diff options
Diffstat (limited to 'lib/ext2fs/punch.c')
| -rw-r--r-- | lib/ext2fs/punch.c | 192 |
1 files changed, 166 insertions, 26 deletions
diff --git a/lib/ext2fs/punch.c b/lib/ext2fs/punch.c index b53653a0..a3d020ec 100644 --- a/lib/ext2fs/punch.c +++ b/lib/ext2fs/punch.c @@ -50,17 +50,18 @@ static errcode_t ind_punch(ext2_filsys fs, struct ext2_inode *inode, blk_t start, blk_t count, int max) { errcode_t retval; - blk_t b, offset; - int i, incr; + blk_t b; + int i; + blk64_t offset, incr; int freed = 0; #ifdef PUNCH_DEBUG printf("Entering ind_punch, level %d, start %u, count %u, " "max %d\n", level, start, count, max); #endif - incr = 1 << ((EXT2_BLOCK_SIZE_BITS(fs->super)-2)*level); + incr = 1ULL << ((EXT2_BLOCK_SIZE_BITS(fs->super)-2)*level); for (i=0, offset=0; i < max; i++, p++, offset += incr) { - if (offset > count) + if (offset >= start + count) break; if (*p == 0 || (offset+incr) <= start) continue; @@ -87,7 +88,7 @@ static errcode_t ind_punch(ext2_filsys fs, struct ext2_inode *inode, continue; } #ifdef PUNCH_DEBUG - printf("Freeing block %u (offset %d)\n", b, offset); + printf("Freeing block %u (offset %llu)\n", b, offset); #endif ext2fs_block_alloc_stats(fs, b, -1); *p = 0; @@ -108,7 +109,7 @@ static errcode_t ext2fs_punch_ind(ext2_filsys fs, struct ext2_inode *inode, int num = EXT2_NDIR_BLOCKS; blk_t *bp = inode->i_block; blk_t addr_per_block; - blk_t max = EXT2_NDIR_BLOCKS; + blk64_t max = EXT2_NDIR_BLOCKS; if (!block_buf) { retval = ext2fs_get_array(3, fs->blocksize, &buf); @@ -119,10 +120,10 @@ static errcode_t ext2fs_punch_ind(ext2_filsys fs, struct ext2_inode *inode, addr_per_block = (blk_t) fs->blocksize >> 2; - for (level=0; level < 4; level++, max *= addr_per_block) { + for (level = 0; level < 4; level++, max *= (blk64_t)addr_per_block) { #ifdef PUNCH_DEBUG printf("Main loop level %d, start %u count %u " - "max %d num %d\n", level, start, count, max, num); + "max %llu num %d\n", level, start, count, max, num); #endif if (start < max) { retval = ind_punch(fs, inode, block_buf, bp, level, @@ -176,6 +177,75 @@ static void dbg_print_extent(char *desc, struct ext2fs_extent *extent) #define dbg_printf(f, a...) do { } while (0) #endif +/* Free a range of blocks, respecting cluster boundaries */ +static errcode_t punch_extent_blocks(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode, + blk64_t lfree_start, blk64_t free_start, + __u32 free_count, int *freed) +{ + blk64_t pblk; + int freed_now = 0; + __u32 cluster_freed; + errcode_t retval = 0; + + /* No bigalloc? Just free each block. */ + if (EXT2FS_CLUSTER_RATIO(fs) == 1) { + *freed += free_count; + while (free_count-- > 0) + ext2fs_block_alloc_stats2(fs, free_start++, -1); + return retval; + } + + /* + * Try to free up to the next cluster boundary. We assume that all + * blocks in a logical cluster map to blocks from the same physical + * cluster, and that the offsets within the [pl]clusters match. + */ + if (free_start & EXT2FS_CLUSTER_MASK(fs)) { + retval = ext2fs_map_cluster_block(fs, ino, inode, + lfree_start, &pblk); + if (retval) + goto errout; + if (!pblk) { + ext2fs_block_alloc_stats2(fs, free_start, -1); + freed_now++; + } + cluster_freed = EXT2FS_CLUSTER_RATIO(fs) - + (free_start & EXT2FS_CLUSTER_MASK(fs)); + if (cluster_freed > free_count) + cluster_freed = free_count; + free_count -= cluster_freed; + free_start += cluster_freed; + lfree_start += cluster_freed; + } + + /* Free whole clusters from the middle of the range. */ + while (free_count > 0 && free_count >= EXT2FS_CLUSTER_RATIO(fs)) { + ext2fs_block_alloc_stats2(fs, free_start, -1); + freed_now++; + cluster_freed = EXT2FS_CLUSTER_RATIO(fs); + free_count -= cluster_freed; + free_start += cluster_freed; + lfree_start += cluster_freed; + } + + /* Try to free the last cluster. */ + if (free_count > 0) { + retval = ext2fs_map_cluster_block(fs, ino, inode, + lfree_start, &pblk); + if (retval) + goto errout; + if (!pblk) { + ext2fs_block_alloc_stats2(fs, free_start, -1); + freed_now++; + } + } + +errout: + *freed += freed_now; + return retval; +} + static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, struct ext2_inode *inode, blk64_t start, blk64_t end) @@ -183,18 +253,34 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, ext2_extent_handle_t handle = 0; struct ext2fs_extent extent; errcode_t retval; - blk64_t free_start, next; + blk64_t free_start, next, lfree_start; __u32 free_count, newlen; int freed = 0; + int op; retval = ext2fs_extent_open2(fs, ino, inode, &handle); if (retval) return retval; + /* + * Find the extent closest to the start of the punch range. We don't + * check the return value because _goto() sets the current node to the + * next-lowest extent if 'start' is in a hole, and doesn't set a + * current node if there was a real error reading the extent tree. + * In that case, _get() will error out. + * + * Note: If _get() returns 'no current node', that simply means that + * there aren't any blocks mapped past this point in the file, so we're + * done. + */ ext2fs_extent_goto(handle, start); retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, &extent); - if (retval) + if (retval == EXT2_ET_NO_CURRENT_NODE) { + retval = 0; + goto errout; + } else if (retval) goto errout; while (1) { + op = EXT2_EXTENT_NEXT_LEAF; dbg_print_extent("main loop", &extent); next = extent.e_lblk + extent.e_len; dbg_printf("start %llu, end %llu, next %llu\n", @@ -202,12 +288,17 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, (unsigned long long) end, (unsigned long long) next); if (start <= extent.e_lblk) { + /* + * Have we iterated past the end of the punch region? + * If so, we can stop. + */ if (end < extent.e_lblk) - goto next_extent; + break; dbg_printf("Case #%d\n", 1); /* Start of deleted region before extent; adjust beginning of extent */ free_start = extent.e_pblk; + lfree_start = extent.e_lblk; if (next > end) free_count = end - extent.e_lblk + 1; else @@ -216,13 +307,19 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, extent.e_lblk += free_count; extent.e_pblk += free_count; } else if (end >= next-1) { + /* + * Is the punch region beyond this extent? This can + * happen if start is already inside a hole. Try to + * advance to the next extent if this is the case. + */ if (start >= next) - break; + goto next_extent; /* End of deleted region after extent; adjust end of extent */ dbg_printf("Case #%d\n", 2); newlen = start - extent.e_lblk; free_start = extent.e_pblk + newlen; + lfree_start = extent.e_lblk + newlen; free_count = extent.e_len - newlen; extent.e_len = newlen; } else { @@ -238,6 +335,7 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, extent.e_len = start - extent.e_lblk; free_start = extent.e_pblk + extent.e_len; + lfree_start = extent.e_lblk + extent.e_len; free_count = end - start + 1; dbg_print_extent("inserting", &newex); @@ -255,22 +353,65 @@ static errcode_t ext2fs_punch_extent(ext2_filsys fs, ext2_ino_t ino, if (extent.e_len) { dbg_print_extent("replacing", &extent); retval = ext2fs_extent_replace(handle, 0, &extent); + if (retval) + goto errout; + retval = ext2fs_extent_fix_parents(handle); } else { + struct ext2fs_extent newex; + blk64_t old_lblk, next_lblk; dbg_printf("deleting current extent%s\n", ""); + + /* + * Save the location of the next leaf, then slip + * back to the current extent. + */ + retval = ext2fs_extent_get(handle, EXT2_EXTENT_CURRENT, + &newex); + if (retval) + goto errout; + old_lblk = newex.e_lblk; + + retval = ext2fs_extent_get(handle, + EXT2_EXTENT_NEXT_LEAF, + &newex); + if (retval == EXT2_ET_EXTENT_NO_NEXT) + next_lblk = old_lblk; + else if (retval) + goto errout; + else + next_lblk = newex.e_lblk; + + retval = ext2fs_extent_goto(handle, old_lblk); + if (retval) + goto errout; + + /* Now delete the extent. */ retval = ext2fs_extent_delete(handle, 0); + if (retval) + goto errout; + + retval = ext2fs_extent_fix_parents(handle); + if (retval && retval != EXT2_ET_NO_CURRENT_NODE) + goto errout; + retval = 0; + + /* Jump forward to the next extent. */ + ext2fs_extent_goto(handle, next_lblk); + op = EXT2_EXTENT_CURRENT; } if (retval) goto errout; dbg_printf("Free start %llu, free count = %u\n", free_start, free_count); - while (free_count-- > 0) { - ext2fs_block_alloc_stats(fs, free_start++, -1); - freed++; - } + retval = punch_extent_blocks(fs, ino, inode, lfree_start, + free_start, free_count, &freed); + if (retval) + goto errout; next_extent: - retval = ext2fs_extent_get(handle, EXT2_EXTENT_NEXT_LEAF, + retval = ext2fs_extent_get(handle, op, &extent); - if (retval == EXT2_ET_EXTENT_NO_NEXT) + if (retval == EXT2_ET_EXTENT_NO_NEXT || + retval == EXT2_ET_NO_CURRENT_NODE) break; if (retval) goto errout; @@ -286,10 +427,10 @@ errout: * Deallocate all logical blocks starting at start to end, inclusive. * If end is ~0, then this is effectively truncate. */ -extern errcode_t ext2fs_punch(ext2_filsys fs, ext2_ino_t ino, - struct ext2_inode *inode, - char *block_buf, blk64_t start, - blk64_t end) +errcode_t ext2fs_punch(ext2_filsys fs, ext2_ino_t ino, + struct ext2_inode *inode, + char *block_buf, blk64_t start, + blk64_t end) { errcode_t retval; struct ext2_inode inode_buf; @@ -297,9 +438,6 @@ extern errcode_t ext2fs_punch(ext2_filsys fs, ext2_ino_t ino, if (start > end) return EINVAL; - if (start == end) - return 0; - /* Read inode structure if necessary */ if (!inode) { retval = ext2fs_read_inode(fs, ino, &inode_buf); @@ -314,7 +452,9 @@ extern errcode_t ext2fs_punch(ext2_filsys fs, ext2_ino_t ino, if (start > ~0U) return 0; - count = ((end - start) < ~0U) ? (end - start) : ~0U; + if (end > ~0U) + end = ~0U; + count = ((end - start + 1) < ~0U) ? (end - start + 1) : ~0U; retval = ext2fs_punch_ind(fs, inode, block_buf, (blk_t) start, count); } |