/* * This file is part of UBIFS. * * Copyright (C) 2006-2008 Nokia Corporation. * * This program is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 as published by * the Free Software Foundation. * * This program 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 General Public License for * more details. * * You should have received a copy of the GNU General Public License along with * this program; if not, write to the Free Software Foundation, Inc., 51 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA * * Authors: Artem Bityutskiy (Битюцкий Артём) * Adrian Hunter */ /* * This file implements UBIFS initialization and VFS superblock operations. Some * initialization stuff which is rather large and complex is placed at * corresponding subsystems, but most of it is here. */ #include <linux/init.h> #include <linux/slab.h> #include <linux/module.h> #include <linux/ctype.h> #include <linux/kthread.h> #include <linux/parser.h> #include <linux/seq_file.h> #include <linux/mount.h> #include <linux/math64.h> #include <linux/writeback.h> #include "ubifs.h" /* * Maximum amount of memory we may 'kmalloc()' without worrying that we are * allocating too much. */ #define UBIFS_KMALLOC_OK (128*1024) /* Slab cache for UBIFS inodes */ struct kmem_cache *ubifs_inode_slab; /* UBIFS TNC shrinker description */ static struct shrinker ubifs_shrinker_info = { .shrink = ubifs_shrinker, .seeks = DEFAULT_SEEKS, }; /** * validate_inode - validate inode. * @c: UBIFS file-system description object * @inode: the inode to validate * * This is a helper function for 'ubifs_iget()' which validates various fields * of a newly built inode to make sure they contain sane values and prevent * possible vulnerabilities. Returns zero if the inode is all right and * a non-zero error code if not. */ static int validate_inode(struct ubifs_info *c, const struct inode *inode) { int err; const struct ubifs_inode *ui = ubifs_inode(inode); if (inode->i_size > c->max_inode_sz) { ubifs_err("inode is too large (%lld)", (long long)inode->i_size); return 1; } if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) { ubifs_err("unknown compression type %d", ui->compr_type); return 2; } if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX) return 3; if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA) return 4; if (ui->xattr && (inode->i_mode & S_IFMT) != S_IFREG) return 5; if (!ubifs_compr_present(ui->compr_type)) { ubifs_warn("inode %lu uses '%s' compression, but it was not " "compiled in", inode->i_ino, ubifs_compr_name(ui->compr_type)); } err = dbg_check_dir_size(c, inode); return err; } struct inode *ubifs_iget(struct super_block *sb, unsigned long inum) { int err; union ubifs_key key; struct ubifs_ino_node *ino; struct ubifs_info *c = sb->s_fs_info; struct inode *inode; struct ubifs_inode *ui; dbg_gen("inode %lu", inum); inode = iget_locked(sb, inum); if (!inode) return ERR_PTR(-ENOMEM); if (!(inode->i_state & I_NEW)) return inode; ui = ubifs_inode(inode); ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS); if (!ino) { err = -ENOMEM; goto out; } ino_key_init(c, &key, inode->i_ino); err = ubifs_tnc_lookup(c, &key, ino); if (err) goto out_ino; inode->i_flags |= (S_NOCMTIME | S_NOATIME); inode->i_nlink = le32_to_cpu(ino->nlink); inode->i_uid = le32_to_cpu(ino->uid); inode->i_gid = le32_to_cpu(ino->gid); inode->i_atime.tv_sec = (int64_t)le64_to_cpu(ino->atime_sec); inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec); inode->i_mtime.tv_sec = (int64_t)le64_to_cpu(ino->mtime_sec); inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec); inode->i_ctime.tv_sec = (int64_t)le64_to_cpu(ino->ctime_sec); inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec); inode->i_mode = le32_to_cpu(ino->mode); inode->i_size = le64_to_cpu(ino->size); ui->data_len = le32_to_cpu(ino->data_len); ui->flags = le32_to_cpu(ino->flags); ui->compr_type = le16_to_cpu(ino->compr_type); ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum); ui->xattr_cnt = le32_to_cpu(ino->xattr_cnt); ui->xattr_size = le32_to_cpu(ino->xattr_size); ui->xattr_names = le32_to_cpu(ino->xattr_names); ui->synced_i_size = ui->ui_size = inode->i_size; ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0; err = validate_inode(c, inode); if (err) goto out_invalid; /* Disable read-ahead */ inode->i_mapping->backing_dev_info = &c->bdi; switch (inode->i_mode & S_IFMT) { case S_IFREG: inode->i_mapping->a_ops = &ubifs_file_address_operations; inode->i_op = &ubifs_file_inode_operations; inode->i_fop = &ubifs_file_operations; if (ui->xattr) { ui->data = kmalloc(ui->data_len + 1, GFP_NOFS); if (!ui->data) { err = -ENOMEM; goto out_ino; } memcpy(ui->data, ino->data, ui->data_len); ((char *)ui->data)[ui->data_len] = '\0'; } else if (ui->data_len != 0) { err = 10; goto out_invalid; } break; case S_IFDIR: inode->i_op = &ubifs_dir_inode_operations; inode->i_fop = &ubifs_dir_operations; if (ui->data_len != 0) { err = 11; goto out_invalid; } break; case S_IFLNK: inode->i_op = &ubifs_symlink_inode_operations; if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) { err = 12; goto out_invalid; } ui->data = kmalloc(ui->data_len + 1, GFP_NOFS); if (!ui->data) { err = -ENOMEM; goto out_ino; } memcpy(ui->data, ino->data, ui->data_len); ((char *)ui->data)[ui->data_len] = '\0'; break; case S_IFBLK: case S_IFCHR: { dev_t rdev; union ubifs_dev_desc *dev; ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!ui->data) { err = -ENOMEM; goto out_ino; } dev = (union ubifs_dev_desc *)ino->data; if (ui->data_len == sizeof(dev->new)) rdev = new_decode_dev(le32_to_cpu(dev->new)); else if (ui->data_len == sizeof(dev->huge)) rdev = huge_decode_dev(le64_to_cpu(dev->huge)); else { err = 13; goto out_invalid; } memcpy(ui->data, ino->data, ui->data_len); inode->i_op = &ubifs_file_inode_operations; init_special_inode(inode, inode->i_mode, rdev); break; } case S_IFSOCK: case S_IFIFO: inode->i_op = &ubifs_file_inode_operations; init_special_inode(inode, inode->i_mode, 0); if (ui->data_len != 0) { err = 14; goto out_invalid; } break; default: err = 15; goto out_invalid; } kfree(ino); ubifs_set_inode_flags(inode); unlock_new_inode(inode); return inode; out_invalid: ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err); dbg_dump_node(c, ino); dbg_dump_inode(c, inode); err = -EINVAL; out_ino: kfree(ino); out: ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err); iget_failed(inode); return ERR_PTR(err); } static struct inode *ubifs_alloc_inode(struct super_block *sb) { struct ubifs_inode *ui; ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS); if (!ui) return NULL; memset((void *)ui + sizeof(struct inode), 0, sizeof(struct ubifs_inode) - sizeof(struct inode)); mutex_init(&ui->ui_mutex); spin_lock_init(&ui->ui_lock); return &ui->vfs_inode; }; static void ubifs_destroy_inode(struct inode *inode) { struct ubifs_inode *ui = ubifs_inode(inode); kfree(ui->data); kmem_cache_free(ubifs_inode_slab, inode); } /* * Note, Linux write-back