static const char *autofs4_get_link(struct dentry *dentry, struct inode *inode, struct delayed_call *done) { struct autofs_sb_info *sbi; struct autofs_info *ino; if (!dentry) return ERR_PTR(-ECHILD); sbi = autofs4_sbi(dentry->d_sb); ino = autofs4_dentry_ino(dentry); if (ino && !autofs4_oz_mode(sbi)) ino->last_used = jiffies; return d_inode(dentry)->i_private; }
static int autofs4_dir_symlink(struct inode *dir, struct dentry *dentry, const char *symname) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); struct inode *inode; char *cp; DPRINTK("%s <- %.*s", symname, dentry->d_name.len, dentry->d_name.name); if (!autofs4_oz_mode(sbi)) return -EACCES; ino = autofs4_init_ino(ino, sbi, S_IFLNK | 0555); if (ino == NULL) return -ENOSPC; ino->size = strlen(symname); ino->u.symlink = cp = kmalloc(ino->size + 1, GFP_KERNEL); if (cp == NULL) { kfree(ino); return -ENOSPC; } strcpy(cp, symname); inode = autofs4_get_inode(dir->i_sb, ino); d_instantiate(dentry, inode); if (dir == dir->i_sb->s_root->d_inode) dentry->d_op = &autofs4_root_dentry_operations; else dentry->d_op = &autofs4_dentry_operations; dentry->d_fsdata = ino; ino->dentry = dget(dentry); ino->inode = inode; dir->i_mtime = CURRENT_TIME; return 0; }
/* * NOTE! * * Normal filesystems would do a "d_delete()" to tell the VFS dcache * that the file no longer exists. However, doing that means that the * VFS layer can turn the dentry into a negative dentry. We don't want * this, because since the unlink is probably the result of an expire. * We simply d_drop it, which allows the dentry lookup to remount it * if necessary. * * If a process is blocked on the dentry waiting for the expire to finish, * it will invalidate the dentry and try to mount with a new one. * * Also see autofs4_dir_rmdir().. */ static int autofs4_dir_unlink(struct inode *dir, struct dentry *dentry) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); /* This allows root to remove symlinks */ if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) return -EACCES; dput(ino->dentry); dentry->d_inode->i_size = 0; dentry->d_inode->i_nlink = 0; dir->i_mtime = CURRENT_TIME; d_drop(dentry); return 0; }
/* * ioctl()'s on the root directory is the chief method for the daemon to * generate kernel reactions */ static int autofs4_root_ioctl(struct inode *inode, struct file *filp, unsigned int cmd, unsigned long arg) { struct autofs_sb_info *sbi = autofs4_sbi(inode->i_sb); DPRINTK(("autofs_ioctl: cmd = 0x%08x, arg = 0x%08lx, sbi = %p, pgrp = %u\n", cmd,arg,sbi,process_group(current))); if ( _IOC_TYPE(cmd) != _IOC_TYPE(AUTOFS_IOC_FIRST) || _IOC_NR(cmd) - _IOC_NR(AUTOFS_IOC_FIRST) >= AUTOFS_IOC_COUNT ) return -ENOTTY; if ( !autofs4_oz_mode(sbi) && !capable(CAP_SYS_ADMIN) ) return -EPERM; switch(cmd) { case AUTOFS_IOC_READY: /* Wait queue: go ahead and retry */ return autofs4_wait_release(sbi,(autofs_wqt_t)arg,0); case AUTOFS_IOC_FAIL: /* Wait queue: fail with ENOENT */ return autofs4_wait_release(sbi,(autofs_wqt_t)arg,-ENOENT); case AUTOFS_IOC_CATATONIC: /* Enter catatonic mode (daemon shutdown) */ autofs4_catatonic_mode(sbi); return 0; case AUTOFS_IOC_PROTOVER: /* Get protocol version */ return autofs4_get_protover(sbi, (int *)arg); case AUTOFS_IOC_SETTIMEOUT: return autofs4_get_set_timeout(sbi,(unsigned long *)arg); /* return a single thing to expire */ case AUTOFS_IOC_EXPIRE: return autofs4_expire_run(inode->i_sb,filp->f_vfsmnt,sbi, (struct autofs_packet_expire *)arg); /* same as above, but can send multiple expires through pipe */ case AUTOFS_IOC_EXPIRE_MULTI: return autofs4_expire_multi(inode->i_sb,filp->f_vfsmnt,sbi, (int *)arg); default: return -ENOSYS; } }
