From 003ff182fddde09ddfb8d079bbdb02f9d2122082 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Tue, 12 May 2009 03:58:47 +0900 Subject: nilfs2: allow future expansion of metadata read out via get info ioctl Nilfs has some ioctl commands to read out metadata from meta data files: - NILFS_IOCTL_GET_CPINFO for checkpoint file, - NILFS_IOCTL_GET_SUINFO for segment usage file, and - NILFS_IOCTL_GET_VINFO for Disk Address Transalation (DAT) file, respectively. Every routine on these metadata files is implemented so that it allows future expansion of on-disk format. But, the above ioctl commands do not support expansion even though nilfs_argv structure can handle arbitrary size for data exchanged via ioctl. This allows future expansion of the following structures which give basic format of the "get information" ioctls: - struct nilfs_cpinfo - struct nilfs_suinfo - struct nilfs_vinfo So, this introduces forward compatility of such ioctl commands. In this patch, a sanity check in nilfs_ioctl_get_info() function is changed to accept larger data structure [1], and metadata read routines are rewritten so that they become compatible for larger structures; the routines will just ignore the remaining fields which the current version of nilfs doesn't know. [1] The ioctl function already has another upper limit (PAGE_SIZE against a structure, which appears in nilfs_ioctl_wrap_copy function), and this will not cause security problem. Signed-off-by: Ryusuke Konishi --- fs/nilfs2/dat.c | 21 +++++++++++---------- 1 file changed, 11 insertions(+), 10 deletions(-) (limited to 'fs/nilfs2/dat.c') diff --git a/fs/nilfs2/dat.c b/fs/nilfs2/dat.c index 1827f62c772d..0b2710e2d565 100644 --- a/fs/nilfs2/dat.c +++ b/fs/nilfs2/dat.c @@ -376,36 +376,37 @@ int nilfs_dat_translate(struct inode *dat, __u64 vblocknr, sector_t *blocknrp) return ret; } -ssize_t nilfs_dat_get_vinfo(struct inode *dat, struct nilfs_vinfo *vinfo, +ssize_t nilfs_dat_get_vinfo(struct inode *dat, void *buf, unsigned visz, size_t nvi) { struct buffer_head *entry_bh; struct nilfs_dat_entry *entry; + struct nilfs_vinfo *vinfo = buf; __u64 first, last; void *kaddr; unsigned long entries_per_block = NILFS_MDT(dat)->mi_entries_per_block; int i, j, n, ret; for (i = 0; i < nvi; i += n) { - ret = nilfs_palloc_get_entry_block(dat, vinfo[i].vi_vblocknr, + ret = nilfs_palloc_get_entry_block(dat, vinfo->vi_vblocknr, 0, &entry_bh); if (ret < 0) return ret; kaddr = kmap_atomic(entry_bh->b_page, KM_USER0); /* last virtual block number in this block */ - first = vinfo[i].vi_vblocknr; + first = vinfo->vi_vblocknr; do_div(first, entries_per_block); first *= entries_per_block; last = first + entries_per_block - 1; for (j = i, n = 0; - j < nvi && vinfo[j].vi_vblocknr >= first && - vinfo[j].vi_vblocknr <= last; - j++, n++) { + j < nvi && vinfo->vi_vblocknr >= first && + vinfo->vi_vblocknr <= last; + j++, n++, vinfo = (void *)vinfo + visz) { entry = nilfs_palloc_block_get_entry( - dat, vinfo[j].vi_vblocknr, entry_bh, kaddr); - vinfo[j].vi_start = le64_to_cpu(entry->de_start); - vinfo[j].vi_end = le64_to_cpu(entry->de_end); - vinfo[j].vi_blocknr = le64_to_cpu(entry->de_blocknr); + dat, vinfo->vi_vblocknr, entry_bh, kaddr); + vinfo->vi_start = le64_to_cpu(entry->de_start); + vinfo->vi_end = le64_to_cpu(entry->de_end); + vinfo->vi_blocknr = le64_to_cpu(entry->de_blocknr); } kunmap_atomic(kaddr, KM_USER0); brelse(entry_bh); -- cgit v1.2.3