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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-05-11 20:58:47 +0200
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-06-10 16:41:11 +0200
commit003ff182fddde09ddfb8d079bbdb02f9d2122082 (patch)
treed949fa673353767d8854355987e49d82821935f6 /fs/nilfs2/sufile.h
parentNILFS2: Pagecache usage optimization on NILFS2 (diff)
downloadlinux-003ff182fddde09ddfb8d079bbdb02f9d2122082.tar.xz
linux-003ff182fddde09ddfb8d079bbdb02f9d2122082.zip
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 <konishi.ryusuke@lab.ntt.co.jp>
Diffstat (limited to 'fs/nilfs2/sufile.h')
-rw-r--r--fs/nilfs2/sufile.h2
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/nilfs2/sufile.h b/fs/nilfs2/sufile.h
index fd6232e365ca..a2c4d76c3366 100644
--- a/fs/nilfs2/sufile.h
+++ b/fs/nilfs2/sufile.h
@@ -43,7 +43,7 @@ void nilfs_sufile_put_segment_usage(struct inode *, __u64,
struct buffer_head *);
int nilfs_sufile_get_stat(struct inode *, struct nilfs_sustat *);
int nilfs_sufile_get_ncleansegs(struct inode *, unsigned long *);
-ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, struct nilfs_suinfo *,
+ssize_t nilfs_sufile_get_suinfo(struct inode *, __u64, void *, unsigned,
size_t);
int nilfs_sufile_updatev(struct inode *, __u64 *, size_t, int, size_t *,