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VFS: fix locking bug in clone_opcl

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When VFS runs out of vnodes after closing a vnode in opcl, common_open
will try to unlock a vnode through unlock_filp that has already been
unlocked in clone_opcl. By first obtaining and locking a new vnode this
situation is prevented; if there are no free vnodes, common_open will
unlock a still locked vnode.
This commit is contained in:
Thomas Veerman 2012-07-26 12:28:03 +00:00
parent f6b0d662b5
commit 66dbf73049
1 changed files with 14 additions and 16 deletions
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10
servers/vfs/device.c
View file

@ -900,16 +900,14 @@ int clone_opcl(
}
/* Drop old node and use the new values */
assert(FD_ISSET(scratch(fp).file.fd_nr, &fp->fp_filp_inuse));
vp = fp->fp_filp[scratch(fp).file.fd_nr]->filp_vno;
unlock_vnode(vp);
put_vnode(vp);
if ((vp = get_free_vnode()) == NULL)
return(err_code);
lock_vnode(vp, VNODE_OPCL);
assert(FD_ISSET(scratch(fp).file.fd_nr, &fp->fp_filp_inuse));
unlock_vnode(fp->fp_filp[scratch(fp).file.fd_nr]->filp_vno);
put_vnode(fp->fp_filp[scratch(fp).file.fd_nr]->filp_vno);
vp->v_fs_e = res.fs_e;
vp->v_vmnt = NULL;
vp->v_dev = NO_DEV;