/* * mount.c * * This file implements mounting of WIM files using FUSE, which stands for * Filesystem in Userspace. FUSE allows a filesystem to be implemented in a * userspace process by implementing the filesystem primitives--- read(), * write(), readdir(), etc. */ /* * Copyright (C) 2012 Eric Biggers * * This file is part of wimlib, a library for working with WIM files. * * wimlib is free software; you can redistribute it and/or modify it under the * terms of the GNU Lesser General Public License as published by the Free * Software Foundation; either version 2.1 of the License, or (at your option) * any later version. * * wimlib is distributed in the hope that it will be useful, but WITHOUT ANY * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR * A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more * details. * * You should have received a copy of the GNU Lesser General Public License * along with wimlib; if not, see http://www.gnu.org/licenses/. */ #include "wimlib_internal.h" #ifdef WITH_FUSE #include "sha1.h" #include "lookup_table.h" #include "xml.h" #include "timestamp.h" #include #include #include #define FUSE_USE_VERSION 26 #include #include #include #include #include #include /* The WIMStruct for the mounted WIM. */ static WIMStruct *w; /* Working directory when `imagex mount' is run. */ static const char *working_directory; /* Name of the staging directory for a read-write mount. Whenever a new file is * created, it is done so in the staging directory. Furthermore, whenever a * file in the WIM is modified, it is extracted to the staging directory. If * changes are commited when the WIM is unmounted, the file resources are merged * in from the staging directory when writing the new WIM. */ static char *staging_dir_name; static size_t staging_dir_name_len; /* Flags passed to wimlib_mount(). */ static int mount_flags; /* Name of the directory on which the WIM file is mounted. */ static const char *mount_dir; /* * Creates a randomly named staging directory and returns its name into the * static variable staging_dir_name. * * If the staging directory cannot be created, staging_dir_name is set to NULL. * */ static void make_staging_dir() { /* XXX Give the user an option of where to stage files */ static char prefix[] = "wimlib-staging-"; static const size_t prefix_len = 15; static const size_t suffix_len = 10; size_t pwd_len = strlen(working_directory); staging_dir_name_len = pwd_len + 1 + prefix_len + suffix_len; staging_dir_name = MALLOC(staging_dir_name_len + 1); if (!staging_dir_name) { ERROR("Out of memory"); return; } memcpy(staging_dir_name, working_directory, pwd_len); staging_dir_name[pwd_len] = '/'; memcpy(staging_dir_name + pwd_len + 1, prefix, prefix_len); randomize_char_array_with_alnum(staging_dir_name + pwd_len + 1 + prefix_len, suffix_len); staging_dir_name[staging_dir_name_len] = '\0'; if (mkdir(staging_dir_name, 0700) != 0) { ERROR_WITH_ERRNO("Failed to create temporary directory `%s'", staging_dir_name); FREE(staging_dir_name); staging_dir_name = NULL; } } static int remove_file_or_directory(const char *fpath, const struct stat *sb, int typeflag, struct FTW *ftwbuf) { if (remove(fpath) == 0) return 0; else return WIMLIB_ERR_DELETE_STAGING_DIR; } /* * Deletes the staging directory and all the files contained in it. */ static inline int delete_staging_dir() { int ret; ret = nftw(staging_dir_name, remove_file_or_directory,10, FTW_DEPTH); staging_dir_name = NULL; return ret; } /* Name and message queue descriptors for message queues between the filesystem * daemon process and the unmount process. These are used when the filesystem * is unmounted and the process running wimlib_mount() (i.e. the `imagex * unmount' command) needs to communicate with the filesystem daemon running * fuse_main() (i.e. that spawned by the `imagex mount' or `imagex mountrw' * commands */ static