diff options
Diffstat (limited to 'fs/ubifs/super.c')
| -rw-r--r-- | fs/ubifs/super.c | 1951 |
1 files changed, 1951 insertions, 0 deletions
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c new file mode 100644 index 0000000..00eb9c6 --- /dev/null +++ b/fs/ubifs/super.c @@ -0,0 +1,1951 @@ +/* + * 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/random.h> +#include <linux/kthread.h> +#include <linux/parser.h> +#include <linux/seq_file.h> +#include <linux/mount.h> +#include "ubifs.h" + +/* 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 readahead */ + 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, int wait) +{ + int err; + 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; + } + + dbg_gen("inode %lu", inode->i_ino); + err = ubifs_jnl_write_inode(c, inode, 0); + if (err) + ubifs_err("can't write inode %lu, error %d", inode->i_ino, err); + + ui->dirty = 0; + mutex_unlock(&ui->ui_mutex); + ubifs_release_dirty_inode_budget(c, ui); + return err; +} + +static void ubifs_delete_inode(struct inode *inode) +{ + int err; + struct ubifs_info *c = inode->i_sb->s_fs_info; + + if (ubifs_inode(inode)->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", inode->i_ino); + ubifs_assert(!atomic_read(&inode->i_count)); + ubifs_assert(inode->i_nlink == 0); + + truncate_inode_pages(&inode->i_data, 0); + if (is_bad_inode(inode)) + goto out; + + ubifs_inode(inode)->ui_size = inode->i_size = 0; + err = ubifs_jnl_write_inode(c, inode, 1); + if (err) + /* + * Worst case we have a lost orphan inode wasting space, so a + * simple error message is ok here. + */ + ubifs_err("can't write inode %lu, error %d", inode->i_ino, err); +out: + clear_inode(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; + + free = ubifs_budg_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; + + 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"); + + return 0; +} + +static int ubifs_sync_fs(struct super_block *sb, int wait) +{ + struct ubifs_info *c = sb->s_fs_info; + int i, ret = 0, err; + + if (c->jheads) + for (i = 0; i < c->jhead_cnt; i++) { + err = ubifs_wbuf_sync(&c->jheads[i].wbuf); + if (err && !ret) + ret = err; + } + /* + * We ought to call sync for c->ubi but it does not have one. If it had + * it would in turn call mtd->sync, however mtd operations are + * synchronous anyway, so we don't lose any sleep here. + */ + return ret; +} + +/** + * 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. + * + * Dead space is the space which cannot be used. Its watermark is + * equivalent to min. I/O unit or minimum node size if it is greater + * then min. I/O unit. + * + * Dark space is the space which might be used, or might not, depending + * on which node should be written to the LEB. Its watermark is + * equivalent to maximum UBIFS node size. + */ + c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size); + c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_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_late - 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_late(struct ubifs_info *c) +{ + int tmp, err; + uint64_t 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; + tmp = do_div(tmp64, c->leb_size); + c->max_bud_cnt = tmp64 + !!tmp; + 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 = (uint64_t)(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; + + c->min_idx_lebs = ubifs_calc_min_idx_lebs(c); + + /* + * 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 and the LEB which is reserved for + * deletions. + * + * Review 'ubifs_calc_available()' if changing this calculation. + */ + tmp64 = c->main_lebs - 2; + tmp64 *= (uint64_t)c->leb_size - c->dark_wm; + tmp64 = ubifs_reported_space(c, tmp64); + c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT; + + return 0; +} + +/** + * take_gc_lnum - reserve GC LEB. + * @c: UBIFS file-system description object + * + * This function ensures that the LEB reserved for garbage collection is + * unmapped and 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; + } + + err = ubifs_leb_unmap(c, c->gc_lnum); + if (err) + return err; + + /* 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.timeout = 0; + + 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_err: just end of array marker + */ +enum { + Opt_fast_unmount, + Opt_norm_unmount, + Opt_err, +}; + +static match_table_t tokens = { + {Opt_fast_unmount, "fast_unmount"}, + {Opt_norm_unmount, "norm_unmount"}, + {Opt_err, NULL}, +}; + +/** + * 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) { + case Opt_fast_unmount: + c->mount_opts.unmount_mode = 2; + c->fast_unmount = 1; + break; + case Opt_norm_unmount: + c->mount_opts.unmount_mode = 1; + c->fast_unmount = 0; + break; + default: + ubifs_err("unrecognized mount option \"%s\" " + "or missing value", p); + return -EINVAL; + } + } + + 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); +} + +/** + * 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) +{ + struct super_block *sb = c->vfs_sb; + int err, mounted_read_only = (sb->s_flags & MS_RDONLY); + long long x; + size_t sz; + + err = init_constants_early(c); + if (err) + return err; + +#ifdef CONFIG_UBIFS_FS_DEBUG + c->dbg_buf = vmalloc(c->leb_size); + if (!c->dbg_buf) + return -ENOMEM; +#endif + + err = check_volume_empty(c); + if (err) + goto out_free; + + if (c->empty && (mounted_read_only || 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 && !mounted_read_only) { + 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 (!mounted_read_only) { + c->ileb_buf = vmalloc(c->leb_size); + if (!c->ileb_buf) + goto out_free; + } + + err = ubifs_read_superblock(c); + if (err) + goto out_free; + + /* + * Make sure the compressor which is set as the default on in the + * superblock was actually compiled in. + */ + if (!ubifs_compr_present(c->default_compr)) { + ubifs_warn("'%s' compressor is set by superblock, but not " + "compiled in", ubifs_compr_name(c->default_compr)); + c->default_compr = UBIFS_COMPR_NONE; + } + + dbg_failure_mode_registration(c); + + err = init_constants_late(c); + if (err) + goto out_dereg; + + 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_dereg; + } + + if (!mounted_read_only) { + err = alloc_wbufs(c); + if (err) + goto out_cbuf; + + /* Create background thread */ + sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, + c->vi.vol_id); + c->bgt = kthread_create(ubifs_bg_thread, c, c->bgt_name); + if (!c->bgt) + c->bgt = ERR_PTR(-EINVAL); + 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; + + if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) { + ubifs_msg("recovery needed"); + c->need_recovery = 1; + if (!mounted_read_only) { + err = ubifs_recover_inl_heads(c, c->sbuf); + if (err) + goto out_master; + } + } else if (!mounted_read_only) { + /* + * 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, !mounted_read_only); + 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; + + err = ubifs_mount_orphans(c, c->need_recovery, mounted_read_only); + if (err) + goto out_orphans; + + if (!mounted_read_only) { + int lnum; + + /* Check for enough free space */ + if (ubifs_calc_available(c, c->min_idx_lebs) <= 0) { + ubifs_err("insufficient available space"); + err = -EINVAL; + 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); + } else + err = take_gc_lnum(c); + 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; + } + + spin_lock(&ubifs_infos_lock); + list_add_tail(&c->infos_list, &ubifs_infos); + spin_unlock(&ubifs_infos_lock); + + if (c->need_recovery) { + if (mounted_read_only) + ubifs_msg("recovery deferred"); + else { + c->need_recovery = 0; + ubifs_msg("recovery completed"); + } + } + + err = dbg_check_filesystem(c); + if (err) + goto out_infos; + + ubifs_msg("mounted UBI device %d, volume %d", c->vi.ubi_num, + c->vi.vol_id); + if (mounted_read_only) + 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("default compressor: %s", ubifs_compr_name(c->default_compr)); + ubifs_msg("media format %d, latest format %d", + c->fmt_version, UBIFS_FORMAT_VERSION); + + 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 / 1024); + dbg_msg("data journal heads: %d", + c->jhead_cnt - NONDATA_JHEADS_CNT); + dbg_msg("UUID: %02X%02X%02X%02X-%02X%02X" + "-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X", + c->uuid[0], c->uuid[1], c->uuid[2], c->uuid[3], + c->uuid[4], c->uuid[5], c->uuid[6], c->uuid[7], + c->uuid[8], c->uuid[9], c->uuid[10], c->uuid[11], + c->uuid[12], c->uuid[13], c->uuid[14], c->uuid[15]); + dbg_msg("fast unmount: %d", c->fast_unmount); + 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("dead watermark: %d", c->dead_wm); + dbg_msg("dark watermark: %d", c->dark_wm); + 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_dereg: + dbg_failure_mode_deregistration(c); +out_free: + vfree(c->ileb_buf); + vfree(c->sbuf); + kfree(c->bottom_up_buf); + UBIFS_DBG(vfree(c->dbg_buf)); + 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); + + 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); + vfree(c->sbuf); + kfree(c->bottom_up_buf); + UBIFS_DBG(vfree(c->dbg_buf)); + vfree(c->ileb_buf); + dbg_failure_mode_deregistration(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->ro_media) + return -EINVAL; + + mutex_lock(&c->umount_mutex); + c->remounting_rw = 1; + + /* Check for enough free space */ + if (ubifs_calc_available(c, c->min_idx_lebs) <= 0) { + ubifs_err("insufficient available space"); + err = -EINVAL; + 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; + } + + 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, c->bgt_name); + if (!c->bgt) + c->bgt = ERR_PTR(-EINVAL); + if (IS_ERR(c->bgt)) { + err = PTR_ERR(c->bgt); + c->bgt = NULL; + ubifs_err("cannot spawn \"%s\", error %d", + c->bgt_name, err); + return err; + } + wake_up_process(c->bgt); + + c->orph_buf = vmalloc(c->leb_size); + if (!c->orph_buf) + return -ENOMEM; + + /* 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 = take_gc_lnum(c); + if (err) + goto out; + + if (c->need_recovery) { + c->need_recovery = 0; + ubifs_msg("deferred recovery completed"); + } + + dbg_gen("re-mounted read-write"); + c->vfs_sb->s_flags &= ~MS_RDONLY; + c->remounting_rw = 0; + mutex_unlock(&c->umount_mutex); + return 0; + +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; + mutex_unlock(&c->umount_mutex); + return err; +} + +/** + * commit_on_unmount - commit the journal when un-mounting. + * @c: UBIFS file-system description object + * + * This function is called during un-mounting and it commits