Currently, fsck.erofs traverses the filesystem tree and verifies inodes synchronously on the main thread. While decompression compute is offloaded, the main thread remains a bottleneck during the I/O-heavy directory walk.
This patch parallelizes the directory traversal and inode extraction processes. To achieve this safely, the globally shared fsckcfg.extract_path and fsckcfg.dirstack states are decoupled and localized into individual struct erofsfsck_inode_task payloads, which are deep-copied and handed off to the worker pool. Global statistics and hardlink tables are secured using native erofs_mutex_t primitives. To prevent thread pool exhaustion deadlocks—where workers processing a deep directory tree occupy all available execution slots and block on erofs_cond_wait, starving their own spawned decompression tasks—this patch introduces a dedicated erofs_traverse_wq. By isolating the producers (traversal and verification) from the consumers (pcluster decompression), the pipeline avoids gridlock. Signed-off-by: Nithurshen <[email protected]> --- fsck/main.c | 300 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 211 insertions(+), 89 deletions(-) diff --git a/fsck/main.c b/fsck/main.c index 7a1e573..f047b8d 100644 --- a/fsck/main.c +++ b/fsck/main.c @@ -19,14 +19,45 @@ #include "../lib/liberofs_compress.h" extern struct erofs_workqueue erofs_wq; +struct erofs_workqueue erofs_traverse_wq; -static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid); +static EROFS_DEFINE_MUTEX(fsck_global_lock); +static EROFS_DEFINE_MUTEX(fsck_hardlink_lock); + +static int fsck_pending_tasks = 0; +static EROFS_DEFINE_MUTEX(fsck_task_lock); +static erofs_cond_t fsck_task_cond; + +static void fsck_inc_task(void) { + erofs_mutex_lock(&fsck_task_lock); + fsck_pending_tasks++; + erofs_mutex_unlock(&fsck_task_lock); +} + +static void fsck_dec_task(void) { + erofs_mutex_lock(&fsck_task_lock); + fsck_pending_tasks--; + if (fsck_pending_tasks == 0) + erofs_cond_signal(&fsck_task_cond); + erofs_mutex_unlock(&fsck_task_lock); +} + +static void fsck_wait_tasks(void) { + erofs_mutex_lock(&fsck_task_lock); + while (fsck_pending_tasks > 0) + erofs_cond_wait(&fsck_task_cond, &fsck_task_lock); + erofs_mutex_unlock(&fsck_task_lock); +} struct erofsfsck_dirstack { erofs_nid_t dirs[PATH_MAX]; int top; }; +static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid, + char *current_path, size_t pos, + struct erofsfsck_dirstack *dirstack); + struct erofsfsck_cfg { struct erofsfsck_dirstack dirstack; u64 physical_blocks; @@ -437,7 +468,7 @@ out: return ret; } -static int erofsfsck_dump_xattrs(struct erofs_inode *inode) +static int erofsfsck_dump_xattrs(struct erofs_inode *inode, const char *current_path) { static bool ignore_xattrs = false; char *keylst, *key; @@ -484,7 +515,7 @@ static int erofsfsck_dump_xattrs(struct erofs_inode *inode) break; } if (fsckcfg.extract_path) - ret = erofs_sys_lsetxattr(fsckcfg.extract_path, key, + ret = erofs_sys_lsetxattr(current_path, key, value, size); else ret = 0; @@ -599,9 +630,11 @@ out: erofs_mutex_unlock(&ctx.lock); if (fsckcfg.print_comp_ratio) { + erofs_mutex_lock(&fsck_global_lock); if (!erofs_is_packed_inode(inode)) fsckcfg.logical_blocks += BLK_ROUND_UP(inode->sbi, inode->i_size); fsckcfg.physical_blocks += BLK_ROUND_UP(inode->sbi, pchunk_len); + erofs_mutex_unlock(&fsck_global_lock); } if (outfd >= 0 && ret >= 0) @@ -612,11 +645,11 @@ out: return ret < 0 ? ret : 0; } -static inline int erofs_extract_dir(struct erofs_inode *inode) +static inline int erofs_extract_dir(struct