| Message ID | 500edb962a76f3b9a6df9a6183efdc814d68d4d6.1604065695.git.naohiro.aota@wdc.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: zoned block device support | expand |
On 10/30/20 9:51 AM, Naohiro Aota wrote: > This is the 1/4 patch to support device-replace in ZONED mode. > > We have two types of I/Os during the device-replace process. One is an I/O > to "copy" (by the scrub functions) all the device extents on the source > device to the destination device. The other one is an I/O to "clone" (by > handle_ops_on_dev_replace()) new incoming write I/Os from users to the > source device into the target device. > > Cloning incoming I/Os can break the sequential write rule in the target > device. When writing is mapped in the middle of a block group, the I/O is > directed in the middle of a target device zone, which breaks the sequential > write rule. > > However, the cloning function cannot be merely disabled since incoming I/Os > targeting already copied device extents must be cloned so that the I/O is > executed on the target device. > > We cannot use dev_replace->cursor_{left,right} to determine whether bio is > going to not yet copied region. Since we have a time gap between finishing > btrfs_scrub_dev() and rewriting the mapping tree in > btrfs_dev_replace_finishing(), we can have a newly allocated device extent > which is never cloned nor copied. > > So the point is to copy only already existing device extents. This patch > introduces mark_block_group_to_copy() to mark existing block groups as a > target of copying. Then, handle_ops_on_dev_replace() and dev-replace can > check the flag to do their job. > > Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> > --- > fs/btrfs/block-group.h | 1 + > fs/btrfs/dev-replace.c | 175 +++++++++++++++++++++++++++++++++++++++++ > fs/btrfs/dev-replace.h | 3 + > fs/btrfs/scrub.c | 17 ++++ > 4 files changed, 196 insertions(+) > > diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h > index b2a8a3beceac..e91123495d68 100644 > --- a/fs/btrfs/block-group.h > +++ b/fs/btrfs/block-group.h > @@ -95,6 +95,7 @@ struct btrfs_block_group { > unsigned int iref:1; > unsigned int has_caching_ctl:1; > unsigned int removed:1; > + unsigned int to_copy:1; > > int disk_cache_state; > > diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c > index 5e3554482af1..e86aff38aea4 100644 > --- a/fs/btrfs/dev-replace.c > +++ b/fs/btrfs/dev-replace.c > @@ -22,6 +22,7 @@ > #include "dev-replace.h" > #include "sysfs.h" > #include "zoned.h" > +#include "block-group.h" > > /* > * Device replace overview > @@ -437,6 +438,176 @@ static char* btrfs_dev_name(struct btrfs_device *device) > return rcu_str_deref(device->name); > } > > +static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, > + struct btrfs_device *src_dev) > +{ > + struct btrfs_path *path; > + struct btrfs_key key; > + struct btrfs_key found_key; > + struct btrfs_root *root = fs_info->dev_root; > + struct btrfs_dev_extent *dev_extent = NULL; > + struct btrfs_block_group *cache; > + struct extent_buffer *l; > + struct btrfs_trans_handle *trans; > + int slot; > + int ret = 0; > + u64 chunk_offset, length; > + > + /* Do not use "to_copy" on non-ZONED for now */ > + if (!btrfs_fs_incompat(fs_info, ZONED)) > + return 0; if (!btrfs_is_zoned()) > + > + mutex_lock(&fs_info->chunk_mutex); > + > + /* ensulre we don't have pending new block group */ ensure. > + while (fs_info->running_transaction && > + !list_empty(&fs_info->running_transaction->dev_update_list)) { This is not safe to check, running_transaction can change without the trans_lock held. > + mutex_unlock(&fs_info->chunk_mutex); > + trans = btrfs_attach_transaction(root); > + if (IS_ERR(trans)) { > + ret = PTR_ERR(trans); > + mutex_lock(&fs_info->chunk_mutex); > + if (ret == -ENOENT) > + continue; > + else > + goto out; > + } > + > + ret = btrfs_commit_transaction(trans); > + mutex_lock(&fs_info->chunk_mutex); > + if (ret) > + goto out; > + } > + > + path = btrfs_alloc_path(); > + if (!path) { > + ret = -ENOMEM; > + goto out; > + } > + > + path->reada = READA_FORWARD; > + path->search_commit_root = 1; > + path->skip_locking = 1; > + > + key.objectid = src_dev->devid; > + key.offset = 0ull; 0 is fine here right? > + key.type = BTRFS_DEV_EXTENT_KEY; > + > + while (1) { > + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); > + if (ret < 0) > + break; > + if (ret > 0) { > + if (path->slots[0] >= > + btrfs_header_nritems(path->nodes[0])) { > + ret = btrfs_next_leaf(root, path); > + if (ret < 0) > + break; > + if (ret > 0) { > + ret = 0; > + break; > + } > + } else { > + ret = 0; > + } > + } > + > + l = path->nodes[0]; > + slot = path->slots[0]; > + > + btrfs_item_key_to_cpu(l, &found_key, slot); > + > + if (found_key.objectid != src_dev->devid) > + break; > + > + if (found_key.type != BTRFS_DEV_EXTENT_KEY) > + break; > + > + if (found_key.offset < key.offset) > + break; > + > + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); > + length = btrfs_dev_extent_length(l, dev_extent); > + > + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); > + > + cache = btrfs_lookup_block_group(fs_info, chunk_offset); > + if (!cache) > + goto skip; > + > + spin_lock(&cache->lock); > + cache->to_copy = 1; > + spin_unlock(&cache->lock); > + > + btrfs_put_block_group(cache); > + > +skip: > + key.offset = found_key.offset + length; > + btrfs_release_path(path); Why are you releasing the path here? This can be re-arranged into a loop that just uses btrfs_next_item(). > + } > + > + btrfs_free_path(path); > +out: > + mutex_unlock(&fs_info->chunk_mutex); > + > + return ret; > +} > + > +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, > + struct btrfs_block_group *cache, > + u64 physical) > +{ > + struct btrfs_fs_info *fs_info = cache->fs_info; > + struct extent_map *em; > + struct map_lookup *map; > + u64 chunk_offset = cache->start; > + int num_extents, cur_extent; > + int i; > + > + /* Do not use "to_copy" on non-ZONED for now */ > + if (!btrfs_fs_incompat(fs_info, ZONED)) > + return true; btrfs_is_zoned(); > + > + spin_lock(&cache->lock); > + if (cache->removed) { > + spin_unlock(&cache->lock); > + return true; > + } > + spin_unlock(&cache->lock); > + > + em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); > + BUG_ON(IS_ERR(em)); ASSERT(!IS_ERR(em)); > + map = em->map_lookup; > + > + num_extents = cur_extent = 0; > + for (i = 0; i < map->num_stripes; i++) { > + /* we have more device extent to copy */ > + if (srcdev != map->stripes[i].dev) > + continue; > + > + num_extents++; > + if (physical == map->stripes[i].physical) > + cur_extent = i; > + } > + > + free_extent_map(em); > + > + if (num_extents > 1 && cur_extent < num_extents - 1) { > + /* > + * Has more stripes on this device. Keep this BG > + * readonly until we finish all the stripes. > + */ > + return false; > + } > + > + /* last stripe on this device */ > + spin_lock(&cache->lock); > + cache->to_copy = 0; > + spin_unlock(&cache->lock); > + > + return true; > +} > + > static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, > const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, > int read_src) > @@ -478,6 +649,10 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, > if (ret) > return ret; > > + ret = mark_block_group_to_copy(fs_info, src_device); > + if (ret) > + return ret; > + > down_write(&dev_replace->rwsem); > switch (dev_replace->replace_state) { > case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: > diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h > index 60b70dacc299..3911049a5f23 100644 > --- a/fs/btrfs/dev-replace.h > +++ b/fs/btrfs/dev-replace.h > @@ -18,5 +18,8 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); > void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info); > int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info); > int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace); > +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, > + struct btrfs_block_group *cache, > + u64 physical); > > #endif > diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c > index aa1b36cf5c88..d0d7db3c8b0b 100644 > --- a/fs/btrfs/scrub.c > +++ b/fs/btrfs/scrub.c > @@ -3500,6 +3500,17 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, > if (!cache) > goto skip; > > + > + if (sctx->is_dev_replace && btrfs_fs_incompat(fs_info, ZONED)) { btrfs_is_zoned(). Thanks, Josef
