* [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system
@ 2012-12-28 3:42 Jeff Liu
2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu
2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu
0 siblings, 2 replies; 6+ messages in thread
From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw)
To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba
Hello,
Here is the updated version of introduce get/set_or_change label upon a mounted filesystem.
v8->v7:
btrfs_ioc_fs_getlabel():
- Examine the label length with strnlen().
- Tweak up warn() info if the label is not NUL terminated according to Goffredo's suggestions.
The old versions can be found at:
v7:
http://www.spinics.net/lists/linux-btrfs/msg20994.html
v6:
http://www.spinics.net/lists/linux-btrfs/msg20922.html
v5:
http://www.spinics.net/lists/linux-btrfs/msg20888.html
v4:
http://permalink.gmane.org/gmane.comp.file-systems.btrfs/21618
v3:
https://patchwork.kernel.org/patch/1124642/
v2:
http://permalink.gmane.org/gmane.comp.file-systems.btrfs/12877
v1:
http://permalink.gmane.org/gmane.comp.file-systems.btrfs/12872
Thanks,
-Jeff
^ permalink raw reply [flat|nested] 6+ messages in thread
* [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the label of a mounted file system
2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu
@ 2012-12-28 3:42 ` Jeff Liu
2012-12-28 11:51 ` David Sterba
2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu
1 sibling, 1 reply; 6+ messages in thread
From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw)
To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba
Add a new ioctl(2) BTRFS_IOC_GET_FSLABLE, so that we can get the label upon a mounted file system.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Cc: Miao Xie <miaox@cn.fujitsu.com>
Cc: Goffredo Baroncelli <kreijack@inwind.it>
Cc: David Sterba <dsterba@suse.cz>
---
fs/btrfs/ioctl.c | 22 ++++++++++++++++++++++
fs/btrfs/ioctl.h | 2 ++
2 files changed, 24 insertions(+)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 8fcf9a5..4be5d15 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3699,6 +3699,26 @@ out:
return ret;
}
+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);
+ int ret;
+
+ if (len == BTRFS_LABEL_SIZE) {
+ len--;
+ WARN(1, "btrfs: device label is not zero terminated, "
+ "it will be truncated to %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);
+
+ return ret ? -EFAULT : 0;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3797,6 +3817,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_qgroup_create(root, argp);
case BTRFS_IOC_QGROUP_LIMIT:
return btrfs_ioctl_qgroup_limit(root, argp);
+ case BTRFS_IOC_GET_FSLABEL:
+ return btrfs_ioctl_get_fslabel(file, argp);
}
return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 731e287..5b2cbef 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -451,6 +451,8 @@ struct btrfs_ioctl_send_args {
struct btrfs_ioctl_qgroup_create_args)
#define BTRFS_IOC_QGROUP_LIMIT _IOR(BTRFS_IOCTL_MAGIC, 43, \
struct btrfs_ioctl_qgroup_limit_args)
+#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \
+ char[BTRFS_LABEL_SIZE])
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
struct btrfs_ioctl_get_dev_stats)
#endif
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system
2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu
2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu
@ 2012-12-28 3:42 ` Jeff Liu
2012-12-28 12:03 ` David Sterba
1 sibling, 1 reply; 6+ messages in thread
From: Jeff Liu @ 2012-12-28 3:42 UTC (permalink / raw)
To: linux-btrfs; +Cc: anand.jain, miaox, Goffredo Baroncelli, dsterba
With this new ioctl(2) BTRFS_IOC_SET_FSLABEL, we can set/change the label of a mounted file system.
