diff mbox series

[v2,6/7] btrfs-progs: temporally set zoned flag for initial tree reading

Message ID 20211005062305.549871-7-naohiro.aota@wdc.com (mailing list archive)
State New, archived
Headers show
Series btrfs-progs: use direct-IO for zoned device | expand

Commit Message

Naohiro Aota Oct. 5, 2021, 6:23 a.m. UTC 
Functions to read data/metadata e.g. read_extent_from_disk() now depend on
the fs_info->zoned flag to determine if they do direct-IO or not.

The flag (and zone_size) is not known before reading the chunk tree and it
set to 0 while in the initial chunk tree setup process. That will cause
btrfs_pread() to fail because it does not align the buffer.

Use fcntl() to find out the file descriptor is opened with O_DIRECT or not,
and if it is, set the zoned flag to 1 temporally for this initial process.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com>
Signed-off-by: David Sterba <dsterba@suse.com>
---
 kernel-shared/disk-io.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)
diff mbox series

Patch

diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c
index 740500f9fdc9..dd48599a5f1f 100644
--- a/kernel-shared/disk-io.c
+++ b/kernel-shared/disk-io.c
@@ -1302,10 +1302,22 @@  static struct btrfs_fs_info *__open_ctree_fd(int fp, struct open_ctree_flags *oc
 	if (ret)
 		goto out_devices;
 
+	/*
+	 * fs_info->zone_size (and zoned) are not known before reading the
+	 * chunk tree, so it's 0 at this point. But, fs_info->zoned == 0
+	 * will cause btrfs_pread() not to use an aligned bounce buffer,
+	 * causing EINVAL when the file is opened with O_DIRECT. Temporally
+	 * set zoned = 1 in that case.
+	 */
+	if (fcntl(fp, F_GETFL) & O_DIRECT)
+		fs_info->zoned = 1;
+
 	ret = btrfs_setup_chunk_tree_and_device_map(fs_info, ocf->chunk_tree_bytenr);
 	if (ret)
 		goto out_chunk;
 
+	fs_info->zoned = 0;
+
 	/* Chunk tree root is unable to read, return directly */
 	if (!fs_info->chunk_root)
 		return fs_info;