diff --git a/fs/btrfs/block-group.h b/fs/btrfs/block-group.h index b2a8a3beceac..e91123495d68 100644 --- a/fs/btrfs/block-group.h +++ b/fs/btrfs/block-group.h @@ -95,6 +95,7 @@ struct btrfs_block_group { unsigned int iref:1; unsigned int has_caching_ctl:1; unsigned int removed:1; + unsigned int to_copy:1; int disk_cache_state; diff --git a/fs/btrfs/dev-replace.c b/fs/btrfs/dev-replace.c index 5e3554482af1..e86aff38aea4 100644 --- a/fs/btrfs/dev-replace.c +++ b/fs/btrfs/dev-replace.c @@ -22,6 +22,7 @@ #include "dev-replace.h" #include "sysfs.h" #include "zoned.h" +#include "block-group.h" /* * Device replace overview @@ -437,6 +438,176 @@ static char* btrfs_dev_name(struct btrfs_device *device) return rcu_str_deref(device->name); } +static int mark_block_group_to_copy(struct btrfs_fs_info *fs_info, + struct btrfs_device *src_dev) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_key found_key; + struct btrfs_root *root = fs_info->dev_root; + struct btrfs_dev_extent *dev_extent = NULL; + struct btrfs_block_group *cache; + struct extent_buffer *l; + struct btrfs_trans_handle *trans; + int slot; + int ret = 0; + u64 chunk_offset, length; + + /* Do not use "to_copy" on non-ZONED for now */ + if (!btrfs_fs_incompat(fs_info, ZONED)) + return 0; + + mutex_lock(&fs_info->chunk_mutex); + + /* ensulre we don't have pending new block group */ + while (fs_info->running_transaction && + !list_empty(&fs_info->running_transaction->dev_update_list)) { + mutex_unlock(&fs_info->chunk_mutex); + trans = btrfs_attach_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + mutex_lock(&fs_info->chunk_mutex); + if (ret == -ENOENT) + continue; + else + goto out; + } + + ret = btrfs_commit_transaction(trans); + mutex_lock(&fs_info->chunk_mutex); + if (ret) + goto out; + } + + path = btrfs_alloc_path(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + path->reada = READA_FORWARD; + path->search_commit_root = 1; + path->skip_locking = 1; + + key.objectid = src_dev->devid; + key.offset = 0ull; + key.type = BTRFS_DEV_EXTENT_KEY; + + while (1) { + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret < 0) + break; + if (ret > 0) { + if (path->slots[0] >= + btrfs_header_nritems(path->nodes[0])) { + ret = btrfs_next_leaf(root, path); + if (ret < 0) + break; + if (ret > 0) { + ret = 0; + break; + } + } else { + ret = 0; + } + } + + l = path->nodes[0]; + slot = path->slots[0]; + + btrfs_item_key_to_cpu(l, &found_key, slot); + + if (found_key.objectid != src_dev->devid) + break; + + if (found_key.type != BTRFS_DEV_EXTENT_KEY) + break; + + if (found_key.offset < key.offset) + break; + + dev_extent = btrfs_item_ptr(l, slot, struct btrfs_dev_extent); + length = btrfs_dev_extent_length(l, dev_extent); + + chunk_offset = btrfs_dev_extent_chunk_offset(l, dev_extent); + + cache = btrfs_lookup_block_group(fs_info, chunk_offset); + if (!cache) + goto skip; + + spin_lock(&cache->lock); + cache->to_copy = 1; + spin_unlock(&cache->lock); + + btrfs_put_block_group(cache); + +skip: + key.offset = found_key.offset + length; + btrfs_release_path(path); + } + + btrfs_free_path(path); +out: + mutex_unlock(&fs_info->chunk_mutex); + + return ret; +} + +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, + struct btrfs_block_group *cache, + u64 physical) +{ + struct btrfs_fs_info *fs_info = cache->fs_info; + struct extent_map *em; + struct map_lookup *map; + u64 chunk_offset = cache->start; + int num_extents, cur_extent; + int i; + + /* Do not use "to_copy" on non-ZONED for now */ + if (!btrfs_fs_incompat(fs_info, ZONED)) + return true; + + spin_lock(&cache->lock); + if (cache->removed) { + spin_unlock(&cache->lock); + return true; + } + spin_unlock(&cache->lock); + + em = btrfs_get_chunk_map(fs_info, chunk_offset, 1); + BUG_ON(IS_ERR(em)); + map = em->map_lookup; + + num_extents = cur_extent = 0; + for (i = 0; i < map->num_stripes; i++) { + /* we have more device extent to