char *unmount_to_daemon_mq_name; static char *daemon_to_unmount_mq_name; static int unmount_to_daemon_mq; static int daemon_to_unmount_mq; /* Simple function that returns the concatenation of 4 strings. */ static char *strcat_dup(const char *s1, const char *s2, const char *s3, const char *s4) { size_t len = strlen(s1) + strlen(s2) + strlen(s3) + strlen(s4) + 1; char *p = MALLOC(len); if (!p) return NULL; *p = '\0'; strcat(p, s1); strcat(p, s2); strcat(p, s3); strcat(p, s4); return p; } /* Removes trailing forward slashes in a string. */ static void remove_trailing_slashes(char *s) { long len = strlen(s); for (long i = len - 1; i >= 1; i--) { if (s[i] == '/') s[i] = '\0'; else break; } } /* Changes forward slashes to underscores in a string. */ static void s_slashes_underscores_g(char *s) { while (*s) { if (*s == '/') *s = '_'; s++; } } /* * Opens two POSIX message queue: one for sending messages from the unmount * process to the daemon process, and one to go the other way. The names of the * message queues, which must be system-wide unique, are be based on the mount * point. (There of course is still a possibility of a collision if one were to * unmount two identically named directories simultaneously...) * * @daemon specifies whether the calling process is the filesystem daemon or the * unmount process. */ static int open_message_queues(bool daemon) { static const char *slash = "/"; static const char *prefix = "wimlib-"; static const char *u2d_suffix = "unmount-to-daemon-mq"; static const char *d2u_suffix = "daemon-to-unmount-mq"; const char *mount_dir_basename = path_basename(mount_dir); int flags; int ret; unmount_to_daemon_mq_name = strcat_dup(slash, mount_dir_basename, prefix, u2d_suffix); if (!unmount_to_daemon_mq_name) { ERROR("Out of memory"); return WIMLIB_ERR_NOMEM; } daemon_to_unmount_mq_name = strcat_dup(slash, mount_dir_basename, prefix, d2u_suffix); if (!daemon_to_unmount_mq_name) { ERROR("Out of memory"); ret = WIMLIB_ERR_NOMEM; goto err1; } remove_trailing_slashes(unmount_to_daemon_mq_name); remove_trailing_slashes(daemon_to_unmount_mq_name); s_slashes_underscores_g(unmount_to_daemon_mq_name + 1); s_slashes_underscores_g(daemon_to_unmount_mq_name + 1); if (daemon) flags = O_RDONLY | O_CREAT; else flags = O_WRONLY | O_CREAT; unmount_to_daemon_mq = mq_open(unmount_to_daemon_mq_name, flags, 0700, NULL); if (unmount_to_daemon_mq == -1) { ERROR_WITH_ERRNO("mq_open()"); ret = WIMLIB_ERR_MQUEUE; goto err2; } if (daemon) flags = O_WRONLY | O_CREAT; else flags = O_RDONLY | O_CREAT; daemon_to_unmount_mq = mq_open(daemon_to_unmount_mq_name, flags, 0700, NULL); if (daemon_to_unmount_mq == -1) { ERROR_WITH_ERRNO("mq_open()"); ret = WIMLIB_ERR_MQUEUE; goto err3; } return 0; err3: mq_close(unmount_to_daemon_mq); mq_unlink(unmount_to_daemon_mq_name); err2: FREE(daemon_to_unmount_mq_name); err1: FREE(unmount_to_daemon_mq_name); return ret; } static int mq_get_msgsize(mqd_t mq) { static const char *msgsize_max_file = "/proc/sys/fs/mqueue/msgsize_max"; FILE *fp; struct mq_attr attr; int msgsize; if (mq_getattr(unmount_to_daemon_mq, &attr) == 0) { msgsize = attr.mq_msgsize; } else { ERROR_WITH_ERRNO("mq_getattr()"); ERROR("Attempting to read %s", msgsize_max_file); fp = fopen(msgsize_max_file, "rb"); if (fp) { if (fscanf(fp, "%d", &msgsize) != 1) { ERROR("Assuming message size of 8192"); msgsize = 8192; } fclose(fp); } else { ERROR_WITH_ERRNO("Failed to open the file `%s'", msgsize_max_file); ERROR("Assuming message size of 8192"); msgsize = 8192; } } return msgsize; } /* Closes the message queues, which are allocated in static variables */ static void close_message_queues() { mq_close(unmount_to_daemon_mq); mq_close(daemon_to_unmount_mq); mq_unlink(unmount_to_daemon_mq_name); mq_unlink(daemon_to_unmount_mq_name); } static int wimfs_access(const char *path, int mask) { /* XXX Permissions not implemented */ return 0; } /* Closes the staging file descriptor associated with the lookup table entry, if * it is opened. */ static int close_staging_file(struct lookup_table_entry *lte, void *ignore) { if (lte->staging_file_name && lte->staging_num_times_opened) { if (close(lte->staging_fd) != 0) { ERROR_WITH_ERRNO("Failed close file `%s'", lte->staging_file_name); return WIMLIB_ERR_WRITE; } } return 0; } /* Calculates the SHA1 sum for @dentry if its file resource is in a staging * file. Updates the SHA1 sum in the dentry and the lookup table entry. If * there is already a lookup table entry with the same checksum, increment its * reference count and destroy the lookup entry with the updated checksum. */ static int calculate_sha1sum_for_staging_file(struct dentry *dentry, void *lookup_table) { struct lookup_table *table; struct lookup_table_entry *lte; struct lookup_table_entry *existing; int ret; table = lookup_table; lte = lookup_resource(table, dentry->hash); if (lte && lte->staging_file_name) { DEBUG("Calculating SHA1 hash for file `%s'", dentry->file_name_utf8); ret = sha1sum(lte->staging_file_name, dentry->hash); if (ret != 0) return ret; lookup_table_unlink(table, lte); memcpy(lte->hash, dentry->hash, WIM_HASH_SIZE); existing = lookup_resource(table, dentry->hash); if (existing) { DEBUG("Merging duplicate lookup table entries for file " "`%s'", dentry->file_name_utf8); free_lookup_table_entry(lte); existing->refcnt++; } else { lookup_table_insert(table, lte); } } return 0; } /* Overwrites the WIM file, with changes saved. */ static int rebuild_wim(WIMStruct *w, bool check_integrity) { int ret; struct dentry *root; root = wim_root_dentry(w); DEBUG("Closing all staging file descriptors."); /* Close all the staging file descriptors. */ ret = for_lookup_table_entry(w->lookup_table, close_staging_file, NULL); if (ret != 0) { ERROR("Failed to close all staging files"); return ret; } DEBUG("Calculating SHA1 checksums for all new staging files."); /* Calculate SHA1 checksums for all staging files, and merge unnecessary * lookup table entries. */ ret = for_dentry_in_tree(root, calculate_sha1sum_for_staging_file, w->lookup_table); if (ret != 0) { ERROR("Failed to calculate new SHA1 checksums"); return ret; } xml_update_image_info(w, w->current_image); ret = wimlib_overwrite(w, check_integrity); if (ret != 0) { ERROR("Failed to commit changes"); return ret; } return ret; } /* Called when the filesystem is unmounted. */ static void wimfs_destroy(void *p) { /* For read-write mounts, the `imagex unmount' command, which is * running in a separate process and is executing the * wimlib_unmount() function, will send this process a byte * through a message queue that indicates whether the --commit * option was specified or not. */ int msgsize; struct timespec timeout; struct timeval now; ssize_t bytes_received; int ret; char commit; char check_integrity; char status; ret = open_message_queues(true); if (ret != 0) exit(1); msgsize = mq_get_msgsize(unmount_to_daemon_mq); char msg[msgsize]; msg[0] = 0; msg[1] = 0; /* Wait at most 3 seconds before giving up and discarding changes. */ gettimeofday(&now, NULL); timeout.tv_sec = now.tv_sec + 3; timeout.tv_nsec = now.tv_usec * 1000; DEBUG("Waiting for message telling us whether to commit or not, and " "whether to include integrity checks."); bytes_received = mq_timedreceive(unmount_to_daemon_mq, msg, msgsize, NULL, &timeout); commit = msg[0]; check_integrity = msg[1]; if (bytes_received == -1) { if (errno == ETIMEDOUT) { ERROR("Timed out."); } else { ERROR_WITH_ERRNO("mq_timedreceive()"); } ERROR("Not committing."); } else { DEBUG("Received message: [%d %d]", msg[0], msg[1]); } status = 0; if (mount_flags & WIMLIB_MOUNT_FLAG_READWRITE) { if (commit) { status = chdir(working_directory); if (status != 0) { ERROR_WITH_ERRNO("chdir()"); status = WIMLIB_ERR_NOTDIR; goto done; } status = rebuild_wim(w, (check_integrity != 0)); } ret = delete_staging_dir(); if (ret != 0) { ERROR_WITH_ERRNO("Failed to delete the staging " "directory"); if (status == 0) status = ret; } } done: ret = mq_send(daemon_to_unmount_mq, &status, 1, 1); if (ret == -1) ERROR_WITH_ERRNO("Failed to send status to unmount process"); close_message_queues(); } /* * Fills in a `struct stat' that corresponds to a file or directory in the WIM. */ static int wimfs_getattr(const char *path, struct stat *stbuf) { struct dentry *dentry = get_dentry(w, path); if (!dentry) return -ENOENT; dentry_to_stbuf(dentry, stbuf, w->lookup_table); return 0; } /* * Create a directory in the WIM. * @mode is currently ignored. */ static int wimfs_mkdir(const char *path, mode_t mode) { struct dentry *parent; struct dentry *newdir; const char *basename; parent = get_parent_dentry(w, path); if (!parent) return -ENOENT; if (!dentry_is_directory(parent)) return -ENOTDIR; basename = path_basename(path); if (get_dentry_child_with_name(parent, basename)) return -EEXIST; newdir = new_dentry(basename); newdir->attributes |= FILE_ATTRIBUTE_DIRECTORY; link_dentry(newdir, parent); return 0; } /* Creates a new staging file and returns its file descriptor opened for * writing. * * @name_ret: A location into which the a pointer to the newly allocated name of * the staging file is stored. * @return: The file descriptor for the new file. Returns -1 and sets errno on * error, for any reason possible from the creat() function. */ static int create_staging_file(char **name_ret) { size_t name_len; char *name; struct stat stbuf; int fd; int errno_save; name_len = staging_dir_name_len + 1 + WIM_HASH_SIZE; name = MALLOC(name_len + 1); if (!name) { errno = ENOMEM; return -1; } memcpy(name, staging_dir_name, staging_dir_name_len); name[staging_dir_name_len] = '/'; randomize_char_array_with_alnum(name + staging_dir_name_len + 1, WIM_HASH_SIZE); name[name_len] = '\0'; /* Just in case, verify that the randomly generated name doesn't name an * existing file, and try again if so */ if (stat(name, &stbuf) == 0) { /* stat succeeded-- the file must exist. Try another name. */ FREE(name); return create_staging_file(name_ret); } else { if (errno != ENOENT) /* other error! */ return -1; /* doesn't exist--- ok */ } DEBUG("Creating staging file '%s'", name); fd = creat(name, 0600); if (fd == -1) { errno_save = errno; FREE(name); errno = errno_save; } else { *name_ret = name; } return fd; } /* Creates a regular file. This is done in the staging directory. */ static int wimfs_mknod(const char *path, mode_t mode, dev_t rdev) { struct dentry *parent, *dentry; const char *basename; struct lookup_table_entry *lte; char *tmpfile_name; int fd; int err; /* Make sure that the parent of @path exists and is a directory, and * that the dentry named by @path does not already exist. */ parent = get_parent_dentry(w, path); if (!parent) return -ENOENT; if (!dentry_is_directory(parent)) return -ENOTDIR; basename = path_basename(path); if (get_dentry_child_with_name(parent, path)) return -EEXIST; dentry = new_dentry(basename); /* XXX fill in a temporary random hash value- really should check for * duplicates */ randomize_byte_array(dentry->hash, WIM_HASH_SIZE); /* Create a lookup table entry having the same hash value */ lte = new_lookup_table_entry(); memcpy(lte->hash, dentry->hash, WIM_HASH_SIZE); fd = create_staging_file(&tmpfile_name); if (fd == -1) goto mknod_error; if (close(fd) != 0) goto mknod_error; lte->staging_file_name = tmpfile_name; /* Insert the lookup table entry, and link the new dentry with its * parent. */ lookup_table_insert(w->lookup_table, lte); link_dentry(dentry, parent); return 0; mknod_error: err = errno; free_lookup_table_entry(lte); return -err; } /* Open a file. */ static int wimfs_open(const char *path, struct fuse_file_info *fi) { struct dentry *dentry; struct