* for partial write.
*/
set_buffer_new(bh);
+ set_buffer_mapped(bh);
}
return 0;
}
Indirect chain[4];
Indirect *partial;
__le32 nr = 0;
- int n;
- ext4_lblk_t last_block;
+ int n = 0;
+ ext4_lblk_t last_block, max_block;
unsigned blocksize = inode->i_sb->s_blocksize;
trace_ext4_truncate_enter(inode);
last_block = (inode->i_size + blocksize-1)
>> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
+ max_block = (EXT4_SB(inode->i_sb)->s_bitmap_maxbytes + blocksize-1)
+ >> EXT4_BLOCK_SIZE_BITS(inode->i_sb);
if (inode->i_size & (blocksize - 1))
if (ext4_block_truncate_page(handle, mapping, inode->i_size))
goto out_stop;
- n = ext4_block_to_path(inode, last_block, offsets, NULL);
- if (n == 0)
- goto out_stop; /* error */
+ if (last_block != max_block) {
+ n = ext4_block_to_path(inode, last_block, offsets, NULL);
+ if (n == 0)
+ goto out_stop; /* error */
+ }
/*
* OK. This truncate is going to happen. We add the inode to the
*/
ei->i_disksize = inode->i_size;
- if (n == 1) { /* direct blocks */
+ if (last_block == max_block) {
+ /*
+ * It is unnecessary to free any data blocks if last_block is
+ * equal to the indirect block limit.
+ */
+ goto out_unlock;
+ } else if (n == 1) { /* direct blocks */
ext4_free_data(handle, inode, NULL, i_data+offsets[0],
i_data + EXT4_NDIR_BLOCKS);
goto do_indirects;
;
}
+out_unlock:
up_write(&ei->i_data_sem);
inode->i_mtime = inode->i_ctime = ext4_current_time(inode);
ext4_mark_inode_dirty(handle, inode);
/* if nrblocks are contiguous */
if (chunk) {
/*
- * With N contiguous data blocks, it need at most
- * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) indirect blocks
- * 2 dindirect blocks
- * 1 tindirect block
+ * With N contiguous data blocks, we need at most
+ * N/EXT4_ADDR_PER_BLOCK(inode->i_sb) + 1 indirect blocks,
+ * 2 dindirect blocks, and 1 tindirect block
*/
- indirects = nrblocks / EXT4_ADDR_PER_BLOCK(inode->i_sb);
- return indirects + 3;
+ return DIV_ROUND_UP(nrblocks,
+ EXT4_ADDR_PER_BLOCK(inode->i_sb)) + 4;
}
/*
* if nrblocks are not contiguous, worse case, each block touch