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brintos / linux-shallow public Read only

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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * This file is part of UBIFS.4 *5 * Copyright (C) 2006-2008 Nokia Corporation.6 *7 * Authors: Artem Bityutskiy (Битюцкий Артём)8 *          Adrian Hunter9 */10 11/*12 * This file implements UBIFS initialization and VFS superblock operations. Some13 * initialization stuff which is rather large and complex is placed at14 * corresponding subsystems, but most of it is here.15 */16 17#include <linux/init.h>18#include <linux/slab.h>19#include <linux/module.h>20#include <linux/ctype.h>21#include <linux/kthread.h>22#include <linux/parser.h>23#include <linux/seq_file.h>24#include <linux/mount.h>25#include <linux/math64.h>26#include <linux/writeback.h>27#include "ubifs.h"28 29static int ubifs_default_version_set(const char *val, const struct kernel_param *kp)30{31	int n = 0, ret;32 33	ret = kstrtoint(val, 10, &n);34	if (ret != 0 || n < 4 || n > UBIFS_FORMAT_VERSION)35		return -EINVAL;36	return param_set_int(val, kp);37}38 39static const struct kernel_param_ops ubifs_default_version_ops = {40	.set = ubifs_default_version_set,41	.get = param_get_int,42};43 44int ubifs_default_version = UBIFS_FORMAT_VERSION;45module_param_cb(default_version, &ubifs_default_version_ops, &ubifs_default_version, 0600);46 47/*48 * Maximum amount of memory we may 'kmalloc()' without worrying that we are49 * allocating too much.50 */51#define UBIFS_KMALLOC_OK (128*1024)52 53/* Slab cache for UBIFS inodes */54static struct kmem_cache *ubifs_inode_slab;55 56/* UBIFS TNC shrinker description */57static struct shrinker *ubifs_shrinker_info;58 59/**60 * validate_inode - validate inode.61 * @c: UBIFS file-system description object62 * @inode: the inode to validate63 *64 * This is a helper function for 'ubifs_iget()' which validates various fields65 * of a newly built inode to make sure they contain sane values and prevent66 * possible vulnerabilities. Returns zero if the inode is all right and67 * a non-zero error code if not.68 */69static int validate_inode(struct ubifs_info *c, const struct inode *inode)70{71	int err;72	const struct ubifs_inode *ui = ubifs_inode(inode);73 74	if (inode->i_size > c->max_inode_sz) {75		ubifs_err(c, "inode is too large (%lld)",76			  (long long)inode->i_size);77		return 1;78	}79 80	if (ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {81		ubifs_err(c, "unknown compression type %d", ui->compr_type);82		return 2;83	}84 85	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)86		return 3;87 88	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)89		return 4;90 91	if (ui->xattr && !S_ISREG(inode->i_mode))92		return 5;93 94	if (!ubifs_compr_present(c, ui->compr_type)) {95		ubifs_warn(c, "inode %lu uses '%s' compression, but it was not compiled in",96			   inode->i_ino, ubifs_compr_name(c, ui->compr_type));97	}98 99	err = dbg_check_dir(c, inode);100	return err;101}102 103struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)104{105	int err;106	union ubifs_key key;107	struct ubifs_ino_node *ino;108	struct ubifs_info *c = sb->s_fs_info;109	struct inode *inode;110	struct ubifs_inode *ui;111 112	dbg_gen("inode %lu", inum);113 114	inode = iget_locked(sb, inum);115	if (!inode)116		return ERR_PTR(-ENOMEM);117	if (!(inode->i_state & I_NEW))118		return inode;119	ui = ubifs_inode(inode);120 121	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);122	if (!ino) {123		err = -ENOMEM;124		goto out;125	}126 127	ino_key_init(c, &key, inode->i_ino);128 129	err = ubifs_tnc_lookup(c, &key, ino);130	if (err)131		goto out_ino;132 133	inode->i_flags |= S_NOCMTIME;134 135	if (!IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))136		inode->i_flags |= S_NOATIME;137 138	set_nlink(inode, le32_to_cpu(ino->nlink));139	i_uid_write(inode, le32_to_cpu(ino->uid));140	i_gid_write(inode, le32_to_cpu(ino->gid));141	inode_set_atime(inode, (int64_t)le64_to_cpu(ino->atime_sec),142			le32_to_cpu(ino->atime_nsec));143	inode_set_mtime(inode, (int64_t)le64_to_cpu(ino->mtime_sec),144			le32_to_cpu(ino->mtime_nsec));145	inode_set_ctime(inode, (int64_t)le64_to_cpu(ino->ctime_sec),146			le32_to_cpu(ino->ctime_nsec));147	inode->i_mode = le32_to_cpu(ino->mode);148	inode->i_size = le64_to_cpu(ino->size);149 150	ui->data_len    = le32_to_cpu(ino->data_len);151	ui->flags       = le32_to_cpu(ino->flags);152	ui->compr_type  = le16_to_cpu(ino->compr_type);153	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);154	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);155	ui->xattr_size  = le32_to_cpu(ino->xattr_size);156	ui->xattr_names = le32_to_cpu(ino->xattr_names);157	ui->synced_i_size = ui->ui_size = inode->i_size;158 159	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;160 161	err = validate_inode(c, inode);162	if (err)163		goto out_invalid;164 165	switch (inode->i_mode & S_IFMT) {166	case S_IFREG:167		inode->i_mapping->a_ops = &ubifs_file_address_operations;168		inode->i_op = &ubifs_file_inode_operations;169		inode->i_fop = &ubifs_file_operations;170		if (ui->xattr) {171			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);172			if (!ui->data) {173				err = -ENOMEM;174				goto out_ino;175			}176			memcpy(ui->data, ino->data, ui->data_len);177			((char *)ui->data)[ui->data_len] = '\0';178		} else if (ui->data_len != 0) {179			err = 10;180			goto out_invalid;181		}182		break;183	case S_IFDIR:184		inode->i_op  = &ubifs_dir_inode_operations;185		inode->i_fop = &ubifs_dir_operations;186		if (ui->data_len != 0) {187			err = 11;188			goto out_invalid;189		}190		break;191	case S_IFLNK:192		inode->i_op = &ubifs_symlink_inode_operations;193		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {194			err = 12;195			goto out_invalid;196		}197		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);198		if (!ui->data) {199			err = -ENOMEM;200			goto out_ino;201		}202		memcpy(ui->data, ino->data, ui->data_len);203		((char *)ui->data)[ui->data_len] = '\0';204		break;205	case S_IFBLK:206	case S_IFCHR:207	{208		dev_t rdev;209		union ubifs_dev_desc *dev;210 211		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);212		if (!ui->data) {213			err = -ENOMEM;214			goto out_ino;215		}216 217		dev = (union ubifs_dev_desc *)ino->data;218		if (ui->data_len == sizeof(dev->new))219			rdev = new_decode_dev(le32_to_cpu(dev->new));220		else if (ui->data_len == sizeof(dev->huge))221			rdev = huge_decode_dev(le64_to_cpu(dev->huge));222		else {223			err = 13;224			goto out_invalid;225		}226		memcpy(ui->data, ino->data, ui->data_len);227		inode->i_op = &ubifs_file_inode_operations;228		init_special_inode(inode, inode->i_mode, rdev);229		break;230	}231	case S_IFSOCK:232	case S_IFIFO:233		inode->i_op = &ubifs_file_inode_operations;234		init_special_inode(inode, inode->i_mode, 0);235		if (ui->data_len != 0) {236			err = 14;237			goto out_invalid;238		}239		break;240	default:241		err = 15;242		goto out_invalid;243	}244 245	kfree(ino);246	ubifs_set_inode_flags(inode);247	unlock_new_inode(inode);248	return inode;249 250out_invalid:251	ubifs_err(c, "inode %lu validation failed, error %d", inode->i_ino, err);252	ubifs_dump_node(c, ino, UBIFS_MAX_INO_NODE_SZ);253	ubifs_dump_inode(c, inode);254	err = -EINVAL;255out_ino:256	kfree(ino);257out:258	ubifs_err(c, "failed to read inode %lu, error %d", inode->i_ino, err);259	iget_failed(inode);260	return ERR_PTR(err);261}262 263static struct inode *ubifs_alloc_inode(struct super_block *sb)264{265	struct ubifs_inode *ui;266 267	ui = alloc_inode_sb(sb, ubifs_inode_slab, GFP_NOFS);268	if (!ui)269		return NULL;270 271	memset((void *)ui + sizeof(struct inode), 0,272	       sizeof(struct ubifs_inode) - sizeof(struct inode));273	mutex_init(&ui->ui_mutex);274	init_rwsem(&ui->xattr_sem);275	spin_lock_init(&ui->ui_lock);276	return &ui->vfs_inode;277};278 279static void ubifs_free_inode(struct inode *inode)280{281	struct ubifs_inode *ui = ubifs_inode(inode);282 283	kfree(ui->data);284	fscrypt_free_inode(inode);285 286	kmem_cache_free(ubifs_inode_slab, ui);287}288 289/*290 * Note, Linux write-back code calls this without 'i_mutex'.291 */292static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc)293{294	int err = 0;295	struct ubifs_info *c = inode->i_sb->s_fs_info;296	struct ubifs_inode *ui = ubifs_inode(inode);297 298	ubifs_assert(c, !ui->xattr);299	if (is_bad_inode(inode))300		return 0;301 302	mutex_lock(&ui->ui_mutex);303	/*304	 * Due to races between write-back forced by budgeting305	 * (see 'sync_some_inodes()') and background write-back, the inode may306	 * have already been synchronized, do not do this again. This might307	 * also happen if it was synchronized in an VFS operation, e.g.308	 * 'ubifs_link()'.309	 */310	if (!ui->dirty) {311		mutex_unlock(&ui->ui_mutex);312		return 0;313	}314 315	/*316	 * As an optimization, do not write orphan inodes to the media just317	 * because this is not needed.318	 */319	dbg_gen("inode %lu, mode %#x, nlink %u",320		inode->i_ino, (int)inode->i_mode, inode->i_nlink);321	if (inode->i_nlink) {322		err = ubifs_jnl_write_inode(c, inode);323		if (err)324			ubifs_err(c, "can't write inode %lu, error %d",325				  inode->i_ino, err);326		