copy */ + if (srcdev != map->stripes[i].dev) + continue; + + num_extents++; + if (physical == map->stripes[i].physical) + cur_extent = i; + } + + free_extent_map(em); + + if (num_extents > 1 && cur_extent < num_extents - 1) { + /* + * Has more stripes on this device. Keep this BG + * readonly until we finish all the stripes. + */ + return false; + } + + /* last stripe on this device */ + spin_lock(&cache->lock); + cache->to_copy = 0; + spin_unlock(&cache->lock); + + return true; +} + static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, const char *tgtdev_name, u64 srcdevid, const char *srcdev_name, int read_src) @@ -478,6 +649,10 @@ static int btrfs_dev_replace_start(struct btrfs_fs_info *fs_info, if (ret) return ret; + ret = mark_block_group_to_copy(fs_info, src_device); + if (ret) + return ret; + down_write(&dev_replace->rwsem); switch (dev_replace->replace_state) { case BTRFS_IOCTL_DEV_REPLACE_STATE_NEVER_STARTED: diff --git a/fs/btrfs/dev-replace.h b/fs/btrfs/dev-replace.h index 60b70dacc299..3911049a5f23 100644 --- a/fs/btrfs/dev-replace.h +++ b/fs/btrfs/dev-replace.h @@ -18,5 +18,8 @@ int btrfs_dev_replace_cancel(struct btrfs_fs_info *fs_info); void btrfs_dev_replace_suspend_for_unmount(struct btrfs_fs_info *fs_info); int btrfs_resume_dev_replace_async(struct btrfs_fs_info *fs_info); int __pure btrfs_dev_replace_is_ongoing(struct btrfs_dev_replace *dev_replace); +bool btrfs_finish_block_group_to_copy(struct btrfs_device *srcdev, + struct btrfs_block_group *cache, + u64 physical); #endif diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c index aa1b36cf5c88..d0d7db3c8b0b 100644 --- a/fs/btrfs/scrub.c +++ b/fs/btrfs/scrub.c @@ -3500,6 +3500,17 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, if (!cache) goto skip; + + if (sctx->is_dev_replace && btrfs_fs_incompat(fs_info, ZONED)) { + spin_lock(&cache->lock); + if (!cache->to_copy) { + spin_unlock(&cache->lock); + ro_set = 0; + goto done; + } + spin_unlock(&cache->lock); + } + /* * Make sure that while we are scrubbing the corresponding block * group doesn't get its logical address and its device extents @@ -3631,6 +3642,12 @@ int scrub_enumerate_chunks(struct scrub_ctx *sctx, scrub_pause_off(fs_info); + if (sctx->is_dev_replace && + !btrfs_finish_block_group_to_copy(dev_replace->srcdev, + cache, found_key.offset)) + ro_set = 0; + +done: down_write(&dev_replace->rwsem); dev_replace->cursor_left = dev_replace->cursor_right; dev_replace->item_needs_writeback = 1;
This is the 1/4 patch to support device-replace in ZONED mode. We have two types of I/Os during the device-replace process. One is an I/O to "copy" (by the scrub functions) all the device extents on the source device to the destination device. The other one is an I/O to "clone" (by handle_ops_on_dev_replace()) new incoming write I/Os from users to the source device into the target device. Cloning incoming I/Os can break the sequential write rule in the target device. When writing is mapped in the middle of a block group, the I/O is directed in the middle of a target device zone, which breaks the sequential write rule. However, the cloning function cannot be merely disabled since incoming I/Os targeting already copied device extents must be cloned so that the I/O is executed on the target device. We cannot use dev_replace->cursor_{left,right} to determine whether bio is going to not yet copied region. Since we have a time gap between finishing btrfs_scrub_dev() and rewriting the mapping tree in btrfs_dev_replace_finishing(), we can have a newly allocated device extent which is never cloned nor copied. So the point is to copy only already existing device extents. This patch introduces mark_block_group_to_copy() to mark existing block groups as a target of copying. Then, handle_ops_on_dev_replace() and dev-replace can check the flag to do their job. Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> --- fs/btrfs/block-group.h | 1 + fs/btrfs/dev-replace.c | 175 +++++++++++++++++++++++++++++++++++++++++ fs/btrfs/dev-replace.h | 3 + fs/btrfs/scrub.c | 17 ++++ 4 files changed, 196 insertions(+)