code calls this without 'i_mutex'. */ static int ubifs_write_inode(struct inode *inode, struct writeback_control *wbc) { int err = 0; struct ubifs_info *c = inode->i_sb->s_fs_info; struct ubifs_inode *ui = ubifs_inode(inode); ubifs_assert(!ui->xattr); if (is_bad_inode(inode)) return 0; mutex_lock(&ui->ui_mutex); /* * Due to races between write-back forced by budgeting * (see 'sync_some_inodes()') and pdflush write-back, the inode may * have already been synchronized, do not do this again. This might * also happen if it was synchronized in an VFS operation, e.g. * 'ubifs_link()'. */ if (!ui->dirty) { mutex_unlock(&ui->ui_mutex); return 0; } /* * As an optimization, do not write orphan inodes to the media just * because this is not needed. */ dbg_gen("inode %lu, mode %#x, nlink %u", inode->i_ino, (int)inode->i_mode, inode->i_nlink); if (inode->i_nlink) { err = ubifs_jnl_write_inode(c, inode); if (err) ubifs_err("can't write inode %lu, error %d", inode->i_ino, err); else err = dbg_check_inode_size(c, inode, ui->ui_size); } ui->dirty = 0; mutex_unlock(&ui->ui_mutex); ubifs_release_dirty_inode_budget(c, ui); return err; } static void ubifs_evict_inode(struct inode *inode) { int err; struct ubifs_info *c = inode->i_sb->s_fs_info; struct ubifs_inode *ui = ubifs_inode(inode); if (ui->xattr) /* * Extended attribute inode deletions are fully handled in * 'ubifs_removexattr()'. These inodes are special and have * limited usage, so there is nothing to do here. */ goto out; dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode); ubifs_assert(!atomic_read(&inode->i_count)); truncate_inode_pages(&inode->i_data, 0); if (inode->i_nlink) goto done; if (is_bad_inode(inode)) goto out; ui->ui_size = inode->i_size = 0; err = ubifs_jnl_delete_inode(c, inode); if (err) /* * Worst case we have a lost orphan inode wasting space, so a * simple error message is OK here. */ ubifs_err("can't delete inode %lu, error %d", inode->i_ino, err); out: if (ui->dirty) ubifs_release_dirty_inode_budget(c, ui); else { /* We've deleted something - clean the "no space" flags */ c->nospace = c->nospace_rp = 0; smp_wmb(); } done: end_writeback(inode); } static void ubifs_dirty_inode(struct inode *inode) { struct ubifs_inode *ui = ubifs_inode(inode); ubifs_assert(mutex_is_locked(&ui->ui_mutex)); if (!ui->dirty) { ui->dirty = 1; dbg_gen("inode %lu", inode->i_ino); } } static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf) { struct ubifs_info *c = dentry->d_sb->s_fs_info; unsigned long long free; __le32 *uuid = (__le32 *)c->uuid; free = ubifs_get_free_space(c); dbg_gen("free space %lld bytes (%lld blocks)", free, free >> UBIFS_BLOCK_SHIFT); buf->f_type = UBIFS_SUPER_MAGIC; buf->f_bsize = UBIFS_BLOCK_SIZE; buf->f_blocks = c->block_cnt; buf->f_bfree = free >> UBIFS_BLOCK_SHIFT; if (free > c->report_rp_size) buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT; else buf->f_bavail = 0; buf->f_files = 0; buf->f_ffree = 0; buf->f_namelen = UBIFS_MAX_NLEN; buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]); buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]); ubifs_assert(buf->f_bfree <= c->block_cnt); return 0; } static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt) { struct ubifs_info *c = mnt->mnt_sb->s_fs_info; if (c->mount_opts.unmount_mode == 2) seq_printf(s, ",fast_unmount"); else if (c->mount_opts.unmount_mode == 1) seq_printf(s, ",norm_unmount"); if (c->mount_opts.bulk_read == 2) seq_printf(s, ",bulk_read"); else if (c->mount_opts.bulk_read == 1) seq_printf(s, ",no_bulk_read"); if (c->mount_opts.chk_data_crc == 2) seq_printf(s, ",chk_data_crc"); else if (c->mount_opts.chk_data_crc == 1) seq_printf(s, ",no_chk_data_crc"); if (c->mount_opts.override_compr) { seq_printf(s, ",compr=%s", ubifs_compr_name(c->mount_opts.compr_type)); } return 0; } static int ubifs_sync_fs(struct super_block *sb, int wait) { int i, err; struct ubifs_info *c = sb->s_fs_info; /* * Zero @wait is just an advisory thing to help the file system shove * lots of data into the queues, and there will be the second * '->sync_fs()' call, with non-zero @wait. */ if (!wait) return 0; /* * Synchronize write buffers, because 'ubifs_run_commit()' does not * do this if it waits for an already running commit. */ for (i = 0; i < c->jhead_cnt; i++) { err = ubifs_wbuf_sync(&c->jheads[i].wbuf); if (err) return err; } /* * Strictly speaking, it is not necessary to commit the journal here, * synchronizing write-buffers would be enough. But committing makes * UBIFS free space predictions much more accurate, so we want to let * the user be able to get more accurate results of 'statfs()' after * they synchronize the file system. */ err = ubifs_run_commit(c); if (err) return err; return ubi_sync(c->vi.ubi_num); } /** * init_constants_early - initialize UBIFS constants. * @c: UBIFS file-system description object * * This function initialize UBIFS constants which do not need the superblock to * be read. It also checks that the UBI volume satisfies basic UBIFS * requirements. Returns zero in case of success and a negative error code in * case of failure. */ static int init_constants_early(struct ubifs_info *c) { if (c->vi.corrupted) { ubifs_warn("UBI volume is corrupted - read-only mode"); c->ro_media = 1; } if (c->di.ro_mode) { ubifs_msg("read-only UBI device"); c->ro_media = 1; } if (c->vi.vol_type == UBI_STATIC_VOLUME) { ubifs_msg("static UBI volume - read-only mode"); c->ro_media = 1; } c->leb_cnt = c->vi.size; c->leb_size = c->vi.usable_leb_size; c->half_leb_size = c->leb_size / 2; c->min_io_size = c->di.min_io_size; c->min_io_shift = fls(c->min_io_size) - 1; if (c->leb_size < UBIFS_MIN_LEB_SZ) { ubifs_err("too small LEBs (%d bytes), min. is %d bytes", c->leb_size, UBIFS_MIN_LEB_SZ); return -EINVAL; } if (c->leb_cnt < UBIFS_MIN_LEB_CNT) { ubifs_err("too few LEBs (%d), min. is %d", c->leb_cnt, UBIFS_MIN_LEB_CNT); return -EINVAL; } if (!is_power_of_2(c->min_io_size)) { ubifs_err("bad min. I/O size %d", c->min_io_size); return -EINVAL; } /* * UBIFS aligns all node to 8-byte boundary, so to make function in * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is * less than 8. */ if (c->min_io_size < 8) { c->min_io_size = 8; c->min_io_shift = 3; } c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size); c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size); /* * Initialize node length ranges which are mostly needed for node * length validation. */ c->ranges[UBIFS_PAD_NODE].len = UBIFS_PAD_NODE_SZ; c->ranges[UBIFS_SB_NODE].len = UBIFS_SB_NODE_SZ; c->ranges[UBIFS_MST_NODE].len = UBIFS_MST_NODE_SZ; c->ranges[UBIFS_REF_NODE].len = UBIFS_REF_NODE_SZ; c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ; c->ranges[UBIFS_CS_NODE].len = UBIFS_CS_NODE_SZ; c->ranges[UBIFS_INO_NODE].min_len = UBIFS_INO_NODE_SZ; c->ranges[UBIFS_INO_NODE].max_len = UBIFS_MAX_INO_NODE_SZ; c->ranges[UBIFS_ORPH_NODE].min_len = UBIFS_ORPH_NODE_SZ + sizeof(__le64); c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size; c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ; c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ; c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ; c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ; c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ; c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ; /* * Minimum indexing node size is amended later when superblock is * read and the key length is known. */ c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ; /* * Maximum indexing node size is amended later when superblock is * read and the fanout is known. */ c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX; /* * Initialize dead and dark LEB space watermarks. See gc.c for comments * about these values. */ c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size); c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size); /* * Calculate how many bytes would be wasted at the end of LEB if it was * fully filled with data nodes of maximum size. This is used in * calculations when reporting free space. */ c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ; /* Buffer size for bulk-reads */ c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ; if (c->max_bu_buf_len > c->leb_size) c->max_bu_buf_len = c->leb_size; return 0; } /** * bud_wbuf_callback - bud LEB write-buffer synchronization call-back. * @c: UBIFS file-system description object * @lnum: LEB the write-buffer was synchronized to * @free: how many free bytes left in this LEB * @pad: how many bytes were padded * * This is a callback function which is called by the I/O unit when the * write-buffer is synchronized. We need this to correctly maintain space * accounting in bud logical eraseblocks. This function returns zero in case of * success and a negative error code in case of failure. * * This function actually belongs to the journal, but we keep it here because * we want to keep it static. */ static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad) { return ubifs_update_one_lp(c, lnum, free, pad, 0, 0); } /* * init_constants_sb - initialize UBIFS constants. * @c: UBIFS file-system description object * * This is a helper function which initializes various UBIFS constants after * the superblock has been read. It also checks various UBIFS parameters and * makes sure they are all right. Returns zero in case of success and a * negative error code in case of failure. */ static int init_constants_sb(struct ubifs_info *c) { int tmp, err; long long tmp64; c->main_bytes = (long long)c->main_lebs * c->leb_size; c->max_znode_sz = sizeof(struct ubifs_znode) + c->fanout * sizeof(struct ubifs_zbranch); tmp = ubifs_idx_node_sz(c, 1); c->ranges[UBIFS_IDX_NODE].min_len = tmp; c->min_idx_node_sz = ALIGN(tmp, 8); tmp = ubifs_idx_node_sz(c, c->fanout); c->ranges[UBIFS_IDX_NODE].max_len = tmp; c->max_idx_node_sz = ALIGN(tmp, 8); /* Make sure LEB size is large enough to fit full commit */ tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt; tmp = ALIGN(tmp, c->min_io_size); if (tmp > c->leb_size) { dbg_err("too small LEB size %d, at least %d needed", c->leb_size, tmp); return -EINVAL; } /* * Make sure that the log is large enough to fit reference nodes for * all buds plus one reserved LEB. */ tmp64 = c->max_bud_bytes + c->leb_size - 1; c->max_bud_cnt = div_u64(tmp64, c->leb_size); tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1); tmp /= c->leb_size; tmp += 1; if (c->log_lebs < tmp) { dbg_err("too small log %d LEBs, required min. %d LEBs", c->log_lebs, tmp); return -EINVAL; } /* * When budgeting we assume worst-case scenarios when the pages are not * be compressed and direntries are of the maximum size. * * Note, data, which may be stored in inodes is budgeted separately, so * it is not included into 'c->inode_budget'. */ c->page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE; c->inode_budget = UBIFS_INO_NODE_SZ; c->dent_budget = UBIFS_MAX_DENT_NODE_SZ; /* * When the amount of flash space used by buds becomes * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit. * The writers are unblocked when the commit is finished. To avoid * writers to be blocked UBIFS initiates background commit in advance, * when number of bud bytes becomes above the limit defined below. */ c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4; /* * Ensure minimum journal size. All the bytes in the journal heads are * considered to be used, when calculating the current journal usage. * Consequently, if the journal is too small, UBIFS will treat it as * always full. */ tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1; if (c->bg_bud_bytes < tmp64) c->bg_bud_bytes = tmp64; if (c->max_bud_bytes < tmp64 + c->leb_size) c->max_bud_bytes = tmp64 + c->leb_size; err = ubifs_calc_lpt_geom(c); if (err) return err; /* Initialize effective LEB size used in budgeting calculations */ c->idx_leb_size = c->leb_size - c->max_idx_node_sz; return 0; } /* * init_constants_master - initialize UBIFS constants. * @c: UBIFS file-system description object * * This is a helper function which initializes various UBIFS constants after * the master node has been read. It also checks various UBIFS parameters and * makes sure they are all right. */ static void init_constants_master(struct ubifs_info *c) { long long tmp64; c->min_idx_lebs = ubifs_calc_min_idx_lebs(c); c->report_rp_size = ubifs_reported_space(c, c->rp_size); /* * Calculate total amount of FS blocks. This number is not used * internally because it does not make much sense for UBIFS, but it is * necessary to report something for the 'statfs()' call. * * Subtract the LEB reserved for GC, the LEB which is reserved for * deletions, minimum LEBs for the index, and assume only one journal * head is available. */ tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1; tmp64 *= (long long)c->leb_size - c->leb_overhead; tmp64 = ubifs_reported_space(c, tmp64); c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT; } /** * take_gc_lnum - reserve GC LEB. * @c: UBIFS file-system description object * * This function ensures that the LEB reserved for garbage collection is marked * as "taken" in lprops. We also have to set free space to LEB size and dirty * space to zero, because lprops may contain out-of-date information if the * file-system was un-mounted before it has been committed. This function * returns zero in case of success and a negative error code in case of * failure. */ static int take_gc_lnum(struct ubifs_info *c) { int err; if (c->gc_lnum == -1) { ubifs_err("no LEB for GC"); return -EINVAL; } /* And we have to tell lprops that this LEB is taken */ err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0, LPROPS_TAKEN, 0, 0); return err; } /** * alloc_wbufs - allocate write-buffers. * @c: UBIFS file-system description object * * This helper function allocates and initializes UBIFS write-buffers. Returns * zero in case of success and %-ENOMEM in case of failure. */ static int alloc_wbufs(struct