lookup_table_entry *lte; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; if (dentry_is_directory(dentry)) return -EISDIR; lte = wim_lookup_resource(w, dentry); if (lte) { /* If this file is in the staging directory and the file is not * currently open, open it. */ if (lte->staging_file_name && lte->staging_num_times_opened == 0) { lte->staging_fd = open(lte->staging_file_name, O_RDWR); if (lte->staging_fd == -1) return -errno; lte->staging_offset = 0; } } else { /* no lookup table entry, so the file must be empty. Create a * lookup table entry for the file, unless it's a read-only * filesystem. */ char *tmpfile_name; int fd; if (!staging_dir_name) /* Read-only filesystem */ return 0; lte = new_lookup_table_entry(); if (!lte) return -ENOMEM; fd = create_staging_file(&tmpfile_name); if (fd == -1) { int err = errno; free(lte); return -err; } lte->resource_entry.original_size = 0; randomize_byte_array(lte->hash, WIM_HASH_SIZE); memcpy(dentry->hash, lte->hash, WIM_HASH_SIZE); lte->staging_file_name = tmpfile_name; lte->staging_fd = fd; lte->staging_offset = 0; lookup_table_insert(w->lookup_table, lte); } lte->staging_num_times_opened++; return 0; } /* Opens a directory. */ static int wimfs_opendir(const char *path, struct fuse_file_info *fi) { struct dentry *dentry; dentry = get_dentry(w, path); if (!dentry || !dentry_is_directory(dentry)) return -ENOTDIR; return 0; } /* * Read data from a file in the WIM or in the staging directory. */ static int wimfs_read(const char *path, char *buf, size_t size, off_t offset, struct fuse_file_info *fi) { struct dentry *dentry; struct lookup_table_entry *lte; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; if (!dentry_is_regular_file(dentry)) return -EISDIR; lte = wim_lookup_resource(w, dentry); if (!lte) return 0; if (lte->staging_file_name) { /* Read from staging */ int fd; off_t cur_offset; ssize_t ret; if (lte->staging_num_times_opened == 0) return -EBADF; fd = lte->staging_fd; cur_offset = lte->staging_offset; if (cur_offset != offset) if (lseek(fd, offset, SEEK_SET) == -1) return -errno; lte->staging_offset = offset; ret = read(fd, buf, size); if (ret == -1) return -errno; lte->staging_offset = offset + ret; return ret; } else { /* Read from WIM */ struct resource_entry *res_entry; int ctype; res_entry = <e->resource_entry; ctype = wim_resource_compression_type(w, res_entry); if (offset > res_entry->original_size) return -EOVERFLOW; size = min(size, res_entry->original_size - offset); if (read_resource(w->fp, res_entry->size, res_entry->original_size, res_entry->offset, ctype, size, offset, buf) != 0) return -EIO; return size; } } /* Fills in the entries of the directory specified by @path using the * FUSE-provided function @filler. */ static int wimfs_readdir(const char *path, void *buf, fuse_fill_dir_t filler, off_t offset, struct fuse_file_info *fi) { struct dentry *parent; struct dentry *child; struct stat st; parent = get_dentry(w, path); if (!parent) return -EEXIST; if (!dentry_is_directory(parent)) return -ENOTDIR; filler(buf, ".", NULL, 0); filler(buf, "..", NULL, 0); child = parent->children; if (!child) return 0; do { memset(&st, 0, sizeof(st)); if (filler(buf, child->file_name_utf8, &st, 0)) return 0; child = child->next; } while (child != parent->children); return 0; } /* Close a file. */ static int wimfs_release(const char *path, struct fuse_file_info *fi) { struct dentry *dentry; struct lookup_table_entry *lte; int ret; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; lte = wim_lookup_resource(w, dentry); if (!lte) return 0; if (lte->staging_num_times_opened == 0) return -EBADF; if (--lte->staging_num_times_opened == 0 && lte->staging_file_name) { ret = close(lte->staging_fd); if (ret != 0) return -errno; } return 0; } /* Renames a file or directory. See rename (3) */ static int wimfs_rename(const char *from, const char *to) { struct