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path: root/fs/btrfs/ioctl.c
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Diffstat (limited to 'fs/btrfs/ioctl.c')
-rw-r--r--fs/btrfs/ioctl.c107
1 files changed, 79 insertions, 28 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 982c0b9ceea5..afbf3ac2079d 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1340,7 +1340,7 @@ static noinline int btrfs_ioctl_resize(struct file *file,
1)) {
pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
mnt_drop_write_file(file);
- return -EINPROGRESS;
+ return -EINVAL;
}
mutex_lock(&root->fs_info->volume_mutex);
@@ -1446,8 +1446,8 @@ out_free:
kfree(vol_args);
out:
mutex_unlock(&root->fs_info->volume_mutex);
- mnt_drop_write_file(file);
atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+ mnt_drop_write_file(file);
return ret;
}
@@ -2186,19 +2186,20 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
struct btrfs_ioctl_defrag_range_args *range;
int ret;
- if (btrfs_root_readonly(root))
- return -EROFS;
+ ret = mnt_want_write_file(file);
+ if (ret)
+ return ret;
if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1)) {
pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
- return -EINPROGRESS;
+ mnt_drop_write_file(file);
+ return -EINVAL;
}
- ret = mnt_want_write_file(file);
- if (ret) {
- atomic_set(&root->fs_info->mutually_exclusive_operation_running,
- 0);
- return ret;
+
+ if (btrfs_root_readonly(root)) {
+ ret = -EROFS;
+ goto out;
}
switch (inode->i_mode & S_IFMT) {
@@ -2250,8 +2251,8 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
ret = -EINVAL;
}
out:
- mnt_drop_write_file(file);
atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+ mnt_drop_write_file(file);
return ret;
}
@@ -2266,7 +2267,7 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root, void __user *arg)
if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
1)) {
pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
- return -EINPROGRESS;
+ return -EINVAL;
}
mutex_lock(&root->fs_info->volume_mutex);
@@ -2303,7 +2304,7 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
1)) {
pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
mnt_drop_write_file(file);
- return -EINPROGRESS;
+ return -EINVAL;
}
mutex_lock(&root->fs_info->volume_mutex);
@@ -2319,8 +2320,8 @@ static long btrfs_ioctl_rm_dev(struct file *file, void __user *arg)
kfree(vol_args);
out:
mutex_unlock(&root->fs_info->volume_mutex);
- mnt_drop_write_file(file);
atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
+ mnt_drop_write_file(file);
return ret;
}
@@ -3440,8 +3441,8 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_ioctl_balance_args *bargs;
struct btrfs_balance_control *bctl;
+ bool need_unlock; /* for mut. excl. ops lock */
int ret;
- int need_to_clear_lock = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -3450,14 +3451,61 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
if (ret)
return ret;
- mutex_lock(&fs_info->volume_mutex);
+again:
+ if (!atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1)) {
+ mutex_lock(&fs_info->volume_mutex);
+ mutex_lock(&fs_info->balance_mutex);
+ need_unlock = true;
+ goto locked;
+ }
+
+ /*
+ * mut. excl. ops lock is locked. Three possibilites:
+ * (1) some other op is running
+ * (2) balance is running
+ * (3) balance is paused -- special case (think resume)
+ */
mutex_lock(&fs_info->balance_mutex);
+ if (fs_info->balance_ctl) {
+ /* this is either (2) or (3) */
+ if (!atomic_read(&fs_info->balance_running)) {
+ mutex_unlock(&fs_info->balance_mutex);
+ if (!mutex_trylock(&fs_info->volume_mutex))
+ goto again;
+ mutex_lock(&fs_info->balance_mutex);
+
+ if (fs_info->balance_ctl &&
+ !atomic_read(&fs_info->balance_running)) {
+ /* this is (3) */
+ need_unlock = false;
+ goto locked;
+ }
+
+ mutex_unlock(&fs_info->balance_mutex);
+ mutex_unlock(&fs_info->volume_mutex);
+ goto again;
+ } else {
+ /* this is (2) */
+ mutex_unlock(&fs_info->balance_mutex);
+ ret = -EINPROGRESS;
+ goto out;
+ }
+ } else {
+ /* this is (1) */
+ mutex_unlock(&fs_info->balance_mutex);
+ pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
+ ret = -EINVAL;
+ goto out;
+ }
+
+locked:
+ BUG_ON(!atomic_read(&fs_info->mutually_exclusive_operation_running));
if (arg) {
bargs = memdup_user(arg, sizeof(*bargs));
if (IS_ERR(bargs)) {
ret = PTR_ERR(bargs);
- goto out;
+ goto out_unlock;
}
if (bargs->flags & BTRFS_BALANCE_RESUME) {
@@ -3477,13 +3525,10 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
bargs = NULL;
}
- if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
- 1)) {
- pr_info("btrfs: dev add/delete/balance/replace/resize operation in progress\n");
+ if (fs_info->balance_ctl) {
ret = -EINPROGRESS;
goto out_bargs;
}
- need_to_clear_lock = 1;
bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
if (!bctl) {
@@ -3504,11 +3549,17 @@ static long btrfs_ioctl_balance(struct file *file, void __user *arg)
}
do_balance:
- ret = btrfs_balance(bctl, bargs);
/*
- * bctl is freed in __cancel_balance or in free_fs_info if
- * restriper was paused all the way until unmount
+ * Ownership of bctl and mutually_exclusive_operation_running
+ * goes to to btrfs_balance. bctl is freed in __cancel_balance,
+ * or, if restriper was paused all the way until unmount, in
+ * free_fs_info. mutually_exclusive_operation_running is
+ * cleared in __cancel_balance.
*/
+ need_unlock = false;
+
+ ret = btrfs_balance(bctl, bargs);
+
if (arg) {
if (copy_to_user(arg, bargs, sizeof(*bargs)))
ret = -EFAULT;
@@ -3516,12 +3567,12 @@ do_balance:
out_bargs:
kfree(bargs);
-out:
- if (need_to_clear_lock)
- atomic_set(&root->fs_info->mutually_exclusive_operation_running,
- 0);
+out_unlock:
mutex_unlock(&fs_info->balance_mutex);
mutex_unlock(&fs_info->volume_mutex);
+ if (need_unlock)
+ atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
+out:
mnt_drop_write_file(file);
return ret;
}
generated by cgit v1.2.3-58-ga151 (git 2.39.0) at 2024-11-22 10:20:31 +0000