ubifs_info *c) { int i, err; c->jheads = kzalloc(c->jhead_cnt * sizeof(struct ubifs_jhead), GFP_KERNEL); if (!c->jheads) return -ENOMEM; /* Initialize journal heads */ for (i = 0; i < c->jhead_cnt; i++) { INIT_LIST_HEAD(&c->jheads[i].buds_list); err = ubifs_wbuf_init(c, &c->jheads[i].wbuf); if (err) return err; c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback; c->jheads[i].wbuf.jhead = i; } c->jheads[BASEHD].wbuf.dtype = UBI_SHORTTERM; /* * Garbage Collector head likely contains long-term data and * does not need to be synchronized by timer. */ c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM; c->jheads[GCHD].wbuf.no_timer = 1; return 0; } /** * free_wbufs - free write-buffers. * @c: UBIFS file-system description object */ static void free_wbufs(struct ubifs_info *c) { int i; if (c->jheads) { for (i = 0; i < c->jhead_cnt; i++) { kfree(c->jheads[i].wbuf.buf); kfree(c->jheads[i].wbuf.inodes); } kfree(c->jheads); c->jheads = NULL; } } /** * free_orphans - free orphans. * @c: UBIFS file-system description object */ static void free_orphans(struct ubifs_info *c) { struct ubifs_orphan *orph; while (c->orph_dnext) { orph = c->orph_dnext; c->orph_dnext = orph->dnext; list_del(&orph->list); kfree(orph); } while (!list_empty(&c->orph_list)) { orph = list_entry(c->orph_list.next, struct ubifs_orphan, list); list_del(&orph->list); kfree(orph); dbg_err("orphan list not empty at unmount"); } vfree(c->orph_buf); c->orph_buf = NULL; } /** * free_buds - free per-bud objects. * @c: UBIFS file-system description object */ static void free_buds(struct ubifs_info *c) { struct rb_node *this = c->buds.rb_node; struct ubifs_bud *bud; while (this) { if (this->rb_left) this = this->rb_left; else if (this->rb_right) this = this->rb_right; else { bud = rb_entry(this, struct ubifs_bud, rb); this = rb_parent(this); if (this) { if (this->rb_left == &bud->rb) this->rb_left = NULL; else this->rb_right = NULL; } kfree(bud); } } } /** * check_volume_empty - check if the UBI volume is empty. * @c: UBIFS file-system description object * * This function checks if the UBIFS volume is empty by looking if its LEBs are * mapped or not. The result of checking is stored in the @c->empty variable. * Returns zero in case of success and a negative error code in case of * failure. */ static int check_volume_empty(struct ubifs_info *c) { int lnum, err; c->empty = 1; for (lnum = 0; lnum < c->leb_cnt; lnum++) { err = ubi_is_mapped(c->ubi, lnum); if (unlikely(err < 0)) return err; if (err == 1) { c->empty = 0; break; } cond_resched(); } return 0; } /* * UBIFS mount options. * * Opt_fast_unmount: do not run a journal commit before un-mounting * Opt_norm_unmount: run a journal commit before un-mounting * Opt_bulk_read: enable bulk-reads * Opt_no_bulk_read: disable bulk-reads * Opt_chk_data_crc: check CRCs when reading data nodes * Opt_no_chk_data_crc: do not check CRCs when reading data nodes * Opt_override_compr: override default compressor * Opt_err: just end of array marker */ enum { Opt_fast_unmount, Opt_norm_unmount, Opt_bulk_read, Opt_no_bulk_read, Opt_chk_data_crc, Opt_no_chk_data_crc, Opt_override_compr, Opt_err, }; static const match_table_t tokens = { {Opt_fast_unmount, "fast_unmount"}, {Opt_norm_unmount, "norm_unmount"}, {Opt_bulk_read, "bulk_read"}, {Opt_no_bulk_read, "no_bulk_read"}, {Opt_chk_data_crc, "chk_data_crc"}, {Opt_no_chk_data_crc, "no_chk_data_crc"}, {Opt_override_compr, "compr=%s"}, {Opt_err, NULL}, }; /** * parse_standard_option - parse a standard mount option. * @option: the option to parse * * Normally, standard mount options like "sync" are passed to file-systems as * flags. However, when a "rootflags=" kernel boot parameter is used, they may * be present in the options string. This function tries to deal with this * situation and parse standard options. Returns 0 if the option was not * recognized, and the corresponding integer flag if it was. * * UBIFS is only interested in the "sync" option, so do not check for anything * else. */ static int parse_standard_option(const char *option) { ubifs_msg("parse %s", option); if (!strcmp(option, "sync")) return MS_SYNCHRONOUS; return 0; } /** * ubifs_parse_options - parse mount parameters. * @c: UBIFS file-system description object * @options: parameters to parse * @is_remount: non-zero if this is FS re-mount * * This function parses UBIFS mount options and returns zero in case success * and a negative error code in case of failure. */ static int ubifs_parse_options(struct ubifs_info *c, char *options, int is_remount) { char *p; substring_t args[MAX_OPT_ARGS]; if (!options) return 0; while ((p = strsep(&options, ","))) { int token; if (!*p) continue; token = match_token(p, tokens, args); switch (token) { /* * %Opt_fast_unmount and %Opt_norm_unmount options are ignored. * We accept them in order to be backward-compatible. But this * should be removed at some point. */ case Opt_fast_unmount: c->mount_opts.unmount_mode = 2; break; case Opt_norm_unmount: c->mount_opts.unmount_mode = 1; break; case Opt_bulk_read: c->mount_opts.bulk_read = 2; c->bulk_read = 1; break; case Opt_no_bulk_read: c->mount_opts.bulk_read = 1; c->bulk_read = 0; break; case Opt_chk_data_crc: c->mount_opts.chk_data_crc = 2; c->no_chk_data_crc = 0; break; case Opt_no_chk_data_crc: c->mount_opts.chk_data_crc = 1; c->no_chk_data_crc = 1; break; case Opt_override_compr: { char *name = match_strdup(&args[0]); if (!name) return -ENOMEM; if (!strcmp(name, "none")) c->mount_opts.compr_type = UBIFS_COMPR_NONE; else if (!strcmp(name, "lzo")) c->mount_opts.compr_type = UBIFS_COMPR_LZO; else if (!strcmp(name, "zlib")) c->mount_opts.compr_type = UBIFS_COMPR_ZLIB; else { ubifs_err("unknown compressor \"%s\"", name); kfree(name); return -EINVAL; } kfree(name); c->mount_opts.override_compr = 1; c->default_compr = c->mount_opts.compr_type; break; } default: { unsigned long flag; struct super_block *sb = c->vfs_sb; flag = parse_standard_option(p); if (!flag) { ubifs_err("unrecognized mount option \"%s\" " "or missing value", p); return -EINVAL; } sb->s_flags |= flag; break; } } } return 0; } /** * destroy_journal - destroy journal data structures. * @c: UBIFS file-system description object * * This function destroys journal data structures including those that may have * been created by recovery functions. */ static void destroy_journal(struct ubifs_info *c) { while (!list_empty(&c->unclean_leb_list)) { struct ubifs_unclean_leb *ucleb; ucleb = list_entry(c->unclean_leb_list.next, struct ubifs_unclean_leb, list); list_del(&ucleb->list); kfree(ucleb); } while (!list_empty(&c->old_buds)) { struct ubifs_bud *bud; bud = list_entry(c->old_buds.next, struct ubifs_bud, list); list_del(&bud->list); kfree(bud); } ubifs_destroy_idx_gc(c); ubifs_destroy_size_tree(c); ubifs_tnc_close(c); free_buds(c); } /** * bu_init - initialize bulk-read information. * @c: UBIFS file-system description object */ static void bu_init(struct ubifs_info *c) { ubifs_assert(c->bulk_read == 1); if (c->bu.buf) return; /* Already initialized */ again: c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN); if (!c->bu.buf) { if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) { c->max_bu_buf_len = UBIFS_KMALLOC_OK; goto again; } /* Just disable bulk-read */ ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, " "disabling it", c->max_bu_buf_len); c->mount_opts.bulk_read = 1; c->bulk_read = 0; return; } } /** * check_free_space - check if there is enough free space to mount. * @c: UBIFS file-system description object * * This function makes sure UBIFS has enough free space to be mounted in * read/write mode. UBIFS must always have some free space to allow deletions. */ static int check_free_space(struct ubifs_info *c) { ubifs_assert(c->dark_wm > 0); if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) { ubifs_err("insufficient free space to mount in read/write mode"); dbg_dump_budg(c); dbg_dump_lprops(c); return -ENOSPC; } return 0; } /** * mount_ubifs - mount UBIFS file-system. * @c: UBIFS file-system description object * * This function mounts UBIFS file system. Returns zero in case of success and * a negative error code in case of failure. * * Note, the function does not de-allocate resources it it fails half way * through, and the caller has to do this instead. */ static int mount_ubifs(struct ubifs_info *c) { int err; long long x; size_t sz; c->ro_mount = !!(c->vfs_sb->s_flags & MS_RDONLY); err = init_constants_early(c); if (err) return err; err = ubifs_debugging_init(c); if (err) return err; err = check_volume_empty(c); if (err) goto out_free; if (c->empty && (c->ro_mount || c->ro_media)) { /* * This UBI volume is empty, and read-only, or the file system * is mounted read-only - we cannot format it. */ ubifs_err("can't format empty UBI volume: read-only %s", c->ro_media ? "UBI volume" : "mount"); err = -EROFS; goto out_free; } if (c->ro_media && !c->ro_mount) { ubifs_err("cannot mount read-write - read-only media"); err = -EROFS; goto out_free; } /* * The requirement for the buffer is that it should fit indexing B-tree * height amount of integers. We assume the height if the TNC tree will * never exceed 64. */ err = -ENOMEM; c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL); if (!c->bottom_up_buf) goto out_free; c->sbuf = vmalloc(c->leb_size); if (!c->sbuf) goto out_free; if (!c->ro_mount) { c->ileb_buf = vmalloc(c->leb_size); if (!c->ileb_buf) goto out_free; } if (c->bulk_read == 1) bu_init(c); /* * We have to check all CRCs, even for data nodes, when we mount the FS * (specifically, when we are replaying). */ c->always_chk_crc = 1; err = ubifs_read_superblock(c); if (err) goto out_free; /* * Make sure the compressor which is set as default in the superblock * or overridden by mount options is actually compiled in. */ if (!ubifs_compr_present(c->default_compr)) { ubifs_err("'compressor \"%s\" is not compiled in", ubifs_compr_name(c->default_compr)); err = -ENOTSUPP; goto out_free; } err = init_constants_sb(c); if (err) goto out_free; sz = ALIGN(c->max_idx_node_sz, c->min_io_size); sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size); c->cbuf = kmalloc(sz, GFP_NOFS); if (!c->cbuf) { err = -ENOMEM; goto out_free; } sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id); if (!c->ro_mount) { err = alloc_wbufs(c); if (err) goto out_cbuf; /* Create background thread */ c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name); if (IS_ERR(c->bgt)) { err = PTR_ERR(c->bgt); c->bgt = NULL; ubifs_err("cannot spawn \"%s\", error %d", c->bgt_name, err); goto out_wbufs; } wake_up_process(c->bgt); } err = ubifs_read_master(c); if (err) goto out_master; init_constants_master(c); if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) { ubifs_msg("recovery needed"); c->need_recovery = 1; if (!c->ro_mount) { err = ubifs_recover_inl_heads(c, c->sbuf); if (err) goto out_master; } } else if (!c->ro_mount) { /* * Set the "dirty" flag so that if we reboot uncleanly we * will notice this immediately on the next mount. */ c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); err = ubifs_write_master(c); if (err) goto out_master; } err = ubifs_lpt_init(c, 1, !c->ro_mount); if (err) goto out_lpt; err = dbg_check_idx_size(c, c->old_idx_sz); if (err) goto out_lpt; err = ubifs_replay_journal(c); if (err) goto out_journal; /* Calculate 'min_idx_lebs' after journal replay */ c->min_idx_lebs = ubifs_calc_min_idx_lebs(c); err = ubifs_mount_orphans(c, c->need_recovery, c->ro_mount); if (err) goto out_orphans; if (!c->ro_mount) { int lnum; err = check_free_space(c); if (err) goto out_orphans; /* Check for enough log space */ lnum = c->lhead_lnum + 1; if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) lnum = UBIFS_LOG_LNUM; if (lnum == c->ltail_lnum) { err = ubifs_consolidate_log(c); if (err) goto out_orphans; } if (c->need_recovery) { err = ubifs_recover_size(c); if (err) goto out_orphans; err = ubifs_rcvry_gc_commit(c); if (err) goto out_orphans; } else { err = take_gc_lnum(c); if (err) goto out_orphans; /* * GC LEB may contain garbage if there was an unclean * reboot, and it should be un-mapped. */ err = ubifs_leb_unmap(c, c->gc_lnum); if (err) goto out_orphans; } err = dbg_check_lprops(c); if (err) goto out_orphans; } else if (c->need_recovery) { err = ubifs_recover_size(c); if (err) goto out_orphans; } else { /* * Even if we mount read-only, we have to set space in GC LEB * to proper value because this affects UBIFS free space * reporting. We do not want to have a situation when * re-mounting from R/O to R/W changes amount of free space. */ err = take_gc_lnum(c); if (err) goto out_orphans; } spin_lock(&ubifs_infos_lock); list_add_tail(&c->infos_list, &ubifs_infos); spin_unlock(&ubifs_infos_lock); if (c->need_recovery) { if (c->ro_mount) ubifs_msg("recovery deferred"); else { c->need_recovery = 0; ubifs_msg("recovery completed"); /* * GC LEB has to be empty and taken at this point. But * the journal head LEBs may also be accounted as * "empty taken" if they are empty. */ ubifs_assert(c->lst.taken_empty_lebs > 0); } } else ubifs_assert(c->lst.taken_empty_lebs > 0); err = dbg_check_filesystem(c); if (err) goto out_infos; err = dbg_debugfs_init_fs(c); if (err) goto out_infos; c->always_chk_crc = 0; ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"", c->vi.ubi_num, c->vi.vol_id, c->vi.name); if (c->ro_mount) ubifs_msg("mounted read-only"); x = (long long)c->main_lebs * c->leb_size; ubifs_msg("file system size: %lld bytes (%lld KiB, %lld MiB, %d " "LEBs)", x, x >> 10, x >> 20, c->main_lebs); x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes; ubifs_msg("journal size: %lld bytes (%lld KiB, %lld MiB, %d " "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt); ubifs_msg("media format: w%d/r%d (latest is w%d/r%d)", c->fmt_version, c->ro_compat_version, UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION); ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr)); ubifs_msg("reserved