else327			err = dbg_check_inode_size(c, inode, ui->ui_size);328	}329 330	ui->dirty = 0;331	mutex_unlock(&ui->ui_mutex);332	ubifs_release_dirty_inode_budget(c, ui);333	return err;334}335 336static int ubifs_drop_inode(struct inode *inode)337{338	int drop = generic_drop_inode(inode);339 340	if (!drop)341		drop = fscrypt_drop_inode(inode);342 343	return drop;344}345 346static void ubifs_evict_inode(struct inode *inode)347{348	int err;349	struct ubifs_info *c = inode->i_sb->s_fs_info;350	struct ubifs_inode *ui = ubifs_inode(inode);351 352	if (ui->xattr)353		/*354		 * Extended attribute inode deletions are fully handled in355		 * 'ubifs_removexattr()'. These inodes are special and have356		 * limited usage, so there is nothing to do here.357		 */358		goto out;359 360	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);361	ubifs_assert(c, !atomic_read(&inode->i_count));362 363	truncate_inode_pages_final(&inode->i_data);364 365	if (inode->i_nlink)366		goto done;367 368	if (is_bad_inode(inode))369		goto out;370 371	ui->ui_size = inode->i_size = 0;372	err = ubifs_jnl_delete_inode(c, inode);373	if (err)374		/*375		 * Worst case we have a lost orphan inode wasting space, so a376		 * simple error message is OK here.377		 */378		ubifs_err(c, "can't delete inode %lu, error %d",379			  inode->i_ino, err);380 381out:382	if (ui->dirty)383		ubifs_release_dirty_inode_budget(c, ui);384	else {385		/* We've deleted something - clean the "no space" flags */386		c->bi.nospace = c->bi.nospace_rp = 0;387		smp_wmb();388	}389done:390	clear_inode(inode);391	fscrypt_put_encryption_info(inode);392}393 394static void ubifs_dirty_inode(struct inode *inode, int flags)395{396	struct ubifs_info *c = inode->i_sb->s_fs_info;397	struct ubifs_inode *ui = ubifs_inode(inode);398 399	ubifs_assert(c, mutex_is_locked(&ui->ui_mutex));400	if (!ui->dirty) {401		ui->dirty = 1;402		dbg_gen("inode %lu",  inode->i_ino);403	}404}405 406static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)407{408	struct ubifs_info *c = dentry->d_sb->s_fs_info;409	unsigned long long free;410	__le32 *uuid = (__le32 *)c->uuid;411 412	free = ubifs_get_free_space(c);413	dbg_gen("free space %lld bytes (%lld blocks)",414		free, free >> UBIFS_BLOCK_SHIFT);415 416	buf->f_type = UBIFS_SUPER_MAGIC;417	buf->f_bsize = UBIFS_BLOCK_SIZE;418	buf->f_blocks = c->block_cnt;419	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;420	if (free > c->report_rp_size)421		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;422	else423		buf->f_bavail = 0;424	buf->f_files = 0;425	buf->f_ffree = 0;426	buf->f_namelen = UBIFS_MAX_NLEN;427	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);428	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);429	ubifs_assert(c, buf->f_bfree <= c->block_cnt);430	return 0;431}432 433static int ubifs_show_options(struct seq_file *s, struct dentry *root)434{435	struct ubifs_info *c = root->d_sb->s_fs_info;436 437	if (c->mount_opts.unmount_mode == 2)438		seq_puts(s, ",fast_unmount");439	else if (c->mount_opts.unmount_mode == 1)440		seq_puts(s, ",norm_unmount");441 442	if (c->mount_opts.bulk_read == 2)443		seq_puts(s, ",bulk_read");444	else if (c->mount_opts.bulk_read == 1)445		seq_puts(s, ",no_bulk_read");446 447	if (c->mount_opts.chk_data_crc == 2)448		seq_puts(s, ",chk_data_crc");449	else if (c->mount_opts.chk_data_crc == 1)450		seq_puts(s, ",no_chk_data_crc");451 452	if (c->mount_opts.override_compr) {453		seq_printf(s, ",compr=%s",454			   ubifs_compr_name(c, c->mount_opts.compr_type));455	}456 457	seq_printf(s, ",assert=%s", ubifs_assert_action_name(c));458	seq_printf(s, ",ubi=%d,vol=%d", c->vi.ubi_num, c->vi.vol_id);459 460	return 0;461}462 463static int ubifs_sync_fs(struct super_block *sb, int wait)464{465	int i, err;466	struct ubifs_info *c = sb->s_fs_info;467 468	/*469	 * Zero @wait is just an advisory thing to help the file system shove470	 * lots of data into the queues, and there will be the second471	 * '->sync_fs()' call, with non-zero @wait.472	 */473	if (!wait)474		return 0;475 476	/*477	 * Synchronize write buffers, because 'ubifs_run_commit()' does not478	 * do this if it waits for an already running commit.479	 */480	for (i = 0; i < c->jhead_cnt; i++) {481		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);482		if (err)483			return err;484	}485 486	/*487	 * Strictly speaking, it is not necessary to commit the journal here,488	 * synchronizing write-buffers would be enough. But committing makes489	 * UBIFS free space predictions much more accurate, so we want to let490	 * the user be able to get more accurate results of 'statfs()' after491	 * they synchronize the file system.492	 */493	err = ubifs_run_commit(c);494	if (err)495		return err;496 497	return ubi_sync(c->vi.ubi_num);498}499 500/**501 * init_constants_early - initialize UBIFS constants.502 * @c: UBIFS file-system description object503 *504 * This function initialize UBIFS constants which do not need the superblock to505 * be read. It also checks that the UBI volume satisfies basic UBIFS506 * requirements. Returns zero in case of success and a negative error code in507 * case of failure.508 */509static int init_constants_early(struct ubifs_info *c)510{511	if (c->vi.corrupted) {512		ubifs_warn(c, "UBI volume is corrupted - read-only mode");513		c->ro_media = 1;514	}515 516	if (c->di.ro_mode) {517		ubifs_msg(c, "read-only UBI device");518		c->ro_media = 1;519	}520 521	if (c->vi.vol_type == UBI_STATIC_VOLUME) {522		ubifs_msg(c, "static UBI volume - read-only mode");523		c->ro_media = 1;524	}525 526	c->leb_cnt = c->vi.size;527	c->leb_size = c->vi.usable_leb_size;528	c->leb_start = c->di.leb_start;529	c->half_leb_size = c->leb_size / 2;530	c->min_io_size = c->di.min_io_size;531	c->min_io_shift = fls(c->min_io_size) - 1;532	c->max_write_size = c->di.max_write_size;533	c->max_write_shift = fls(c->max_write_size) - 1;534 535	if (c->leb_size < UBIFS_MIN_LEB_SZ) {536		ubifs_errc(c, "too small LEBs (%d bytes), min. is %d bytes",537			   c->leb_size, UBIFS_MIN_LEB_SZ);538		return -EINVAL;539	}540 541	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {542		ubifs_errc(c, "too few LEBs (%d), min. is %d",543			   c->leb_cnt, UBIFS_MIN_LEB_CNT);544		return -EINVAL;545	}546 547	if (!is_power_of_2(c->min_io_size)) {548		ubifs_errc(c, "bad min. I/O size %d", c->min_io_size);549		return -EINVAL;550	}551 552	/*553	 * Maximum write size has to be greater or equivalent to min. I/O554	 * size, and be multiple of min. I/O size.555	 */556	if (c->max_write_size < c->min_io_size ||557	    c->max_write_size % c->min_io_size ||558	    !is_power_of_2(c->max_write_size)) {559		ubifs_errc(c, "bad write buffer size %d for %d min. I/O unit",560			   c->max_write_size, c->min_io_size);561		return -EINVAL;562	}563 564	/*565	 * UBIFS aligns all node to 8-byte boundary, so to make function in566	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is567	 * less than 8.568	 */569	if (c->min_io_size < 8) {570		c->min_io_size = 8;571		c->min_io_shift = 3;572		if (c->max_write_size < c->min_io_size) {573			c->max_write_size = c->min_io_size;574			c->max_write_shift = c->min_io_shift;575		}576	}577 578	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);579	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);580 581	/*582	 * Initialize node length ranges which are mostly needed for node583	 * length validation.584	 */585	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;586	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;587	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;588	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;589	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;590	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;591	c->ranges[UBIFS_AUTH_NODE].min_len = UBIFS_AUTH_NODE_SZ;592	c->ranges[UBIFS_AUTH_NODE].max_len = UBIFS_AUTH_NODE_SZ +593				UBIFS_MAX_HMAC_LEN;594	c->ranges[UBIFS_SIG_NODE].min_len = UBIFS_SIG_NODE_SZ;595	c->ranges[UBIFS_SIG_NODE].max_len = c->leb_size - UBIFS_SB_NODE_SZ;596 597	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;598	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;599	c->ranges[UBIFS_ORPH_NODE].min_len =600				UBIFS_ORPH_NODE_SZ + sizeof(__le64);601	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;602	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;603	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;604	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;605	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;606	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;607	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;608	/*609	 * Minimum indexing node size is amended later when superblock is610	 * read and the key length is known.611	 */612	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;613	/*614	 * Maximum indexing node size is amended later when superblock is615	 * read and the fanout is known.616	 */617	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;618 619	/*620	 * Initialize dead and dark LEB space watermarks. See gc.c for comments621	 * about these values.622	 */623	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);624	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);625 626	