diff options
| author | Anand Jain <anand.jain@oracle.com> | 2018-05-29 14:10:20 +0800 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-09-15 09:46:56 +0200 |
| commit | 0b40d58d469f3e78ec644b3a0ada4295e596e190 (patch) | |
| tree | 73f7ec8e6a9fdd47cea6007963056bd47f5a66fa /fs | |
| parent | 2d4bbb81bac654db2d5e66887d0a3be704aab060 (diff) | |
btrfs: extend locked section when adding a new device in device_list_add
[ Upstream commit 9c6d173ea6e4c8c939ae6c257c7fc18f7b320316 ]
Make sure the device_list_lock is held the whole time:
* when the device is being looked up
* new device is initialized and put to the list
* the list counters are updated (fs_devices::opened, fs_devices::total_devices)
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ update changelog ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/volumes.c | 16 |
1 files changed, 12 insertions, 4 deletions
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 118c9275a2e2..b53e5b63f116 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -765,21 +765,26 @@ static noinline struct btrfs_device *device_list_add(const char *path, if (IS_ERR(fs_devices)) return ERR_CAST(fs_devices); + mutex_lock(&fs_devices->device_list_mutex); list_add(&fs_devices->fs_list, &fs_uuids); device = NULL; } else { + mutex_lock(&fs_devices->device_list_mutex); device = find_device(fs_devices, devid, disk_super->dev_item.uuid); } if (!device) { - if (fs_devices->opened) + if (fs_devices->opened) { + mutex_unlock(&fs_devices->device_list_mutex); return ERR_PTR(-EBUSY); + } device = btrfs_alloc_device(NULL, &devid, disk_super->dev_item.uuid); if (IS_ERR(device)) { + mutex_unlock(&fs_devices->device_list_mutex); /* we can safely leave the fs_devices entry around */ return device; } @@ -787,14 +792,13 @@ static noinline struct btrfs_device *device_list_add(const char *path, name = rcu_string_strdup(path, GFP_NOFS); if (!name) { btrfs_free_device(device); + mutex_unlock(&fs_devices->device_list_mutex); return ERR_PTR(-ENOMEM); } rcu_assign_pointer(device->name, name); - mutex_lock(&fs_devices->device_list_mutex); list_add_rcu(&device->dev_list, &fs_devices->devices); fs_devices->num_devices++; - mutex_unlock(&fs_devices->device_list_mutex); device->fs_devices = fs_devices; *new_device_added = true; @@ -841,12 +845,15 @@ static noinline struct btrfs_device *device_list_add(const char *path, * with larger generation number or the last-in if * generation are equal. */ + mutex_unlock(&fs_devices->device_list_mutex); return ERR_PTR(-EEXIST); } name = rcu_string_strdup(path, GFP_NOFS); - if (!name) + if (!name) { + mutex_unlock(&fs_devices->device_list_mutex); return ERR_PTR(-ENOMEM); + } rcu_string_free(device->name); rcu_assign_pointer(device->name, name); if (test_bit(BTRFS_DEV_STATE_MISSING, &device->dev_state)) { @@ -866,6 +873,7 @@ static noinline struct btrfs_device *device_list_add(const char *path, fs_devices->total_devices = btrfs_super_num_devices(disk_super); + mutex_unlock(&fs_devices->device_list_mutex); return device; } |