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Commit 5509826f authored by S. Wendy Cheng's avatar S. Wendy Cheng Committed by Steven Whitehouse
Browse files

[GFS2] Fix change nlink deadlock 



Bugzilla 215088

Fix deadlock in gfs2_change_nlink() while installing RHEL5 into GFS2
partition. The gfs2_rename() apparently needs block allocation for the
new name (into the directory) where it requires rg locks. At the same
time, while updating the nlink count for the replaced file,
gfs2_change_nlink() tries to return the inode meta-data back to resource
group where it needs rg locks too. Our logic doesn't allow process to
acquire these locks recursively by the same process  (RHEL installer)
that results a BUG call. This only happens within rename code path and
only if the destination file exists before the rename operation.

Signed-off-by: default avatarS. Wendy Cheng <wcheng@redhat.com>
Signed-off-by: default avatarSteven Whitehouse <swhiteho@redhat.com>
parent e1d5b18a

fs/gfs2/inode.c

+16 −4
Original line number Diff line number Diff line
@@ -281,16 +281,14 @@ int gfs2_dinode_dealloc(struct gfs2_inode *ip) 
}



/**

 * gfs2_change_nlink - Change nlink count on inode

 * gfs2_change_nlink_i - Change nlink count on inode

 * @ip: The GFS2 inode

 * @diff: The change in the nlink count required

 *

 * Returns: errno

 */



int gfs2_change_nlink(struct gfs2_inode *ip, int diff)

int gfs2_change_nlink_i(struct gfs2_inode *ip, int diff)

{

	struct gfs2_sbd *sdp = ip->i_inode.i_sb->s_fs_info;

	struct buffer_head *dibh;

	u32 nlink;

	int error;
@@ -322,6 +320,20 @@ int gfs2_change_nlink(struct gfs2_inode *ip, int diff) 
	brelse(dibh);

	mark_inode_dirty(&ip->i_inode);



	return error;

}



int gfs2_change_nlink(struct gfs2_inode *ip, int diff)

{

	struct gfs2_sbd *sdp = ip->i_inode.i_sb->s_fs_info;

	int error;



	/* update the nlink */

	error = gfs2_change_nlink_i(ip, diff);

	if (error)

		return error;



	/* return meta data block back to rg */

	if (ip->i_inode.i_nlink == 0) {

		struct gfs2_rgrpd *rgd;

		struct gfs2_holder ri_gh, rg_gh;

fs/gfs2/inode.h

+1 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ int gfs2_inode_refresh(struct gfs2_inode *ip); 


int gfs2_dinode_dealloc(struct gfs2_inode *inode);

int gfs2_change_nlink(struct gfs2_inode *ip, int diff);

int gfs2_change_nlink_i(struct gfs2_inode *ip, int diff);

struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name,

			   int is_root, struct nameidata *nd);

struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name,

fs/gfs2/ops_inode.c

+22 −3
Original line number Diff line number Diff line
@@ -553,6 +553,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, 
	int alloc_required;

	unsigned int x;

	int error;

	struct gfs2_rgrpd *rgd;



	if (ndentry->d_inode) {

		nip = GFS2_I(ndentry->d_inode);
@@ -684,12 +685,12 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, 
		error = gfs2_trans_begin(sdp, sdp->sd_max_dirres +

					 al->al_rgd->rd_ri.ri_length +

					 4 * RES_DINODE + 4 * RES_LEAF +

					 RES_STATFS + RES_QUOTA, 0);

					 RES_STATFS + RES_QUOTA + 1, 0);

		if (error)

			goto out_ipreserv;

	} else {

		error = gfs2_trans_begin(sdp, 4 * RES_DINODE +

					 5 * RES_LEAF, 0);

					 5 * RES_LEAF + 1, 0);

		if (error)

			goto out_gunlock;

	}
@@ -703,7 +704,25 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, 
			error = gfs2_dir_del(ndip, &ndentry->d_name);

			if (error)

				goto out_end_trans;

			error = gfs2_change_nlink(nip, -1);

			error = gfs2_change_nlink_i(nip, -1);

			if ((!error) && (nip->i_inode.i_nlink == 0)) {

				error = -EIO;

				rgd = gfs2_blk2rgrpd(sdp, nip->i_num.no_addr);

				if (rgd) {

					struct gfs2_holder nlink_rg_gh;

					if (rgd != nip->i_alloc.al_rgd)

						error = gfs2_glock_nq_init(

						rgd->rd_gl, LM_ST_EXCLUSIVE,

						0, &nlink_rg_gh);

					else

						error = 0;

                			if (!error) {

						gfs2_unlink_di(&nip->i_inode);

						if (rgd != nip->i_alloc.al_rgd)

							gfs2_glock_dq_uninit(&nlink_rg_gh);

					}

				}

			}

		}

		if (error)

			goto out_end_trans;