erofs_inode *inode, const char *current_path) { int ret; - erofs_dbg("create directory %s", fsckcfg.extract_path); + erofs_dbg("create directory %s", current_path); /* verify data chunk layout */ ret = erofs_verify_inode_data(inode, -1); @@ -629,19 +662,19 @@ static inline int erofs_extract_dir(struct erofs_inode *inode) * write/execute permission. These are fixed up later in * erofsfsck_set_attributes(). */ - if (mkdir(fsckcfg.extract_path, 0700) < 0) { + if (mkdir(current_path, 0700) < 0) { struct stat st; if (errno != EEXIST) { erofs_err("failed to create directory: %s (%s)", - fsckcfg.extract_path, strerror(errno)); + current_path, strerror(errno)); return -errno; } - if (lstat(fsckcfg.extract_path, &st) || + if (lstat(current_path, &st) || !S_ISDIR(st.st_mode)) { erofs_err("path is not a directory: %s", - fsckcfg.extract_path); + current_path); return -ENOTDIR; } @@ -649,9 +682,9 @@ static inline int erofs_extract_dir(struct erofs_inode *inode) * Try to change permissions of existing directory so * that we can write to it */ - if (chmod(fsckcfg.extract_path, 0700) < 0) { + if (chmod(current_path, 0700) < 0) { erofs_err("failed to set permissions: %s (%s)", - fsckcfg.extract_path, strerror(errno)); + current_path, strerror(errno)); return -errno; } } @@ -663,11 +696,17 @@ static char *erofsfsck_hardlink_find(erofs_nid_t nid) struct list_head *head = &erofsfsck_link_hashtable[nid % NR_HARDLINK_HASHTABLE]; struct erofsfsck_hardlink_entry *entry; + char *path = NULL; - list_for_each_entry(entry, head, list) - if (entry->nid == nid) + erofs_mutex_lock(&fsck_hardlink_lock); + list_for_each_entry(entry, head, list){ + if (entry->nid == nid){ return entry->path; - return NULL; + break; + } + } + erofs_mutex_unlock(&fsck_hardlink_lock); + return path; } static int erofsfsck_hardlink_insert(erofs_nid_t nid, const char *path) @@ -685,8 +724,10 @@ static int erofsfsck_hardlink_insert(erofs_nid_t nid, const char *path) return -ENOMEM; } + erofs_mutex_lock(&fsck_hardlink_lock); list_add_tail(&entry->list, &erofsfsck_link_hashtable[nid % NR_HARDLINK_HASHTABLE]); + erofs_mutex_unlock(&fsck_hardlink_lock); return 0; } @@ -715,37 +756,37 @@ static void erofsfsck_hardlink_exit(void) } } -static inline int erofs_extract_file(struct erofs_inode *inode) +static inline int erofs_extract_file(struct erofs_inode *inode, const char *current_path) { bool tryagain = true; int ret, fd; - erofs_dbg("extract file to path: %s", fsckcfg.extract_path); + erofs_dbg("extract file to path: %s", current_path); again: - fd = open(fsckcfg.extract_path, + fd = open(current_path, O_WRONLY | O_CREAT | O_NOFOLLOW | (fsckcfg.overwrite ? O_TRUNC : O_EXCL), 0700); if (fd < 0) { if (fsckcfg.overwrite && tryagain) { if (errno == EISDIR) { erofs_warn("try to forcely remove directory %s", - fsckcfg.extract_path); - if (rmdir(fsckcfg.extract_path) < 0) { + current_path); + if (rmdir(current_path) < 0) { erofs_err("failed to remove: %s (%s)", - fsckcfg.extract_path, strerror(errno)); + current_path, strerror(errno)); return -EISDIR; } } else if (errno == EACCES && - chmod(fsckcfg.extract_path, 0700) < 0) { + chmod(current_path, 0700) < 0) { erofs_err("failed to set permissions: %s (%s)", - fsckcfg.extract_path, strerror(errno)); + current_path, strerror(errno)); return -errno; } tryagain = false; goto again; } - erofs_err("failed to open: %s (%s)", fsckcfg.extract_path, + erofs_err("failed to open: %s (%s)", current_path, strerror(errno)); return -errno; } @@ -756,14 +797,14 @@ again: return ret; } -static inline int