diff options
| -rw-r--r-- | fs/ioctl.c | 75 |
1 files changed, 55 insertions, 20 deletions
diff --git a/fs/ioctl.c b/fs/ioctl.c index ac2d47e4392..82d9c42b8ba 100644 --- a/fs/ioctl.c +++ b/fs/ioctl.c @@ -258,7 +258,7 @@ int __generic_block_fiemap(struct inode *inode, long long length = 0, map_len = 0; u64 logical = 0, phys = 0, size = 0; u32 flags = FIEMAP_EXTENT_MERGED; - int ret = 0; + int ret = 0, past_eof = 0, whole_file = 0; if ((ret = fiemap_check_flags(fieinfo, FIEMAP_FLAG_SYNC))) return ret; @@ -266,6 +266,9 @@ int __generic_block_fiemap(struct inode *inode, start_blk = logical_to_blk(inode, start); length = (long long)min_t(u64, len, i_size_read(inode)); + if (length < len) + whole_file = 1; + map_len = length; do { @@ -282,11 +285,26 @@ int __generic_block_fiemap(struct inode *inode, /* HOLE */ if (!buffer_mapped(&tmp)) { + length -= blk_to_logical(inode, 1); + start_blk++; + + /* + * we want to handle the case where there is an + * allocated block at the front of the file, and then + * nothing but holes up to the end of the file properly, + * to make sure that extent at the front gets properly + * marked with FIEMAP_EXTENT_LAST + */ + if (!past_eof && + blk_to_logical(inode, start_blk) >= + blk_to_logical(inode, 0)+i_size_read(inode)) + past_eof = 1; + /* * first hole after going past the EOF, this is our * last extent */ - if (length <= 0) { + if (past_eof && size) { flags = FIEMAP_EXTENT_MERGED|FIEMAP_EXTENT_LAST; ret = fiemap_fill_next_extent(fieinfo, logical, phys, size, @@ -294,15 +312,37 @@ int __generic_block_fiemap(struct inode *inode, break; } - length -= blk_to_logical(inode, 1); - /* if we have holes up to/past EOF then we're done */ - if (length <= 0) + if (length <= 0 || past_eof) break; - - start_blk++; } else { - if (length <= 0 && size) { + /* + * we have gone over the length of what we wanted to + * map, and it wasn't the entire file, so add the extent + * we got last time and exit. + * + * This is for the case where say we want to map all the + * way up to the second to the last block in a file, but + * the last block is a hole, making the second to last + * block FIEMAP_EXTENT_LAST. In this case we want to + * see if there is a hole after the second to last block + * so we can mark it properly. If we found data after + * we exceeded the length we were requesting, then we + * are good to go, just add the extent to the fieinfo + * and break + */ + if (length <= 0 && !whole_file) { + ret = fiemap_fill_next_extent(fieinfo, logical, + phys, size, + flags); + break; + } + + /* + * if size != 0 then we know we already have an extent + * to add, so add it. + */ + if (size) { ret = fiemap_fill_next_extent(fieinfo, logical, phys, size, flags); @@ -319,19 +359,14 @@ int __generic_block_fiemap(struct inode *inode, start_blk += logical_to_blk(inode, size); /* - * if we are past the EOF we need to loop again to see - * if there is a hole so we can mark this extent as the - * last one, and if not keep mapping things until we - * find a hole, or we run out of slots in the extent - * array + * If we are past the EOF, then we need to make sure as + * soon as we find a hole that the last extent we found + * is marked with FIEMAP_EXTENT_LAST */ - if (length <= 0) - continue; - - ret = fiemap_fill_next_extent(fieinfo, logical, phys, - size, flags); - if (ret) - break; + if (!past_eof && + logical+size >= + blk_to_logical(inode, 0)+i_size_read(inode)) + past_eof = 1; } cond_resched(); } while (1); |