X-Git-Url: http://pilppa.org/gitweb/gitweb.cgi?a=blobdiff_plain;f=fs%2Fbfs%2Ffile.c;h=b11e63e8fbcd88389e4fb2e2a62b41465595dc04;hb=94dc7ad5502e7d74e2fd74651743f5f1773aa1fe;hp=911b4ccf470f4d4d0bd4bb77199f67a7f0cd3ca0;hpb=fe2520094d88018423dfc42b3cd0015f74e8adea;p=linux-2.6-omap-h63xx.git diff --git a/fs/bfs/file.c b/fs/bfs/file.c index 911b4ccf470..b11e63e8fbc 100644 --- a/fs/bfs/file.c +++ b/fs/bfs/file.c @@ -2,6 +2,11 @@ * fs/bfs/file.c * BFS file operations. * Copyright (C) 1999,2000 Tigran Aivazian + * + * Make the file block allocation algorithm understand the size + * of the underlying block device. + * Copyright (C) 2007 Dmitri Vorobiev + * */ #include @@ -27,7 +32,8 @@ const struct file_operations bfs_file_operations = { .splice_read = generic_file_splice_read, }; -static int bfs_move_block(unsigned long from, unsigned long to, struct super_block *sb) +static int bfs_move_block(unsigned long from, unsigned long to, + struct super_block *sb) { struct buffer_head *bh, *new; @@ -43,21 +49,22 @@ static int bfs_move_block(unsigned long from, unsigned long to, struct super_blo } static int bfs_move_blocks(struct super_block *sb, unsigned long start, - unsigned long end, unsigned long where) + unsigned long end, unsigned long where) { unsigned long i; dprintf("%08lx-%08lx->%08lx\n", start, end, where); for (i = start; i <= end; i++) if(bfs_move_block(i, where + i, sb)) { - dprintf("failed to move block %08lx -> %08lx\n", i, where + i); + dprintf("failed to move block %08lx -> %08lx\n", i, + where + i); return -EIO; } return 0; } -static int bfs_get_block(struct inode * inode, sector_t block, - struct buffer_head * bh_result, int create) +static int bfs_get_block(struct inode *inode, sector_t block, + struct buffer_head *bh_result, int create) { unsigned long phys; int err; @@ -66,9 +73,6 @@ static int bfs_get_block(struct inode * inode, sector_t block, struct bfs_inode_info *bi = BFS_I(inode); struct buffer_head *sbh = info->si_sbh; - if (block > info->si_blocks) - return -EIO; - phys = bi->i_sblock + block; if (!create) { if (phys <= bi->i_eblock) { @@ -79,21 +83,29 @@ static int bfs_get_block(struct inode * inode, sector_t block, return 0; } - /* if the file is not empty and the requested block is within the range - of blocks allocated for this file, we can grant it */ - if (inode->i_size && phys <= bi->i_eblock) { + /* + * If the file is not empty and the requested block is within the + * range of blocks allocated for this file, we can grant it. + */ + if (bi->i_sblock && (phys <= bi->i_eblock)) { dprintf("c=%d, b=%08lx, phys=%08lx (interim block granted)\n", create, (unsigned long)block, phys); map_bh(bh_result, sb, phys); return 0; } - /* the rest has to be protected against itself */ + /* The file will be extended, so let's see if there is enough space. */ + if (phys >= info->si_blocks) + return -ENOSPC; + + /* The rest has to be protected against itself. */ lock_kernel(); - /* if the last data block for this file is the last allocated - block, we can extend the file trivially, without moving it - anywhere */ + /* + * If the last data block for this file is the last allocated + * block, we can extend the file trivially, without moving it + * anywhere. + */ if (bi->i_eblock == info->si_lf_eblk) { dprintf("c=%d, b=%08lx, phys=%08lx (simple extension)\n", create, (unsigned long)block, phys); @@ -106,13 +118,19 @@ static int bfs_get_block(struct inode * inode, sector_t block, goto out; } - /* Ok, we have to move this entire file to the next free block */ + /* Ok, we have to move this entire file to the next free block. */ phys = info->si_lf_eblk + 1; - if (bi->i_sblock) { /* if data starts on block 0 then there is no data */ + if (phys + block >= info->si_blocks) { + err = -ENOSPC; + goto out; + } + + if (bi->i_sblock) { err = bfs_move_blocks(inode->i_sb, bi->i_sblock, - bi->i_eblock, phys); + bi->i_eblock, phys); if (err) { - dprintf("failed to move ino=%08lx -> fs corruption\n", inode->i_ino); + dprintf("failed to move ino=%08lx -> fs corruption\n", + inode->i_ino); goto out; } } else @@ -124,8 +142,10 @@ static int bfs_get_block(struct inode * inode, sector_t block, phys += block; info->si_lf_eblk = bi->i_eblock = phys; - /* this assumes nothing can write the inode back while we are here - * and thus update inode->i_blocks! (XXX)*/ + /* + * This assumes nothing can write the inode back while we are here + * and thus update inode->i_blocks! (XXX) + */ info->si_freeb -= bi->i_eblock - bi->i_sblock + 1 - inode->i_blocks; mark_inode_dirty(inode); mark_buffer_dirty(sbh);