static int autofs4_root_readdir(struct file *file, void *dirent, filldir_t filldir) { struct autofs_sb_info *sbi = autofs4_sbi(file->f_dentry->d_sb); int oz_mode = autofs4_oz_mode(sbi); DPRINTK("called, filp->f_pos = %lld", file->f_pos); /* * Don't set reghost flag if: * 1) f_pos is larger than zero -- we've already been here. * 2) we haven't even enabled reghosting in the 1st place. * 3) this is the daemon doing a readdir */ if (oz_mode && file->f_pos == 0 && sbi->reghost_enabled) sbi->needs_reghost = 1; DPRINTK("needs_reghost = %d", sbi->needs_reghost); return autofs4_dcache_readdir(file, dirent, filldir); }
/* * Revalidate is called on every cache lookup. Some of those * cache lookups may actually happen while the dentry is not * yet completely filled in, and revalidate has to delay such * lookups.. */ static int autofs4_revalidate(struct dentry * dentry, struct nameidata *nd) { struct inode * dir = dentry->d_parent->d_inode; struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); int oz_mode = autofs4_oz_mode(sbi); int flags = nd ? nd->flags : 0; int status = 1; /* Pending dentry */ if (autofs4_ispending(dentry)) { if (!oz_mode) status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags); return status; } /* Negative dentry.. invalidate if "old" */ if (dentry->d_inode == NULL) return (dentry->d_time - jiffies <= AUTOFS_NEGATIVE_TIMEOUT); /* Check for a non-mountpoint directory with no contents */ spin_lock(&dcache_lock); if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { DPRINTK("dentry=%p %.*s, emptydir", dentry, dentry->d_name.len, dentry->d_name.name); spin_unlock(&dcache_lock); if (!oz_mode) status = try_to_fill_dentry(dentry, dir->i_sb, sbi, flags); return status; } spin_unlock(&dcache_lock); /* Update the usage list */ if (!oz_mode) autofs4_update_usage(dentry); return 1; }
static int autofs4_dir_mkdir(struct inode *dir, struct dentry *dentry, int mode) { struct autofs_sb_info *sbi = autofs4_sbi(dir->i_sb); struct autofs_info *ino = autofs4_dentry_ino(dentry); struct inode *inode; lock_kernel(); if ( !autofs4_oz_mode(sbi) ) { unlock_kernel(); return -EACCES; } DPRINTK(("autofs_dir_mkdir: dentry %p, creating %.*s\n", dentry, dentry->d_name.len, dentry->d_name.name)); ino = autofs4_init_ino(ino, sbi, S_IFDIR | 0555); if (ino == NULL) { unlock_kernel(); return -ENOSPC; } inode = autofs4_get_inode(dir->i_sb, ino); d_instantiate(dentry, inode); if (dir == dir->i_sb->s_root->d_inode) dentry->d_op = &autofs4_root_dentry_operations; else dentry->d_op = &autofs4_dentry_operations; dentry->d_fsdata = ino; ino->dentry = dget(dentry); ino->inode = inode; dir->i_nlink++; dir->i_mtime = CURRENT_TIME; unlock_kernel(); return 0; }
/* ioctl dispatcher */ static int _autofs_dev_ioctl(unsigned int command, struct autofs_dev_ioctl __user *user) { struct autofs_dev_ioctl *param; struct file *fp; struct autofs_sb_info *sbi; unsigned int cmd_first, cmd; ioctl_fn fn = NULL; int err = 0; /* only root can play with this */ if (!capable(CAP_SYS_ADMIN)) return -EPERM; cmd_first = _IOC_NR(AUTOFS_DEV_IOCTL_IOC_FIRST); cmd = _IOC_NR(command); if (_IOC_TYPE(command) != _IOC_TYPE(AUTOFS_DEV_IOCTL_IOC_FIRST) || cmd - cmd_first >= AUTOFS_DEV_IOCTL_IOC_COUNT) { return -ENOTTY; } /* Copy the parameters into kernel space. */ param = copy_dev_ioctl(user); if (IS_ERR(param)) return PTR_ERR(param); err = validate_dev_ioctl(command, param); if (err) goto out; /* The validate routine above always sets the version */ if (cmd == AUTOFS_DEV_IOCTL_VERSION_CMD) goto done; fn = lookup_dev_ioctl(cmd); if (!fn) { AUTOFS_WARN("unknown command 0x%08x", command); return -ENOTTY; } fp = NULL; sbi = NULL; /* * For obvious reasons the openmount can't have a file * descriptor yet. We don't take a reference to the * file during close to allow for immediate release. */ if (cmd != AUTOFS_DEV_IOCTL_OPENMOUNT_CMD && cmd != AUTOFS_DEV_IOCTL_CLOSEMOUNT_CMD) { fp = fget(param->ioctlfd); if (!fp) { if (cmd == AUTOFS_DEV_IOCTL_ISMOUNTPOINT_CMD) goto cont; err = -EBADF; goto out; } if (!fp->f_op) { err = -ENOTTY; fput(fp); goto out; } sbi = autofs_dev_ioctl_sbi(fp); if (!sbi || sbi->magic != AUTOFS_SBI_MAGIC) { err = -EINVAL; fput(fp); goto out; } /* * Admin needs to be able to set the mount catatonic in * order to be able to perform the re-open. */ if (!autofs4_oz_mode(sbi) && cmd != AUTOFS_DEV_IOCTL_CATATONIC_CMD) { err = -EACCES; fput(fp); goto out; } } cont: err = fn(fp, sbi, param); if (fp) fput(fp); done: if (err >= 0 && copy_to_user(user, param, AUTOFS_DEV_IOCTL_SIZE)) err = -EFAULT; out: free_dev_ioctl(param); return err; }
static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi) { struct autofs_info *de_info = autofs4_dentry_ino(dentry); int status = 0; /* Block on any pending expiry here; invalidate the dentry when expiration is done to trigger mount request with a new dentry */ if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) { DPRINTK(("try_to_fill_entry: waiting for expire %p name=%.*s, flags&PENDING=%s de_info=%p de_info->flags=%x\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_flags & DCACHE_AUTOFS_PENDING?"t":"f", de_info, de_info?de_info->flags:0)); status = autofs4_wait(sbi, &dentry->d_name, NFY_NONE); DPRINTK(("try_to_fill_entry: expire done status=%d\n", status)); return 0; } DPRINTK(("try_to_fill_entry: dentry=%p %.*s ino=%p\n", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode)); /* Wait for a pending mount, triggering one if there isn't one already */ while(dentry->d_inode == NULL) { DPRINTK(("try_to_fill_entry: waiting for mount name=%.*s, de_info=%p de_info->flags=%x\n", dentry->d_name.len, dentry->d_name.name, de_info, de_info?de_info->flags:0)); status = autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT); DPRINTK(("try_to_fill_entry: mount done status=%d\n", status)); if (status && dentry->d_inode) return 0; /* Try to get the kernel to invalidate this dentry */ /* Turn this into a real negative dentry? */ if (status == -ENOENT) { dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT; dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; return 1; } else if (status) { /* Return a negative dentry, but leave it "pending" */ return 1; } } /* If this is an unused directory that isn't a mount point, bitch at the daemon and fix it in user space */ spin_lock(&dcache_lock); if (S_ISDIR(dentry->d_inode->i_mode) && !d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) { DPRINTK(("try_to_fill_entry: mounting existing dir\n")); spin_unlock(&dcache_lock); return autofs4_wait(sbi, &dentry->d_name, NFY_MOUNT) == 0; } spin_unlock(&dcache_lock); /* We don't update the usages for the autofs daemon itself, this is necessary for recursive autofs mounts */ if (!autofs4_oz_mode(sbi)) autofs4_update_usage(dentry); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; return 1; }
