| Message ID | 0366b5e12a7e6f95d9f274df52f32231dcbe8b05.1599072541.git.boris@bur.io (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs-progs: support free space tree in mkfs | expand |
On 9/2/20 2:50 PM, Boris Burkov wrote: > Add a runtime feature (-R) flag for the free space tree. A filesystem > that is mkfs'd with -R free-space-tree then mounted with no options has > the same contents as one mkfs'd without the option, then mounted with > '-o space_cache=v2'. > > The only tricky thing is in exactly how to call the tree creation code. > Using btrfs_create_free_space_tree as is did not quite work, because an > extra reference to the eb (root->commit_root) is leaked, which mkfs > complains about with a warning. I opted to follow how the uuid tree is > created by adding it to the dirty roots list for cleanup by > commit_tree_roots in commit_transaction. As a result, > btrfs_create_free_space_tree no longer exactly matches the version in > the kernel sources. > > Signed-off-by: Boris Burkov <boris@bur.io> For those of you playing along at home, this applies to the devel branch, not the main branch. Built and made sure it did the right thing, you can add Reviewed-by: Josef Bacik <josef@toxicpanda.com> Thanks, Josef
On Wed, Sep 02, 2020 at 11:50:49AM -0700, Boris Burkov wrote: > Add a runtime feature (-R) flag for the free space tree. A filesystem > that is mkfs'd with -R free-space-tree then mounted with no options has > the same contents as one mkfs'd without the option, then mounted with > '-o space_cache=v2'. > > The only tricky thing is in exactly how to call the tree creation code. > Using btrfs_create_free_space_tree as is did not quite work, because an > extra reference to the eb (root->commit_root) is leaked, which mkfs > complains about with a warning. I opted to follow how the uuid tree is > created by adding it to the dirty roots list for cleanup by > commit_tree_roots in commit_transaction. As a result, > btrfs_create_free_space_tree no longer exactly matches the version in > the kernel sources. > > Signed-off-by: Boris Burkov <boris@bur.io> Thanks. > --- > common/fsfeatures.c | 3 +++ > common/fsfeatures.h | 3 ++- > kernel-shared/disk-io.c | 5 +++++ > kernel-shared/free-space-tree.c | 1 + > mkfs/main.c | 8 ++++++++ > 5 files changed, 19 insertions(+), 1 deletion(-) > > diff --git a/common/fsfeatures.c b/common/fsfeatures.c > index 48ab37ca..3bebc97f 100644 > --- a/common/fsfeatures.c > +++ b/common/fsfeatures.c > @@ -107,6 +107,9 @@ static const struct btrfs_feature runtime_features[] = { > { "quota", BTRFS_RUNTIME_FEATURE_QUOTA, NULL, > VERSION_TO_STRING2(3, 4), NULL, 0, NULL, 0, > "quota support (qgroups)" }, > + { "free-space-tree", BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE, NULL, > + VERSION_TO_STRING2(4, 5), NULL, 0, NULL, 0, > + "free space tree (space_cache=v2)" }, The unfilled items are: sysfs file (we have that, free_space_tree), the safe version is 4.9 (that's where the FREE_SPACE_TREE_VALID bit comes from). I've run the mkfs tests with the -R flag and all passed, so I'll enable it in the CI script, with the fixes mentioned above. We should still have a separate test, similar to what mkfs/021-rfeatures-quota-rootdir does but this time the presence of the feature should be checked at least after mkfs (by inspect+dump-super) and conditionally by mount in case the kernel supports it. Last but not least the documentation should be updated for mkfs in the section 'RUNTIME FEATURES'. Thanks.
