In some circumstances (filesystems with many extents and backrefs), the global reserve gets overrun causing balance and device deletion operations to fail with -ENOSPC. Providing a way for users to increase the global reserve size can allow them to complete the operation.
Signed-off-by: Vladimir Panteleev <g...@thecybershadow.net> --- fs/btrfs/block-rsv.c | 2 +- fs/btrfs/ctree.h | 3 +++ fs/btrfs/disk-io.c | 1 + fs/btrfs/super.c | 17 ++++++++++++++++- 4 files changed, 21 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/block-rsv.c b/fs/btrfs/block-rsv.c index 698470b9f32d..5e5f5521de0e 100644 --- a/fs/btrfs/block-rsv.c +++ b/fs/btrfs/block-rsv.c @@ -272,7 +272,7 @@ void btrfs_update_global_block_rsv(struct btrfs_fs_info *fs_info) spin_lock(&sinfo->lock); spin_lock(&block_rsv->lock); - block_rsv->size = min_t(u64, num_bytes, SZ_512M); + block_rsv->size = min_t(u64, num_bytes, fs_info->global_reserve_size); if (block_rsv->reserved < block_rsv->size) { num_bytes = btrfs_space_info_used(sinfo, true); diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 299e11e6c554..d975d4f5723c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -775,6 +775,8 @@ struct btrfs_fs_info { */ u64 max_inline; + u64 global_reserve_size; + struct btrfs_transaction *running_transaction; wait_queue_head_t transaction_throttle; wait_queue_head_t transaction_wait; @@ -1359,6 +1361,7 @@ static inline u32 BTRFS_MAX_XATTR_SIZE(const struct btrfs_fs_info *info) #define BTRFS_DEFAULT_COMMIT_INTERVAL (30) #define BTRFS_DEFAULT_MAX_INLINE (2048) +#define BTRFS_DEFAULT_GLOBAL_RESERVE_SIZE (SZ_512M) #define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt) #define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt) diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c index 5f7ee70b3d1a..06f835a44b8a 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -2723,6 +2723,7 @@ int open_ctree(struct super_block *sb, atomic64_set(&fs_info->tree_mod_seq, 0); fs_info->sb = sb; fs_info->max_inline = BTRFS_DEFAULT_MAX_INLINE; + fs_info->global_reserve_size = BTRFS_DEFAULT_GLOBAL_RESERVE_SIZE; fs_info->metadata_ratio = 0; fs_info->defrag_inodes = RB_ROOT; atomic64_set(&fs_info->free_chunk_space, 0); diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 78de9d5d80c6..f44223a44cb8 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -327,6 +327,7 @@ enum { Opt_treelog, Opt_notreelog, Opt_usebackuproot, Opt_user_subvol_rm_allowed, + Opt_global_reserve_size, /* Deprecated options */ Opt_alloc_start, @@ -394,6 +395,7 @@ static const match_table_t tokens = { {Opt_notreelog, "notreelog"}, {Opt_usebackuproot, "usebackuproot"}, {Opt_user_subvol_rm_allowed, "user_subvol_rm_allowed"}, + {Opt_global_reserve_size, "global_reserve_size=%s"}, /* Deprecated options */ {Opt_alloc_start, "alloc_start=%s"}, @@ -426,7 +428,7 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, unsigned long new_flags) { substring_t args[MAX_OPT_ARGS]; - char *p, *num; + char *p, *num, *retptr; u64 cache_gen; int intarg; int ret = 0; @@ -746,6 +748,15 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char *options, case Opt_user_subvol_rm_allowed: btrfs_set_opt(info->mount_opt, USER_SUBVOL_RM_ALLOWED); break; + case Opt_global_reserve_size: + info->global_reserve_size = memparse(args[0].from, &retptr); + if (retptr != args[0].to || info->global_reserve_size == 0) { + ret = -EINVAL; + goto out; + } + btrfs_info(info, "global_reserve_size at %llu", + info->global_reserve_size); + break; case Opt_enospc_debug: btrfs_set_opt(info->mount_opt, ENOSPC_DEBUG); break; @@ -1336,6 +1347,8 @@ static int btrfs_show_options(struct seq_file *seq, struct dentry *dentry) seq_puts(seq, ",clear_cache"); if (btrfs_test_opt(info, USER_SUBVOL_RM_ALLOWED)) seq_puts(seq, ",user_subvol_rm_allowed"); + if (info->global_reserve_size != BTRFS_DEFAULT_GLOBAL_RESERVE_SIZE) + seq_printf(seq, ",global_reserve_size=%llu", info->global_reserve_size); if (btrfs_test_opt(info, ENOSPC_DEBUG)) seq_puts(seq, ",enospc_debug"); if (btrfs_test_opt(info, AUTO_DEFRAG)) @@ -1725,6 +1738,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) u64 old_max_inline = fs_info->max_inline; u32 old_thread_pool_size = fs_info->thread_pool_size; u32 old_metadata_ratio = fs_info->metadata_ratio; + u64 old_global_reserve_size = fs_info->global_reserve_size; int ret; sync_filesystem(sb); @@ -1859,6 +1873,7 @@ static int btrfs_remount(struct super_block *sb, int *flags, char *data) btrfs_resize_thread_pool(fs_info, old_thread_pool_size, fs_info->thread_pool_size); fs_info->metadata_ratio = old_metadata_ratio; + fs_info->global_reserve_size = old_global_reserve_size; btrfs_remount_cleanup(fs_info, old_opts); return ret; } -- 2.22.0