This adds ioctl BTRFS_IOC_GET_FSIDS which reads the fs
info through the btrfs-control
v2: accepts Zach suggested
now holds uuid_mutex
Signed-off-by: Anand Jain <anand.j...@oracle.com>
---
fs/btrfs/super.c | 66 ++++++++++++++++++++++++++++++++++++++++----
fs/btrfs/volumes.c | 39 ++++++++++++++++++++++++++
fs/btrfs/volumes.h | 2 +
include/uapi/linux/btrfs.h | 19 ++++++++++++
4 files changed, 120 insertions(+), 6 deletions(-)
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index e9c4e41..241f401 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -1646,38 +1646,92 @@ static struct file_system_type btrfs_fs_type = {
};
MODULE_ALIAS_FS("btrfs");
+static int btrfs_ioc_get_fslist(void __user *arg)
+{
+ int ret = 0;
+ u64 sz_fslist_arg;
+ u64 sz_fslist;
+ u64 sz_out;
+ struct btrfs_ioctl_fslist_args *fslist_arg;
+ struct btrfs_ioctl_fslist_args *fslist_arg_tmp;
+ struct btrfs_ioctl_fslist *fslist;
+
+ u64 cnt = 0, ucnt;
+
+ sz_fslist_arg = sizeof(*fslist_arg);
+ sz_fslist = sizeof(*fslist);
+ if (copy_from_user(&ucnt,
+ (struct btrfs_ioctl_fslist_args __user *)(arg +
+ offsetof(struct btrfs_ioctl_fslist_args, count)),
+ sizeof(ucnt)))
+ return -EFAULT;
+
+ cnt = btrfs_get_fslist_cnt();
+
+ if (cnt > ucnt) {
+ if (copy_to_user(arg +
+ offsetof(struct btrfs_ioctl_fslist_args, count),
+ &cnt, sizeof(cnt)))
+ return -EFAULT;
+ return 1;
+ }
+
+ sz_out = sz_fslist_arg + sz_fslist * cnt;
+ fslist_arg_tmp = fslist_arg = memdup_user(arg, sz_out);
+ if (IS_ERR(fslist_arg))
+ return PTR_ERR(fslist_arg);
+ fslist = (struct btrfs_ioctl_fslist *) (++fslist_arg_tmp);
+ cnt = btrfs_get_fslist(fslist, cnt);
+ fslist_arg->count = cnt;
+ if (copy_to_user(arg, fslist_arg, sz_out)) {
+ ret = -EFAULT;
+ goto out;
+ }
+ ret = 0;
+out:
+ kfree(fslist_arg);
+ return ret;
+}
+
/*
* used by btrfsctl to scan devices when no FS is mounted
*/
static long btrfs_control_ioctl(struct file *file, unsigned int cmd,
unsigned long arg)
{
- struct btrfs_ioctl_vol_args *vol;
+ struct btrfs_ioctl_vol_args *vol = NULL;
struct btrfs_fs_devices *fs_devices;
int ret = -ENOTTY;
+ void __user *argp = (void __user *)arg;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- vol = memdup_user((void __user *)arg, sizeof(*vol));
- if (IS_ERR(vol))
- return PTR_ERR(vol);
-
switch (cmd) {
case BTRFS_IOC_SCAN_DEV:
+ vol = memdup_user((void __user *)arg, sizeof(*vol));
+ if (IS_ERR(vol))
+ return PTR_ERR(vol);
ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices);
+ kfree(vol);
break;
case BTRFS_IOC_DEVICES_READY:
+ vol = memdup_user((void __user *)arg, sizeof(*vol));
+ if (IS_ERR(vol))
+ return PTR_ERR(vol);
ret = btrfs_scan_one_device(vol->name, FMODE_READ,
&btrfs_fs_type, &fs_devices);
+ kfree(vol);
if (ret)
break;
ret = !(fs_devices->num_devices == fs_devices->total_devices);
break;
+ case BTRFS_IOC_GET_FSLIST:
+ ret = btrfs_ioc_get_fslist(argp);
+ break;
}
- kfree(vol);
return ret;
}
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 5103cfe..b114372 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -6289,3 +6289,42 @@ int btrfs_scratch_superblock(struct btrfs_device *device)
return 0;
}
+
+int btrfs_get_fslist_cnt(void)
+{
+ int cnt = 0;
+ struct btrfs_fs_devices *fs_devices;
+
+ mutex_lock(&uuid_mutex);
+ list_for_each_entry(fs_devices, &fs_uuids, list)
+ cnt++;
+ mutex_unlock(&uuid_mutex);
+
+ return cnt;
+}
+
+u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt)
+{
+ u64 cnt = 0;
+ struct btrfs_fs_devices *fs_devices;
+
+ mutex_lock(&uuid_mutex);
+ list_for_each_entry(fs_devices, &fs_uuids, list) {
+ if (!(cnt < ucnt))
+ break;
+ memcpy(fslist->fsid, fs_devices->fsid,
+ BTRFS_FSID_SIZE);
+ fslist->num_devices = fs_devices->num_devices;
+ fslist->missing_devices = fs_devices->missing_devices;
+ fslist->total_devices = fs_devices->total_devices;
+
+ if (fs_devices->opened)
+ fslist->flags = BTRFS_FS_MOUNTED;
+
+ fslist++;
+ cnt++;
+ }
+ mutex_unlock(&uuid_mutex);
+
+ return cnt;
+}
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index b72f540..d8079e6 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -388,4 +388,6 @@ static inline void btrfs_dev_stat_reset(struct btrfs_device
*dev,
{
btrfs_dev_stat_set(dev, index, 0);
}
+int btrfs_get_fslist_cnt(void);
+u64 btrfs_get_fslist(struct btrfs_ioctl_fslist *fslist, u64 ucnt);
#endif
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index 45e6189..6690551 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -512,6 +512,23 @@ static inline char *btrfs_err_str(enum btrfs_err_code
err_code)
}
}
+/* fs flags */
+#define BTRFS_FS_MOUNTED (1LLU << 0)
+
+struct btrfs_ioctl_fslist {
+ __u64 self_sz; /* in/out */
+ __u8 fsid[BTRFS_FSID_SIZE]; /* out */
+ __u64 num_devices;
+ __u64 missing_devices;
+ __u64 total_devices;
+ __u64 flags;
+};
+
+struct btrfs_ioctl_fslist_args {
+ __u64 self_sz; /* in/out */
+ __u64 count; /* out */
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -606,5 +623,7 @@ static inline char *btrfs_err_str(enum btrfs_err_code
err_code)
struct btrfs_ioctl_dev_replace_args)
#define BTRFS_IOC_FILE_EXTENT_SAME _IOWR(BTRFS_IOCTL_MAGIC, 54, \
struct btrfs_ioctl_same_args)
+#define BTRFS_IOC_GET_FSLIST _IOWR(BTRFS_IOCTL_MAGIC, 56, \
+ struct btrfs_ioctl_fslist_args)
#endif /* _UAPI_LINUX_BTRFS_H */
--
1.7.1
--
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