Re: [PATCH] btrfs: delete chunk allocation attemp when setting block group ro
On Fri, Jan 09, 2015 at 10:50:17AM +0800, Miao Xie wrote:
On Thu, 08 Jan 2015 18:06:50 -0800, Shaohua Li wrote:
On Fri, Jan 09, 2015 at 09:01:57AM +0800, Miao Xie wrote:
On Thu, 08 Jan 2015 13:23:13 -0800, Shaohua Li wrote:
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
---
fs/btrfs/extent-tree.c | 31 +++
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..430101b6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8493,22 +8493,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache-space_info;
u64 num_bytes;
- u64 min_allocable_bytes;
int ret = -ENOSPC;
-
- /*
- * We need some metadata space and system metadata space for
- * allocating chunks in some corner cases until we force to set
- * it to be readonly.
- */
- if ((sinfo-flags
- (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA))
- !force)
- min_allocable_bytes = 1 * 1024 * 1024;
- else
- min_allocable_bytes = 0;
-
spin_lock(sinfo-lock);
spin_lock(cache-lock);
[SNIP]
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8544,11 @@ int btrfs_set_block_group_ro(struct btrfs_root
*root,
goto out;
ret = set_block_group_ro(cache, 0);
out:
+ if (cache-flags BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache-flags);
+ check_system_chunk(trans, root, alloc_flags);
Please consider the case that the following patch fixed
199c36eaa95077a47ae1bc55532fc0fbeb80cc95
If there is no free device space, check_system_chunk can not allocate
new system metadata chunk, so when we run final step of the chunk
allocation to update the device item and insert the new chunk item, we
would fail.
So the relocation will always fail in this case. The check just makes
the failure earlier, right? We don't have the BUG_ON in
do_chunk_alloc() currently.
The final step of the chunk allocation is a delayed operation, we must make
sure
it can be done successfully, or we would abort the transaction, make the
filesystem readonly and lose the data that is written into the filesystem
before
we do balance, it would make the users unconfortable.
With this patch, we will set the block group successfully at the first time we
invoke set_block_group_ro(). But if the block group that will be set to RO is
the only system metadata block group in the filesystem, and there is no device
space to allocate a new one, that is we have no space to deal with the pending
final step of chunk allocation, so the problem I said above will happen.
Ok, makes sense. Updated patch:
commit d8c84ce6d40b471f5d0fb3d4e8b76d5ba424dca4
Author: Shaohua Li s...@fb.com
Date: Wed Jan 7 14:29:49 2015 -0800
btrfs: delete chunk allocation attemp when setting block group ro
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..be1aac6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8548,14 +8548,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
if (IS_ERR(trans))
return PTR_ERR(trans);
- alloc_flags = update_block_group_flags(root, cache-flags);
- if (alloc_flags != cache-flags) {
- ret = do_chunk_alloc(trans, root, alloc_flags,
-CHUNK_ALLOC_FORCE);
- if (ret 0)
- goto out;
- }
-
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8558,11 @@ int
Re: [PATCH] btrfs: delete chunk allocation attemp when setting block group ro
On Thu, 08 Jan 2015 13:23:13 -0800, Shaohua Li wrote:
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
---
fs/btrfs/extent-tree.c | 31 +++
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..430101b6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8493,22 +8493,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache-space_info;
u64 num_bytes;
- u64 min_allocable_bytes;
int ret = -ENOSPC;
-
- /*
- * We need some metadata space and system metadata space for
- * allocating chunks in some corner cases until we force to set
- * it to be readonly.
