diff options
| -rw-r--r-- | fs/ext4/indirect.c | 105 |
1 files changed, 71 insertions, 34 deletions
diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c index 36b369697a13..5e7af1c69577 100644 --- a/fs/ext4/indirect.c +++ b/fs/ext4/indirect.c @@ -1393,10 +1393,7 @@ end_range: * to free. Everything was covered by the start * of the range. */ - return 0; - } else { - /* Shared branch grows from an indirect block */ - partial2--; + goto do_indirects; } } else { /* @@ -1427,56 +1424,96 @@ end_range: /* Punch happened within the same level (n == n2) */ partial = ext4_find_shared(inode, n, offsets, chain, &nr); partial2 = ext4_find_shared(inode, n2, offsets2, chain2, &nr2); - /* - * ext4_find_shared returns Indirect structure which - * points to the last element which should not be - * removed by truncate. But this is end of the range - * in punch_hole so we need to point to the next element - */ - partial2->p++; - while ((partial > chain) || (partial2 > chain2)) { - /* We're at the same block, so we're almost finished */ - if ((partial->bh && partial2->bh) && - (partial->bh->b_blocknr == partial2->bh->b_blocknr)) { - if ((partial > chain) && (partial2 > chain2)) { + + /* Free top, but only if partial2 isn't its subtree. */ + if (nr) { + int level = min(partial - chain, partial2 - chain2); + int i; + int subtree = 1; + + for (i = 0; i <= level; i++) { + if (offsets[i] != offsets2[i]) { + subtree = 0; + break; + } + } + + if (!subtree) { + if (partial == chain) { + /* Shared branch grows from the inode */ + ext4_free_branches(handle, inode, NULL, + &nr, &nr+1, + (chain+n-1) - partial); + *partial->p = 0; + } else { + /* Shared branch grows from an indirect block */ + BUFFER_TRACE(partial->bh, "get_write_access"); ext4_free_branches(handle, inode, partial->bh, - partial->p + 1, - partial2->p, + partial->p, + partial->p+1, (chain+n-1) - partial); - BUFFER_TRACE(partial->bh, "call brelse"); - brelse(partial->bh); - BUFFER_TRACE(partial2->bh, "call brelse"); - brelse(partial2->bh); } - return 0; } + } + + if (!nr2) { /* - * Clear the ends of indirect blocks on the shared branch - * at the start of the range + * ext4_find_shared returns Indirect structure which + * points to the last element which should not be + * removed by truncate. But this is end of the range + * in punch_hole so we need to point to the next element */ - if (partial > chain) { + partial2->p++; + } + + while (partial > chain || partial2 > chain2) { + int depth = (chain+n-1) - partial; + int depth2 = (chain2+n2-1) - partial2; + + if (partial > chain && partial2 > chain2 && + partial->bh->b_blocknr == partial2->bh->b_blocknr) { + /* + * We've converged on the same block. Clear the range, + * then we're done. + */ ext4_free_branches(handle, inode, partial->bh, - partial->p + 1, - (__le32 *)partial->bh->b_data+addr_per_block, - (chain+n-1) - partial); + partial->p + 1, + partial2->p, + (chain+n-1) - partial); BUFFER_TRACE(partial->bh, "call brelse"); brelse(partial->bh); - partial--; + BUFFER_TRACE(partial2->bh, "call brelse"); + brelse(partial2->bh); + return 0; } + /* - * Clear the ends of indirect blocks on the shared branch - * at the end of the range + * The start and end partial branches may not be at the same + * level even though the punch happened within one level. So, we + * give them a chance to arrive at the same level, then walk + * them in step with each other until we converge on the same + * block. */ - if (partial2 > chain2) { + if (partial > chain && depth <= depth2) { + ext4_free_branches(handle, inode, partial->bh, + partial->p + 1, + (__le32 *)partial->bh->b_data+addr_per_block, + (chain+n-1) - partial); + BUFFER_TRACE(partial->bh, "call brelse"); + brelse(partial->bh); + partial--; + } + if (partial2 > chain2 && depth2 <= depth) { ext4_free_branches(handle, inode, partial2->bh, (__le32 *)partial2->bh->b_data, partial2->p, - (chain2+n-1) - partial2); + (chain2+n2-1) - partial2); BUFFER_TRACE(partial2->bh, "call brelse"); brelse(partial2->bh); partial2--; } } + return 0; do_indirects: /* Kill the remaining (whole) subtrees */ |
