From 944d3f9fac61e24e13a056b25974df3831994f29 Mon Sep 17 00:00:00 2001 From: Nikolay Borisov Date: Thu, 16 Jul 2020 10:25:33 +0300 Subject: [PATCH] btrfs: switch seed device to list api While this patch touches a bunch of files the conversion is straighforward. Instead of using the implicit linked list anchored at btrfs_fs_devices::seed the code is switched to using list_for_each_entry. Previous patches in the series already factored out code that processed both main and seed devices so in those cases the factored out functions are called on the main fs_devices and then on every seed dev inside list_for_each_entry. Using list api also allows to simplify deletion from the seed dev list performed in btrfs_rm_device and btrfs_rm_dev_replace_free_srcdev by substituting a while() loop with a simple list_del_init. Reviewed-by: Josef Bacik Reviewed-by: Anand Jain Signed-off-by: Nikolay Borisov Signed-off-by: David Sterba --- fs/btrfs/disk-io.c | 39 ++++++++--------- fs/btrfs/reada.c | 9 ++-- fs/btrfs/volumes.c | 105 +++++++++++++++++++++------------------------ fs/btrfs/volumes.h | 2 +- 4 files changed, 71 insertions(+), 84 deletions(-) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index a496219baa39..84799ef76758 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -545,33 +545,30 @@ static int csum_dirty_buffer(struct btrfs_fs_info *fs_info, struct page *page) static int check_tree_block_fsid(struct extent_buffer *eb) { struct btrfs_fs_info *fs_info = eb->fs_info; - struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; u8 fsid[BTRFS_FSID_SIZE]; - int ret = 1; + u8 *metadata_uuid; read_extent_buffer(eb, fsid, offsetof(struct btrfs_header, fsid), BTRFS_FSID_SIZE); - while (fs_devices) { - u8 *metadata_uuid; + /* + * Checking the incompat flag is only valid for the current fs. For + * seed devices it's forbidden to have their uuid changed so reading + * ->fsid in this case is fine + */ + if (btrfs_fs_incompat(fs_info, METADATA_UUID)) + metadata_uuid = fs_devices->metadata_uuid; + else + metadata_uuid = fs_devices->fsid; - /* - * Checking the incompat flag is only valid for the current - * fs. For seed devices it's forbidden to have their uuid - * changed so reading ->fsid in this case is fine - */ - if (fs_devices == fs_info->fs_devices && - btrfs_fs_incompat(fs_info, METADATA_UUID)) - metadata_uuid = fs_devices->metadata_uuid; - else - metadata_uuid = fs_devices->fsid; + if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE)) + return 0; - if (!memcmp(fsid, metadata_uuid, BTRFS_FSID_SIZE)) { - ret = 0; - break; - } - fs_devices = fs_devices->seed; - } - return ret; + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) + if (!memcmp(fsid, seed_devs->fsid, BTRFS_FSID_SIZE)) + return 0; + + return 1; } static int btree_readpage_end_io_hook(struct btrfs_io_bio *io_bio, diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c index a6bfe7ec14cb..e20972230823 100644 --- a/fs/btrfs/reada.c +++ b/fs/btrfs/reada.c @@ -791,16 +791,13 @@ static int reada_start_for_fsdevs(struct btrfs_fs_devices *fs_devices) static void __reada_start_machine(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; int i; u64 enqueued = 0; -again: enqueued += reada_start_for_fsdevs(fs_devices); - if (fs_devices->seed) { - fs_devices = fs_devices->seed; - goto again; - } + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) + enqueued += reada_start_for_fsdevs(seed_devs); if (enqueued == 0) return; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 