- */
- if ((sinfo-flags
- (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA))
- !force)
- min_allocable_bytes = 1 * 1024 * 1024;
- else
- min_allocable_bytes = 0;
-
spin_lock(sinfo-lock);
spin_lock(cache-lock);
@@ -8521,8 +8507,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
cache-bytes_super - btrfs_block_group_used(cache-item);
if (sinfo-bytes_used + sinfo-bytes_reserved + sinfo-bytes_pinned +
- sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes +
- min_allocable_bytes = sinfo-total_bytes) {
+ sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes
+ = sinfo-total_bytes) {
sinfo-bytes_readonly += num_bytes;
cache-ro = 1;
list_add_tail(cache-ro_list, sinfo-ro_bgs);
@@ -8548,14 +8534,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
if (IS_ERR(trans))
return PTR_ERR(trans);
- alloc_flags = update_block_group_flags(root, cache-flags);
- if (alloc_flags != cache-flags) {
- ret = do_chunk_alloc(trans, root, alloc_flags,
- CHUNK_ALLOC_FORCE);
- if (ret 0)
- goto out;
- }
-
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8544,11 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
goto out;
ret = set_block_group_ro(cache, 0);
out:
+ if (cache-flags BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache-flags);
+ check_system_chunk(trans, root, alloc_flags);
Please consider the case that the following patch fixed
199c36eaa95077a47ae1bc55532fc0fbeb80cc95
If there is no free device space, check_system_chunk can not allocate
new system metadata chunk, so when we run final step of the chunk
allocation to update the device item and insert the new chunk item, we
would fail.
Thanks
Miao
+ }
+
btrfs_end_transaction(trans, root);
return ret;
}
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Re: [PATCH] btrfs: delete chunk allocation attemp when setting block group ro
On Fri, Jan 09, 2015 at 09:01:57AM +0800, Miao Xie wrote:
On Thu, 08 Jan 2015 13:23:13 -0800, Shaohua Li wrote:
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
---
fs/btrfs/extent-tree.c | 31 +++
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..430101b6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8493,22 +8493,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache-space_info;
u64 num_bytes;
- u64 min_allocable_bytes;
int ret = -ENOSPC;
-
- /*
-* We need some metadata space and system metadata space for
-* allocating chunks in some corner cases until we force to set
-* it to be readonly.
-*/
- if ((sinfo-flags
-(BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA))
- !force)
- min_allocable_bytes = 1 * 1024 * 1024;
- else
- min_allocable_bytes = 0;
-
spin_lock(sinfo-lock);
spin_lock(cache-lock);
@@ -8521,8 +8507,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
cache-bytes_super - btrfs_block_group_used(cache-item);
if (sinfo-bytes_used + sinfo-bytes_reserved + sinfo-bytes_pinned +
- sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes +
- min_allocable_bytes = sinfo-total_bytes) {
+ sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes
+ = sinfo-total_bytes) {
sinfo-bytes_readonly += num_bytes;
cache-ro = 1;
list_add_tail(cache-ro_list, sinfo-ro_bgs);
@@ -8548,14 +8534,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
if (IS_ERR(trans))
return PTR_ERR(trans);
- alloc_flags = update_block_group_flags(root, cache-flags);
- if (alloc_flags != cache-flags) {
- ret = do_chunk_alloc(trans, root, alloc_flags,
-CHUNK_ALLOC_FORCE);
- if (ret 0)
- goto out;
- }
-
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8544,11 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
goto out;
ret = set_block_group_ro(cache, 0);
out:
+ if (cache-flags BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache-flags);
+ check_system_chunk(trans, root, alloc_flags);
Please consider the case that the following patch fixed
199c36eaa95077a47ae1bc55532fc0fbeb80cc95
If there is no free device space, check_system_chunk can not allocate
new system metadata chunk, so when we run final step of the chunk
allocation to update the device item and insert the new chunk item, we
would fail.
So the relocation will always fail in this case. The check just makes
the failure earlier, right? We don't have the BUG_ON in
do_chunk_alloc() currently.
Thanks,
Shaohua
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Re: [PATCH] btrfs: delete chunk allocation attemp when setting block group ro
On Thu, 08 Jan 2015 18:06:50 -0800, Shaohua Li wrote:
On Fri, Jan 09, 2015 at 09:01:57AM +0800, Miao Xie wrote:
On Thu, 08 Jan 2015 13:23:13 -0800, Shaohua Li wrote:
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
---
fs/btrfs/extent-tree.c | 31 +++
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..430101b6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8493,22 +8493,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache-space_info;
u64 num_bytes;
- u64 min_allocable_bytes;
int ret = -ENOSPC;
-
- /*
-* We need some metadata space and system metadata space for
-* allocating chunks in some corner cases until we force to set
-* it to be readonly.
