Revert "btrfs: split btrfs_direct_IO to read and write part"

This reverts commit d8f3e73587ce574f7a9bc165e0db69b0b148f6f8.

The patch is a cleanup of direct IO port to iomap infrastructure,
which gets reverted.

Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 1615330..47b8874 100644 (file)
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -28,7 +28,6 @@
 #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"
@@ -2935,8 +2934,6 @@ 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 fde1256..dff89d0 100644 (file)
--- a/fs/btrfs/file.c
+++ b/fs/btrfs/file.c
@@ -1809,61 +1809,21 @@ again:
        return num_written ? num_written : ret;
 }
 
-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)
+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);
-       struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
-       loff_t pos = iocb->ki_pos;
-       ssize_t written = 0;
+       loff_t pos;
+       ssize_t written;
        ssize_t written_buffered;
        loff_t endbyte;
        int err;
-       size_t count = 0;
-       bool relock = false;
 
-       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;
-       }
-
-       down_read(&BTRFS_I(inode)->dio_sem);
-       written = iomap_dio_rw(iocb, from, &btrfs_dio_iomap_ops, &btrfs_dops,
-                              is_sync_kiocb(iocb));
-       up_read(&BTRFS_I(inode)->dio_sem);
-
-       if (relock)
-               inode_lock(inode);
+       written = btrfs_direct_IO(iocb, from);
 
        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) {
@@ -2002,7 +1962,7 @@ 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)
@@ -3516,44 +3476,16 @@ 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;
-
-       if (check_direct_read(btrfs_sb(inode->i_sb), to, iocb->ki_pos))
-               return 0;
-
-       inode_lock_shared(inode);
-        ret = iomap_dio_rw(iocb, to, &btrfs_dio_iomap_ops, &btrfs_dops,
-                          is_sync_kiocb(iocb));
-       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) {
-               ret = btrfs_direct_read(iocb, to);
+               struct inode *inode = file_inode(iocb->ki_filp);
+
+               inode_lock_shared(inode);
+               ret = btrfs_direct_IO(iocb, to);
+               inode_unlock_shared(inode);
                if (ret < 0)
                        return ret;
        }

diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1242d0a..44d948f 100644 (file)
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -29,6 +29,7 @@
 #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"
@@ -7819,15 +7820,92 @@ out_err:
        return BLK_QC_T_NONE;
 }
 
-const struct iomap_ops btrfs_dio_iomap_ops = {
+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 = {
        .iomap_begin            = btrfs_dio_iomap_begin,
        .iomap_end              = btrfs_dio_iomap_end,
 };
 
-const struct iomap_dio_ops btrfs_dops = {
+static 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;
+
+       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;
+               } else if (iocb->ki_flags & IOCB_NOWAIT) {
+                       ret = -EAGAIN;
+                       goto out;
+               }
+               down_read(&BTRFS_I(inode)->dio_sem);
+       }
+
+       ret = iomap_dio_rw(iocb, iter, &btrfs_dio_iomap_ops, &btrfs_dops,
+                       is_sync_kiocb(iocb));
+
+       if (iov_iter_rw(iter) == WRITE) {
+               up_read(&BTRFS_I(inode)->dio_sem);
+       }
+out:
+       if (relock)
+               inode_lock(inode);
+       extent_changeset_free(data_reserved);
+       return ret;
+}
+
 #define BTRFS_FIEMAP_FLAGS     (FIEMAP_FLAG_SYNC)
 
 static int btrfs_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,