Until now ubifsload pads the destination with 0 up to a multiple of UBIFS_BLOCK_SIZE (4KiB) while reading a file to memory. This patch changes this behaviour to only read to the requested length. This is either the file length or the length/size provided as parameter to the ubifsload command.
Signed-off-by: Stefan Roese sr@denx.de --- v2: - Added error checking to malloc and read_block as suggested by Wolfgang - Changed comment issues as suggested by Ben
fs/ubifs/ubifs.c | 71 ++++++++++++++++++++++++++++++++++++++++++++---------- 1 files changed, 58 insertions(+), 13 deletions(-)
diff --git a/fs/ubifs/ubifs.c b/fs/ubifs/ubifs.c index 1cc31a9..d16d2b0 100644 --- a/fs/ubifs/ubifs.c +++ b/fs/ubifs/ubifs.c @@ -3,7 +3,7 @@ * * Copyright (C) 2006-2008 Nokia Corporation. * - * (C) Copyright 2008-2009 + * (C) Copyright 2008-2010 * Stefan Roese, DENX Software Engineering, sr@denx.de. * * This program is free software; you can redistribute it and/or modify it @@ -567,7 +567,8 @@ dump: return -EINVAL; }
-static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *page) +static int do_readpage(struct ubifs_info *c, struct inode *inode, + struct page *page, int last_block_size) { void *addr; int err = 0, i; @@ -601,17 +602,54 @@ static int do_readpage(struct ubifs_info *c, struct inode *inode, struct page *p err = -ENOENT; memset(addr, 0, UBIFS_BLOCK_SIZE); } else { - ret = read_block(inode, addr, block, dn); - if (ret) { - err = ret; - if (err != -ENOENT) + /* + * Reading last block? Make sure to not write beyond + * the requested size in the destination buffer. + */ + if (((block + 1) == beyond) || last_block_size) { + void *buff; + int dlen; + + /* + * We need to buffer the data locally for the + * last block. This is to not pad the + * destination area to a multiple of + * UBIFS_BLOCK_SIZE. + */ + buff = malloc(UBIFS_BLOCK_SIZE); + if (!buff) { + printf("%s: Error, malloc fails!\n", + __func__); + err = -ENOMEM; break; - } else if (block + 1 == beyond) { - int dlen = le32_to_cpu(dn->size); - int ilen = i_size & (UBIFS_BLOCK_SIZE - 1); - - if (ilen && ilen < dlen) - memset(addr + ilen, 0, dlen - ilen); + } + + /* Read block-size into temp buffer */ + ret = read_block(inode, buff, block, dn); + if (ret) { + err = ret; + if (err != -ENOENT) { + free(buff); + break; + } + } + + if (last_block_size) + dlen = last_block_size; + else + dlen = le32_to_cpu(dn->size); + + /* Now copy required size back to dest */ + memcpy(addr, buff, dlen); + + free(buff); + } else { + ret = read_block(inode, addr, block, dn); + if (ret) { + err = ret; + if (err != -ENOENT) + break; + } } } if (++i >= UBIFS_BLOCKS_PER_PAGE) @@ -649,6 +687,7 @@ int ubifs_load(char *filename, u32 addr, u32 size) int err = 0; int i; int count; + int last_block_size = 0;
c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READONLY); /* ubifs_findfile will resolve symlinks, so we know that we get @@ -684,7 +723,13 @@ int ubifs_load(char *filename, u32 addr, u32 size) page.index = 0; page.inode = inode; for (i = 0; i < count; i++) { - err = do_readpage(c, inode, &page); + /* + * Make sure to not read beyond the requested size + */ + if (((i + 1) == count) && (size < inode->i_size)) + last_block_size = size - (i * PAGE_SIZE); + + err = do_readpage(c, inode, &page, last_block_size); if (err) break;