/*627	 * Calculate how many bytes would be wasted at the end of LEB if it was628	 * fully filled with data nodes of maximum size. This is used in629	 * calculations when reporting free space.630	 */631	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;632 633	/* Buffer size for bulk-reads */634	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;635	if (c->max_bu_buf_len > c->leb_size)636		c->max_bu_buf_len = c->leb_size;637 638	/* Log is ready, preserve one LEB for commits. */639	c->min_log_bytes = c->leb_size;640 641	return 0;642}643 644/**645 * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.646 * @c: UBIFS file-system description object647 * @lnum: LEB the write-buffer was synchronized to648 * @free: how many free bytes left in this LEB649 * @pad: how many bytes were padded650 *651 * This is a callback function which is called by the I/O unit when the652 * write-buffer is synchronized. We need this to correctly maintain space653 * accounting in bud logical eraseblocks. This function returns zero in case of654 * success and a negative error code in case of failure.655 *656 * This function actually belongs to the journal, but we keep it here because657 * we want to keep it static.658 */659static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)660{661	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);662}663 664/*665 * init_constants_sb - initialize UBIFS constants.666 * @c: UBIFS file-system description object667 *668 * This is a helper function which initializes various UBIFS constants after669 * the superblock has been read. It also checks various UBIFS parameters and670 * makes sure they are all right. Returns zero in case of success and a671 * negative error code in case of failure.672 */673static int init_constants_sb(struct ubifs_info *c)674{675	int tmp, err;676	long long tmp64;677 678	c->main_bytes = (long long)c->main_lebs * c->leb_size;679	c->max_znode_sz = sizeof(struct ubifs_znode) +680				c->fanout * sizeof(struct ubifs_zbranch);681 682	tmp = ubifs_idx_node_sz(c, 1);683	c->ranges[UBIFS_IDX_NODE].min_len = tmp;684	c->min_idx_node_sz = ALIGN(tmp, 8);685 686	tmp = ubifs_idx_node_sz(c, c->fanout);687	c->ranges[UBIFS_IDX_NODE].max_len = tmp;688	c->max_idx_node_sz = ALIGN(tmp, 8);689 690	/* Make sure LEB size is large enough to fit full commit */691	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;692	tmp = ALIGN(tmp, c->min_io_size);693	if (tmp > c->leb_size) {694		ubifs_err(c, "too small LEB size %d, at least %d needed",695			  c->leb_size, tmp);696		return -EINVAL;697	}698 699	/*700	 * Make sure that the log is large enough to fit reference nodes for701	 * all buds plus one reserved LEB.702	 */703	tmp64 = c->max_bud_bytes + c->leb_size - 1;704	c->max_bud_cnt = div_u64(tmp64, c->leb_size);705	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);706	tmp /= c->leb_size;707	tmp += 1;708	if (c->log_lebs < tmp) {709		ubifs_err(c, "too small log %d LEBs, required min. %d LEBs",710			  c->log_lebs, tmp);711		return -EINVAL;712	}713 714	/*715	 * When budgeting we assume worst-case scenarios when the pages are not716	 * be compressed and direntries are of the maximum size.717	 *718	 * Note, data, which may be stored in inodes is budgeted separately, so719	 * it is not included into 'c->bi.inode_budget'.720	 */721	c->bi.page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;722	c->bi.inode_budget = UBIFS_INO_NODE_SZ;723	c->bi.dent_budget = UBIFS_MAX_DENT_NODE_SZ;724 725	/*726	 * When the amount of flash space used by buds becomes727	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.728	 * The writers are unblocked when the commit is finished. To avoid729	 * writers to be blocked UBIFS initiates background commit in advance,730	 * when number of bud bytes becomes above the limit defined below.731	 */732	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;733 734	/*735	 * Ensure minimum journal size. All the bytes in the journal heads are736	 * considered to be used, when calculating the current journal usage.737	 * Consequently, if the journal is too small, UBIFS will treat it as738	 * always full.739	 */740	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;741	if (c->bg_bud_bytes < tmp64)742		c->bg_bud_bytes = tmp64;743	if (c->max_bud_bytes < tmp64 + c->leb_size)744		c->max_bud_bytes = tmp64 + c->leb_size;745 746	err = ubifs_calc_lpt_geom(c);747	if (err)748		return err;749 750	/* Initialize effective LEB size used in budgeting calculations */751	c->idx_leb_size = c->leb_size - c->max_idx_node_sz;752	return 0;753}754 755/*756 * init_constants_master - initialize UBIFS constants.757 * @c: UBIFS file-system description object758 *759 * This is a helper function which initializes various UBIFS constants after760 * the master node has been read. It also checks various UBIFS parameters and761 * makes sure they are all right.762 */763static void init_constants_master(struct ubifs_info *c)764{765	long long tmp64;766 767	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);768	c->report_rp_size = ubifs_reported_space(c, c->rp_size);769 770	/*771	 * Calculate total amount of FS blocks. This number is not used772	 * internally because it does not make much sense for UBIFS, but it is773	 * necessary to report something for the 'statfs()' call.774	 *775	 * Subtract the LEB reserved for GC, the LEB which is reserved for776	 * deletions, minimum LEBs for the index, and assume only one journal777	 * head is available.778	 */779	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;780	tmp64 *= (long long)c->leb_size - c->leb_overhead;781	tmp64 = ubifs_reported_space(c, tmp64);782	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;783}784 785/**786 * take_gc_lnum - reserve GC LEB.787 * @c: UBIFS file-system description object788 *789 * This function ensures that the LEB reserved for garbage collection is marked790 * as "taken" in lprops. We also have to set free space to LEB size and dirty791 * space to zero, because lprops may contain out-of-date information if the792 * file-system was un-mounted before it has been committed. This function793 * returns zero in case of success and a negative error code in case of794 * failure.795 */796static int take_gc_lnum(struct ubifs_info *c)797{798	int err;799 800	if (c->gc_lnum == -1) {801		ubifs_err(c, "no LEB for GC");802		return -EINVAL;803	}804 805	/* And we have to tell lprops that this LEB is taken */806	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,807				  LPROPS_TAKEN, 0, 0);808	return err;809}810 811/**812 * alloc_wbufs - allocate write-buffers.813 * @c: UBIFS file-system description object814 *815 * This helper function allocates and initializes UBIFS write-buffers. Returns816 * zero in case of success and %-ENOMEM in case of failure.817 */818static int alloc_wbufs(struct ubifs_info *c)819{820	int i, err;821 822	c->jheads = kcalloc(c->jhead_cnt, sizeof(struct ubifs_jhead),823			    GFP_KERNEL);824	if (!c->jheads)825		return -ENOMEM;826 827	/* Initialize journal heads */828	for (i = 0; i < c->jhead_cnt; i++) {829		INIT_LIST_HEAD(&c->jheads[i].buds_list);830		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);831		if (err)832			goto out_wbuf;833 834		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;835		c->jheads[i].wbuf.jhead = i;836		c->jheads[i].grouped = 1;837		c->jheads[i].log_hash = ubifs_hash_get_desc(c);838		if (IS_ERR(c->jheads[i].log_hash)) {839			err = PTR_ERR(c->jheads[i].log_hash);840			goto out_log_hash;841		}842	}843 844	/*845	 * Garbage Collector head does not need to be synchronized by timer.846	 * Also GC head nodes are not grouped.847	 */848	c->jheads[GCHD].wbuf.no_timer = 1;849	c->jheads[GCHD].grouped = 0;850 851	return 0;852 853out_log_hash:854	kfree(c->jheads[i].wbuf.buf);855	kfree(c->jheads[i].wbuf.inodes);856 857out_wbuf:858	while (i--) {859		kfree(c->jheads[i].wbuf.buf);860		kfree(c->jheads[i].wbuf.inodes);861		kfree(c->jheads[i].log_hash);862	}863	kfree(c->jheads);864	c->jheads = NULL;865 866	return err;867}868 869/**870 * free_wbufs - free write-buffers.871 * @c: UBIFS file-system description object872 */873static void free_wbufs(struct ubifs_info *c)874{875	int i;876 877	if (c->jheads) {878		for (i = 0; i < c->jhead_cnt; i++) {879			kfree(c->jheads[i].wbuf.buf);880			kfree(c->jheads[i].wbuf.inodes);881			kfree(c->jheads[i].log_hash);882		}883		kfree(c->jheads);884		c->jheads = NULL;885	}886}887 888/**889 * free_orphans - free orphans.890 * @c: UBIFS file-system description object891 */892static void free_orphans(struct ubifs_info *c)893{894	struct ubifs_orphan *orph;895 896	while (c->orph_dnext) {897		orph = c->orph_dnext;898		c->orph_dnext = orph->dnext;899		list_del(&orph->list);900		kfree(orph);901	}902 903	while (!list_empty(&c->orph_list)) {904		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);905		list_del(&orph->list);906		kfree(orph);907		ubifs_err(c, "orphan list not empty at unmount");908	}909 910	vfree(c->orph_buf);911	c->orph_buf = NULL;912}913 914/**915 * free_buds - free per-bud objects.916 * @c: UBIFS file-system description object917 */918static void free_buds(struct ubifs_info *c)919{920	struct ubifs_bud *bud, *n;921 922	rbtree_postorder_for_each_entry_safe(bud, n, &c->buds, rb) {923		