the journal unless + * the "fast unmount" mode is enabled. It also avoids committing the journal if + * it contains too few data. + * + * Sometimes recovery requires the journal to be committed at least once, and + * this function takes care about this. + */ +static void commit_on_unmount(struct ubifs_info *c) +{ + if (!c->fast_unmount) { + long long bud_bytes; + + spin_lock(&c->buds_lock); + bud_bytes = c->bud_bytes; + spin_unlock(&c->buds_lock); + if (bud_bytes > c->leb_size) + ubifs_run_commit(c); + } +} + +/** + * ubifs_remount_ro - re-mount in read-only mode. + * @c: UBIFS file-system description object + * + * We rely on VFS to have 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); + commit_on_unmount(c); + + mutex_lock(&c->umount_mutex); + if (c->bgt) { + kthread_stop(c->bgt); + c->bgt = NULL; + } + + for (i = 0; i < c->jhead_cnt; i++) { + ubifs_wbuf_sync(&c->jheads[i].wbuf); + del_timer_sync(&c->jheads[i].wbuf.timer); + } + + if (!c->ro_media) { + 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); + } + + ubifs_destroy_idx_gc(c); + free_wbufs(c); + vfree(c->orph_buf); + c->orph_buf = NULL; + vfree(c->ileb_buf); + c->ileb_buf = NULL; + ubifs_lpt_free(c, 1); + 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_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->vfs_sb->s_flags & MS_RDONLY)) { + /* + * 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; + } + + /* Synchronize write-buffers */ + if (c->jheads) + for (i = 0; i < c->jhead_cnt; i++) { + ubifs_wbuf_sync(&c->jheads[i].wbuf); + del_timer_sync(&c->jheads[i].wbuf.timer); + } + + /* + * On fatal errors c->ro_media is set to 1, in which case we do + * not write the master node. + */ + if (!c->ro_media) { + /* + * We are being cleanly unmounted which means the + * orphans were killed - indicate this in the master + * node. Also save the reserved GC LEB number. + */ + int err; + + 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); + } + } + + 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 ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) { + err = ubifs_remount_rw(c); + if (err) + return err; + } else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) + ubifs_remount_ro(c); + + return 0; +} + +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, + .delete_inode = ubifs_delete_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 + * + * There are several ways to specify UBI volumes when mounting UBIFS: + * o ubiX_Y - UBI device number X, volume Y; + * o ubiY - 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 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) +{ + int dev, vol; + char *endptr; + + 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); + 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->highest_inum = UBIFS_FIRST_INO; + get_random_bytes(&c->vfs_gen, sizeof(int)); + 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 provids 'backing_dev_info' in order to disable readahead. 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 readahead I/O as well i.e. completely pointless. + * + * Read-ahead will be disabled because @c->bdi.ra_pages is 0. + */ + 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 = ubifs_parse_options(c, data, 0); + if (err) + goto out_bdi; + + c->vfs_sb = sb; + + 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_dev = c->vi.cdev; + 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; + + return sb->s_dev == *dev; +} + +static int sb_set(struct super_block *sb, void *data) +{ + dev_t *dev = data; + + sb->s_dev = *dev; + return 0; +} + +static int ubifs_get_sb(struct file_system_type *fs_type, int flags, + const char *name, void *data, struct vfsmount *mnt) +{ + 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)) { + ubifs_err("cannot open \"%s\", error %d", + name, (int)PTR_ERR(ubi)); + return PTR_ERR(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, &sb_set, &vi.cdev); + if (IS_ERR(sb)) { + err = PTR_ERR(sb); + goto out_close; + } + + if (sb->s_root) { + /* A new mount point for already mounted UBIFS */ + dbg_gen("this ubi volume is already mounted"); + if ((flags ^ sb->s_flags) & MS_RDONLY) { + 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 simple_set_mnt(mnt, sb); + +out_deact: + up_write(&sb->s_umount); + deactivate_super(sb); +out_close: + ubi_close_volume(ubi); + return err; +} + +static void ubifs_kill_sb(struct super_block *sb) +{ + struct ubifs_info *c = sb->s_fs_info; + + /* + * We do 'commit_on_unmount()' here instead of 'ubifs_put_super()' + * in order to be outside BKL. + */ + if (sb->s_root && !(sb->s_flags & MS_RDONLY)) + commit_on_unmount(c); + /* The un-mount routine is actually done in put_super() */ + generic_shutdown_super(sb); +} + +static struct file_system_type ubifs_fs_type = { + .name = "ubifs", + .owner = THIS_MODULE, + .get_sb = ubifs_get_sb, + .kill_sb = ubifs_kill_sb +}; + +/* + * Inode slab cache constructor. + */ +static void inode_slab_ctor(struct kmem_cache *cachep, 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 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_compr; + + return 0; + +out_compr: + 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); + + 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"); |
