btrfs_ioctl_get_fslabel() and btrfs_ioctl_set_fslabel()
used root->fs_info->volume_mutex mutex which caused operations
like balance to block set/get label operation until its
completion and generally balance operation takes a long
time to complete, so it will be annoying to the user when
cli appears hung
This patch will use mutex uuid_mutex. which is defined
in volume.c, and so it is moved to volume.h as well.
also this patch will add a bit of optimization within
the btrfs_ioctl_get_falabel() function.
Signed-off-by: Anand Jain <anand.jain@xxxxxxxxxx>
---
fs/btrfs/ioctl.c | 16 ++++++++++------
fs/btrfs/volumes.c | 1 -
fs/btrfs/volumes.h | 1 +
3 files changed, 11 insertions(+), 7 deletions(-)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 2177bea..d67d7d3 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -4043,17 +4043,21 @@ static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
const char *label = root->fs_info->super_copy->label;
- size_t len = strnlen(label, BTRFS_LABEL_SIZE);
+ char label_copy[BTRFS_LABEL_SIZE];
+ size_t len;
int ret;
+ mutex_lock(&uuid_mutex);
+ memcpy(label_copy, label, BTRFS_LABEL_SIZE);
+ mutex_unlock(&uuid_mutex);
+
+ len = strnlen(label_copy, BTRFS_LABEL_SIZE);
if (len == BTRFS_LABEL_SIZE) {
pr_warn("btrfs: label is too long, return the first %zu bytes\n",
--len);
}
- mutex_lock(&root->fs_info->volume_mutex);
- ret = copy_to_user(arg, label, len);
- mutex_unlock(&root->fs_info->volume_mutex);
+ ret = copy_to_user(arg, label_copy, len);
return ret ? -EFAULT : 0;
}
@@ -4082,7 +4086,7 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
if (ret)
return ret;
- mutex_lock(&root->fs_info->volume_mutex);
+ mutex_lock(&uuid_mutex);
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
@@ -4093,7 +4097,7 @@ static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
ret = btrfs_end_transaction(trans, root);
out_unlock:
- mutex_unlock(&root->fs_info->volume_mutex);
+ mutex_unlock(&uuid_mutex);
mnt_drop_write_file(file);
return ret;
}
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 557a743..a5b3eb3 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -49,7 +49,6 @@ static void __btrfs_reset_dev_stats(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_error(struct btrfs_device *dev);
static void btrfs_dev_stat_print_on_load(struct btrfs_device *device);
-static DEFINE_MUTEX(uuid_mutex);
static LIST_HEAD(fs_uuids);
static void lock_chunks(struct btrfs_root *root)
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 8670558..7855ef9 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -26,6 +26,7 @@
#define BTRFS_STRIPE_LEN (64 * 1024)
+static DEFINE_MUTEX(uuid_mutex);
struct buffer_head;
struct btrfs_pending_bios {
struct bio *head;
--
1.8.1.227.g44fe835
--
To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