kfree(bud->log_hash);924		kfree(bud);925	}926}927 928/**929 * check_volume_empty - check if the UBI volume is empty.930 * @c: UBIFS file-system description object931 *932 * This function checks if the UBIFS volume is empty by looking if its LEBs are933 * mapped or not. The result of checking is stored in the @c->empty variable.934 * Returns zero in case of success and a negative error code in case of935 * failure.936 */937static int check_volume_empty(struct ubifs_info *c)938{939	int lnum, err;940 941	c->empty = 1;942	for (lnum = 0; lnum < c->leb_cnt; lnum++) {943		err = ubifs_is_mapped(c, lnum);944		if (unlikely(err < 0))945			return err;946		if (err == 1) {947			c->empty = 0;948			break;949		}950 951		cond_resched();952	}953 954	return 0;955}956 957/*958 * UBIFS mount options.959 *960 * Opt_fast_unmount: do not run a journal commit before un-mounting961 * Opt_norm_unmount: run a journal commit before un-mounting962 * Opt_bulk_read: enable bulk-reads963 * Opt_no_bulk_read: disable bulk-reads964 * Opt_chk_data_crc: check CRCs when reading data nodes965 * Opt_no_chk_data_crc: do not check CRCs when reading data nodes966 * Opt_override_compr: override default compressor967 * Opt_assert: set ubifs_assert() action968 * Opt_auth_key: The key name used for authentication969 * Opt_auth_hash_name: The hash type used for authentication970 * Opt_err: just end of array marker971 */972enum {973	Opt_fast_unmount,974	Opt_norm_unmount,975	Opt_bulk_read,976	Opt_no_bulk_read,977	Opt_chk_data_crc,978	Opt_no_chk_data_crc,979	Opt_override_compr,980	Opt_assert,981	Opt_auth_key,982	Opt_auth_hash_name,983	Opt_ignore,984	Opt_err,985};986 987static const match_table_t tokens = {988	{Opt_fast_unmount, "fast_unmount"},989	{Opt_norm_unmount, "norm_unmount"},990	{Opt_bulk_read, "bulk_read"},991	{Opt_no_bulk_read, "no_bulk_read"},992	{Opt_chk_data_crc, "chk_data_crc"},993	{Opt_no_chk_data_crc, "no_chk_data_crc"},994	{Opt_override_compr, "compr=%s"},995	{Opt_auth_key, "auth_key=%s"},996	{Opt_auth_hash_name, "auth_hash_name=%s"},997	{Opt_ignore, "ubi=%s"},998	{Opt_ignore, "vol=%s"},999	{Opt_assert, "assert=%s"},1000	{Opt_err, NULL},1001};1002 1003/**1004 * parse_standard_option - parse a standard mount option.1005 * @option: the option to parse1006 *1007 * Normally, standard mount options like "sync" are passed to file-systems as1008 * flags. However, when a "rootflags=" kernel boot parameter is used, they may1009 * be present in the options string. This function tries to deal with this1010 * situation and parse standard options. Returns 0 if the option was not1011 * recognized, and the corresponding integer flag if it was.1012 *1013 * UBIFS is only interested in the "sync" option, so do not check for anything1014 * else.1015 */1016static int parse_standard_option(const char *option)1017{1018 1019	pr_notice("UBIFS: parse %s\n", option);1020	if (!strcmp(option, "sync"))1021		return SB_SYNCHRONOUS;1022	return 0;1023}1024 1025/**1026 * ubifs_parse_options - parse mount parameters.1027 * @c: UBIFS file-system description object1028 * @options: parameters to parse1029 * @is_remount: non-zero if this is FS re-mount1030 *1031 * This function parses UBIFS mount options and returns zero in case success1032 * and a negative error code in case of failure.1033 */1034static int ubifs_parse_options(struct ubifs_info *c, char *options,1035			       int is_remount)1036{1037	char *p;1038	substring_t args[MAX_OPT_ARGS];1039 1040	if (!options)1041		return 0;1042 1043	while ((p = strsep(&options, ","))) {1044		int token;1045 1046		if (!*p)1047			continue;1048 1049		token = match_token(p, tokens, args);1050		switch (token) {1051		/*1052		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.1053		 * We accept them in order to be backward-compatible. But this1054		 * should be removed at some point.1055		 */1056		case Opt_fast_unmount:1057			c->mount_opts.unmount_mode = 2;1058			break;1059		case Opt_norm_unmount:1060			c->mount_opts.unmount_mode = 1;1061			break;1062		case Opt_bulk_read:1063			c->mount_opts.bulk_read = 2;1064			c->bulk_read = 1;1065			break;1066		case Opt_no_bulk_read:1067			c->mount_opts.bulk_read = 1;1068			c->bulk_read = 0;1069			break;1070		case Opt_chk_data_crc:1071			c->mount_opts.chk_data_crc = 2;1072			c->no_chk_data_crc = 0;1073			break;1074		case Opt_no_chk_data_crc:1075			c->mount_opts.chk_data_crc = 1;1076			c->no_chk_data_crc = 1;1077			break;1078		case Opt_override_compr:1079		{1080			char *name = match_strdup(&args[0]);1081 1082			if (!name)1083				return -ENOMEM;1084			if (!strcmp(name, "none"))1085				c->mount_opts.compr_type = UBIFS_COMPR_NONE;1086			else if (!strcmp(name, "lzo"))1087				c->mount_opts.compr_type = UBIFS_COMPR_LZO;1088			else if (!strcmp(name, "zlib"))1089				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;1090			else if (!strcmp(name, "zstd"))1091				c->mount_opts.compr_type = UBIFS_COMPR_ZSTD;1092			else {1093				ubifs_err(c, "unknown compressor \"%s\"", name); //FIXME: is c ready?1094				kfree(name);1095				return -EINVAL;1096			}1097			kfree(name);1098			c->mount_opts.override_compr = 1;1099			c->default_compr = c->mount_opts.compr_type;1100			break;1101		}1102		case Opt_assert:1103		{1104			char *act = match_strdup(&args[0]);1105 1106			if (!act)1107				return -ENOMEM;1108			if (!strcmp(act, "report"))1109				c->assert_action = ASSACT_REPORT;1110			else if (!strcmp(act, "read-only"))1111				c->assert_action = ASSACT_RO;1112			else if (!strcmp(act, "panic"))1113				c->assert_action = ASSACT_PANIC;1114			else {1115				ubifs_err(c, "unknown assert action \"%s\"", act);1116				kfree(act);1117				return -EINVAL;1118			}1119			kfree(act);1120			break;1121		}1122		case Opt_auth_key:1123			if (!is_remount) {1124				c->auth_key_name = kstrdup(args[0].from,1125								GFP_KERNEL);1126				if (!c->auth_key_name)1127					return -ENOMEM;1128			}1129			break;1130		case Opt_auth_hash_name:1131			if (!is_remount) {1132				c->auth_hash_name = kstrdup(args[0].from,1133								GFP_KERNEL);1134				if (!c->auth_hash_name)1135					return -ENOMEM;1136			}1137			break;1138		case Opt_ignore:1139			break;1140		default:1141		{1142			unsigned long flag;1143			struct super_block *sb = c->vfs_sb;1144 1145			flag = parse_standard_option(p);1146			if (!flag) {1147				ubifs_err(c, "unrecognized mount option \"%s\" or missing value",1148					  p);1149				return -EINVAL;1150			}1151			sb->s_flags |= flag;1152			break;1153		}1154		}1155	}1156 1157	return 0;1158}1159 1160/*1161 * ubifs_release_options - release mount parameters which have been dumped.1162 * @c: UBIFS file-system description object1163 */1164static void ubifs_release_options(struct ubifs_info *c)1165{1166	kfree(c->auth_key_name);1167	c->auth_key_name = NULL;1168	kfree(c->auth_hash_name);1169	c->auth_hash_name = NULL;1170}1171 1172/**1173 * destroy_journal - destroy journal data structures.1174 * @c: UBIFS file-system description object1175 *1176 * This function destroys journal data structures including those that may have1177 * been created by recovery functions.1178 */1179static void destroy_journal(struct ubifs_info *c)1180{1181	while (!list_empty(&c->unclean_leb_list)) {1182		struct ubifs_unclean_leb *ucleb;1183 1184		ucleb = list_entry(c->unclean_leb_list.next,1185				   struct ubifs_unclean_leb, list);1186		list_del(&ucleb->list);1187		kfree(ucleb);1188	}1189	while (!list_empty(&c->old_buds)) {1190		struct ubifs_bud *bud;1191 1192		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);1193		list_del(&bud->list);1194		kfree(bud->log_hash);1195		kfree(bud);1196	}1197	ubifs_destroy_idx_gc(c);1198	ubifs_destroy_size_tree(c);1199	ubifs_tnc_close(c);1200	free_buds(c);1201}1202 1203/**1204 * bu_init - initialize bulk-read information.1205 * @c: UBIFS file-system description object1206 */1207static void bu_init(struct ubifs_info *c)1208{1209	ubifs_assert(c, c->bulk_read == 1);1210 1211	if (c->bu.buf)1212		return; /* Already initialized */1213 1214again:1215	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);1216	if (!c->bu.buf) {1217		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {1218			c->max_bu_buf_len = UBIFS_KMALLOC_OK;1219			goto again;1220		}1221 1222		/* Just disable bulk-read */1223		ubifs_warn(c, "cannot allocate %d bytes of memory for bulk-read, disabling it",1224			   c->max_bu_buf_len);1225		c->mount_opts.bulk_read = 1;1226		c->bulk_read = 0;1227		return;1228	}1229}1230 1231/**1232 * check_free_space - check if there is enough free space to mount.1233 * @c: UBIFS file-system description object1234 *1235 * This function makes sure UBIFS has enough free space to be mounted in1236 * read/write mode. UBIFS must always have some free space to allow deletions.1237 */1238static int check_free_space(struct ubifs_info *c)1239{1240	ubifs_assert(c, c->dark_wm > 0);1241	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {1242		ubifs_err(c, "insufficient free space to mount in R/W mode");1243		ubifs_dump_budg(c, &c->bi);1244		ubifs_dump_lprops(c);1245		return -ENOSPC;1246	}1247	return 0;1248}1249 1250/**1251 * mount_ubifs - mount UBIFS file-system.1252 * @c: UBIFS file-system description object1253 *1254 * This function mounts UBIFS file system. Returns zero in case of success and1255 * a negative error code in case of failure.1256 */1257static int mount_ubifs(struct ubifs_info *c)1258{1259	int err;1260	long long x, y;1261	size_t sz;1262 1263	c->ro_mount = !!sb_rdonly(c->vfs_sb);1264	/* Suppress error messages while probing if SB_SILENT is set */1265	c->probing = !!