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

[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
......@@ -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;
......
......@@ -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,
......
......@@ -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;
......
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