dentry *src; struct dentry *dst; struct dentry *parent_of_dst; src = get_dentry(w, from); if (!src) return -ENOENT; dst = get_dentry(w, to); if (dst) { if (!dentry_is_directory(src)) { /* Cannot rename non-directory to directory. */ if (dentry_is_directory(dst)) return -EISDIR; } else { /* Cannot rename directory to a non-directory or a non-empty * directory */ if (!dentry_is_directory(dst)) return -ENOTDIR; if (dst->children != NULL) return -ENOTEMPTY; } parent_of_dst = dst->parent; unlink_dentry(dst); lookup_table_decrement_refcnt(w->lookup_table, dst->hash); free_dentry(dst); } else { parent_of_dst = get_parent_dentry(w, to); if (!parent_of_dst) return -ENOENT; } unlink_dentry(src); change_dentry_name(src, path_basename(to)); link_dentry(src, parent_of_dst); /*calculate_dentry_full_path(src);*/ return 0; } /* Remove a directory */ static int wimfs_rmdir(const char *path) { struct dentry *dentry; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; if (!dentry_is_empty_directory(dentry)) return -EEXIST; unlink_dentry(dentry); free_dentry(dentry); return 0; } /* Extracts the resource corresponding to @dentry and its lookup table entry * @lte to a file in the staging directory. The lookup table entry for @dentry * is updated to point to the new file. If @lte has multiple dentries * referencing it, a new lookup table entry is created and the hash of @dentry * is changed to point to the new lookup table entry. * * Only @size bytes are extracted, to support truncating the file. * * Returns the negative error code on failure. */ static int extract_resource_to_staging_dir(struct dentry *dentry, struct lookup_table_entry *lte, u64 size) { int fd; bool ret; char *staging_file_name; struct lookup_table_entry *new_lte; /* File in WIM. Copy it to the staging directory. */ fd = create_staging_file(&staging_file_name); if (fd == -1) return -errno; ret = extract_resource_to_fd(w, <e->resource_entry, fd, size); if (ret != 0) { if (errno != 0) ret = -errno; else ret = -EIO; unlink(staging_file_name); FREE(staging_file_name); return ret; } if (lte->refcnt != 1) { /* Need to make a new lookup table entry if we are * changing only one copy of a hardlinked entry */ lte->refcnt--; new_lte = new_lookup_table_entry(); if (!new_lte) return -ENOMEM; randomize_byte_array(dentry->hash, WIM_HASH_SIZE); memcpy(new_lte->hash, dentry->hash, WIM_HASH_SIZE); new_lte->resource_entry.flags = 0; new_lte->staging_num_times_opened = lte->staging_num_times_opened; lookup_table_insert(w->lookup_table, new_lte); lte = new_lte; } lte->resource_entry.original_size = size; lte->staging_file_name = staging_file_name; if (lte->staging_num_times_opened == 0) close(fd); else lte->staging_fd = fd; return 0; } /* Reduce the size of a file */ static int wimfs_truncate(const char *path, off_t size) { struct dentry *dentry; struct lookup_table_entry *lte; int ret; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; lte = wim_lookup_resource(w, dentry); if (!lte) /* Already a zero-length file */ return 0; if (lte->staging_file_name) { /* File on disk. Call POSIX API */ if (lte->staging_num_times_opened != 0) ret = ftruncate(lte->staging_fd, size); else ret = truncate(lte->staging_file_name, size); if (ret != 0) return -errno; dentry_update_all_timestamps(dentry); lte->resource_entry.original_size = size; return 0; } else { /* File in WIM. Extract it to the staging directory, but only * the first @size bytes of it. */ return extract_resource_to_staging_dir(dentry, lte, size); } } /* Remove a regular file */ static int wimfs_unlink(const char *path) { struct dentry *dentry; struct lookup_table_entry *lte; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; if (!dentry_is_regular_file(dentry)) return -EEXIST; lte = wim_lookup_resource(w, dentry); if (lte) { if (lte->staging_file_name) if (unlink(lte->staging_file_name) != 0) return -errno; lookup_table_decrement_refcnt(w->lookup_table, dentry->hash); } unlink_dentry(dentry); free_dentry(dentry); return 0; } static int wimfs_utimens(const char *path, const struct timespec tv[2]) { struct dentry *dentry = get_dentry(w, path); if (!dentry) return -ENOENT; time_t last_access_t = (tv[0].tv_nsec == UTIME_NOW) ? time(NULL) : tv[0].tv_sec; dentry->last_access_time = unix_timestamp_to_ms(last_access_t); time_t last_mod_t = (tv[1].tv_nsec == UTIME_NOW) ? time(NULL) : tv[1].tv_sec; dentry->last_write_time = unix_timestamp_to_ms(last_mod_t); return 0; } /* Writes to a file in the WIM filesystem. */ static int wimfs_write(const char *path, const char *buf, size_t size, off_t offset, struct fuse_file_info *fi) { struct dentry *dentry; struct lookup_table_entry *lte; ssize_t ret; dentry = get_dentry(w, path); if (!dentry) return -EEXIST; lte = wim_lookup_resource(w, dentry); if (!lte) /* this should not happen */ return -EEXIST; if (lte->staging_num_times_opened == 0) return -EBADF; if (lte->staging_file_name) { /* File in staging directory. We can write to it directly. */ /* Seek to correct position in file if needed. */ if (lte->staging_offset != offset) { if (lseek(lte->staging_fd, offset, SEEK_SET) == -1) return -errno; lte->staging_offset = offset; } /* Write the data. */ ret = write(lte->staging_fd, buf, size); if (ret == -1) return -errno; /* Adjust the stored offset of staging_fd. */ lte->staging_offset = offset + ret; /* Increase file size if needed. */ if (lte->resource_entry.original_size < lte->staging_offset) lte->resource_entry.original_size = lte->staging_offset; /* The file has been modified, so all its timestamps must be * updated. */ dentry_update_all_timestamps(dentry); return ret; } else { /* File in the WIM. We must extract it to the staging directory * before it can be written to. */ ret = extract_resource_to_staging_dir(dentry, lte, lte->resource_entry.original_size); if (ret != 0) return ret; else return wimfs_write(path, buf, size, offset, fi); } } static struct fuse_operations wimfs_oper = { .access = wimfs_access, .destroy = wimfs_destroy, .getattr = wimfs_getattr, .mkdir = wimfs_mkdir, .mknod = wimfs_mknod, .open = wimfs_open, .opendir = wimfs_opendir, .read = wimfs_read, .readdir = wimfs_readdir, .release = wimfs_release, .rename = wimfs_rename, .rmdir = wimfs_rmdir, .truncate = wimfs_truncate, .unlink = wimfs_unlink, .utimens = wimfs_utimens, .write = wimfs_write, }; /* Mounts a WIM file. */ WIMLIBAPI int wimlib_mount(WIMStruct *wim, int image, const char *dir, int flags) { int argc = 0; char *argv[6]; int ret; char *p; DEBUG("Mount: wim = %p, image = %d, dir = %s, flags = %d, ", wim, image, dir, flags); if (!dir) return WIMLIB_ERR_INVALID_PARAM; ret = wimlib_select_image(wim, image); if (ret != 0) return ret; if (flags & WIMLIB_MOUNT_FLAG_READWRITE) wim_get_current_image_metadata(wim)->modified = true; if (!(flags & (WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_NONE | WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR | WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_WINDOWS))) flags |= WIMLIB_MOUNT_FLAG_STREAM_INTERFACE_XATTR; mount_dir = dir; working_directory = getcwd(NULL, 0); if (!working_directory) { ERROR_WITH_ERRNO("Could not determine current directory"); return WIMLIB_ERR_NOTDIR; } p = STRDUP(dir); if (!p) return WIMLIB_ERR_NOMEM; argv[argc++] = "mount"; argv[argc++] = p; argv[argc++] = "-s"; /* disable multi-threaded operation */ if (flags & WIMLIB_MOUNT_FLAG_DEBUG) { argv[argc++] = "-d"; } if (!(flags & WIMLIB_MOUNT_FLAG_READWRITE)) { argv[argc++] = "-o"; argv[argc++] = "ro"; } else { make_staging_dir(); if (!staging_dir_name) { FREE(p); return WIMLIB_ERR_MKDIR; } } #ifdef ENABLE_DEBUG { int i; DEBUG("FUSE command line (argc = %d): ", argc); for (i = 0; i < argc; i++) { fputs(argv[i], stdout); putchar(' '); } putchar('\n'); fflush(stdout); } #endif /* Set static variables. */ w = wim; mount_flags = flags; ret = fuse_main(argc, argv, &wimfs_oper, NULL); return (ret == 0) ? 