(c->vfs_sb->s_flags & SB_SILENT);1266 1267	err = init_constants_early(c);1268	if (err)1269		return err;1270 1271	err = ubifs_debugging_init(c);1272	if (err)1273		return err;1274 1275	err = ubifs_sysfs_register(c);1276	if (err)1277		goto out_debugging;1278 1279	err = check_volume_empty(c);1280	if (err)1281		goto out_free;1282 1283	if (c->empty && (c->ro_mount || c->ro_media)) {1284		/*1285		 * This UBI volume is empty, and read-only, or the file system1286		 * is mounted read-only - we cannot format it.1287		 */1288		ubifs_err(c, "can't format empty UBI volume: read-only %s",1289			  c->ro_media ? "UBI volume" : "mount");1290		err = -EROFS;1291		goto out_free;1292	}1293 1294	if (c->ro_media && !c->ro_mount) {1295		ubifs_err(c, "cannot mount read-write - read-only media");1296		err = -EROFS;1297		goto out_free;1298	}1299 1300	/*1301	 * The requirement for the buffer is that it should fit indexing B-tree1302	 * height amount of integers. We assume the height if the TNC tree will1303	 * never exceed 64.1304	 */1305	err = -ENOMEM;1306	c->bottom_up_buf = kmalloc_array(BOTTOM_UP_HEIGHT, sizeof(int),1307					 GFP_KERNEL);1308	if (!c->bottom_up_buf)1309		goto out_free;1310 1311	c->sbuf = vmalloc(c->leb_size);1312	if (!c->sbuf)1313		goto out_free;1314 1315	if (!c->ro_mount) {1316		c->ileb_buf = vmalloc(c->leb_size);1317		if (!c->ileb_buf)1318			goto out_free;1319	}1320 1321	if (c->bulk_read == 1)1322		bu_init(c);1323 1324	if (!c->ro_mount) {1325		c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \1326					       UBIFS_CIPHER_BLOCK_SIZE,1327					       GFP_KERNEL);1328		if (!c->write_reserve_buf)1329			goto out_free;1330	}1331 1332	c->mounting = 1;1333 1334	if (c->auth_key_name) {1335		if (IS_ENABLED(CONFIG_UBIFS_FS_AUTHENTICATION)) {1336			err = ubifs_init_authentication(c);1337			if (err)1338				goto out_free;1339		} else {1340			ubifs_err(c, "auth_key_name, but UBIFS is built without"1341				  " authentication support");1342			err = -EINVAL;1343			goto out_free;1344		}1345	}1346 1347	err = ubifs_read_superblock(c);1348	if (err)1349		goto out_auth;1350 1351	c->probing = 0;1352 1353	/*1354	 * Make sure the compressor which is set as default in the superblock1355	 * or overridden by mount options is actually compiled in.1356	 */1357	if (!ubifs_compr_present(c, c->default_compr)) {1358		ubifs_err(c, "'compressor \"%s\" is not compiled in",1359			  ubifs_compr_name(c, c->default_compr));1360		err = -ENOTSUPP;1361		goto out_auth;1362	}1363 1364	err = init_constants_sb(c);1365	if (err)1366		goto out_auth;1367 1368	sz = ALIGN(c->max_idx_node_sz, c->min_io_size) * 2;1369	c->cbuf = kmalloc(sz, GFP_NOFS);1370	if (!c->cbuf) {1371		err = -ENOMEM;1372		goto out_auth;1373	}1374 1375	err = alloc_wbufs(c);1376	if (err)1377		goto out_cbuf;1378 1379	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);1380	if (!c->ro_mount) {1381		/* Create background thread */1382		c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);1383		if (IS_ERR(c->bgt)) {1384			err = PTR_ERR(c->bgt);1385			c->bgt = NULL;1386			ubifs_err(c, "cannot spawn \"%s\", error %d",1387				  c->bgt_name, err);1388			goto out_wbufs;1389		}1390	}1391 1392	err = ubifs_read_master(c);1393	if (err)1394		goto out_master;1395 1396	init_constants_master(c);1397 1398	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {1399		ubifs_msg(c, "recovery needed");1400		c->need_recovery = 1;1401	}1402 1403	if (c->need_recovery && !c->ro_mount) {1404		err = ubifs_recover_inl_heads(c, c->sbuf);1405		if (err)1406			goto out_master;1407	}1408 1409	err = ubifs_lpt_init(c, 1, !c->ro_mount);1410	if (err)1411		goto out_master;1412 1413	if (!c->ro_mount && c->space_fixup) {1414		err = ubifs_fixup_free_space(c);1415		if (err)1416			goto out_lpt;1417	}1418 1419	if (!c->ro_mount && !c->need_recovery) {1420		/*1421		 * Set the "dirty" flag so that if we reboot uncleanly we1422		 * will notice this immediately on the next mount.1423		 */1424		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);1425		err = ubifs_write_master(c);1426		if (err)1427			goto out_lpt;1428	}1429 1430	/*1431	 * Handle offline signed images: Now that the master node is1432	 * written and its validation no longer depends on the hash1433	 * in the superblock, we can update the offline signed1434	 * superblock with a HMAC version,1435	 */1436	if (ubifs_authenticated(c) && ubifs_hmac_zero(c, c->sup_node->hmac)) {1437		err = ubifs_hmac_wkm(c, c->sup_node->hmac_wkm);1438		if (err)1439			goto out_lpt;1440		c->superblock_need_write = 1;1441	}1442 1443	if (!c->ro_mount && c->superblock_need_write) {1444		err = ubifs_write_sb_node(c, c->sup_node);1445		if (err)1446			goto out_lpt;1447		c->superblock_need_write = 0;1448	}1449 1450	err = dbg_check_idx_size(c, c->bi.old_idx_sz);1451	if (err)1452		goto out_lpt;1453 1454	err = ubifs_replay_journal(c);1455	if (err)1456		goto out_journal;1457 1458	/* Calculate 'min_idx_lebs' after journal replay */1459	c->bi.min_idx_lebs = ubifs_calc_min_idx_lebs(c);1460 1461	err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount);1462	if (err)1463		goto out_orphans;1464 1465	if (!c->ro_mount) {1466		int lnum;1467 1468		err = check_free_space(c);1469		if (err)1470			goto out_orphans;1471 1472		/* Check for enough log space */1473		lnum = c->lhead_lnum + 1;1474		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)1475			lnum = UBIFS_LOG_LNUM;1476		if (lnum == c->ltail_lnum) {1477			err = ubifs_consolidate_log(c);1478			if (err)1479				goto out_orphans;1480		}1481 1482		if (c->need_recovery) {1483			if (!ubifs_authenticated(c)) {1484				err = ubifs_recover_size(c, true);1485				if (err)1486					goto out_orphans;1487			}1488 1489			err = ubifs_rcvry_gc_commit(c);1490			if (err)1491				goto out_orphans;1492 1493			if (ubifs_authenticated(c)) {1494				err = ubifs_recover_size(c, false);1495				if (err)1496					goto out_orphans;1497			}1498		} else {1499			err = take_gc_lnum(c);1500			if (err)1501				goto out_orphans;1502 1503			/*1504			 * GC LEB may contain garbage if there was an unclean1505			 * reboot, and it should be un-mapped.1506			 */1507			err = ubifs_leb_unmap(c, c->gc_lnum);1508			if (err)1509				goto out_orphans;1510		}1511 1512		err = dbg_check_lprops(c);1513		if (err)1514			goto out_orphans;1515	} else if (c->need_recovery) {1516		err = ubifs_recover_size(c, false);1517		if (err)1518			goto out_orphans;1519	} else {1520		/*1521		 * Even if we mount read-only, we have to set space in GC LEB1522		 * to proper value because this affects UBIFS free space1523		 * reporting. We do not want to have a situation when1524		 * re-mounting from R/O to R/W changes amount of free space.1525		 */1526		err = take_gc_lnum(c);1527		if (err)1528			goto out_orphans;1529	}1530 1531	spin_lock(&ubifs_infos_lock);1532	list_add_tail(&c->infos_list, &ubifs_infos);1533	spin_unlock(&ubifs_infos_lock);1534 1535	if (c->need_recovery) {1536		if (c->ro_mount)1537			ubifs_msg(c, "recovery deferred");1538		else {1539			c->need_recovery = 0;1540			ubifs_msg(c, "recovery completed");1541			/*1542			 * GC LEB has to be empty and taken at this point. But1543			 * the journal head LEBs may also be accounted as1544			 * "empty taken" if they are empty.1545			 */1546			ubifs_assert(c, c->lst.taken_empty_lebs > 0);1547		}1548	} else1549		ubifs_assert(c, c->lst.taken_empty_lebs > 0);1550 1551	err = dbg_check_filesystem(c);1552	if (err)1553		goto out_infos;1554 1555	dbg_debugfs_init_fs(c);1556 1557	c->mounting = 0;1558 1559	ubifs_msg(c, "UBIFS: mounted UBI device %d, volume %d, name \"%s\"%s",1560		  c->vi.ubi_num, c->vi.vol_id, c->vi.name,1561		  c->ro_mount ? ", R/O mode" : "");1562	x = (long long)c->main_lebs * c->leb_size;1563	y = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;1564	ubifs_msg(c, "LEB size: %d bytes (%d KiB), min./max. I/O unit sizes: %d bytes/%d bytes",1565		  c->leb_size, c->leb_size >> 10, c->min_io_size,1566		  c->max_write_size);1567	ubifs_msg(c, "FS size: %lld bytes (%lld MiB, %d LEBs), max %d LEBs, journal size %lld bytes (%lld MiB, %d LEBs)",1568		  x, x >> 20, c->main_lebs, c->max_leb_cnt,1569		  y, y >> 20, c->log_lebs + c->max_bud_cnt);1570	ubifs_msg(c, "reserved for root: %llu bytes (%llu KiB)",1571		  c->report_rp_size, c->report_rp_size >> 10);1572	ubifs_msg(c, "media format: w%d/r%d (latest is w%d/r%d), UUID %pUB%s",1573		  c->fmt_version, c->ro_compat_version,1574		  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION, c->uuid,1575		  c->big_lpt ? ", big LPT model" : ", small LPT model");1576 1577	dbg_gen("default compressor:  %s", ubifs_compr_name(c, c->default_compr));1578	dbg_gen("data journal heads:  %d",1579		c->jhead_cnt - NONDATA_JHEADS_CNT);1580	dbg_gen("log LEBs:            %d (%d - %d)",1581		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);1582	dbg_gen("LPT area LEBs:       %d (%d - %d)",1583		c->lpt_lebs, c->lpt_first, c->lpt_last);1584	dbg_gen("orphan area LEBs:    %d (%d - %d)",1585		c->orph_lebs, c->orph_first, c->orph_last);1586	dbg_gen("main area LEBs:      %d (%d - %d)",1587		c->main_lebs, c->main_first, c->leb_cnt - 1);1588	dbg_gen("index LEBs:          %d", c->lst.idx_lebs);1589	dbg_gen("total index bytes:   %llu (%llu KiB, %llu MiB)",1590		c->bi.old_idx_sz, c->bi.old_idx_sz >> 10,1591		c->bi.old_idx_sz >> 20);1592	dbg_gen("key hash type:       %d", c->key_hash_type);1593	dbg_gen("tree fanout:         %d", c->fanout);1594	dbg_gen("reserved GC LEB:     %d", c->gc_lnum);1595	dbg_gen("max. znode size      %d", c->max_znode_sz);1596	dbg_gen("max. index node size %d", c->max_idx_node_sz);1597	dbg_gen("node sizes:          data %zu, inode %zu, dentry %zu",1598		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);1599	dbg_gen("node sizes:          trun %zu, sb %zu, master %zu",1600		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);1601	dbg_gen("node sizes:          ref %zu, cmt. start %zu, orph %zu",1602		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);1603	dbg_gen("max. node sizes:     data %zu, inode %zu dentry %zu, idx %d",1604		UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,1605		UBIFS_MAX_DENT_NODE_SZ, ubifs_idx_node_sz(c, c->fanout));1606	dbg_gen("dead watermark:      %d", c->dead_wm);1607	dbg_gen("dark watermark:      %d", c->dark_wm);1608	dbg_gen("LEB overhead:        %d", c->leb_overhead);1609	x = (long long)c->main_lebs * c->dark_wm;1610	dbg_gen("max. dark space:     %lld (%lld KiB, %lld MiB)",1611		x, x >> 10, x >> 20);1612	dbg_gen("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",1613		c->max_bud_bytes, c->max_bud_bytes >> 10,1614		c->max_bud_bytes >> 20);1615	dbg_gen("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",1616		c->bg_bud_bytes, c->bg_bud_bytes >> 10,1617		c->bg_bud_bytes >> 20);1618	dbg_gen("current bud bytes    %lld (%lld KiB, %lld MiB)",1619		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);1620	dbg_gen("max. seq. number:    %llu", c->max_sqnum);1621	dbg_gen("commit number:       %llu", c->cmt_no);1622	dbg_gen("max. xattrs per inode: %d", ubifs_xattr_max_cnt(c));1623	dbg_gen("max orphans:           %d", c->max_orphans);1624 1625	return 0;1626 1627out_infos:1628	spin_lock(&ubifs_infos_lock);1629	list_del(&c->infos_list);1630	spin_unlock(&ubifs_infos_lock);1631out_orphans:1632	free_orphans(c);1633out_journal:1634	destroy_journal(c);1635out_lpt:1636	ubifs_lpt_free(c, 0);1637out_master:1638	kfree(c->mst_node);1639	kfree(c->rcvrd_mst_node);1640	if (c->bgt)1641		kthread_stop(c->bgt);1642out_wbufs:1643	free_wbufs(c);1644out_cbuf:1645	kfree(c->cbuf);1646out_auth:1647	ubifs_exit_authentication(c);1648out_free:1649	kfree(c->write_reserve_buf);1650	kfree(c->bu.buf);1651	vfree(c->ileb_buf);1652	vfree(c->sbuf);1653	kfree(c->bottom_up_buf);1654	kfree(c->sup_node);1655	ubifs_sysfs_unregister(c);1656out_debugging:1657	ubifs_debugging_exit(c);1658	return err;1659}1660 1661/**1662 * ubifs_umount - un-mount UBIFS file-system.1663 * @c: UBIFS file-system description object1664 *1665 * Note, this function is called to free allocated resourced when un-mounting,1666 * as well as free resources when an error occurred while we were half way1667 * through mounting (error path cleanup function). So it has to make sure the1668 * resource was actually allocated before freeing it.1669 */1670static void ubifs_umount(struct ubifs_info *c)1671{1672	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,1673		c->vi.vol_id);1674 1675	dbg_debugfs_exit_fs(c);1676	spin_lock(&ubifs_infos_lock);1677	list_del(&c->infos_list);1678	spin_unlock(&ubifs_infos_lock);1679 1680	if (c->bgt)1681		kthread_stop(c->bgt);1682 1683	destroy_journal(c);1684	free_wbufs(c);1685	free_orphans(c);1686	ubifs_lpt_free(c, 0);1687	ubifs_exit_authentication(c);1688 1689	ubifs_release_options(c);1690	kfree(c->cbuf);1691	kfree(c->rcvrd_mst_node);1692	kfree(c->mst_node);1693	kfree(c->write_reserve_buf);1694	kfree(c->bu.buf);1695	vfree(c->ileb_buf);1696	vfree(c->sbuf);1697	kfree(c->bottom_up_buf);1698	kfree(c->sup_node);1699	ubifs_debugging_exit(c);1700	ubifs_sysfs_unregister(c);1701}1702 1703/**1704 * ubifs_remount_rw - re-mount in read-write mode.1705 * @c: UBIFS file-system description object1706 *1707 * UBIFS avoids allocating many unnecessary resources when mounted in read-only1708 * mode. This function allocates the needed resources and re-mounts UBIFS in1709 * read-write mode.1710 */1711static int ubifs_remount_rw(struct ubifs_info *c)1712{1713	int err, lnum;1714 1715	if (c->rw_incompat) {1716		ubifs_err(c, "the file-system is not R/W-compatible");1717		ubifs_msg(c, "on-flash format version is w%d/r%d, but software only supports up to version w%d/r%d",1718			  c->fmt_version, c->ro_compat_version,1719			  UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION);1720		return -EROFS;1721	}1722 1723	mutex_lock(&c->umount_mutex);1724	dbg_save_space_info(c);1725	c->remounting_rw = 1;1726	c->ro_mount = 0;1727 1728	if (c->space_fixup) {1729		err = ubifs_fixup_free_space(c);1730		if (err)1731			goto out;1732	}1733 1734	err = check_free_space(c);1735	if (err)1736		goto out;1737 1738	if (c->need_recovery) {1739		ubifs_msg(c, "completing deferred recovery");1740		err = ubifs_write_rcvrd_mst_node(c);1741		if (err)1742			goto out;1743		if (!ubifs_authenticated(c)) {1744			err = ubifs_recover_size(c, true);1745			if (err)1746				goto out;1747		}1748		err = ubifs_clean_lebs(c, c->sbuf);1749		if (err)1750			goto out;1751		err = ubifs_recover_inl_heads(c, c->sbuf);1752		if (err)1753			goto out;1754	} else {1755		/* A readonly mount is not allowed to have orphans */1756		ubifs_assert(c, c->tot_orphans == 0);1757		err = ubifs_clear_orphans(c);1758		if (err)1759			goto out;1760	}1761 1762	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {1763		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);1764		err = ubifs_write_master(c);1765		if (err)1766			goto out;1767	}1768 1769	if (c->superblock_need_write) {1770		struct ubifs_sb_node *sup = c->sup_node;1771 1772		err = ubifs_write_sb_node(c, sup);1773		if (err)1774			goto out;1775 1776		c->superblock_need_write = 0;1777	}1778 1779	c->ileb_buf = vmalloc(c->leb_size);1780	if (!c->ileb_buf) {1781		err = -ENOMEM;1782		goto out;1783	}1784 1785	c->write_reserve_buf = kmalloc(COMPRESSED_DATA_NODE_BUF_SZ + \1786				       UBIFS_CIPHER_BLOCK_SIZE, GFP_KERNEL);1787	if (!c->write_reserve_buf) {1788		err = -ENOMEM;1789		goto out;1790	}1791 1792	err = ubifs_lpt_init(c, 0, 1);1793	if (err)1794		goto out;1795 1796	/* Create background thread */1797	c->bgt = kthread_run(ubifs_bg_thread, c, "%s", c->bgt_name);1798	if (IS_ERR(c->bgt)) {1799		err = PTR_ERR(c->bgt);1800		c->bgt = NULL;1801		ubifs_err(c, "cannot spawn \"%s\", error %d",1802			  c->bgt_name, err);1803		goto out;1804	}1805 1806	c->orph_buf = vmalloc(c->leb_size);1807	if (!c->orph_buf) {1808		err = -ENOMEM;1809		goto out;1810	}1811 1812	/* Check for enough log space */1813	lnum = c->lhead_lnum + 1;1814	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)1815		lnum = UBIFS_LOG_LNUM;1816	if (lnum == c->ltail_lnum) {1817		err = ubifs_consolidate_log(c);1818		if (err)1819			goto out;1820	}1821 1822	if (c->need_recovery) {1823		err = ubifs_rcvry_gc_commit(c);1824		if (err)1825			goto out;1826 1827		if (ubifs_authenticated(c)) {1828			err = ubifs_recover_size(c, false);1829			if (err)1830				goto out;1831		}1832	} else {1833		err = ubifs_leb_unmap(c, c->gc_lnum);1834	}1835	if (err)1836		goto out;1837 1838	dbg_gen("re-mounted read-write");1839	c->remounting_rw = 0;1840 1841	if (c->need_recovery) {1842		c->need_recovery = 0;1843		ubifs_msg(c, "deferred recovery completed");1844	} else {1845		/*1846		 * Do not run the debugging space check if the were doing1847		 * recovery, because when we saved the information we had the1848		 * file-system in a state where the TNC and lprops has been1849		 * modified in memory, but all the I/O operations (including a1850		 * commit) were deferred. So the file-system was in1851		 * "non-committed" state. Now the file-system is in committed1852		 * state, and of course the amount of free space will change1853		 * because, for example, the old index size was imprecise.1854		 */1855		err = dbg_check_space_info(c);1856	}1857 1858	mutex_unlock(&c->umount_mutex);1859	return err;1860 1861out:1862	c->ro_mount = 1;1863	vfree(c->orph_buf);1864	c->orph_buf = NULL;1865	if (c->bgt) {1866		kthread_stop(c->bgt);1867		c->bgt = NULL;1868	}1869	kfree(c->write_reserve_buf);1870	c->write_reserve_buf = NULL;1871	vfree(c->ileb_buf);1872	c->ileb_buf = NULL;1873	ubifs_lpt_free(c, 1);1874	c->remounting_rw = 0;1875	mutex_unlock(&c->umount_mutex);1876	return err;1877}1878 1879/**1880 * ubifs_remount_ro - re-mount in read-only mode.1881 * @c: UBIFS file-system description object1882 *1883 * We assume VFS has stopped writing. Possibly the background thread could be1884 * running a commit, however kthread_stop will wait in that case.1885 */1886static void ubifs_remount_ro(struct ubifs_info *c)1887{1888	int i, err;1889 1890	ubifs_assert(c, !c->need_recovery);1891	ubifs_assert(c, !c->ro_mount);1892 1893	mutex_lock(&c->umount_mutex);1894	if (c->bgt) {1895		kthread_stop(c->bgt);1896		c->bgt = NULL;1897	}1898 1899	