/* Lookups in the root directory */ static struct dentry *autofs4_root_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { struct autofs_sb_info *sbi; int oz_mode; DPRINTK(("autofs_root_lookup: name = %.*s\n", dentry->d_name.len, dentry->d_name.name)); if (dentry->d_name.len > NAME_MAX) return ERR_PTR(-ENAMETOOLONG);/* File name too long to exist */ sbi = autofs4_sbi(dir->i_sb); lock_kernel(); oz_mode = autofs4_oz_mode(sbi); DPRINTK(("autofs_lookup: pid = %u, pgrp = %u, catatonic = %d, oz_mode = %d\n", current->pid, process_group(current), sbi->catatonic, oz_mode)); /* * Mark the dentry incomplete, but add it. This is needed so * that the VFS layer knows about the dentry, and we can count * on catching any lookups through the revalidate. * * Let all the hard work be done by the revalidate function that * needs to be able to do this anyway.. * * We need to do this before we release the directory semaphore. */ dentry->d_op = &autofs4_root_dentry_operations; if (!oz_mode) dentry->d_flags |= DCACHE_AUTOFS_PENDING; dentry->d_fsdata = NULL; d_add(dentry, NULL); if (dentry->d_op && dentry->d_op->d_revalidate) { up(&dir->i_sem); (dentry->d_op->d_revalidate)(dentry, nd); down(&dir->i_sem); } /* * If we are still pending, check if we had to handle * a signal. If so we can force a restart.. */ if (dentry->d_flags & DCACHE_AUTOFS_PENDING) { if (signal_pending(current)) { unlock_kernel(); return ERR_PTR(-ERESTARTNOINTR); } } unlock_kernel(); /* * If this dentry is unhashed, then we shouldn't honour this * lookup even if the dentry is positive. Returning ENOENT here * doesn't do the right thing for all system calls, but it should * be OK for the operations we permit from an autofs. */ if ( dentry->d_inode && d_unhashed(dentry) ) return ERR_PTR(-ENOENT); return NULL; }
static int try_to_fill_dentry(struct dentry *dentry, struct super_block *sb, struct autofs_sb_info *sbi, int flags) { struct autofs_info *de_info = autofs4_dentry_ino(dentry); int status = 0; /* Block on any pending expiry here; invalidate the dentry when expiration is done to trigger mount request with a new dentry */ if (de_info && (de_info->flags & AUTOFS_INF_EXPIRING)) { DPRINTK("waiting for expire %p name=%.*s", dentry, dentry->d_name.len, dentry->d_name.name); status = autofs4_wait(sbi, dentry, NFY_NONE); DPRINTK("expire done status=%d", status); return 0; } DPRINTK("dentry=%p %.*s ino=%p", dentry, dentry->d_name.len, dentry->d_name.name, dentry->d_inode); /* Wait for a pending mount, triggering one if there isn't one already */ if (dentry->d_inode == NULL) { DPRINTK("waiting for mount name=%.*s", dentry->d_name.len, dentry->d_name.name); status = autofs4_wait(sbi, dentry, NFY_MOUNT); DPRINTK("mount done status=%d", status); if (status && dentry->d_inode) return 0; /* Try to get the kernel to invalidate this dentry */ /* Turn this into a real negative dentry? */ if (status == -ENOENT) { dentry->d_time = jiffies + AUTOFS_NEGATIVE_TIMEOUT; spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); return 1; } else if (status) { /* Return a negative dentry, but leave it "pending" */ return 1; } /* Trigger mount for path component or follow link */ } else if (flags & (LOOKUP_CONTINUE | LOOKUP_DIRECTORY) || current->link_count) { DPRINTK("waiting for mount name=%.*s", dentry->d_name.len, dentry->d_name.name); spin_lock(&dentry->d_lock); dentry->d_flags |= DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); status = autofs4_wait(sbi, dentry, NFY_MOUNT); DPRINTK("mount done status=%d", status); if (status) { spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); return 0; } } /* We don't update the usages for the autofs daemon itself, this is necessary for recursive autofs mounts */ if (!autofs4_oz_mode(sbi)) autofs4_update_usage(dentry); spin_lock(&dentry->d_lock); dentry->d_flags &= ~DCACHE_AUTOFS_PENDING; spin_unlock(&dentry->d_lock); return 1; }