Btrfs admin operations that are manually started from user mode
and that cannot be executed at the same time return -EINPROGRESS.
A common way to enter and leave this locked section is introduced
since it used to be specific to the balance operation.
Signed-off-by: Stefan Behrens <sbehr...@giantdisaster.de>
---
fs/btrfs/ctree.h | 2 ++
fs/btrfs/ioctl.c | 53 ++++++++++++++++++++++++++++++++++++-----------------
fs/btrfs/volumes.c | 2 ++
3 files changed, 40 insertions(+), 17 deletions(-)
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 4bffc63..f9ceea9 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -1527,6 +1527,8 @@ struct btrfs_fs_info {
/* device replace state */
struct btrfs_dev_replace dev_replace;
+
+ atomic_t mutually_exclusive_operation_running;
};
/*
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 7ece1fe..d912c64 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1314,13 +1314,13 @@ static noinline int btrfs_ioctl_resize(struct
btrfs_root *root,
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- mutex_lock(&root->fs_info->volume_mutex);
- if (root->fs_info->balance_ctl) {
- printk(KERN_INFO "btrfs: balance in progress\n");
- ret = -EINVAL;
- goto out;
+ 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;
}
+ mutex_lock(&root->fs_info->volume_mutex);
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
@@ -1416,6 +1416,7 @@ out_free:
kfree(vol_args);
out:
mutex_unlock(&root->fs_info->volume_mutex);
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
return ret;
}
@@ -2157,9 +2158,17 @@ static int btrfs_ioctl_defrag(struct file *file, void
__user *argp)
if (btrfs_root_readonly(root))
return -EROFS;
+ 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;
+ }
ret = mnt_want_write_file(file);
- if (ret)
+ if (ret) {
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running,
+ 0);
return ret;
+ }
switch (inode->i_mode & S_IFMT) {
case S_IFDIR:
@@ -2211,6 +2220,7 @@ static int btrfs_ioctl_defrag(struct file *file, void
__user *argp)
}
out:
mnt_drop_write_file(file);
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
return ret;
}
@@ -2222,13 +2232,13 @@ static long btrfs_ioctl_add_dev(struct btrfs_root
*root, void __user *arg)
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
- mutex_lock(&root->fs_info->volume_mutex);
- if (root->fs_info->balance_ctl) {
- printk(KERN_INFO "btrfs: balance in progress\n");
- ret = -EINVAL;
- goto out;
+ 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;
}
+ mutex_lock(&root->fs_info->volume_mutex);
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
@@ -2241,6 +2251,7 @@ static long btrfs_ioctl_add_dev(struct btrfs_root *root,
void __user *arg)
kfree(vol_args);
out:
mutex_unlock(&root->fs_info->volume_mutex);
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
return ret;
}
@@ -2255,13 +2266,13 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root,
void __user *arg)
if (root->fs_info->sb->s_flags & MS_RDONLY)
return -EROFS;
- mutex_lock(&root->fs_info->volume_mutex);
- if (root->fs_info->balance_ctl) {
- printk(KERN_INFO "btrfs: balance in progress\n");
- ret = -EINVAL;
- goto out;
+ 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;
}
+ mutex_lock(&root->fs_info->volume_mutex);
vol_args = memdup_user(arg, sizeof(*vol_args));
if (IS_ERR(vol_args)) {
ret = PTR_ERR(vol_args);
@@ -2274,6 +2285,7 @@ static long btrfs_ioctl_rm_dev(struct btrfs_root *root,
void __user *arg)
kfree(vol_args);
out:
mutex_unlock(&root->fs_info->volume_mutex);
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running, 0);
return ret;
}
@@ -3316,6 +3328,7 @@ static long btrfs_ioctl_balance(struct file *file, void
__user *arg)
struct btrfs_ioctl_balance_args *bargs;
struct btrfs_balance_control *bctl;
int ret;
+ int need_to_clear_lock = 0;
if (!capable(CAP_SYS_ADMIN))
return -EPERM;
@@ -3351,10 +3364,13 @@ static long btrfs_ioctl_balance(struct file *file, void
__user *arg)
bargs = NULL;
}
- if (fs_info->balance_ctl) {
+ if (atomic_xchg(&root->fs_info->mutually_exclusive_operation_running,
+ 1)) {
+ pr_info("btrfs: dev add/delete/balance/replace/resize operation
in progress\n");
ret = -EINPROGRESS;
goto out_bargs;
}
+ need_to_clear_lock = 1;
bctl = kzalloc(sizeof(*bctl), GFP_NOFS);
if (!bctl) {
@@ -3388,6 +3404,9 @@ do_balance:
out_bargs:
kfree(bargs);
out:
+ if (need_to_clear_lock)
+ atomic_set(&root->fs_info->mutually_exclusive_operation_running,
+ 0);
mutex_unlock(&fs_info->balance_mutex);
mutex_unlock(&fs_info->volume_mutex);
mnt_drop_write_file(file);
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 473ae89..1827bcd 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2956,6 +2956,7 @@ static int balance_kthread(void *data)
ret = btrfs_balance(fs_info->balance_ctl, NULL);
}
+ atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
mutex_unlock(&fs_info->balance_mutex);
mutex_unlock(&fs_info->volume_mutex);
@@ -2978,6 +2979,7 @@ int btrfs_resume_balance_async(struct btrfs_fs_info
*fs_info)
return 0;
}
+ WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
tsk = kthread_run(balance_kthread, fs_info, "btrfs-balance");
if (IS_ERR(tsk))
return PTR_ERR(tsk);
--
1.8.0
--
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