diff --git a/common/fsfeatures.c b/common/fsfeatures.c index 48ab37ca..3bebc97f 100644 --- a/common/fsfeatures.c +++ b/common/fsfeatures.c @@ -107,6 +107,9 @@ static const struct btrfs_feature runtime_features[] = { { "quota", BTRFS_RUNTIME_FEATURE_QUOTA, NULL, VERSION_TO_STRING2(3, 4), NULL, 0, NULL, 0, "quota support (qgroups)" }, + { "free-space-tree", BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE, NULL, + VERSION_TO_STRING2(4, 5), NULL, 0, NULL, 0, + "free space tree (space_cache=v2)" }, /* Keep this one last */ { "list-all", BTRFS_FEATURE_LIST_ALL, NULL } }; diff --git a/common/fsfeatures.h b/common/fsfeatures.h index 13141254..f76fc099 100644 --- a/common/fsfeatures.h +++ b/common/fsfeatures.h @@ -39,7 +39,8 @@ #define BTRFS_FEATURE_LIST_ALL (1ULL << 63) -#define BTRFS_RUNTIME_FEATURE_QUOTA (1ULL << 0) +#define BTRFS_RUNTIME_FEATURE_QUOTA (1ULL << 0) +#define BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE (1ULL << 1) void btrfs_list_all_fs_features(u64 mask_disallowed); void btrfs_list_all_runtime_features(u64 mask_disallowed); diff --git a/kernel-shared/disk-io.c b/kernel-shared/disk-io.c index 42f733e3..6f584986 100644 --- a/kernel-shared/disk-io.c +++ b/kernel-shared/disk-io.c @@ -1003,10 +1003,15 @@ int btrfs_setup_all_roots(struct btrfs_fs_info *fs_info, u64 root_tree_bytenr, ret = find_and_setup_root(root, fs_info, BTRFS_FREE_SPACE_TREE_OBJECTID, fs_info->free_space_root); if (ret) { + free(fs_info->free_space_root); + fs_info->free_space_root = NULL; printk("Couldn't read free space tree\n"); return -EIO; } fs_info->free_space_root->track_dirty = 1; + } else { + free(fs_info->free_space_root); + fs_info->free_space_root = NULL; } ret = find_and_setup_log_root(root, fs_info, sb); diff --git a/kernel-shared/free-space-tree.c b/kernel-shared/free-space-tree.c index 3570a9ac..2edc7fc7 100644 --- a/kernel-shared/free-space-tree.c +++ b/kernel-shared/free-space-tree.c @@ -1433,6 +1433,7 @@ int btrfs_create_free_space_tree(struct btrfs_fs_info *fs_info) goto abort; } fs_info->free_space_root = free_space_root; + add_root_to_dirty_list(free_space_root); do { block_group = btrfs_lookup_first_block_group(fs_info, start); diff --git a/mkfs/main.c b/mkfs/main.c index 18dc6f8e..3eb74821 100644 --- a/mkfs/main.c +++ b/mkfs/main.c @@ -34,6 +34,7 @@ #include <blkid/blkid.h> #include "kernel-shared/ctree.h" #include "kernel-shared/disk-io.h" +#include "kernel-shared/free-space-tree.h" #include "kernel-shared/volumes.h" #include "kernel-shared/transaction.h" #include "common/utils.h" @@ -1495,6 +1496,13 @@ raid_groups: goto out; } } + if (runtime_features & BTRFS_RUNTIME_FEATURE_FREE_SPACE_TREE) { + ret = btrfs_create_free_space_tree(fs_info); + if (ret < 0) { + error("failed to create free space tree: %d (%m)", ret); + goto out; + } + } if (verbose) { char features_buf[64];
Add a runtime feature (-R) flag for the free space tree. A filesystem that is mkfs'd with -R free-space-tree then mounted with no options has the same contents as one mkfs'd without the option, then mounted with '-o space_cache=v2'. The only tricky thing is in exactly how to call the tree creation code. Using btrfs_create_free_space_tree as is did not quite work, because an extra reference to the eb (root->commit_root) is leaked, which mkfs complains about with a warning. I opted to follow how the uuid tree is created by adding it to the dirty roots list for cleanup by commit_tree_roots in commit_transaction. As a result, btrfs_create_free_space_tree no longer exactly matches the version in the kernel sources. Signed-off-by: Boris Burkov <boris@bur.io> --- common/fsfeatures.c | 3 +++ common/fsfeatures.h | 3 ++- kernel-shared/disk-io.c | 5 +++++ kernel-shared/free-space-tree.c | 1 + mkfs/main.c | 8 ++++++++ 5 files changed, 19 insertions(+), 1 deletion(-)