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-rw-r--r--fs/btrfs/inode.c82
1 files changed, 80 insertions, 2 deletions
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 1242d0aa108d..44d948fbad21 100644
--- 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,