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| author | Josef Bacik <josef@toxicpanda.com> | 2020-02-15 00:11:47 +0300 |
|---|---|---|
| committer | David Sterba <dsterba@suse.com> | 2020-03-23 19:02:00 +0300 |
| commit | c75e839414d3610e6487ae3145199c500d55f7f7 (patch) | |
| tree | 68e609a6362c4f259afc2e107fffac94e743a126 /fs/btrfs/send.c | |
| parent | efc3453494af78180ac00d9dd8391fd52c4a921e (diff) | |
| download | linux-c75e839414d3610e6487ae3145199c500d55f7f7.tar.xz | |
btrfs: kill the subvol_srcu
Now that we have proper root ref counting everywhere we can kill the
subvol_srcu.
* removal of fs_info::subvol_srcu reduces size of fs_info by 1176 bytes
* the refcount_t used for the references checks for accidental 0->1
in cases where the root lifetime would not be properly protected
* there's a leak detector for roots to catch unfreed roots at umount
time
* SRCU served us well over the years but is was not a proper
synchronization mechanism for some cases
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Diffstat (limited to 'fs/btrfs/send.c')
| -rw-r--r-- | fs/btrfs/send.c | 14 |
1 files changed, 0 insertions, 14 deletions
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index e47f768cec3d..c5f41bd86765 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -7028,7 +7028,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) int clone_sources_to_rollback = 0; unsigned alloc_size; int sort_clone_roots = 0; - int index; if (!capable(CAP_SYS_ADMIN)) return -EPERM; @@ -7155,11 +7154,8 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; - index = srcu_read_lock(&fs_info->subvol_srcu); - clone_root = btrfs_get_fs_root(fs_info, &key, true); if (IS_ERR(clone_root)) { - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = PTR_ERR(clone_root); goto out; } @@ -7168,7 +7164,6 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) btrfs_root_dead(clone_root)) { spin_unlock(&clone_root->root_item_lock); btrfs_put_root(clone_root); - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = -EPERM; goto out; } @@ -7176,13 +7171,11 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) dedupe_in_progress_warn(clone_root); spin_unlock(&clone_root->root_item_lock); btrfs_put_root(clone_root); - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = -EAGAIN; goto out; } clone_root->send_in_progress++; spin_unlock(&clone_root->root_item_lock); - srcu_read_unlock(&fs_info->subvol_srcu, index); sctx->clone_roots[i].root = clone_root; clone_sources_to_rollback = i + 1; @@ -7196,11 +7189,8 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) key.type = BTRFS_ROOT_ITEM_KEY; key.offset = (u64)-1; - index = srcu_read_lock(&fs_info->subvol_srcu); - sctx->parent_root = btrfs_get_fs_root(fs_info, &key, true); if (IS_ERR(sctx->parent_root)) { - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = PTR_ERR(sctx->parent_root); goto out; } @@ -7210,20 +7200,16 @@ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg) if (!btrfs_root_readonly(sctx->parent_root) || btrfs_root_dead(sctx->parent_root)) { spin_unlock(&sctx->parent_root->root_item_lock); - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = -EPERM; goto out; } if (sctx->parent_root->dedupe_in_progress) { dedupe_in_progress_warn(sctx->parent_root); spin_unlock(&sctx->parent_root->root_item_lock); - srcu_read_unlock(&fs_info->subvol_srcu, index); ret = -EAGAIN; goto out; } spin_unlock(&sctx->parent_root->root_item_lock); - - srcu_read_unlock(&fs_info->subvol_srcu, index); } /* |