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Commit 003ff182 authored by Ryusuke Konishi's avatar Ryusuke Konishi
Browse files

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: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
parent 258ef67e

fs/nilfs2/cpfile.c

+21 −12
Original line number Diff line number Diff line
@@ -384,9 +384,10 @@ static void nilfs_cpfile_checkpoint_to_cpinfo(struct inode *cpfile, 
}



static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop,

					  struct nilfs_cpinfo *ci, size_t nci)

					  void *buf, unsigned cisz, size_t nci)

{

	struct nilfs_checkpoint *cp;

	struct nilfs_cpinfo *ci = buf;

	struct buffer_head *bh;

	size_t cpsz = NILFS_MDT(cpfile)->mi_entry_size;

	__u64 cur_cno = nilfs_mdt_cno(cpfile), cno = *cnop;
@@ -410,17 +411,22 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, 
		kaddr = kmap_atomic(bh->b_page, KM_USER0);

		cp = nilfs_cpfile_block_get_checkpoint(cpfile, cno, bh, kaddr);

		for (i = 0; i < ncps && n < nci; i++, cp = (void *)cp + cpsz) {

			if (!nilfs_checkpoint_invalid(cp))

				nilfs_cpfile_checkpoint_to_cpinfo(

					cpfile, cp, &ci[n++]);

			if (!nilfs_checkpoint_invalid(cp)) {

				nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp,

								  ci);

				ci = (void *)ci + cisz;

				n++;

			}

		}

		kunmap_atomic(kaddr, KM_USER0);

		brelse(bh);

	}



	ret = n;

	if (n > 0)

		*cnop = ci[n - 1].ci_cno + 1;

	if (n > 0) {

		ci = (void *)ci - cisz;

		*cnop = ci->ci_cno + 1;

	}



 out:

	up_read(&NILFS_MDT(cpfile)->mi_sem);
@@ -428,11 +434,12 @@ static ssize_t nilfs_cpfile_do_get_cpinfo(struct inode *cpfile, __u64 *cnop, 
}



static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop,

					  struct nilfs_cpinfo *ci, size_t nci)

					  void *buf, unsigned cisz, size_t nci)

{

	struct buffer_head *bh;

	struct nilfs_cpfile_header *header;

	struct nilfs_checkpoint *cp;

	struct nilfs_cpinfo *ci = buf;

	__u64 curr = *cnop, next;

	unsigned long curr_blkoff, next_blkoff;

	void *kaddr;
@@ -472,7 +479,9 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, 
		if (unlikely(nilfs_checkpoint_invalid(cp) ||

			     !nilfs_checkpoint_snapshot(cp)))

			break;

		nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, &ci[n++]);

		nilfs_cpfile_checkpoint_to_cpinfo(cpfile, cp, ci);

		ci = (void *)ci + cisz;

		n++;

		next = le64_to_cpu(cp->cp_snapshot_list.ssl_next);

		if (next == 0)

			break; /* reach end of the snapshot list */
@@ -511,13 +520,13 @@ static ssize_t nilfs_cpfile_do_get_ssinfo(struct inode *cpfile, __u64 *cnop, 
 */



ssize_t nilfs_cpfile_get_cpinfo(struct inode *cpfile, __u64 *cnop, int mode,

				struct nilfs_cpinfo *ci, size_t nci)

				void *buf, unsigned cisz, size_t nci)

{

	switch (mode) {

	case NILFS_CHECKPOINT:

		return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, ci, nci);

		return nilfs_cpfile_do_get_cpinfo(cpfile, cnop, buf, cisz, nci);

	case NILFS_SNAPSHOT:

		return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, ci, nci);

		return nilfs_cpfile_do_get_ssinfo(cpfile, cnop, buf, cisz, nci);

	default:

		return -EINVAL;

	}
@@ -535,7 +544,7 @@ int nilfs_cpfile_delete_checkpoint(struct inode *cpfile, __u64 cno) 
	ssize_t nci;

	int ret;



	nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, 1);

	nci = nilfs_cpfile_do_get_cpinfo(cpfile, &tcno, &ci, sizeof(ci), 1);

	if (nci < 0)

		return nci;

	else if (nci == 0 || ci.ci_cno != cno)

fs/nilfs2/cpfile.h

+2 −2
Original line number Diff line number Diff line
@@ -39,7 +39,7 @@ int nilfs_cpfile_delete_checkpoint(struct inode *, __u64); 
int nilfs_cpfile_change_cpmode(struct inode *, __u64, int);

int nilfs_cpfile_is_snapshot(struct inode *, __u64);

int nilfs_cpfile_get_stat(struct inode *, struct nilfs_cpstat *);

ssize_t nilfs_cpfile_get_cpinfo(struct inode *, __u64 *, int,

				struct nilfs_cpinfo *, size_t);

ssize_t nilfs_cpfile_get_cpinfo(struct inode *, __u64 *, int, void *, unsigned,

				size_t);



#endif	/* _NILFS_CPFILE_H */

fs/nilfs2/dat.c

+11 −10
Original line number Diff line number Diff line
@@ -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);

fs/nilfs2/dat.h

+1 −1
Original line number Diff line number Diff line
@@ -47,6 +47,6 @@ void nilfs_dat_abort_end(struct inode *, struct nilfs_palloc_req *); 
int nilfs_dat_mark_dirty(struct inode *, __u64);

int nilfs_dat_freev(struct inode *, __u64 *, size_t);

int nilfs_dat_move(struct inode *, __u64, sector_t);

ssize_t nilfs_dat_get_vinfo(struct inode *, struct nilfs_vinfo *, size_t);

ssize_t nilfs_dat_get_vinfo(struct inode *, void *, unsigned, size_t);



#endif	/* _NILFS_DAT_H */

fs/nilfs2/ioctl.c

+5 −4
Original line number Diff line number Diff line
@@ -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);