91a413b73b64..2d7c845b8e67 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -356,6 +356,7 @@ static struct btrfs_fs_devices *alloc_fs_devices(const u8 *fsid, INIT_LIST_HEAD(&fs_devs->devices); INIT_LIST_HEAD(&fs_devs->alloc_list); INIT_LIST_HEAD(&fs_devs->fs_list); + INIT_LIST_HEAD(&fs_devs->seed_list); if (fsid) memcpy(fs_devs->fsid, fsid, BTRFS_FSID_SIZE); @@ -1097,14 +1098,13 @@ static void __btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, void btrfs_free_extra_devids(struct btrfs_fs_devices *fs_devices, int step) { struct btrfs_device *latest_dev = NULL; + struct btrfs_fs_devices *seed_dev; mutex_lock(&uuid_mutex); -again: __btrfs_free_extra_devids(fs_devices, step, &latest_dev); - if (fs_devices->seed) { - fs_devices = fs_devices->seed; - goto again; - } + + list_for_each_entry(seed_dev, &fs_devices->seed_list, seed_list) + __btrfs_free_extra_devids(seed_dev, step, &latest_dev); fs_devices->latest_bdev = latest_dev->bdev; @@ -1178,20 +1178,18 @@ static void close_fs_devices(struct btrfs_fs_devices *fs_devices) void btrfs_close_devices(struct btrfs_fs_devices *fs_devices) { - struct btrfs_fs_devices *seed_devices = NULL; + LIST_HEAD(list); + struct btrfs_fs_devices *tmp; mutex_lock(&uuid_mutex); close_fs_devices(fs_devices); - if (!fs_devices->opened) { - seed_devices = fs_devices->seed; - fs_devices->seed = NULL; - } + if (!fs_devices->opened) + list_splice_init(&fs_devices->seed_list, &list); mutex_unlock(&uuid_mutex); - while (seed_devices) { - fs_devices = seed_devices; - seed_devices = fs_devices->seed; + list_for_each_entry_safe(fs_devices, tmp, &list, seed_list) { close_fs_devices(fs_devices); + list_del(&fs_devices->seed_list); free_fs_devices(fs_devices); } } @@ -2169,14 +2167,7 @@ int btrfs_rm_device(struct btrfs_fs_info *fs_info, const char *device_path, btrfs_free_device(device); if (cur_devices->open_devices == 0) { - while (fs_devices) { - if (fs_devices->seed == cur_devices) { - fs_devices->seed = cur_devices->seed; - break; - } - fs_devices = fs_devices->seed; - } - cur_devices->seed = NULL; + list_del_init(&cur_devices->seed_list); close_fs_devices(cur_devices); free_fs_devices(cur_devices); } @@ -2236,8 +2227,6 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev) /* if this is no devs we rather delete the fs_devices */ if (!fs_devices->num_devices) { - struct btrfs_fs_devices *tmp_fs_devices; - /* * On a mounted FS, num_devices can't be zero unless it's a * seed. In case of a seed device being replaced, the replace @@ -2246,15 +2235,7 @@ void btrfs_rm_dev_replace_free_srcdev(struct btrfs_device *srcdev) */ ASSERT(fs_devices->seeding); - tmp_fs_devices = fs_info->fs_devices; - while (tmp_fs_devices) { - if (tmp_fs_devices->seed == fs_devices) { - tmp_fs_devices->seed = fs_devices->seed; - break; - } - tmp_fs_devices = tmp_fs_devices->seed; - } - fs_devices->seed = NULL; + list_del_init(&fs_devices->seed_list); close_fs_devices(fs_devices); free_fs_devices(fs_devices); } @@ -2409,7 +2390,7 @@ static int btrfs_prepare_sprout(struct btrfs_fs_info *fs_info) fs_devices->open_devices = 0; fs_devices->missing_devices = 0; fs_devices->rotating = false; - fs_devices->seed = seed_devices; + list_add(&seed_devices->seed_list, &fs_devices->seed_list); generate_random_uuid(fs_devices->fsid); memcpy(fs_devices->metadata_uuid, fs_devices->fsid, BTRFS_FSID_SIZE); @@ -6465,11 +6446,21 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices, bool seed) { struct btrfs_device *device; + struct btrfs_fs_devices *seed_devs; - while (fs_devices) { + if (!fsid || !memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { + list_for_each_entry(device, &fs_devices->devices, dev_list) { + if (device->devid == devid && + (!uuid || memcmp(device->uuid, uuid, + BTRFS_UUID_SIZE) == 0)) + return device; + } + } + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { if (!fsid || - !memcmp(fs_devices->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { - list_for_each_entry(device, &fs_devices->devices, + !memcmp(seed_devs->metadata_uuid, fsid, BTRFS_FSID_SIZE)) { + list_for_each_entry(device, &seed_devs->devices, dev_list) { if (device->devid == devid && (!uuid || memcmp(device->uuid, uuid, @@ -6477,11 +6468,8 @@ struct btrfs_device *btrfs_find_device(struct btrfs_fs_devices *fs_devices, return device; } } - if (seed) - fs_devices = fs_devices->seed; - else - return NULL; } + return NULL; } @@ -6732,13 +6720,10 @@ static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info, lockdep_assert_held(&uuid_mutex); ASSERT(fsid); - fs_devices = fs_info->fs_devices->seed; - while (fs_devices) { + list_for_each_entry(fs_devices, &fs_info->fs_devices->seed_list, seed_list) if (!memcmp(fs_devices->fsid, fsid, BTRFS_FSID_SIZE)) return fs_devices; - fs_devices = fs_devices->seed; - } fs_devices = find_fsid(fsid, NULL); if (!fs_devices) { @@ -6772,8 +6757,7 @@ static struct btrfs_fs_devices *open_seed_devices(struct btrfs_fs_info *fs_info, goto out; } - fs_devices->seed = fs_info->fs_devices->seed; - fs_info->fs_devices->seed = fs_devices; + list_add(&fs_devices->seed_list, &fs_info->fs_devices->seed_list); out: return fs_devices; } @@ -7193,17 +7177,23 @@ error: void btrfs_init_devices_late(struct btrfs_fs_info *fs_info) { - struct btrfs_fs_devices *fs_devices = fs_info->fs_devices; + struct btrfs_fs_devices *fs_devices = fs_info->fs_devices, *seed_devs; struct btrfs_device *device; - while (fs_devices) { - mutex_lock(&fs_devices->device_list_mutex); - list_for_each_entry(device, &fs_devices->devices, dev_list) - device->fs_info = fs_info; - mutex_unlock(&fs_devices->device_list_mutex); + fs_devices->fs_info = fs_info; - fs_devices->fs_info = fs_info; - fs_devices = fs_devices->seed; + mutex_lock(&fs_devices->device_list_mutex); + list_for_each_entry(device, &fs_devices->devices, dev_list) + device->fs_info = fs_info; + mutex_unlock(&fs_devices->device_list_mutex); + + list_for_each_entry(seed_devs, &fs_devices->seed_list, seed_list) { + mutex_lock(&seed_devs->device_list_mutex); + list_for_each_entry(device, &seed_devs->devices, dev_list) + device->fs_info = fs_info; + mutex_unlock(&seed_devs->device_list_mutex); + + seed_devs->fs_info = fs_info; } } @@ -7581,8 +7571,11 @@ static int verify_one_dev_extent(struct btrfs_fs_info *fs_info, /* It's possible this device is a dummy for seed device */ if (dev->disk_total_bytes == 0) { - dev = btrfs_find_device(fs_info->fs_devices->seed, devid, NULL, - NULL, false); + struct btrfs_fs_devices *devs; + + devs = list_first_entry(&fs_info->fs_devices->seed_list, + struct btrfs_fs_devices, seed_list); + dev = btrfs_find_device(devs, devid, NULL, NULL, false); if (!dev) { btrfs_err(fs_info, "failed to find seed devid %llu", devid); diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h index 524aa5eb5667..48bdca01e237 100644 --- a/fs/btrfs/volumes.h +++ b/fs/btrfs/volumes.h @@ -246,7 +246,7 @@ struct btrfs_fs_devices { */ struct list_head alloc_list; - struct btrfs_fs_devices *seed; + struct list_head seed_list; bool seeding; int opened;