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Miao Xie <miaox@cn.fujitsu.com>
Reviewed-by: Goffredo Baroncelli <kreijack@inwind.it>
Reviewed-by: David Sterba <dsterba@suse.cz>
---
fs/btrfs/ioctl.c | 39 +++++++++++++++++++++++++++++++++++++++
fs/btrfs/ioctl.h | 2 ++
2 files changed, 41 insertions(+)
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 4be5d15..7383f49 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -3719,6 +3719,43 @@ static int btrfs_ioctl_get_fslabel(struct file *file, void __user *arg)
return ret ? -EFAULT : 0;
}
+static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
+{
+ struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
+ struct btrfs_super_block *super_block = root->fs_info->super_copy;
+ struct btrfs_trans_handle *trans;
+ char label[BTRFS_LABEL_SIZE];
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (copy_from_user(label, arg, sizeof(label)))
+ return -EFAULT;
+
+ if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE)
+ return -EINVAL;
+
+ ret = mnt_want_write_file(file);
+ if (ret)
+ return ret;
+
+ mutex_lock(&root->fs_info->volume_mutex);
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out_unlock;
+ }
+
+ strcpy(super_block->label, label);
+ ret = btrfs_end_transaction(trans, root);
+
+out_unlock:
+ mutex_unlock(&root->fs_info->volume_mutex);
+ mnt_drop_write_file(file);
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -3819,6 +3856,8 @@ long btrfs_ioctl(struct file *file, unsigned int
return btrfs_ioctl_qgroup_limit(root, argp);
case BTRFS_IOC_GET_FSLABEL:
return btrfs_ioctl_get_fslabel(file, argp);
+ case BTRFS_IOC_SET_FSLABEL:
+ return btrfs_ioctl_set_fslabel(file, argp);
}
return -ENOTTY;
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 5b2cbef..2abe239 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -453,6 +453,8 @@ struct btrfs_ioctl_send_args {
struct btrfs_ioctl_qgroup_limit_args)
#define BTRFS_IOC_GET_FSLABEL _IOR(BTRFS_IOCTL_MAGIC, 49, \
char[BTRFS_LABEL_SIZE])
+#define BTRFS_IOC_SET_FSLABEL _IOW(BTRFS_IOCTL_MAGIC, 50, \
+ char[BTRFS_LABEL_SIZE])
#define BTRFS_IOC_GET_DEV_STATS _IOWR(BTRFS_IOCTL_MAGIC, 52, \
struct btrfs_ioctl_get_dev_stats)
#endif
--
1.7.9.5
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the label of a mounted file system
2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu
@ 2012-12-28 11:51 ` David Sterba
0 siblings, 0 replies; 6+ messages in thread
From: David Sterba @ 2012-12-28 11:51 UTC (permalink / raw)
To: Jeff Liu; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli, dsterba
On Fri, Dec 28, 2012 at 11:42:36AM +0800, Jeff Liu wrote:
> +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);
> + int ret;
> +
> + if (len == BTRFS_LABEL_SIZE) {
> + len--;
> + WARN(1, "btrfs: device label is not zero terminated, "
> + "it will be truncated to %zu bytes.\n", len);
This will print a stacktrace, it's not needed in this context, the
warning is enough.
printk(KERN_WARNING "...");
> + }
> +
> + mutex_lock(&root->fs_info->volume_mutex);
> + ret = copy_to_user(arg, label, len);
> + mutex_unlock(&root->fs_info->volume_mutex);
> +
> + return ret ? -EFAULT : 0;
> +}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system
2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu
@ 2012-12-28 12:03 ` David Sterba
2012-12-31 10:23 ` Jeff Liu
0 siblings, 1 reply; 6+ messages in thread
From: David Sterba @ 2012-12-28 12:03 UTC (permalink / raw)
To: Jeff Liu; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli, dsterba
On Fri, Dec 28, 2012 at 11:42:40AM +0800, Jeff Liu wrote:
> +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
> +{
> + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
> + struct btrfs_super_block *super_block = root->fs_info->super_copy;
> + struct btrfs_trans_handle *trans;
> + char label[BTRFS_LABEL_SIZE];
> + int ret;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + if (copy_from_user(label, arg, sizeof(label)))
> + return -EFAULT;
> +
> + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE)
I would expect a message if this happens, similar to the 'get_fslabel'
one, otherwise it's difficult to find out the reason.
