[10/13] btrfs: introduce helper functions to perform hot replace

Commit Message

Anand Jain April 12, 2016, 2:16 p.m. UTC

From: Anand Jain <[e-mail]>

Hot replace / auto replace is important volume manager feature
and is critical to the data center operations, so that the degraded
volume can be brought back to a healthy state at the earliest and
without manual intervention.

This modifies the existing replace code to suite the need of auto
replace, in the long run I hope both the codes to be merged.

Signed-off-by: Anand Jain <[e-mail]>
Tested-by: Austin S. Hemmelgarn <[e-mail]>
---
 fs/btrfs/dev-replace.c | 43 +++++++++++++++++++++++++++++++++++++++++++
 fs/btrfs/dev-replace.h |  1 +
 2 files changed, 44 insertions(+)

Comments

kernel test robot April 12, 2016, 2:40 p.m. UTC | #1

Hi Anand,

[auto build test ERROR on btrfs/next]
[also build test ERROR on v4.6-rc3 next-20160412]
[if your patch is applied to the wrong git tree, please drop us a note to help improving the system]

url:    https://github.com/0day-ci/linux/commits/Anand-Jain/Introduce-device-state-failed-spare-device-and-auto-replace/20160412-222557
base:   https://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs.git next
config: x86_64-randconfig-x010-201615 (attached as .config)
reproduce:
        # save the attached .config to linux build tree
        make ARCH=x86_64 

All errors (new ones prefixed by >>):

   fs/btrfs/dev-replace.c: In function 'btrfs_auto_replace_start':
   fs/btrfs/dev-replace.c:979:39: warning: passing argument 2 of 'btrfs_dev_replace_start' from incompatible pointer type [-Wincompatible-pointer-types]
      ret = btrfs_dev_replace_start(root, tgt_path, src_devid, NULL,
                                          ^
   fs/btrfs/dev-replace.c:308:5: note: expected 'struct btrfs_ioctl_dev_replace_args *' but argument is of type 'char *'
    int btrfs_dev_replace_start(struct btrfs_root *root,
        ^
>> fs/btrfs/dev-replace.c:979:9: error: too many arguments to function 'btrfs_dev_replace_start'
      ret = btrfs_dev_replace_start(root, tgt_path, src_devid, NULL,
            ^
   fs/btrfs/dev-replace.c:308:5: note: declared here
    int btrfs_dev_replace_start(struct btrfs_root *root,
        ^

vim +/btrfs_dev_replace_start +979 fs/btrfs/dev-replace.c

   973		}
   974	
   975		if (atomic_xchg(
   976			&root->fs_info->mutually_exclusive_operation_running, 1)) {
   977			ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
   978		} else {
 > 979			ret = btrfs_dev_replace_start(root, tgt_path, src_devid, NULL,
   980			BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS);
   981			atomic_set(
   982				&root->fs_info->mutually_exclusive_operation_running, 0);

---
0-DAY kernel test infrastructure                Open Source Technology Center
https://lists.01.org/pipermail/kbuild-all                   Intel Corporation

Patch

diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c
index 2b926867d136..ddc4843604df 100644
--- a/fs/btrfs/dev-replace.c
+++ b/fs/btrfs/dev-replace.c
@@ -957,3 +957,46 @@  void btrfs_bio_counter_inc_blocked(struct btrfs_fs_info *fs_info)
 				     &fs_info->fs_state));
 	}
 }
+
+int btrfs_auto_replace_start(struct btrfs_root *root, u64 src_devid)
+{
+	int ret;
+	char *tgt_path;
+	struct btrfs_fs_info *fs_info = root->fs_info;
+
+	if (!src_devid)
+		return -EINVAL;
+
+	if (fs_info->sb->s_flags & MS_RDONLY)
+		return -EROFS;
+
+	btrfs_dev_replace_lock(&fs_info->dev_replace, 0);
+	if (btrfs_dev_replace_is_ongoing(&fs_info->dev_replace)) {
+		btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+		return -EBUSY;
+	}
+	btrfs_dev_replace_unlock(&fs_info->dev_replace, 0);
+
+	if (btrfs_get_spare_device(&tgt_path)) {
+		btrfs_err(root->fs_info,
+			"No spare device found/configured in the kernel");
+		return -EINVAL;
+	}
+
+	if (atomic_xchg(
+		&root->fs_info->mutually_exclusive_operation_running, 1)) {
+		ret = BTRFS_ERROR_DEV_EXCL_RUN_IN_PROGRESS;
+	} else {
+		ret = btrfs_dev_replace_start(root, tgt_path, src_devid, NULL,
+		BTRFS_IOCTL_DEV_REPLACE_CONT_READING_FROM_SRCDEV_MODE_ALWAYS);
+		atomic_set(
+			&root->fs_info->mutually_exclusive_operation_running, 0);
+	}
+
+	if (ret)
+		btrfs_put_spare_device(tgt_path);
+
+	kfree(tgt_path);
+
+	return ret;
+}
diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h
index e922b42d91df..54b0812c8ba4 100644
--- a/fs/btrfs/dev-replace.h
+++ b/fs/btrfs/dev-replace.h
@@ -46,4 +46,5 @@  static inline void btrfs_dev_replace_stats_inc(atomic64_t *stat_value)
 {
 	atomic64_inc(stat_value);
 }
+int btrfs_auto_replace_start(struct btrfs_root *root, u64 src_devid);
 #endif