erofs_extract_symlink(struct erofs_inode *inode) +static inline int erofs_extract_symlink(struct erofs_inode *inode, const char *current_path) { struct erofs_vfile vf; bool tryagain = true; int ret; char *buf = NULL; - erofs_dbg("extract symlink to path: %s", fsckcfg.extract_path); + erofs_dbg("extract symlink to path: %s", current_path); /* verify data chunk layout */ ret = erofs_verify_inode_data(inode, -1); @@ -789,13 +830,13 @@ static inline int erofs_extract_symlink(struct erofs_inode *inode) buf[inode->i_size] = '\0'; again: - if (symlink(buf, fsckcfg.extract_path) < 0) { + if (symlink(buf, current_path) < 0) { if (errno == EEXIST && fsckcfg.overwrite && tryagain) { erofs_warn("try to forcely remove file %s", - fsckcfg.extract_path); - if (unlink(fsckcfg.extract_path) < 0) { + current_path); + if (unlink(current_path) < 0) { erofs_err("failed to remove: %s", - fsckcfg.extract_path); + current_path); ret = -errno; goto out; } @@ -803,7 +844,7 @@ again: goto again; } erofs_err("failed to create symlink: %s", - fsckcfg.extract_path); + current_path); ret = -errno; } out: @@ -812,12 +853,12 @@ out: return ret; } -static int erofs_extract_special(struct erofs_inode *inode) +static int erofs_extract_special(struct erofs_inode *inode, const char *current_path) { bool tryagain = true; int ret; - erofs_dbg("extract special to path: %s", fsckcfg.extract_path); + erofs_dbg("extract special to path: %s", current_path); /* verify data chunk layout */ ret = erofs_verify_inode_data(inode, -1); @@ -825,13 +866,13 @@ static int erofs_extract_special(struct erofs_inode *inode) return ret; again: - if (mknod(fsckcfg.extract_path, inode->i_mode, inode->u.i_rdev) < 0) { + if (mknod(current_path, inode->i_mode, inode->u.i_rdev) < 0) { if (errno == EEXIST && fsckcfg.overwrite && tryagain) { erofs_warn("try to forcely remove file %s", - fsckcfg.extract_path); - if (unlink(fsckcfg.extract_path) < 0) { + current_path); + if (unlink(current_path) < 0) { erofs_err("failed to remove: %s", - fsckcfg.extract_path); + current_path); return -errno; } tryagain = false; @@ -839,11 +880,11 @@ again: } if (errno == EEXIST || fsckcfg.superuser) { erofs_err("failed to create special file: %s", - fsckcfg.extract_path); + current_path); ret = -errno; } else { erofs_warn("failed to create special file: %s, skipped", - fsckcfg.extract_path); + current_path); ret = -ECANCELED; } } @@ -866,47 +907,82 @@ static int erofsfsck_get_parent_cb(struct erofs_dir_context *ctx) return 0; } +struct erofsfsck_inode_task { + struct erofs_work work; + erofs_nid_t pnid; + erofs_nid_t nid; + char *path; + size_t path_pos; + struct erofsfsck_dirstack dirstack; +}; + +static void erofsfsck_check_inode_worker(struct erofs_work *work, void *tlsp); + +struct erofsfsck_dir_iter_ctx { + struct erofs_dir_context ctx; + char *base_path; + size_t base_pos; + struct erofsfsck_dirstack *dirstack; +}; + static int erofsfsck_dirent_iter(struct erofs_dir_context *ctx) { - int ret; - size_t prev_pos, curr_pos; + struct erofsfsck_dir_iter_ctx *ictx = (void *)ctx; + size_t curr_pos = ictx->base_pos; + char *new_path = NULL; if (ctx->dot_dotdot) return 0; - prev_pos = fsckcfg.extract_pos; - curr_pos = prev_pos; - - if (prev_pos + ctx->de_namelen >= PATH_MAX) { - erofs_err("unable to fsck since the path is too long (%llu)", - (curr_pos + ctx->de_namelen) | 0ULL); - return -EOPNOTSUPP; - } + if (curr_pos + ctx->de_namelen >= PATH_MAX) { + erofs_err("unable to fsck since the path is too long"); + return -EOPNOTSUPP; + } if (fsckcfg.extract_path) { - fsckcfg.extract_path[curr_pos++] = '/'; - strncpy(fsckcfg.extract_path + curr_pos, ctx->dname, - ctx->de_namelen); + new_path = malloc(PATH_MAX); + if (!new_path) return -ENOMEM; + + if (ictx->base_path) + memcpy(new_path, ictx->base_path, curr_pos); + + new_path[curr_pos++] = '/'; + strncpy(new_path + curr_pos, ctx->dname, ctx->de_namelen); curr_pos += ctx->de_namelen; - fsckcfg.extract_path[curr_pos] = '\0'; + new_path[curr_pos] = '\0'; } else { curr_pos += ctx->de_namelen; } - fsckcfg.extract_pos = curr_pos; - ret = erofsfsck_check_inode(ctx->dir->nid, ctx->de_nid); - if (fsckcfg.extract_path) - fsckcfg.extract_path[prev_pos] = '\0'; - fsckcfg.extract_pos = prev_pos; - return ret; + struct erofsfsck_inode_task *task = malloc(sizeof(*task)); + if (!task) { + free(new_path); + return -ENOMEM; + } + + task->work.fn = erofsfsck_check_inode_worker; + task->work.next = NULL; + task->pnid = ctx->dir->nid; + task->nid = ctx->de_nid; + task->path = new_path; + task->path_pos = curr_pos; + task->dirstack = *(ictx->dirstack); + + fsck_inc_task(); +#ifdef EROFS_MT_ENABLED + erofs_queue_work(&erofs_traverse_wq, &task->work); +#else + task->work.fn(&task->work, NULL); +#endif + return 0; } -static int erofsfsck_extract_inode(struct erofs_inode *inode) +static int erofsfsck_extract_inode(struct erofs_inode *inode, const char *current_path) { int ret; char *oldpath; - if (!fsckcfg.extract_path || erofs_is_packed_inode(inode)) { + if (!current_path || erofs_is_packed_inode(inode)) { verify: /* verify data chunk layout */ return erofs_verify_inode_data(inode, -1); @@ -914,9 +990,9 @@ verify: oldpath = erofsfsck_hardlink_find(inode->nid); if (oldpath) { - if (link(oldpath, fsckcfg.extract_path) == -1) { + if (link(oldpath, current_path) == -1) { erofs_err("failed to extract hard link: %s (%s)", - fsckcfg.extract_path, strerror(errno)); + current_path, strerror(errno)); return -errno; } return 0; @@ -924,19 +1000,19 @@ verify: switch (inode->i_mode & S_IFMT) { case S_IFDIR: - ret = erofs_extract_dir(inode); + ret = erofs_extract_dir(inode, current_path); break; case S_IFREG: - ret = erofs_extract_file(inode); + ret = erofs_extract_file(inode, current_path); break; case S_IFLNK: - ret = erofs_extract_symlink(inode); + ret = erofs_extract_symlink(inode, current_path); break; case S_IFCHR: case S_IFBLK: case S_IFIFO: case S_IFSOCK: - ret = erofs_extract_special(inode); + ret = erofs_extract_special(inode, current_path); break; default: /* TODO */ @@ -948,11 +1024,13 @@ verify: /* record nid and old path for hardlink */ if (inode->i_nlink > 1 && !S_ISDIR(inode->i_mode)) ret = erofsfsck_hardlink_insert(inode->nid, - fsckcfg.extract_path); + current_path); return ret; } -static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid) +static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid, + char *current_path, size_t pos, + struct erofsfsck_dirstack *dirstack) { int ret, i; struct erofs_inode inode = {.sbi = &g_sbi, .nid = nid}; @@ -973,44 +1051,63 @@ static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid) goto out; } - ret = erofsfsck_extract_inode(&inode); + ret = erofsfsck_extract_inode(&inode, current_path); if (ret && ret != -ECANCELED) goto out; if (fsckcfg.check_decomp && fsckcfg.dump_xattrs) { - ret = erofsfsck_dump_xattrs(&inode); + ret = erofsfsck_dump_xattrs(&inode, current_path); if (ret) return ret; } if (S_ISDIR(inode.i_mode)) { - struct erofs_dir_context ctx = { - .flags = EROFS_READDIR_VALID_PNID, - .pnid = pnid, - .dir = &inode, - .cb = erofsfsck_dirent_iter, + struct erofsfsck_dir_iter_ctx