dbg_save_space_info(c);1900 1901	for (i = 0; i < c->jhead_cnt; i++) {1902		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);1903		if (err)1904			ubifs_ro_mode(c, err);1905	}1906 1907	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);1908	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);1909	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);1910	err = ubifs_write_master(c);1911	if (err)1912		ubifs_ro_mode(c, err);1913 1914	vfree(c->orph_buf);1915	c->orph_buf = NULL;1916	kfree(c->write_reserve_buf);1917	c->write_reserve_buf = NULL;1918	vfree(c->ileb_buf);1919	c->ileb_buf = NULL;1920	ubifs_lpt_free(c, 1);1921	c->ro_mount = 1;1922	err = dbg_check_space_info(c);1923	if (err)1924		ubifs_ro_mode(c, err);1925	mutex_unlock(&c->umount_mutex);1926}1927 1928static void ubifs_put_super(struct super_block *sb)1929{1930	int i;1931	struct ubifs_info *c = sb->s_fs_info;1932 1933	ubifs_msg(c, "un-mount UBI device %d", c->vi.ubi_num);1934 1935	/*1936	 * The following asserts are only valid if there has not been a failure1937	 * of the media. For example, there will be dirty inodes if we failed1938	 * to write them back because of I/O errors.1939	 */1940	if (!c->ro_error) {1941		ubifs_assert(c, c->bi.idx_growth == 0);1942		ubifs_assert(c, c->bi.dd_growth == 0);1943		ubifs_assert(c, c->bi.data_growth == 0);1944	}1945 1946	/*1947	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker1948	 * and file system un-mount. Namely, it prevents the shrinker from1949	 * picking this superblock for shrinking - it will be just skipped if1950	 * the mutex is locked.1951	 */1952	mutex_lock(&c->umount_mutex);1953	if (!c->ro_mount) {1954		/*1955		 * First of all kill the background thread to make sure it does1956		 * not interfere with un-mounting and freeing resources.1957		 */1958		if (c->bgt) {1959			kthread_stop(c->bgt);1960			c->bgt = NULL;1961		}1962 1963		/*1964		 * On fatal errors c->ro_error is set to 1, in which case we do1965		 * not write the master node.1966		 */1967		if (!c->ro_error) {1968			int err;1969 1970			/* Synchronize write-buffers */1971			for (i = 0; i < c->jhead_cnt; i++) {1972				err = ubifs_wbuf_sync(&c->jheads[i].wbuf);1973				if (err)1974					ubifs_ro_mode(c, err);1975			}1976 1977			/*1978			 * We are being cleanly unmounted which means the1979			 * orphans were killed - indicate this in the master1980			 * node. Also save the reserved GC LEB number.1981			 */1982			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);1983			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);1984			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);1985			err = ubifs_write_master(c);1986			if (err)1987				/*1988				 * Recovery will attempt to fix the master area1989				 * next mount, so we just print a message and1990				 * continue to unmount normally.1991				 */1992				ubifs_err(c, "failed to write master node, error %d",1993					  err);1994		} else {1995			for (i = 0; i < c->jhead_cnt; i++)1996				/* Make sure write-buffer timers are canceled */1997				hrtimer_cancel(&c->jheads[i].wbuf.timer);1998		}1999	}2000 2001	ubifs_umount(c);2002	ubi_close_volume(c->ubi);2003	mutex_unlock(&c->umount_mutex);2004}2005 2006static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)2007{2008	int err;2009	struct ubifs_info *c = sb->s_fs_info;2010 2011	sync_filesystem(sb);2012	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);2013 2014	err = ubifs_parse_options(c, data, 1);2015	if (err) {2016		ubifs_err(c, "invalid or unknown remount parameter");2017		return err;2018	}2019 2020	if (c->ro_mount && !(*flags & SB_RDONLY)) {2021		if (c->ro_error) {2022			ubifs_msg(c, "cannot re-mount R/W due to prior errors");2023			return -EROFS;2024		}2025		if (c->ro_media) {2026			ubifs_msg(c, "cannot re-mount R/W - UBI volume is R/O");2027			return -EROFS;2028		}2029		err = ubifs_remount_rw(c);2030		if (err)2031			return err;2032	} else if (!c->ro_mount && (*flags & SB_RDONLY)) {2033		if (c->ro_error) {2034			ubifs_msg(c, "cannot re-mount R/O due to prior errors");2035			return -EROFS;2036		}2037		ubifs_remount_ro(c);2038	}2039 2040	if (c->bulk_read == 1)2041		bu_init(c);2042	else {2043		dbg_gen("disable bulk-read");2044		mutex_lock(&c->bu_mutex);2045		kfree(c->bu.buf);2046		c->bu.buf = NULL;2047		mutex_unlock(&c->bu_mutex);2048	}2049 2050	if (!c->need_recovery)2051		ubifs_assert(c, c->lst.taken_empty_lebs > 0);2052 2053	return 0;2054}2055 2056const struct super_operations ubifs_super_operations = {2057	.alloc_inode   = ubifs_alloc_inode,2058	.free_inode    = ubifs_free_inode,2059	.put_super     = ubifs_put_super,2060	.write_inode   = ubifs_write_inode,2061	.drop_inode    = ubifs_drop_inode,2062	.evict_inode   = ubifs_evict_inode,2063	.statfs        = ubifs_statfs,2064	.dirty_inode   = ubifs_dirty_inode,2065	.remount_fs    = ubifs_remount_fs,2066	.show_options  = ubifs_show_options,2067	.sync_fs       = ubifs_sync_fs,2068};2069 2070/**2071 * open_ubi - parse UBI device name string and open the UBI device.2072 * @name: UBI volume name2073 * @mode: UBI volume open mode2074 *2075 * The primary method of mounting UBIFS is by specifying the UBI volume2076 * character device node path. However, UBIFS may also be mounted without any2077 * character device node using one of the following methods:2078 *2079 * o ubiX_Y    - mount UBI device number X, volume Y;2080 * o ubiY      - mount UBI device number 0, volume Y;2081 * o ubiX:NAME - mount UBI device X, volume with name NAME;2082 * o ubi:NAME  - mount UBI device 0, volume with name NAME.2083 *2084 * Alternative '!' separator may be used instead of ':' (because some shells2085 * like busybox may interpret ':' as an NFS host name separator). This function2086 * returns UBI volume description object in case of success and a negative2087 * error code in case of failure.2088 */2089static struct ubi_volume_desc *open_ubi(const char *name, int mode)2090{2091	struct ubi_volume_desc *ubi;2092	int dev, vol;2093	char *endptr;2094 2095	if (!name || !*name)2096		return ERR_PTR(-EINVAL);2097 2098	/* First, try to open using the device node path method */2099	ubi = ubi_open_volume_path(name, mode);2100	if (!IS_ERR(ubi))2101		return ubi;2102 2103	/* Try the "nodev" method */2104	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')2105		return ERR_PTR(-EINVAL);2106 2107	/* ubi:NAME method */2108	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')2109		return ubi_open_volume_nm(0, name + 4, mode);2110 2111	if (!isdigit(name[3]))2112		return ERR_PTR(-EINVAL);2113 2114	dev = simple_strtoul(name + 3, &endptr, 0);2115 2116	/* ubiY method */2117	if (*endptr == '\0')2118		return ubi_open_volume(0, dev, mode);2119 2120	/* ubiX_Y method */2121	if (*endptr == '_' && isdigit(endptr[1])) {2122		vol = simple_strtoul(endptr + 1, &endptr, 0);2123		if (*endptr != '\0')2124			return ERR_PTR(-EINVAL);2125		return ubi_open_volume(dev, vol, mode);2126	}2127 2128	/* ubiX:NAME method */2129	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')2130		return ubi_open_volume_nm(dev, ++endptr, mode);2131 2132	return ERR_PTR(-EINVAL);2133}2134 2135static struct ubifs_info *alloc_ubifs_info(struct ubi_volume_desc *ubi)2136{2137	struct ubifs_info *c;2138 2139	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);2140	if (c) {2141		spin_lock_init(&c->cnt_lock);2142		spin_lock_init(&c->cs_lock);2143		spin_lock_init(&c->buds_lock);2144		spin_lock_init(&c->space_lock);2145		spin_lock_init(&c->orphan_lock);2146		init_rwsem(&c->commit_sem);2147		mutex_init(&c->lp_mutex);2148		mutex_init(&c->tnc_mutex);2149		mutex_init(&c->log_mutex);2150		mutex_init(&c->umount_mutex);2151		mutex_init(&c->bu_mutex);2152		mutex_init(&c->write_reserve_mutex);2153		init_waitqueue_head(&c->cmt_wq);2154		init_waitqueue_head(&c->reserve_space_wq);2155		atomic_set(&c->need_wait_space, 0);2156		c->buds = RB_ROOT;2157		c->old_idx = RB_ROOT;2158		c->size_tree = RB_ROOT;2159		c->orph_tree = RB_ROOT;2160		INIT_LIST_HEAD(&c->infos_list);2161		INIT_LIST_HEAD(&c->idx_gc);2162		INIT_LIST_HEAD(&c->replay_list);2163		INIT_LIST_HEAD(&c->replay_buds);2164		INIT_LIST_HEAD(&c->uncat_list);2165		INIT_LIST_HEAD(&c->empty_list);2166		INIT_LIST_HEAD(&c->freeable_list);2167		INIT_LIST_HEAD(&c->frdi_idx_list);2168		INIT_LIST_HEAD(&c->unclean_leb_list);2169		INIT_LIST_HEAD(&c->old_buds);2170		INIT_LIST_HEAD(&c->orph_list);2171		INIT_LIST_HEAD(&c->orph_new);2172		c->no_chk_data_crc = 1;2173		c->assert_action = ASSACT_RO;2174 2175		c->highest_inum = UBIFS_FIRST_INO;2176		c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;2177 2178		ubi_get_volume_info(ubi, &c->vi);2179		ubi_get_device_info(c->vi.ubi_num, &c->di);2180	}2181	return c;2182}2183 2184static int ubifs_fill_super(struct super_block *sb, void *data, int silent)2185{2186	struct ubifs_info *c = sb->s_fs_info;2187	struct inode *root;2188	int err;2189 2190	c->vfs_sb = sb;2191	/* Re-open the UBI device in read-write mode */2192	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);2193	if (IS_ERR(c->ubi)) {2194		err = PTR_ERR(c->ubi);2195		goto out;2196	}2197 2198	err = ubifs_parse_options(c, data, 0);2199	if (err)2200		goto out_close;2201 2202	/*2203	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For2204	 * UBIFS, I/O is