WRITE) {
- /*
- * If the write DIO is beyond the EOF, we need update
- * the isize, but it is protected by i_mutex. So we can
- * not unlock the i_mutex at this case.
- */
- if (offset + count <= inode->i_size) {
- inode_unlock(inode);
- relock = true;
- }
- down_read(&BTRFS_I(inode)->dio_sem);
- }
-
- if (is_sync_kiocb(iocb))
- flags |= IOMAP_DIO_RWF_SYNCIO;
-
- ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops,
- flags);
-
- if (iov_iter_rw(iter) == WRITE) {
- up_read(&BTRFS_I(inode)->dio_sem);
- }
- if (relock)
- inode_lock(inode);
- extent_changeset_free(data_reserved);
- return ret;
-}
-
static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
__u64 start, __u64 len)
{
--
2.26.2
