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authorChris Mason <chris.mason@fusionio.com>2013-01-21 20:39:06 -0500
committerChris Mason <chris.mason@fusionio.com>2013-01-21 20:39:06 -0500
commit83bfccb5c085658b0ad1450a6fc13b0bb5440970 (patch)
treef1f6fe9dccd23c76f750c25f91e18d7fc0ccccd7 /fs
parentdaf2c08911522d1739c55baf35f03531a29c87ef (diff)
parent25122d15e21cf252e91e4cad7cea760f97df29f1 (diff)
Merge branch 'mutex-ops@next-for-chris' of git://github.com/idryomov/btrfs-unstable into linus
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/ioctl.c107
-rw-r--r--fs/btrfs/volumes.c10
2 files changed, 86 insertions, 31 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 982c0b9ceea..afbf3ac2079 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;
}
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 86279c37de6..9c84dbe64f1 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -2959,6 +2959,8 @@ static void __cancel_balance(struct btrfs_fs_info *fs_info)
unset_balance_control(fs_info);
ret = del_balance_item(fs_info->tree_root);
BUG_ON(ret);
+
+ atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
}
void update_ioctl_balance_args(struct btrfs_fs_info *fs_info, int lock,
@@ -3138,8 +3140,10 @@ int btrfs_balance(struct btrfs_balance_control *bctl,
out:
if (bctl->flags & BTRFS_BALANCE_RESUME)
__cancel_balance(fs_info);
- else
+ else {
kfree(bctl);
+ atomic_set(&fs_info->mutually_exclusive_operation_running, 0);
+ }
return ret;
}
@@ -3156,7 +3160,6 @@ 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);
@@ -3179,7 +3182,6 @@ 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);
@@ -3233,6 +3235,8 @@ int btrfs_recover_balance(struct btrfs_fs_info *fs_info)
btrfs_balance_sys(leaf, item, &disk_bargs);
btrfs_disk_balance_args_to_cpu(&bctl->sys, &disk_bargs);
+ WARN_ON(atomic_xchg(&fs_info->mutually_exclusive_operation_running, 1));
+
mutex_lock(&fs_info->volume_mutex);
mutex_lock(&fs_info->balance_mutex);