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authorRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-05-12 03:58:47 +0900
committerRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>2009-06-10 23:41:11 +0900
commit003ff182fddde09ddfb8d079bbdb02f9d2122082 (patch)
treed949fa673353767d8854355987e49d82821935f6 /fs/nilfs2/ioctl.c
parent258ef67e246fd548e7ad91c23004ad157c03cce5 (diff)
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/ioctl.c')
-rw-r--r--fs/nilfs2/ioctl.c9
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index bdad7e4980b0..6ea5f872e2de 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -152,7 +152,7 @@ nilfs_ioctl_do_get_cpinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_cpfile_get_cpinfo(nilfs->ns_cpfile, posp, flags, buf,
- nmembs);
+ size, nmembs);
up_read(&nilfs->ns_segctor_sem);
return ret;
}
@@ -182,7 +182,8 @@ nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
int ret;
down_read(&nilfs->ns_segctor_sem);
- ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, nmembs);
+ ret = nilfs_sufile_get_suinfo(nilfs->ns_sufile, *posp, buf, size,
+ nmembs);
up_read(&nilfs->ns_segctor_sem);
return ret;
}
@@ -212,7 +213,7 @@ nilfs_ioctl_do_get_vinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
int ret;
down_read(&nilfs->ns_segctor_sem);
- ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, nmembs);
+ ret = nilfs_dat_get_vinfo(nilfs_dat_inode(nilfs), buf, size, nmembs);
up_read(&nilfs->ns_segctor_sem);
return ret;
}
@@ -589,7 +590,7 @@ static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
if (copy_from_user(&argv, argp, sizeof(argv)))
return -EFAULT;
- if (argv.v_size != membsz)
+ if (argv.v_size < membsz)
return -EINVAL;
ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);