| Message ID | 20170727154723.2208-2-jeffm@suse.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2017年07月27日 23:47, jeffm@suse.com wrote: > From: Jeff Mahoney <jeffm@suse.com> > > Commit 522ef705e38 (btrfs-progs: convert: Introduce function to calculate > the available space) changed how we handle migrating file data so that > we never have btrfs space associated with the reserved ranges. This > works pretty well and when we iterate over the file blocks, the > associations are redirected to the migrated locations. > > This commit missed the case in block_iterate_proc where we just check > for intersection with a superblock location before looking up a block > group. intersect_with_sb checks to see if the range intersects with > a stripe containing a superblock but, in fact, we've reserved the > full 0-1MB range at the start of the disk. So a file block located > at e.g. 160kB will fall in the reserved region but won't be excepted > in block_iterate_block. We ultimately hit a BUG_ON when we fail > to look up the block group for that location. > > This is reproducible using convert-tests/003-ext4-basic. > > The fix is to have intersect_with_sb and block_iterate_proc understand > the full size of the reserved ranges. Since we use the range to > determine the boundary for the block iterator, let's just return the > boundary. 0 isn't a valid boundary and means that we proceed normally > with block group lookup. > > Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com> Thanks, Qu > --- > convert/source-fs.c | 25 +++++++++++-------------- > 1 file changed, 11 insertions(+), 14 deletions(-) > > diff --git a/convert/source-fs.c b/convert/source-fs.c > index 80e4e41..09f6995 100644 > --- a/convert/source-fs.c > +++ b/convert/source-fs.c > @@ -28,18 +28,16 @@ const struct simple_range btrfs_reserved_ranges[3] = { > { BTRFS_SB_MIRROR_OFFSET(2), SZ_64K } > }; > > -static int intersect_with_sb(u64 bytenr, u64 num_bytes) > +static u64 intersect_with_reserved(u64 bytenr, u64 num_bytes) > { > int i; > - u64 offset; > > - for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { > - offset = btrfs_sb_offset(i); > - offset &= ~((u64)BTRFS_STRIPE_LEN - 1); > + for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) { > + const struct simple_range *range = &btrfs_reserved_ranges[i]; > > - if (bytenr < offset + BTRFS_STRIPE_LEN && > - bytenr + num_bytes > offset) > - return 1; > + if (bytenr < range_end(range) && > + bytenr + num_bytes >= range->start) > + return range_end(range); > } > return 0; > } > @@ -64,14 +62,14 @@ int block_iterate_proc(u64 disk_block, u64 file_block, > struct blk_iterate_data *idata) > { > int ret = 0; > - int sb_region; > + u64 reserved_boundary; > int do_barrier; > struct btrfs_root *root = idata->root; > struct btrfs_block_group_cache *cache; > u64 bytenr = disk_block * root->sectorsize; > > - sb_region = intersect_with_sb(bytenr, root->sectorsize); > - do_barrier = sb_region || disk_block >= idata->boundary; > + reserved_boundary = intersect_with_reserved(bytenr, root->sectorsize); > + do_barrier = reserved_boundary || disk_block >= idata->boundary; > if ((idata->num_blocks > 0 && do_barrier) || > (file_block > idata->first_block + idata->num_blocks) || > (disk_block != idata->disk_block + idata->num_blocks)) { > @@ -91,9 +89,8 @@ int block_iterate_proc(u64 disk_block, u64 file_block, > goto fail; > } > > - if (sb_region) { > - bytenr += BTRFS_STRIPE_LEN - 1; > - bytenr &= ~((u64)BTRFS_STRIPE_LEN - 1); > + if (reserved_boundary) { > + bytenr = reserved_boundary; > } else { > cache = btrfs_lookup_block_group(root->fs_info, bytenr); > BUG_ON(!cache); > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/convert/source-fs.c b/convert/source-fs.c index 80e4e41..09f6995 100644 --- a/convert/source-fs.c +++ b/convert/source-fs.c @@ -28,18 +28,16 @@ const struct simple_range btrfs_reserved_ranges[3] = { { BTRFS_SB_MIRROR_OFFSET(2), SZ_64K } }; -static int intersect_with_sb(u64 bytenr, u64 num_bytes) +static u64 intersect_with_reserved(u64 bytenr, u64 num_bytes) { int i; - u64 offset; - for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { - offset = btrfs_sb_offset(i); - offset &= ~((u64)BTRFS_STRIPE_LEN - 1); + for (i = 0; i < ARRAY_SIZE(btrfs_reserved_ranges); i++) { + const struct simple_range *range = &btrfs_reserved_ranges[i]; - if (bytenr < offset + BTRFS_STRIPE_LEN && - bytenr + num_bytes > offset) - return 1; + if (bytenr < range_end(range) && + bytenr + num_bytes >= range->start) + return range_end(range); } return 0; } @@ -64,14 +62,14 @@ int block_iterate_proc(u64 disk_block, u64 file_block, struct blk_iterate_data *idata) { int ret = 0; - int sb_region; + u64 reserved_boundary; int do_barrier; struct btrfs_root *root = idata->root; struct btrfs_block_group_cache *cache; u64 bytenr = disk_block * root->sectorsize; - sb_region = intersect_with_sb(bytenr, root->sectorsize); - do_barrier = sb_region || disk_block >= idata->boundary; + reserved_boundary = intersect_with_reserved(bytenr, root->sectorsize); + do_barrier = reserved_boundary || disk_block >= idata->boundary; if ((idata->num_blocks > 0 && do_barrier) || (file_block > idata->first_block + idata->num_blocks) || (disk_block != idata->disk_block + idata->num_blocks)) { @@ -91,9 +89,8 @@ int block_iterate_proc(u64 disk_block, u64 file_block, goto fail; } - if (sb_region) { - bytenr += BTRFS_STRIPE_LEN - 1; - bytenr &= ~((u64)BTRFS_STRIPE_LEN - 1); + if (reserved_boundary) { + bytenr = reserved_boundary; } else { cache = btrfs_lookup_block_group(root->fs_info, bytenr); BUG_ON(!cache);