for root: %llu bytes (%llu KiB)", c->report_rp_size, c->report_rp_size >> 10); dbg_msg("compiled on: " __DATE__ " at " __TIME__); dbg_msg("min. I/O unit size: %d bytes", c->min_io_size); dbg_msg("LEB size: %d bytes (%d KiB)", c->leb_size, c->leb_size >> 10); dbg_msg("data journal heads: %d", c->jhead_cnt - NONDATA_JHEADS_CNT); dbg_msg("UUID: %pUB", c->uuid); dbg_msg("big_lpt %d", c->big_lpt); dbg_msg("log LEBs: %d (%d - %d)", c->log_lebs, UBIFS_LOG_LNUM, c->log_last); dbg_msg("LPT area LEBs: %d (%d - %d)", c->lpt_lebs, c->lpt_first, c->lpt_last); dbg_msg("orphan area LEBs: %d (%d - %d)", c->orph_lebs, c->orph_first, c->orph_last); dbg_msg("main area LEBs: %d (%d - %d)", c->main_lebs, c->main_first, c->leb_cnt - 1); dbg_msg("index LEBs: %d", c->lst.idx_lebs); dbg_msg("total index bytes: %lld (%lld KiB, %lld MiB)", c->old_idx_sz, c->old_idx_sz >> 10, c->old_idx_sz >> 20); dbg_msg("key hash type: %d", c->key_hash_type); dbg_msg("tree fanout: %d", c->fanout); dbg_msg("reserved GC LEB: %d", c->gc_lnum); dbg_msg("first main LEB: %d", c->main_first); dbg_msg("max. znode size %d", c->max_znode_sz); dbg_msg("max. index node size %d", c->max_idx_node_sz); dbg_msg("node sizes: data %zu, inode %zu, dentry %zu", UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ); dbg_msg("node sizes: trun %zu, sb %zu, master %zu", UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ); dbg_msg("node sizes: ref %zu, cmt. start %zu, orph %zu", UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ); dbg_msg("max. node sizes: data %zu, inode %zu dentry %zu", UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ, UBIFS_MAX_DENT_NODE_SZ); dbg_msg("dead watermark: %d", c->dead_wm); dbg_msg("dark watermark: %d", c->dark_wm); dbg_msg("LEB overhead: %d", c->leb_overhead); x = (long long)c->main_lebs * c->dark_wm; dbg_msg("max. dark space: %lld (%lld KiB, %lld MiB)", x, x >> 10, x >> 20); dbg_msg("maximum bud bytes: %lld (%lld KiB, %lld MiB)", c->max_bud_bytes, c->max_bud_bytes >> 10, c->max_bud_bytes >> 20); dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)", c->bg_bud_bytes, c->bg_bud_bytes >> 10, c->bg_bud_bytes >> 20); dbg_msg("current bud bytes %lld (%lld KiB, %lld MiB)", c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20); dbg_msg("max. seq. number: %llu", c->max_sqnum); dbg_msg("commit number: %llu", c->cmt_no); return 0; out_infos: spin_lock(&ubifs_infos_lock); list_del(&c->infos_list); spin_unlock(&ubifs_infos_lock); out_orphans: free_orphans(c); out_journal: destroy_journal(c); out_lpt: ubifs_lpt_free(c, 0); out_master: kfree(c->mst_node); kfree(c->rcvrd_mst_node); if (c->bgt) kthread_stop(c->bgt); out_wbufs: free_wbufs(c); out_cbuf: kfree(c->cbuf); out_free: kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); kfree(c->bottom_up_buf); ubifs_debugging_exit(c); return err; } /** * ubifs_umount - un-mount UBIFS file-system. * @c: UBIFS file-system description object * * Note, this function is called to free allocated resourced when un-mounting, * as well as free resources when an error occurred while we were half way * through mounting (error path cleanup function). So it has to make sure the * resource was actually allocated before freeing it. */ static void ubifs_umount(struct ubifs_info *c) { dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num, c->vi.vol_id); dbg_debugfs_exit_fs(c); spin_lock(&ubifs_infos_lock); list_del(&c->infos_list); spin_unlock(&ubifs_infos_lock); if (c->bgt) kthread_stop(c->bgt); destroy_journal(c); free_wbufs(c); free_orphans(c); ubifs_lpt_free(c, 0); kfree(c->cbuf); kfree(c->rcvrd_mst_node); kfree(c->mst_node); kfree(c->bu.buf); vfree(c->ileb_buf); vfree(c->sbuf); kfree(c->bottom_up_buf); ubifs_debugging_exit(c); } /** * ubifs_remount_rw - re-mount in read-write mode. * @c: UBIFS file-system description object * * UBIFS avoids allocating many unnecessary resources when mounted in read-only * mode. This function allocates the needed resources and re-mounts UBIFS in * read-write mode. */ static int ubifs_remount_rw(struct ubifs_info *c) { int err, lnum; if (c->rw_incompat) { ubifs_err("the file-system is not R/W-compatible"); ubifs_msg("on-flash format version is w%d/r%d, but software " "only supports up to version w%d/r%d", c->fmt_version, c->ro_compat_version, UBIFS_FORMAT_VERSION, UBIFS_RO_COMPAT_VERSION); return -EROFS; } mutex_lock(&c->umount_mutex); dbg_save_space_info(c); c->remounting_rw = 1; c->always_chk_crc = 1; err = check_free_space(c); if (err) goto out; if (c->old_leb_cnt != c->leb_cnt) { struct ubifs_sb_node *sup; sup = ubifs_read_sb_node(c); if (IS_ERR(sup)) { err = PTR_ERR(sup); goto out; } sup->leb_cnt = cpu_to_le32(c->leb_cnt); err = ubifs_write_sb_node(c, sup); if (err) goto out; } if (c->need_recovery) { ubifs_msg("completing deferred recovery"); err = ubifs_write_rcvrd_mst_node(c); if (err) goto out; err = ubifs_recover_size(c); if (err) goto out; err = ubifs_clean_lebs(c, c->sbuf); if (err) goto out; err = ubifs_recover_inl_heads(c, c->sbuf); if (err) goto out; } else { /* A readonly mount is not allowed to have orphans */ ubifs_assert(c->tot_orphans == 0); err = ubifs_clear_orphans(c); if (err) goto out; } if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) { c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY); err = ubifs_write_master(c); if (err) goto out; } c->ileb_buf = vmalloc(c->leb_size); if (!c->ileb_buf) { err = -ENOMEM; goto out; } err = ubifs_lpt_init(c, 0, 1); if (err) goto out; err = alloc_wbufs(c); if (err) goto out; ubifs_create_buds_lists(c); /* Create background thread */ c->bgt = kthread_create(ubifs_bg_thread, c, "%s", c->bgt_name); if (IS_ERR(c->bgt)) { err = PTR_ERR(c->bgt); c->bgt = NULL; ubifs_err("cannot spawn \"%s\", error %d", c->bgt_name, err); goto out; } wake_up_process(c->bgt); c->orph_buf = vmalloc(c->leb_size); if (!c->orph_buf) { err = -ENOMEM; goto out; } /* Check for enough log space */ lnum = c->lhead_lnum + 1; if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) lnum = UBIFS_LOG_LNUM; if (lnum == c->ltail_lnum) { err = ubifs_consolidate_log(c); if (err) goto out; } if (c->need_recovery) err = ubifs_rcvry_gc_commit(c); else err = ubifs_leb_unmap(c, c->gc_lnum); if (err) goto out; if (c->need_recovery) { c->need_recovery = 0; ubifs_msg("deferred recovery completed"); } dbg_gen("re-mounted read-write"); c->ro_mount = 0; c->remounting_rw = 0; c->always_chk_crc = 0; err = dbg_check_space_info(c); mutex_unlock(&c->umount_mutex); return err; out: vfree(c->orph_buf); c->orph_buf = NULL; if (c->bgt) { kthread_stop(c->bgt); c->bgt = NULL; } free_wbufs(c); vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); c->remounting_rw = 0; c->always_chk_crc = 0; mutex_unlock(&c->umount_mutex); return err; } /** * ubifs_remount_ro - re-mount in read-only mode. * @c: UBIFS file-system description object * * We assume VFS has stopped writing. Possibly the background thread could be * running a commit, however kthread_stop will wait in that case. */ static void ubifs_remount_ro(struct ubifs_info *c) { int i, err; ubifs_assert(!c->need_recovery); ubifs_assert(!c->ro_mount); mutex_lock(&c->umount_mutex); if (c->bgt) { kthread_stop(c->bgt); c->bgt = NULL; } dbg_save_space_info(c); for (i = 0; i < c->jhead_cnt; i++) ubifs_wbuf_sync(&c->jheads[i].wbuf); c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY); c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum); err = ubifs_write_master(c); if (err) ubifs_ro_mode(c, err); free_wbufs(c); vfree(c->orph_buf); c->orph_buf = NULL; vfree(c->ileb_buf); c->ileb_buf = NULL; ubifs_lpt_free(c, 1); c->ro_mount = 1; err = dbg_check_space_info(c); if (err) ubifs_ro_mode(c, err); mutex_unlock(&c->umount_mutex); } static void ubifs_put_super(struct super_block *sb) { int i; struct ubifs_info *c = sb->s_fs_info; ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num, c->vi.vol_id); /* * The following asserts are only valid if there has not been a failure * of the media. For example, there will be dirty inodes if we failed * to write them back because of I/O errors. */ ubifs_assert(atomic_long_read(&c->dirty_pg_cnt) == 0); ubifs_assert(c->budg_idx_growth == 0); ubifs_assert(c->budg_dd_growth == 0); ubifs_assert(c->budg_data_growth == 0); /* * The 'c->umount_lock' prevents races between UBIFS memory shrinker * and file system un-mount. Namely, it prevents the shrinker from * picking this superblock for shrinking - it will be just skipped if * the mutex is locked. */ mutex_lock(&c->umount_mutex); if (!c->ro_mount) { /* * First of all kill the background thread to make sure it does * not interfere with un-mounting and freeing resources. */ if (c->bgt) { kthread_stop(c->bgt); c->bgt = NULL; } /* * On fatal errors c->ro_error is set to 1, in which case we do * not write the master node. */ if (!c->ro_error) { int err; /* Synchronize write-buffers */ for (i = 0; i < c->jhead_cnt; i++) ubifs_wbuf_sync(&c->jheads[i].wbuf); /* * We are being cleanly unmounted which means the * orphans were killed - indicate this in the master * node. Also save the reserved GC LEB number. */ c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY); c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS); c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum); err = ubifs_write_master(c); if (err) /* * Recovery will attempt to fix the master area * next mount, so we just print a message and * continue to unmount normally. */ ubifs_err("failed to write master node, " "error %d", err); } else { for (i = 0; i < c->jhead_cnt; i++) /* Make sure write-buffer timers are canceled */ hrtimer_cancel(&c->jheads[i].wbuf.timer); } } ubifs_umount(c); bdi_destroy(&c->bdi); ubi_close_volume(c->ubi); mutex_unlock(&c->umount_mutex); kfree(c); } static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data) { int err; struct ubifs_info *c = sb->s_fs_info; dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags); err = ubifs_parse_options(c, data, 1); if (err) { ubifs_err("invalid or unknown remount parameter"); return err; } if (c->ro_mount && !(*flags & MS_RDONLY)) { if (c->ro_error) { ubifs_msg("cannot re-mount R/W due to prior errors"); return -EROFS; } if (c->ro_media) { ubifs_msg("cannot re-mount R/W - UBI volume is R/O"); return -EROFS; } err = ubifs_remount_rw(c); if (err) return err; } else if (!c->ro_mount && (*flags & MS_RDONLY)) { if (c->ro_error) { ubifs_msg("cannot re-mount R/O due to prior errors"); return -EROFS; } ubifs_remount_ro(c); } if (c->bulk_read == 1) bu_init(c); else { dbg_gen("disable bulk-read"); kfree(c->bu.buf); c->bu.buf = NULL; } ubifs_assert(c->lst.taken_empty_lebs > 0); return 0; } const struct super_operations ubifs_super_operations = { .alloc_inode = ubifs_alloc_inode, .destroy_inode = ubifs_destroy_inode, .put_super = ubifs_put_super, .write_inode = ubifs_write_inode, .evict_inode = ubifs_evict_inode, .statfs = ubifs_statfs, .dirty_inode = ubifs_dirty_inode, .remount_fs = ubifs_remount_fs, .show_options = ubifs_show_options, .sync_fs = ubifs_sync_fs, }; /** * open_ubi - parse UBI device name string and open the UBI device. * @name: UBI volume name * @mode: UBI volume open mode * * The primary method of mounting UBIFS is by specifying the UBI volume * character device node path. However, UBIFS may also be mounted withoug any * character device node using one of the following methods: * * o ubiX_Y - mount UBI device number X, volume Y; * o ubiY - mount UBI device number 0, volume Y; * o ubiX:NAME - mount UBI device X, volume with name NAME; * o ubi:NAME - mount UBI device 0, volume with name NAME. * * Alternative '!' separator may be used instead of ':' (because some shells * like busybox may interpret ':' as an NFS host name separator). This function * returns UBI volume description object in case of success and a negative * error code in case of failure. */ static struct ubi_volume_desc *open_ubi(const char *name, int mode) { struct ubi_volume_desc *ubi; int dev, vol; char *endptr; /* First, try to open using the device node path method */ ubi = ubi_open_volume_path(name, mode); if (!IS_ERR(ubi)) return ubi; /* Try the "nodev" method */ if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i') return ERR_PTR(-EINVAL); /* ubi:NAME method */ if ((name[3] == ':' || name[3] == '!') && name[4] != '\0') return ubi_open_volume_nm(0, name + 4, mode); if (!isdigit(name[3])) return ERR_PTR(-EINVAL); dev = simple_strtoul(name + 3, &endptr, 0); /* ubiY method */ if (*endptr == '\0') return ubi_open_volume(0, dev, mode); /* ubiX_Y method */ if (*endptr == '_' && isdigit(endptr[1])) { vol = simple_strtoul(endptr + 1, &endptr, 0); if (*endptr != '\0') return ERR_PTR(-EINVAL); return ubi_open_volume(dev, vol, mode); } /* ubiX:NAME method */ if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0') return ubi_open_volume_nm(dev, ++endptr, mode); return ERR_PTR(-EINVAL); } static int ubifs_fill_super(struct super_block *sb, void *data, int silent) { struct ubi_volume_desc *ubi = sb->s_fs_info; struct ubifs_info *c; struct inode *root; int err; c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL); if (!c) return -ENOMEM; spin_lock_init(&c->cnt_lock); spin_lock_init(&c->cs_lock); spin_lock_init(&c->buds_lock); spin_lock_init(&c->space_lock); spin_lock_init(&c->orphan_lock); init_rwsem(&c->commit_sem); mutex_init(&c->lp_mutex); mutex_init(&c->tnc_mutex); mutex_init(&c->log_mutex); mutex_init(&c->mst_mutex); mutex_init(&c->umount_mutex); mutex_init(&c->bu_mutex); init_waitqueue_head(&c->cmt_wq); c->buds = RB_ROOT; c->old_idx = RB_ROOT; c->size_tree = RB_ROOT; c->orph_tree = RB_ROOT; INIT_LIST_HEAD(&c->infos_list); INIT_LIST_HEAD(&c->idx_gc); INIT_LIST_HEAD(&c->replay_list); INIT_LIST_HEAD(&c->replay_buds); INIT_LIST_HEAD(&c->uncat_list); INIT_LIST_HEAD(&c->empty_list); INIT_LIST_HEAD(&c->freeable_list); INIT_LIST_HEAD(&c->frdi_idx_list); INIT_LIST_HEAD(&c->unclean_leb_list); INIT_LIST_HEAD(&c->old_buds); INIT_LIST_HEAD(&c->orph_list); INIT_LIST_HEAD(&c->orph_new); c->vfs_sb = sb; c->highest_inum = UBIFS_FIRST_INO; c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM; ubi_get_volume_info(ubi, &c->vi); ubi_get_device_info(c->vi.ubi_num, &c->di); /* Re-open the UBI device in read-write mode */ c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE); if (IS_ERR(c->ubi)) { err = PTR_ERR(c->ubi); goto out_free; } /* * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For * UBIFS, I/O is not deferred, it is done immediately in readpage, * which means the user would have to wait not just for their own I/O * but the read-ahead I/O as well i.e. completely pointless. * * Read-ahead will be disabled because @c->bdi.ra_pages is 0. */ c->bdi.name = "ubifs", c->bdi.capabilities = BDI_CAP_MAP_COPY; c->bdi.unplug_io_fn = default_unplug_io_fn; err = bdi_init(&c->bdi); if (err) goto out_close; err = bdi_register(&c->bdi, NULL, "ubifs_%d_%d", c->vi.ubi_num, c->vi.vol_id); if (err) goto out_bdi; err = ubifs_parse_options(c, data, 0); if (err) goto out_bdi; sb->s_bdi = &c->bdi; sb->s_fs_info = c; sb->s_magic = UBIFS_SUPER_MAGIC; sb->s_blocksize = UBIFS_BLOCK_SIZE; sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT; sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c); if (c->max_inode_sz > MAX_LFS_FILESIZE) sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE; sb->s_op = &ubifs_super_operations; mutex_lock(&c->umount_mutex); err = mount_ubifs(c); if (err) { ubifs_assert(err < 0); goto out_unlock; } /* Read the root inode */ root = ubifs_iget(sb, UBIFS_ROOT_INO); if (IS_ERR(root)) { err = PTR_ERR(root); goto out_umount; } sb->s_root = d_alloc_root(root); if (!sb->s_root) goto out_iput; mutex_unlock(&c->umount_mutex); return 0; out_iput: iput(root); out_umount: ubifs_umount(c); out_unlock: mutex_unlock(&c->umount_mutex); out_bdi: bdi_destroy(&c->bdi); out_close: ubi_close_volume(c->ubi); out_free: kfree(c); return err; } static int sb_test(struct super_block *sb, void *data) { dev_t *dev = data; struct ubifs_info *c = sb->s_fs_info; return c->vi.cdev == *dev; } static struct dentry *ubifs_mount(struct file_system_type *fs_type, int flags, const char *name, void *data) { struct ubi_volume_desc *ubi; struct ubi_volume_info vi; struct super_block *sb; int err; dbg_gen("name %s, flags %#x", name, flags); /* * Get UBI device number and volume ID. Mount it read-only so far * because this might be a new mount point, and UBI allows only one * read-write user at a time. */ ubi = open_ubi(name, UBI_READONLY); if (IS_ERR(ubi)) { dbg_err("cannot open \"%s\", error %d", name, (int)PTR_ERR(ubi)); return ERR_CAST(ubi); } ubi_get_volume_info(ubi, &vi); dbg_gen("opened ubi%d_%d", vi.ubi_num, vi.vol_id); sb = sget(fs_type, &sb_test, &set_anon_super, &vi.cdev); if (IS_ERR(sb)) { err = PTR_ERR(sb); goto out_close; } if (sb->s_root) { struct ubifs_info *c1 = sb->s_fs_info; /* A new mount point for already mounted UBIFS */ dbg_gen("this ubi volume is already mounted"); if (!!(flags & MS_RDONLY) != c1->ro_mount) { err = -EBUSY; goto out_deact; } } else { sb->s_flags = flags; /* * Pass 'ubi' to 'fill_super()' in sb->s_fs_info where it is * replaced by 'c'. */ sb->s_fs_info = ubi; err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); if (err) goto out_deact; /* We do not support atime */ sb->s_flags |= MS_ACTIVE | MS_NOATIME; } /* 'fill_super()' opens ubi again so we must close it here */ ubi_close_volume(ubi); return dget(sb->s_root); out_deact: deactivate_locked_super(sb); out_close: ubi_close_volume(ubi); return ERR_PTR(err); } static struct file_system_type ubifs_fs_type = { .name = "ubifs", .owner = THIS_MODULE, .mount = ubifs_mount, .kill_sb = kill_anon_super, }; /* * Inode slab cache constructor. */ static void inode_slab_ctor(void *obj) { struct ubifs_inode *ui = obj; inode_init_once(&ui->vfs_inode); } static int __init ubifs_init(void) { int err; BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24); /* Make sure node sizes are 8-byte aligned */ BUILD_BUG_ON(UBIFS_CH_SZ & 7); BUILD_BUG_ON(UBIFS_INO_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_SB_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MST_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_REF_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_CS_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ & 7); BUILD_BUG_ON(UBIFS_MAX_NODE_SZ & 7); BUILD_BUG_ON(MIN_WRITE_SZ & 7); /* Check min. node size */ BUILD_BUG_ON(UBIFS_INO_NODE_SZ < MIN_WRITE_SZ); BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ); BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ); BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ); BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ); BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ); BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ); BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ > UBIFS_MAX_NODE_SZ); /* Defined node sizes */ BUILD_BUG_ON(UBIFS_SB_NODE_SZ != 4096); BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512); BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160); BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64); /* * We use 2 bit wide bit-fields to store compression type, which should * be amended if more compressors are added. The bit-fields are: * @compr_type in 'struct ubifs_inode', @default_compr in * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'. */ BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4); /* * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2. */ if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) { ubifs_err("VFS page cache size is %u bytes, but UBIFS requires" " at least 4096 bytes", (unsigned int)PAGE_CACHE_SIZE); return -EINVAL; } err = register_filesystem(&ubifs_fs_type); if (err) { ubifs_err("cannot register file system, error %d", err); return err; } err = -ENOMEM; ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab", sizeof(struct ubifs_inode), 0, SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT, &inode_slab_ctor); if (!ubifs_inode_slab) goto out_reg; register_shrinker(&ubifs_shrinker_info); err = ubifs_compressors_init(); if (err) goto out_shrinker; err = dbg_debugfs_init(); if (err) goto out_compr; return 0; out_compr: ubifs_compressors_exit(); out_shrinker: unregister_shrinker(&ubifs_shrinker_info); kmem_cache_destroy(ubifs_inode_slab); out_reg: unregister_filesystem(&ubifs_fs_type); return err; } /* late_initcall to let compressors initialize first */ late_initcall(ubifs_init); static void __exit ubifs_exit(void) { ubifs_assert(list_empty(&ubifs_infos)); ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0); dbg_debugfs_exit(); ubifs_compressors_exit(); unregister_shrinker(&ubifs_shrinker_info); kmem_cache_destroy(ubifs_inode_slab); unregister_filesystem(&ubifs_fs_type); } module_exit(ubifs_exit); MODULE_LICENSE("GPL"); MODULE_VERSION(__stringify(UBIFS_VERSION)); MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter"); MODULE_DESCRIPTION("UBIFS - UBI File System");