0 : WIMLIB_ERR_FUSE; } /* * Unmounts the WIM file that was previously mounted on @dir by using * wimlib_mount(). */ WIMLIBAPI int wimlib_unmount(const char *dir, int flags) { pid_t pid; int status; int ret; char msg[2]; struct timeval now; struct timespec timeout; int msgsize; int errno_save; /* Execute `fusermount -u', which is installed setuid root, to unmount * the WIM. * * FUSE does not yet implement synchronous unmounts. This means that * fusermount -u will return before the filesystem daemon returns from * wimfs_destroy(). This is partly what we want, because we need to * send a message from this process to the filesystem daemon telling * whether --commit was specified or not. However, after that, the * unmount process must wait for the filesystem daemon to finish writing * the WIM file. */ mount_dir = dir; pid = fork(); if (pid == -1) { ERROR_WITH_ERRNO("Failed to fork()"); return WIMLIB_ERR_FORK; } if (pid == 0) { execlp("fusermount", "fusermount", "-u", dir, NULL); ERROR_WITH_ERRNO("Failed to execute `fusermount'"); return WIMLIB_ERR_FUSERMOUNT; } ret = waitpid(pid, &status, 0); if (ret == -1) { ERROR_WITH_ERRNO("Failed to wait for fusermount process to " "terminate"); return WIMLIB_ERR_FUSERMOUNT; } if (status != 0) { ERROR("fusermount exited with status %d", status); return WIMLIB_ERR_FUSERMOUNT; } /* Open message queues between the unmount process and the * filesystem daemon. */ ret = open_message_queues(false); if (ret != 0) return ret; /* Send a message to the filesystem saying whether to commit or * not. */ msg[0] = (flags & WIMLIB_UNMOUNT_FLAG_COMMIT) ? 1 : 0; msg[1] = (flags & WIMLIB_UNMOUNT_FLAG_CHECK_INTEGRITY) ? 1 : 0; DEBUG("Sending message: %s, %s", (msg[0] == 0) ? "don't commit" : "commit", (msg[1] == 0) ? "don't check" : "check"); ret = mq_send(unmount_to_daemon_mq, msg, 2, 1); if (ret == -1) { ERROR("Failed to notify filesystem daemon whether we want to " "commit changes or not"); close_message_queues(); return WIMLIB_ERR_MQUEUE; } /* Wait for a message from the filesytem daemon indicating whether the * filesystem was unmounted successfully (0) or an error occurred (1). * This may take a long time if a big WIM file needs to be rewritten. */ /* Wait at most 600??? seconds before giving up and returning false. * Either it's a really big WIM file, or (more likely) the * filesystem daemon has crashed or failed for some reason. * * XXX come up with some method to determine if the filesystem * daemon has really crashed or not. */ gettimeofday(&now, NULL); timeout.tv_sec = now.tv_sec + 600; timeout.tv_nsec = now.tv_usec * 1000; msgsize = mq_get_msgsize(daemon_to_unmount_mq); char mailbox[msgsize]; mailbox[0] = 0; DEBUG("Waiting for message telling us whether the unmount was " "successful or not."); ret = mq_timedreceive(daemon_to_unmount_mq, mailbox, msgsize, NULL, &timeout); errno_save = errno; close_message_queues(); if (ret == -1) { if (errno_save == ETIMEDOUT) { ERROR("Timed out- probably the filesystem daemon " "crashed and the WIM was not written " "successfully."); return WIMLIB_ERR_TIMEOUT; } else { ERROR("mq_receive(): %s", strerror(errno_save)); return WIMLIB_ERR_MQUEUE; } } DEBUG("Received message: %s", (mailbox[0] == 0) ? "Unmount OK" : "Unmount Failed"); if (mailbox[0] != 0) ERROR("Unmount failed"); return mailbox[0]; } #else /* WITH_FUSE */ static inline int mount_unsupported_error() { ERROR("WIMLIB was compiled with --without-fuse, which disables support " "for mounting WIMs."); return WIMLIB_ERR_UNSUPPORTED; } WIMLIBAPI int wimlib_unmount(const char *dir, int flags) { return mount_unsupported_error(); } WIMLIBAPI int wimlib_mount(WIMStruct *wim_p, int image, const char *dir, int flags) { return mount_unsupported_error(); } #endif /* WITH_FUSE */