> + return -EINVAL;
> +
> + ret = mnt_want_write_file(file);
> + if (ret)
> + return ret;
> +
> + mutex_lock(&root->fs_info->volume_mutex);
> + trans = btrfs_start_transaction(root, 1);
Do we need to reserve 1 unit here? This does not touch any
non-superblock metadata, modifies superblock in place. This could lead
to an ENOSPC (changing label on a full fs), altghouh it need not happen.
> + if (IS_ERR(trans)) {
> + ret = PTR_ERR(trans);
> + goto out_unlock;
> + }
> +
> + strcpy(super_block->label, label);
> + ret = btrfs_end_transaction(trans, root);
> +
> +out_unlock:
> + mutex_unlock(&root->fs_info->volume_mutex);
> + mnt_drop_write_file(file);
> + return ret;
> +}
^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change the label of a mounted file system
2012-12-28 12:03 ` David Sterba
@ 2012-12-31 10:23 ` Jeff Liu
0 siblings, 0 replies; 6+ messages in thread
From: Jeff Liu @ 2012-12-31 10:23 UTC (permalink / raw)
To: dsterba; +Cc: linux-btrfs, anand.jain, miaox, Goffredo Baroncelli
On 12/28/2012 08:03 PM, David Sterba wrote:
> On Fri, Dec 28, 2012 at 11:42:40AM +0800, Jeff Liu wrote:
>> +static int btrfs_ioctl_set_fslabel(struct file *file, void __user *arg)
>> +{
>> + struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
>> + struct btrfs_super_block *super_block = root->fs_info->super_copy;
>> + struct btrfs_trans_handle *trans;
>> + char label[BTRFS_LABEL_SIZE];
>> + int ret;
>> +
>> + if (!capable(CAP_SYS_ADMIN))
>> + return -EPERM;
>> +
>> + if (copy_from_user(label, arg, sizeof(label)))
>> + return -EFAULT;
>> +
>> + if (strnlen(label, BTRFS_LABEL_SIZE) == BTRFS_LABEL_SIZE)
>
> I would expect a message if this happens, similar to the 'get_fslabel'
> one, otherwise it's difficult to find out the reason.
That's sounds make sense.
>
>> + return -EINVAL;
>> +
>> + ret = mnt_want_write_file(file);
>> + if (ret)
>> + return ret;
>> +
>> + mutex_lock(&root->fs_info->volume_mutex);
>> + trans = btrfs_start_transaction(root, 1);
>
> Do we need to reserve 1 unit here? This does not touch any
> non-superblock metadata, modifies superblock in place. This could lead
> to an ENOSPC (changing label on a full fs), altghouh it need not happen.
Don't need, I can not recalled why I did that before, will fix it.
Thanks,
-Jeff
>
>> + if (IS_ERR(trans)) {
>> + ret = PTR_ERR(trans);
>> + goto out_unlock;
>> + }
>> +
>> + strcpy(super_block->label, label);
>> + ret = btrfs_end_transaction(trans, root);
>> +
>> +out_unlock:
>> + mutex_unlock(&root->fs_info->volume_mutex);
>> + mnt_drop_write_file(file);
>> + return ret;
>> +}
^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-12-31 10:24 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
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2012-12-28 3:42 [RFC PATCH v8 0/2] Btrfs: get/set label of a mounted file system Jeff Liu
2012-12-28 3:42 ` [RFC PATCH v8 1/2] Btrfs: Add a new ioctl to get the " Jeff Liu
2012-12-28 11:51 ` David Sterba
2012-12-28 3:42 ` [RFC PATCH v8 2/2] Btrfs: Add a new ioctl to set/change " Jeff Liu
2012-12-28 12:03 ` David Sterba
2012-12-31 10:23 ` Jeff Liu
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