From: Thomas Veerman Date: Fri, 19 Aug 2011 14:12:07 +0000 (+0000) Subject: Fix locking issues with back calls from FSes X-Git-Tag: v3.2.0~343 X-Git-Url: http://zhaoyanbai.com/repos/pkcs11-list.html?a=commitdiff_plain;h=ae2159c371b2472e2bc26a297bc8cf888b76b5a8;p=minix.git Fix locking issues with back calls from FSes --- diff --git a/servers/avfs/link.c b/servers/avfs/link.c index 90bf4a148..d0e1c762f 100644 --- a/servers/avfs/link.c +++ b/servers/avfs/link.c @@ -417,7 +417,7 @@ struct fproc *rfp; } /*===========================================================================* - * do_rdlink * + * do_rdlink * *===========================================================================*/ PUBLIC int do_rdlink() { diff --git a/servers/avfs/main.c b/servers/avfs/main.c index 2e548b80b..0f70e41dd 100644 --- a/servers/avfs/main.c +++ b/servers/avfs/main.c @@ -385,6 +385,10 @@ PRIVATE void *do_work(void *arg) lock_proc(fp, 0); /* This proc is busy */ + if (verbose) { + printf("Doing call_nr = %d for %d\n", call_nr, who_e); + } + if (call_nr == MAPDRIVER) { error = do_mapdriver(); } else if (call_nr == COMMON_GETSYSINFO) { diff --git a/servers/avfs/misc.c b/servers/avfs/misc.c index 0f0cba7cd..53b19b533 100644 --- a/servers/avfs/misc.c +++ b/servers/avfs/misc.c @@ -284,14 +284,19 @@ PUBLIC int do_fcntl() PUBLIC int do_sync() { struct vmnt *vmp; + int r = OK; + for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) { - lock_vmnt(vmp, VMNT_EXCL); - if (vmp->m_dev != NO_DEV && vmp->m_fs_e != NONE) + if (vmp->m_dev != NO_DEV && vmp->m_fs_e != NONE && + vmp->m_root_node != NULL) { + if ((r = lock_vmnt(vmp, VMNT_EXCL)) != OK) + break; req_sync(vmp->m_fs_e); - unlock_vmnt(vmp); + unlock_vmnt(vmp); + } } - return(OK); + return(r); } /*===========================================================================* @@ -299,23 +304,28 @@ PUBLIC int do_sync() *===========================================================================*/ PUBLIC int do_fsync() { -/* Perform the fsync() system call. For now, don't be unnecessarily smart. */ +/* Perform the fsync() system call. */ struct filp *rfilp; struct vmnt *vmp; dev_t dev; + int r = OK; if ((rfilp = get_filp(m_in.m1_i1, VNODE_READ)) == NULL) return(err_code); dev = rfilp->filp_vno->v_dev; for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) { - lock_vmnt(vmp, VMNT_EXCL); - if (vmp->m_dev != NO_DEV && vmp->m_dev == dev && vmp->m_fs_e != NONE) + if (vmp->m_dev != NO_DEV && vmp->m_dev == dev && + vmp->m_fs_e != NONE && vmp->m_root_node != NULL) { + + if ((r = lock_vmnt(vmp, VMNT_EXCL)) != OK) + break; req_sync(vmp->m_fs_e); - unlock_vmnt(vmp); + unlock_vmnt(vmp); + } } unlock_filp(rfilp); - return(OK); + return(r); } /*===========================================================================* @@ -344,6 +354,7 @@ PUBLIC void pm_reboot() } } + do_sync(); unmount_all(); } diff --git a/servers/avfs/mount.c b/servers/avfs/mount.c index 00f8c8258..9842fd0e8 100644 --- a/servers/avfs/mount.c +++ b/servers/avfs/mount.c @@ -43,7 +43,6 @@ PRIVATE bitchunk_t nonedev[BITMAP_CHUNKS(NR_NONEDEVS)] = { 0 }; FORWARD _PROTOTYPE( dev_t name_to_dev, (int allow_mountpt, char path[PATH_MAX+1]) ); -FORWARD _PROTOTYPE( int is_nonedev, (dev_t dev) ); FORWARD _PROTOTYPE( dev_t find_free_nonedev, (void) ); FORWARD _PROTOTYPE( void update_bspec, (dev_t dev, endpoint_t fs_e, int send_drv_e) ); @@ -153,7 +152,8 @@ PUBLIC int do_mount() return(err_code); /* Do the actual job */ - return mount_fs(dev, fullpath, fs_e, rdonly, mount_label); + r = mount_fs(dev, fullpath, fs_e, rdonly, mount_label); + return(r); } @@ -191,32 +191,18 @@ char mount_label[LABEL_MAX] ) assert(strlen(label) > 0); } - lock_bsf(); - - /* Check whether there is a block special file open which uses the - * same device (partition) */ - for (bspec = &vnode[0]; bspec < &vnode[NR_VNODES]; ++bspec) { - if (bspec->v_ref_count > 0 && bspec->v_sdev == dev) { - /* Found, flush and invalidate any blocks for this device. */ - req_flush(bspec->v_fs_e, dev); - break; - } - } - /* Scan vmnt table to see if dev already mounted. If not, find a free slot.*/ found = FALSE; for (i = 0; i < NR_MNTS; ++i) { if (vmnt[i].m_dev == dev) found = TRUE; } if (found) { - unlock_bsf(); return(EBUSY); } else if ((new_vmp = get_free_vmnt()) == NULL) { - unlock_bsf(); return(ENOMEM); } - lock_vmnt(new_vmp, VMNT_EXCL); + if ((r = lock_vmnt(new_vmp, VMNT_EXCL)) != OK) return(r); isroot = (strcmp(mountpoint, "/") == 0); mount_root = (isroot && have_root < 2); /* Root can be mounted twice: @@ -237,14 +223,15 @@ char mount_label[LABEL_MAX] ) } else r = EBUSY; + if (vp != NULL) + unlock_vmnt(parent_vmp); + if (r != OK) { if (vp != NULL) { unlock_vnode(vp); - unlock_vmnt(parent_vmp); put_vnode(vp); } unlock_vmnt(new_vmp); - unlock_bsf(); return(r); } } @@ -254,11 +241,9 @@ char mount_label[LABEL_MAX] ) if ((root_node = get_free_vnode()) == NULL || dev == 266) { if (vp != NULL) { unlock_vnode(vp); - unlock_vmnt(parent_vmp); put_vnode(vp); } unlock_vmnt(new_vmp); - unlock_bsf(); return(err_code); } @@ -271,19 +256,21 @@ char mount_label[LABEL_MAX] ) else new_vmp->m_flags &= ~VMNT_READONLY; /* Tell FS which device to mount */ + if (verbose) + printf("Tell FS %d to mount device %s %d\n", fs_e, label, dev); if ((r = req_readsuper(fs_e, label, dev, rdonly, isroot, &res)) != OK) { + if (verbose) printf("Failed: %d\n", r); if (vp != NULL) { unlock_vnode(vp); - unlock_vmnt(parent_vmp); put_vnode(vp); } new_vmp->m_fs_e = NONE; new_vmp->m_dev = NO_DEV; unlock_vnode(root_node); unlock_vmnt(new_vmp); - unlock_bsf(); return(r); } + if (verbose) printf("Ok done: r=%d\n", r); /* Fill in root node's fields */ root_node->v_fs_e = res.fs_e; @@ -300,7 +287,9 @@ char mount_label[LABEL_MAX] ) root_node->v_vmnt = new_vmp; root_node->v_dev = new_vmp->m_dev; - if(mount_root) { + lock_bsf(); + + if (mount_root) { /* Superblock and root node already read. * Nothing else can go wrong. Perform the mount. */ new_vmp->m_root_node = root_node; @@ -342,7 +331,6 @@ char mount_label[LABEL_MAX] ) /* If