Apply the same fix to a potential race in the ISDOTDOT code in

ext2_lookup() that was used to fix an actual race in ufs_lookup.c:1.78.
This is not currently a hazard, but the bug would be activated by
marking ext2fs as MPSAFE.

Requested by:	bde
MFC after:	2 weeks
This commit is contained in:
Don Lewis 2005-10-16 21:39:29 +00:00
parent 875e108755
commit 9e4ce0ae8f
Notes: svn2git 2020-12-20 02:59:44 +00:00
svn path=/head/; revision=151391

View File

@ -319,6 +319,7 @@ ext2_lookup(ap)
int flags = cnp->cn_flags;
int nameiop = cnp->cn_nameiop;
struct thread *td = cnp->cn_thread;
ino_t saved_ino;
int DIRBLKSIZ = VTOI(ap->a_dvp)->i_e2fs->s_blocksize;
@ -655,8 +656,9 @@ ext2_lookup(ap)
*/
pdp = vdp;
if (flags & ISDOTDOT) {
saved_ino = dp->i_ino;
VOP_UNLOCK(pdp, 0, td); /* race to get the inode */
error = VFS_VGET(vdp->v_mount, dp->i_ino, LK_EXCLUSIVE, &tdp);
error = VFS_VGET(vdp->v_mount, saved_ino, LK_EXCLUSIVE, &tdp);
vn_lock(pdp, LK_EXCLUSIVE | LK_RETRY, td);
if (error != 0)
return (error);