-*/
- if ((sinfo-flags
-(BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA))
- !force)
- min_allocable_bytes = 1 * 1024 * 1024;
- else
- min_allocable_bytes = 0;
-
spin_lock(sinfo-lock);
spin_lock(cache-lock);
[SNIP]
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8544,11 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
goto out;
ret = set_block_group_ro(cache, 0);
out:
+ if (cache-flags BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache-flags);
+ check_system_chunk(trans, root, alloc_flags);
Please consider the case that the following patch fixed
199c36eaa95077a47ae1bc55532fc0fbeb80cc95
If there is no free device space, check_system_chunk can not allocate
new system metadata chunk, so when we run final step of the chunk
allocation to update the device item and insert the new chunk item, we
would fail.
So the relocation will always fail in this case. The check just makes
the failure earlier, right? We don't have the BUG_ON in
do_chunk_alloc() currently.
The final step of the chunk allocation is a delayed operation, we must make sure
it can be done successfully, or we would abort the transaction, make the
filesystem readonly and lose the data that is written into the filesystem before
we do balance, it would make the users unconfortable.
With this patch, we will set the block group successfully at the first time we
invoke set_block_group_ro(). But if the block group that will be set to RO is
the only system metadata block group in the filesystem, and there is no device
space to allocate a new one, that is we have no space to deal with the pending
final step of chunk allocation, so the problem I said above will happen.
Thanks
Miao
--
To unsubscribe from this list: send the line unsubscribe linux-btrfs in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
[PATCH] btrfs: delete chunk allocation attemp when setting block group ro
Below test will fail currently:
mkfs.ext4 -F /dev/sda
btrfs-convert /dev/sda
mount /dev/sda /mnt
btrfs device add -f /dev/sdb /mnt
btrfs balance start -v -dconvert=raid1 -mconvert=raid1 /mnt
The reason is there are some block groups with usage 0, but the whole
disk hasn't free space to allocate new chunk, so we even can't set such
block group readonly. This patch deletes the chunk allocation when
setting block group ro. For META, we already have reserve. But for
SYSTEM, we don't have, so the check_system_chunk is still required.
Signed-off-by: Shaohua Li s...@fb.com
---
fs/btrfs/extent-tree.c | 31 +++
1 file changed, 7 insertions(+), 24 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a80b971..430101b6 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -8493,22 +8493,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
{
struct btrfs_space_info *sinfo = cache-space_info;
u64 num_bytes;
- u64 min_allocable_bytes;
int ret = -ENOSPC;
-
- /*
-* We need some metadata space and system metadata space for
-* allocating chunks in some corner cases until we force to set
-* it to be readonly.
-*/
- if ((sinfo-flags
-(BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA))
- !force)
- min_allocable_bytes = 1 * 1024 * 1024;
- else
- min_allocable_bytes = 0;
-
spin_lock(sinfo-lock);
spin_lock(cache-lock);
@@ -8521,8 +8507,8 @@ static int set_block_group_ro(struct
btrfs_block_group_cache *cache, int force)
cache-bytes_super - btrfs_block_group_used(cache-item);
if (sinfo-bytes_used + sinfo-bytes_reserved + sinfo-bytes_pinned +
- sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes +
- min_allocable_bytes = sinfo-total_bytes) {
+ sinfo-bytes_may_use + sinfo-bytes_readonly + num_bytes
+ = sinfo-total_bytes) {
sinfo-bytes_readonly += num_bytes;
cache-ro = 1;
list_add_tail(cache-ro_list, sinfo-ro_bgs);
@@ -8548,14 +8534,6 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
if (IS_ERR(trans))
return PTR_ERR(trans);
- alloc_flags = update_block_group_flags(root, cache-flags);
- if (alloc_flags != cache-flags) {
- ret = do_chunk_alloc(trans, root, alloc_flags,
-CHUNK_ALLOC_FORCE);
- if (ret 0)
- goto out;
- }
-
ret = set_block_group_ro(cache, 0);
if (!ret)
goto out;
@@ -8566,6 +8544,11 @@ int btrfs_set_block_group_ro(struct btrfs_root *root,
goto out;
ret = set_block_group_ro(cache, 0);
out:
+ if (cache-flags BTRFS_BLOCK_GROUP_SYSTEM) {
+ alloc_flags = update_block_group_flags(root, cache-flags);
+ check_system_chunk(trans, root, alloc_flags);
+ }
+
btrfs_end_transaction(trans, root);
return ret;
}
--
1.8.1
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