error, return the super block and both inodes; release the vmnt. */ if (r != OK) { unlock_vnode(vp); - unlock_vmnt(parent_vmp); unlock_vnode(root_node); unlock_vmnt(new_vmp); put_vnode(vp); @@ -364,7 +352,6 @@ char mount_label[LABEL_MAX] ) update_bspec(dev, fs_e, 0 /* Don't send new driver endpoint */); unlock_vnode(vp); - unlock_vmnt(parent_vmp); unlock_vnode(root_node); unlock_vmnt(new_vmp); unlock_bsf(); @@ -454,7 +441,10 @@ PUBLIC int unmount( lock_bsf(); - assert(lock_vmnt(vmp, VMNT_EXCL) == OK); + if ((r = lock_vmnt(vmp, VMNT_EXCL)) != OK) { + unlock_bsf(); + return(r); + } /* See if the mounted device is busy. Only 1 vnode using it should be * open -- the root vnode -- and that inode only 1 time. */ @@ -577,7 +567,7 @@ PRIVATE dev_t name_to_dev(int allow_mountpt, char path[PATH_MAX+1]) /*===========================================================================* * is_nonedev * *===========================================================================*/ -PRIVATE int is_nonedev(dev_t dev) +PUBLIC int is_nonedev(dev_t dev) { /* Return whether the given device is a "none" pseudo device. */ diff --git a/servers/avfs/open.c b/servers/avfs/open.c index 54b69a43b..23e8cfb5f 100644 --- a/servers/avfs/open.c +++ b/servers/avfs/open.c @@ -180,7 +180,8 @@ PRIVATE int common_open(char path[PATH_MAX+1], int oflags, mode_t omode) * we default to ROOT_FS. */ vp->v_bfs_e = ROOT_FS_E; /* By default */ for (vmp = &vmnt[0]; vmp < &vmnt[NR_MNTS]; ++vmp) - if (vmp->m_dev == vp->v_sdev) + if (vmp->m_dev == vp->v_sdev && + !is_nonedev(vmp->m_dev)) vp->v_bfs_e = vmp->m_fs_e; /* Get the driver endpoint of the block spec device */ diff --git a/servers/avfs/path.c b/servers/avfs/path.c index 1be54d9ef..213ae27cf 100644 --- a/servers/avfs/path.c +++ b/servers/avfs/path.c @@ -169,6 +169,10 @@ struct fproc *rfp; char *cp; char dir_entry[PATH_MAX+1]; struct vnode *start_dir, *res; + int r; + + *resolve->l_vnode = NULL; + *resolve->l_vmp = NULL; /* Is the path absolute or relative? Initialize 'start_dir' accordingly. */ start_dir = (resolve->l_path[0] == '/' ? rfp->fp_rd : rfp->fp_wd); @@ -195,8 +199,12 @@ struct fproc *rfp; struct vmnt *vmp; vmp = find_vmnt(start_dir->v_fs_e); - if (lock_vmnt(vmp, resolve->l_vmnt_lock) != EBUSY) + r = lock_vmnt(vmp, resolve->l_vmnt_lock); + if (r == EDEADLK) + return(NULL); + else if (r == OK) *resolve->l_vmp = vmp; + lock_vnode(start_dir, resolve->l_vnode_lock); *resolve->l_vnode = start_dir; dup_vnode(start_dir); @@ -285,6 +293,8 @@ struct fproc *rfp; if ((r = lock_vmnt(vmpres, resolve->l_vmnt_lock)) != OK) { if (r == EBUSY) /* vmnt already locked */ vmpres = NULL; + else + return(r); } *(resolve->l_vmp) = vmpres; @@ -320,7 +330,7 @@ struct fproc *rfp; vmp = NULL; } else if (r == EENTERMOUNT) { /* Entering a new partition */ - dir_vp = 0; + dir_vp = NULL; /* Start node is now the mounted partition's root node */ for (vmp = &vmnt[0]; vmp != &vmnt[NR_MNTS]; ++vmp) { if (vmp->m_dev != NO_DEV && vmp->m_mounted_on) { @@ -374,6 +384,8 @@ struct fproc *rfp; if ((r = lock_vmnt(vmpres, resolve->l_vmnt_lock)) != OK) { if (r == EBUSY) vmpres = NULL; /* Already locked */ + else + return(r); } *(resolve->l_vmp) = vmpres; diff --git a/servers/avfs/pipe.c b/servers/avfs/pipe.c index de2128069..bfc918153 100644 --- a/servers/avfs/pipe.c +++ b/servers/avfs/pipe.c @@ -50,14 +50,14 @@ PUBLIC int do_pipe() struct vmnt *vmp; struct node_details res; + /* Get a lock on PFS */ + if ((vmp = find_vmnt(PFS_PROC_NR)) == NULL) panic("PFS gone"); + if ((r = lock_vmnt(vmp, VMNT_WRITE)) != OK) return(r); + /* See if a free vnode is available */ if ((vp = get_free_vnode()) == NULL) return(err_code); lock_vnode(vp, VNODE_OPCL); - /* Get a lock on PFS */ - if ((vmp = find_vmnt(PFS_PROC_NR)) == NULL) panic("PFS gone"); - lock_vmnt(vmp, VMNT_WRITE); - /* Acquire two file descriptors. */ rfp = fp; if ((r = get_fd(0, R_BIT, &fil_des[0], &fil_ptr0)) != OK) { @@ -147,8 +147,13 @@ endpoint_t map_to_fs_e; if ((vmp = find_vmnt(map_to_fs_e)) == NULL) panic("Can't map to unknown endpoint"); - if (lock_vmnt(vmp, VMNT_WRITE) == EBUSY) - vmp = NULL; /* Already locked, do not unlock */ + if ((r = lock_vmnt(vmp, VMNT_WRITE)) != OK) { + if (r == EBUSY) + vmp = NULL; /* Already locked, do not unlock */ + else + return(r); + + } /* Create a temporary mapping of this inode to another FS. Read and write * operations on data will be handled by that FS. The rest by the 'original' diff --git a/servers/avfs/proto.h b/servers/avfs/proto.h index 31f7ca2b9..0fa5761bd 100644 --- a/servers/avfs/proto.h +++ b/servers/avfs/proto.h @@ -141,6 +141,7 @@ _PROTOTYPE( void ds_event, (void) ); _PROTOTYPE( int do_fsready, (void) ); _PROTOTYPE( int do_mount, (void) ); _PROTOTYPE( int do_umount, (void) ); +_PROTOTYPE( int is_nonedev, (dev_t dev) ); _PROTOTYPE( void mount_pfs, (void) ); _PROTOTYPE( int mount_fs, (dev_t dev, char fullpath[PATH_MAX+1], endpoint_t fs_e, int rdonly, diff --git a/servers/avfs/read.c b/servers/avfs/read.c index ffde1f9db..8de5eeb86 100644 --- a/servers/avfs/read.c +++ b/servers/avfs/read.c @@ -137,12 +137,17 @@ int rw_flag; /* READING or WRITING */ } else if (block_spec) { /* Block special files. */ lock_bsf(); + printf("Doing block read_write(%d) from dev %d/ep=%d\n", + rw_flag == READING, + vp->v_sdev, vp->v_bfs_e); r = req_breadwrite(vp->v_bfs_e, who_e, vp->v_sdev, position, m_in.nbytes, m_in.buffer, rw_flag, &res_pos, &res_cum_io); if (r == OK) { + printf("OK res_cum_io = %d\n", res_cum_io); position = res_pos; cum_io += res_cum_io; - } + } else + printf("Failed with %d\n", r); unlock_bsf(); } else { /* Regular files */ diff --git a/servers/avfs/vmnt.c b/servers/avfs/vmnt.c index cbb517f7f..f391aa963 100644 --- a/servers/avfs/vmnt.c +++ b/servers/avfs/vmnt.c @@ -129,6 +129,8 @@ PUBLIC int lock_vmnt(struct vmnt *vmp, tll_access_t locktype) initial_locktype = (locktype == VMNT_EXCL) ? VMNT_WRITE : locktype; + if (vmp->m_fs_e == who_e) return(EDEADLK); + r = tll_lock(&vmp->m_lock, initial_locktype); if (r == EBUSY) return(r);