ctx = { + .ctx.flags = EROFS_READDIR_VALID_PNID, + .ctx.pnid = pnid, + .ctx.dir = &inode, + .ctx.cb = erofsfsck_dirent_iter, + .base_path = current_path, + .base_pos = pos, + .dirstack = dirstack }; - /* XXX: support the deeper cases later */ - if (fsckcfg.dirstack.top >= ARRAY_SIZE(fsckcfg.dirstack.dirs)) + if (dirstack->top >= ARRAY_SIZE(dirstack->dirs)) return -ENAMETOOLONG; - for (i = 0; i < fsckcfg.dirstack.top; ++i) - if (inode.nid == fsckcfg.dirstack.dirs[i]) + for (i = 0; i < dirstack->top; ++i) + if (inode.nid == dirstack->dirs[i]) return -ELOOP; - fsckcfg.dirstack.dirs[fsckcfg.dirstack.top++] = pnid; - ret = erofs_iterate_dir(&ctx, true); - --fsckcfg.dirstack.top; + + dirstack->dirs[dirstack->top++] = pnid; + ret = erofs_iterate_dir(&ctx.ctx, true); + --dirstack->top; } - if (!ret && !erofs_is_packed_inode(&inode)) - erofsfsck_set_attributes(&inode, fsckcfg.extract_path); + if (!ret && !erofs_is_packed_inode(&inode) && current_path) + erofsfsck_set_attributes(&inode, current_path); if (ret == -ECANCELED) ret = 0; out: - if (ret && ret != -EIO) - fsckcfg.corrupted = true; - return ret; + if (ret && ret != -EIO) { + erofs_mutex_lock(&fsck_global_lock); + fsckcfg.corrupted = true; + erofs_mutex_unlock(&fsck_global_lock); + } + return ret; +} + +static void erofsfsck_check_inode_worker(struct erofs_work *work, void *tlsp) +{ + struct erofsfsck_inode_task *task = (struct erofsfsck_inode_task *)work; + + erofsfsck_check_inode(task->pnid, task->nid, task->path, + task->path_pos, &task->dirstack); + + if (task->path) + free(task->path); + free(task); + fsck_dec_task(); } #ifdef FUZZING @@ -1032,6 +1129,7 @@ int main(int argc, char *argv[]) if (workers < 1) workers = 1; erofs_alloc_workqueue(&erofs_wq, workers, 256, NULL, NULL); + erofs_alloc_workqueue(&erofs_traverse_wq, workers, 256, NULL, NULL); #endif fsckcfg.physical_blocks = 0; @@ -1098,6 +1196,8 @@ int main(int argc, char *argv[]) fsckcfg.nid = g_sbi.root_nid; } + erofs_cond_init(&fsck_task_cond); + if (!fsckcfg.inode_path && fsckcfg.nid == g_sbi.root_nid) { if (erofs_sb_has_fragments(&g_sbi) && g_sbi.packed_nid > 0) { err = erofs_packedfile_init(&g_sbi, false); @@ -1107,7 +1207,7 @@ int main(int argc, char *argv[]) goto exit_hardlink; } - err = erofsfsck_check_inode(g_sbi.packed_nid, g_sbi.packed_nid); + err = erofsfsck_check_inode(g_sbi.packed_nid, g_sbi.packed_nid, NULL, 0, &fsckcfg.dirstack); if (err) { erofs_err("failed to verify packed file"); goto exit_packedinode; @@ -1132,7 +1232,26 @@ int main(int argc, char *argv[]) pnid = ctx.pnid; } } - err = erofsfsck_check_inode(pnid, fsckcfg.nid); + + fsck_inc_task(); + struct erofsfsck_inode_task *root_task = calloc(1, sizeof(*root_task)); + root_task->work.fn = erofsfsck_check_inode_worker; + root_task->pnid = pnid; + root_task->nid = fsckcfg.nid; + + if (fsckcfg.extract_path) + root_task->path = strdup(fsckcfg.extract_path); + + root_task->path_pos = fsckcfg.extract_pos; + root_task->dirstack = fsckcfg.dirstack; + +#ifdef EROFS_MT_ENABLED + erofs_queue_work(&erofs_traverse_wq, &root_task->work); +#else + root_task->work.fn(&root_task->work, NULL); +#endif + + fsck_wait_tasks(); } if (fsckcfg.corrupted) { @@ -1156,6 +1275,8 @@ int main(int argc, char *argv[]) } } + erofs_cond_destroy(&fsck_task_cond); + exit_packedinode: erofs_packedfile_exit(&g_sbi); exit_hardlink: @@ -1170,6 +1291,7 @@ exit: erofs_exit_configure(); #ifdef EROFS_MT_ENABLED erofs_destroy_workqueue(&erofs_wq); + erofs_destroy_workqueue(&erofs_traverse_wq); #endif return err ? 1 : 0; } -- 2.52.0