not deferred, it is done immediately in read_folio,2205	 * which means the user would have to wait not just for their own I/O2206	 * but the read-ahead I/O as well i.e. completely pointless.2207	 *2208	 * Read-ahead will be disabled because @sb->s_bdi->ra_pages is 0. Also2209	 * @sb->s_bdi->capabilities are initialized to 0 so there won't be any2210	 * writeback happening.2211	 */2212	err = super_setup_bdi_name(sb, "ubifs_%d_%d", c->vi.ubi_num,2213				   c->vi.vol_id);2214	if (err)2215		goto out_close;2216	sb->s_bdi->ra_pages = 0;2217	sb->s_bdi->io_pages = 0;2218 2219	sb->s_fs_info = c;2220	sb->s_magic = UBIFS_SUPER_MAGIC;2221	sb->s_blocksize = UBIFS_BLOCK_SIZE;2222	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;2223	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);2224	if (c->max_inode_sz > MAX_LFS_FILESIZE)2225		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;2226	sb->s_op = &ubifs_super_operations;2227	sb->s_xattr = ubifs_xattr_handlers;2228	fscrypt_set_ops(sb, &ubifs_crypt_operations);2229 2230	mutex_lock(&c->umount_mutex);2231	err = mount_ubifs(c);2232	if (err) {2233		ubifs_assert(c, err < 0);2234		goto out_unlock;2235	}2236 2237	/* Read the root inode */2238	root = ubifs_iget(sb, UBIFS_ROOT_INO);2239	if (IS_ERR(root)) {2240		err = PTR_ERR(root);2241		goto out_umount;2242	}2243 2244	generic_set_sb_d_ops(sb);2245	sb->s_root = d_make_root(root);2246	if (!sb->s_root) {2247		err = -ENOMEM;2248		goto out_umount;2249	}2250 2251	super_set_uuid(sb, c->uuid, sizeof(c->uuid));2252 2253	mutex_unlock(&c->umount_mutex);2254	return 0;2255 2256out_umount:2257	ubifs_umount(c);2258out_unlock:2259	mutex_unlock(&c->umount_mutex);2260out_close:2261	ubifs_release_options(c);2262	ubi_close_volume(c->ubi);2263out:2264	return err;2265}2266 2267static int sb_test(struct super_block *sb, void *data)2268{2269	struct ubifs_info *c1 = data;2270	struct ubifs_info *c = sb->s_fs_info;2271 2272	return c->vi.cdev == c1->vi.cdev;2273}2274 2275static int sb_set(struct super_block *sb, void *data)2276{2277	sb->s_fs_info = data;2278	return set_anon_super(sb, NULL);2279}2280 2281static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags,2282			const char *name, void *data)2283{2284	struct ubi_volume_desc *ubi;2285	struct ubifs_info *c;2286	struct super_block *sb;2287	int err;2288 2289	dbg_gen("name %s, flags %#x", name, flags);2290 2291	/*2292	 * Get UBI device number and volume ID. Mount it read-only so far2293	 * because this might be a new mount point, and UBI allows only one2294	 * read-write user at a time.2295	 */2296	ubi = open_ubi(name, UBI_READONLY);2297	if (IS_ERR(ubi)) {2298		if (!(flags & SB_SILENT))2299			pr_err("UBIFS error (pid: %d): cannot open \"%s\", error %d",2300			       current->pid, name, (int)PTR_ERR(ubi));2301		return ERR_CAST(ubi);2302	}2303 2304	c = alloc_ubifs_info(ubi);2305	if (!c) {2306		err = -ENOMEM;2307		goto out_close;2308	}2309 2310	dbg_gen("opened ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);2311 2312	sb = sget(fs_type, sb_test, sb_set, flags, c);2313	if (IS_ERR(sb)) {2314		err = PTR_ERR(sb);2315		kfree(c);2316		goto out_close;2317	}2318 2319	if (sb->s_root) {2320		struct ubifs_info *c1 = sb->s_fs_info;2321		kfree(c);2322		/* A new mount point for already mounted UBIFS */2323		dbg_gen("this ubi volume is already mounted");2324		if (!!(flags & SB_RDONLY) != c1->ro_mount) {2325			err = -EBUSY;2326			goto out_deact;2327		}2328	} else {2329		err = ubifs_fill_super(sb, data, flags & SB_SILENT ? 1 : 0);2330		if (err)2331			goto out_deact;2332		/* We do not support atime */2333		sb->s_flags |= SB_ACTIVE;2334		if (IS_ENABLED(CONFIG_UBIFS_ATIME_SUPPORT))2335			ubifs_msg(c, "full atime support is enabled.");2336		else2337			sb->s_flags |= SB_NOATIME;2338	}2339 2340	/* 'fill_super()' opens ubi again so we must close it here */2341	ubi_close_volume(ubi);2342 2343	return dget(sb->s_root);2344 2345out_deact:2346	deactivate_locked_super(sb);2347out_close:2348	ubi_close_volume(ubi);2349	return ERR_PTR(err);2350}2351 2352static void kill_ubifs_super(struct super_block *s)2353{2354	struct ubifs_info *c = s->s_fs_info;2355	kill_anon_super(s);2356	kfree(c);2357}2358 2359static struct file_system_type ubifs_fs_type = {2360	.name    = "ubifs",2361	.owner   = THIS_MODULE,2362	.mount   = ubifs_mount,2363	.kill_sb = kill_ubifs_super,2364};2365MODULE_ALIAS_FS("ubifs");2366 2367/*2368 * Inode slab cache constructor.2369 */2370static void inode_slab_ctor(void *obj)2371{2372	struct ubifs_inode *ui = obj;2373	inode_init_once(&ui->vfs_inode);2374}2375 2376static int __init ubifs_init(void)2377{2378	int err = -ENOMEM;2379 2380	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);2381 2382	/* Make sure node sizes are 8-byte aligned */2383	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);2384	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);2385	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);2386	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);2387	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);2388	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);2389	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);2390	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);2391	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);2392	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);2393	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);2394 2395	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);2396	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);2397	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);2398	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);2399	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);2400	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);2401 2402	/* Check min. node size */2403	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);2404	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);2405	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);2406	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);2407 2408	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);2409	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);2410	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);2411	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);2412 2413	/* Defined node sizes */2414	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);2415	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);2416	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);2417	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);2418 2419	/*2420	 * We use 2 bit wide bit-fields to store compression type, which should2421	 * be amended if more compressors are added. The bit-fields are:2422	 * @compr_type in 'struct ubifs_inode', @default_compr in2423	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.2424	 */2425	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);2426 2427	/*2428	 * We require that PAGE_SIZE is greater-than-or-equal-to2429	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.2430	 */2431	if (PAGE_SIZE < UBIFS_BLOCK_SIZE) {2432		pr_err("UBIFS error (pid %d): VFS page cache size is %u bytes, but UBIFS requires at least 4096 bytes",2433		       current->pid, (unsigned int)PAGE_SIZE);2434		return -EINVAL;2435	}2436 2437	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",2438				sizeof(struct ubifs_inode), 0,2439				SLAB_RECLAIM_ACCOUNT | SLAB_ACCOUNT,2440				&inode_slab_ctor);2441	if (!ubifs_inode_slab)2442		return -ENOMEM;2443 2444	ubifs_shrinker_info = shrinker_alloc(0, "ubifs-slab");2445	if (!ubifs_shrinker_info)2446		goto out_slab;2447 2448	ubifs_shrinker_info->count_objects = ubifs_shrink_count;2449	ubifs_shrinker_info->scan_objects = ubifs_shrink_scan;2450 2451	shrinker_register(ubifs_shrinker_info);2452 2453	err = ubifs_compressors_init();2454	if (err)2455		goto out_shrinker;2456 2457	dbg_debugfs_init();2458 2459	err = ubifs_sysfs_init();2460	if (err)2461		goto out_dbg;2462 2463	err = register_filesystem(&ubifs_fs_type);2464	if (err) {2465		pr_err("UBIFS error (pid %d): cannot register file system, error %d",2466		       current->pid, err);2467		goto out_sysfs;2468	}2469	return 0;2470 2471out_sysfs:2472	ubifs_sysfs_exit();2473out_dbg:2474	dbg_debugfs_exit();2475	ubifs_compressors_exit();2476out_shrinker:2477	shrinker_free(ubifs_shrinker_info);2478out_slab:2479	kmem_cache_destroy(ubifs_inode_slab);2480	return err;2481}2482/* late_initcall to let compressors initialize first */2483late_initcall(ubifs_init);2484 2485static void __exit ubifs_exit(void)2486{2487	WARN_ON(!list_empty(&ubifs_infos));2488	WARN_ON(atomic_long_read(&ubifs_clean_zn_cnt) != 0);2489 2490	dbg_debugfs_exit();2491	ubifs_sysfs_exit();2492	ubifs_compressors_exit();2493	shrinker_free(ubifs_shrinker_info);2494 2495	/*2496	 * Make sure all delayed rcu free inodes are flushed before we2497	 * destroy cache.2498	 */2499	rcu_barrier();2500	kmem_cache_destroy(ubifs_inode_slab);2501	unregister_filesystem(&ubifs_fs_type);2502}2503module_exit(ubifs_exit);2504 2505MODULE_LICENSE("GPL");2506MODULE_VERSION(__stringify(UBIFS_VERSION));2507MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");2508MODULE_DESCRIPTION("UBIFS - UBI File System");2509