diff options
| -rw-r--r-- | fs/btrfs/ctree.h | 7 | ||||
| -rw-r--r-- | fs/btrfs/extent-tree.c | 6 | ||||
| -rw-r--r-- | fs/btrfs/super.c | 12 | ||||
| -rw-r--r-- | fs/btrfs/volumes.c | 7 |
4 files changed, 15 insertions, 17 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index e5f19b49efa8..6d9f81d4e99c 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -230,6 +230,13 @@ struct btrfs_root_backup { #define BTRFS_SUPER_INFO_SIZE 4096 /* + * The reserved space at the beginning of each device. + * It covers the primary super block and leaves space for potential use by other + * tools like bootloaders or to lower potential damage of accidental overwrite. + */ +#define BTRFS_DEVICE_RANGE_RESERVED (SZ_1M) + +/* * the super block basically lists the main trees of the FS * it currently lacks any block count etc etc */ diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 91d2c20c7c8a..a1696e3ffb1e 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -5976,7 +5976,7 @@ int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, */ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) { - u64 start = SZ_1M, len = 0, end = 0; + u64 start = BTRFS_DEVICE_RANGE_RESERVED, len = 0, end = 0; int ret; *trimmed = 0; @@ -6020,8 +6020,8 @@ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) break; } - /* Ensure we skip the reserved area in the first 1M */ - start = max_t(u64, start, SZ_1M); + /* Ensure we skip the reserved space on each device. */ + start = max_t(u64, start, BTRFS_DEVICE_RANGE_RESERVED); /* * If find_first_clear_extent_bit find a range that spans the diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 719dda57dc7a..41652dcd16f4 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -2272,17 +2272,13 @@ static inline int btrfs_calc_avail_data_space(struct btrfs_fs_info *fs_info, avail_space = rounddown(avail_space, BTRFS_STRIPE_LEN); /* - * In order to avoid overwriting the superblock on the drive, - * btrfs starts at an offset of at least 1MB when doing chunk - * allocation. - * - * This ensures we have at least min_stripe_size free space - * after excluding 1MB. + * Ensure we have at least min_stripe_size on top of the + * reserved space on the device. */ - if (avail_space <= SZ_1M + min_stripe_size) + if (avail_space <= BTRFS_DEVICE_RANGE_RESERVED + min_stripe_size) continue; - avail_space -= SZ_1M; + avail_space -= BTRFS_DEVICE_RANGE_RESERVED; devices_info[i].dev = device; devices_info[i].max_avail = avail_space; diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c index 80636fbf28b7..e6af960a6961 100644 --- a/fs/btrfs/volumes.c +++ b/fs/btrfs/volumes.c @@ -1403,12 +1403,7 @@ static u64 dev_extent_search_start(struct btrfs_device *device, u64 start) { switch (device->fs_devices->chunk_alloc_policy) { case BTRFS_CHUNK_ALLOC_REGULAR: - /* - * We don't want to overwrite the superblock on the drive nor - * any area used by the boot loader (grub for example), so we - * make sure to start at an offset of at least 1MB. - */ - return max_t(u64, start, SZ_1M); + return max_t(u64, start, BTRFS_DEVICE_RANGE_RESERVED); case BTRFS_CHUNK_ALLOC_ZONED: /* * We don't care about the starting region like regular |