From 1e51764a3c2ac05a23a22b2a95ddee4d9bffb16d Mon Sep 17 00:00:00 2001 From: Artem Bityutskiy Date: Mon, 14 Jul 2008 19:08:37 +0300 Subject: UBIFS: add new flash file system This is a new flash file system. See http://www.linux-mtd.infradead.org/doc/ubifs.html Signed-off-by: Artem Bityutskiy Signed-off-by: Adrian Hunter --- fs/ubifs/misc.h | 342 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 342 insertions(+) create mode 100644 fs/ubifs/misc.h (limited to 'fs/ubifs/misc.h') diff --git a/fs/ubifs/misc.h b/fs/ubifs/misc.h new file mode 100644 index 000000000000..4beccfc256d2 --- /dev/null +++ b/fs/ubifs/misc.h @@ -0,0 +1,342 @@ +/* + * 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 contains miscellaneous helper functions. + */ + +#ifndef __UBIFS_MISC_H__ +#define __UBIFS_MISC_H__ + +/** + * ubifs_zn_dirty - check if znode is dirty. + * @znode: znode to check + * + * This helper function returns %1 if @znode is dirty and %0 otherwise. + */ +static inline int ubifs_zn_dirty(const struct ubifs_znode *znode) +{ + return !!test_bit(DIRTY_ZNODE, &znode->flags); +} + +/** + * ubifs_wake_up_bgt - wake up background thread. + * @c: UBIFS file-system description object + */ +static inline void ubifs_wake_up_bgt(struct ubifs_info *c) +{ + if (c->bgt && !c->need_bgt) { + c->need_bgt = 1; + wake_up_process(c->bgt); + } +} + +/** + * ubifs_tnc_find_child - find next child in znode. + * @znode: znode to search at + * @start: the zbranch index to start at + * + * This helper function looks for znode child starting at index @start. Returns + * the child or %NULL if no children were found. + */ +static inline struct ubifs_znode * +ubifs_tnc_find_child(struct ubifs_znode *znode, int start) +{ + while (start < znode->child_cnt) { + if (znode->zbranch[start].znode) + return znode->zbranch[start].znode; + start += 1; + } + + return NULL; +} + +/** + * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object. + * @inode: the VFS 'struct inode' pointer + */ +static inline struct ubifs_inode *ubifs_inode(const struct inode *inode) +{ + return container_of(inode, struct ubifs_inode, vfs_inode); +} + +/** + * ubifs_ro_mode - switch UBIFS to read read-only mode. + * @c: UBIFS file-system description object + * @err: error code which is the reason of switching to R/O mode + */ +static inline void ubifs_ro_mode(struct ubifs_info *c, int err) +{ + if (!c->ro_media) { + c->ro_media = 1; + ubifs_warn("switched to read-only mode, error %d", err); + dbg_dump_stack(); + } +} + +/** + * ubifs_compr_present - check if compressor was compiled in. + * @compr_type: compressor type to check + * + * This function returns %1 of compressor of type @compr_type is present, and + * %0 if not. + */ +static inline int ubifs_compr_present(int compr_type) +{ + ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); + return !!ubifs_compressors[compr_type]->capi_name; +} + +/** + * ubifs_compr_name - get compressor name string by its type. + * @compr_type: compressor type + * + * This function returns compressor type string. + */ +static inline const char *ubifs_compr_name(int compr_type) +{ + ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT); + return ubifs_compressors[compr_type]->name; +} + +/** + * ubifs_wbuf_sync - synchronize write-buffer. + * @wbuf: write-buffer to synchronize + * + * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume + * that the write-buffer is already locked. + */ +static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf) +{ + int err; + + mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); + err = ubifs_wbuf_sync_nolock(wbuf); + mutex_unlock(&wbuf->io_mutex); + return err; +} + +/** + * ubifs_leb_unmap - unmap an LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to unmap + * + * This function returns %0 on success and a negative error code on failure. + */ +static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum) +{ + int err; + + if (c->ro_media) + return -EROFS; + err = ubi_leb_unmap(c->ubi, lnum); + if (err) { + ubifs_err("unmap LEB %d failed, error %d", lnum, err); + return err; + } + + return 0; +} + +/** + * ubifs_leb_write - write to a LEB. + * @c: UBIFS file-system description object + * @lnum: LEB number to write + * @buf: buffer to write from + * @offs: offset within LEB to write to + * @len: length to write + * @dtype: data type + * + * This function returns %0 on success and a negative error code on failure. + */ +static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum, + const void *buf, int offs, int len, int dtype) +{ + int err; + + if (c->ro_media) + return -EROFS; + err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype); + if (err) { + ubifs_err("writing %d bytes at %d:%d, error %d", + len, lnum, offs, err); + return err; + } + + return 0; +} + +/** + * ubifs_leb_change - atomic LEB change. + * @c: UBIFS file-system description object + * @lnum: LEB number to write + * @buf: buffer to write from + * @len: length to write + * @dtype: data type + * + * This function returns %0 on success and a negative error code on failure. + */ +static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum, + const void *buf, int len, int dtype) +{ + int err; + + if (c->ro_media) + return -EROFS; + err = ubi_leb_change(c->ubi, lnum, buf, len, dtype); + if (err) { + ubifs_err("changing %d bytes in LEB %d, error %d", + len, lnum, err); + return err; + } + + return 0; +} + +/** + * ubifs_encode_dev - encode device node IDs. + * @dev: UBIFS device node information + * @rdev: device IDs to encode + * + * This is a helper function which encodes major/minor numbers of a device node + * into UBIFS device node description. We use standard Linux "new" and "huge" + * encodings. + */ +static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev) +{ + if (new_valid_dev(rdev)) { + dev->new = cpu_to_le32(new_encode_dev(rdev)); + return sizeof(dev->new); + } else { + dev->huge = cpu_to_le64(huge_encode_dev(rdev)); + return sizeof(dev->huge); + } +} + +/** + * ubifs_add_dirt - add dirty space to LEB properties. + * @c: the UBIFS file-system description object + * @lnum: LEB to add dirty space for + * @dirty: dirty space to add + * + * This is a helper function which increased amount of dirty LEB space. Returns + * zero in case of success and a negative error code in case of failure. + */ +static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty) +{ + return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0); +} + +/** + * ubifs_return_leb - return LEB to lprops. + * @c: the UBIFS file-system description object + * @lnum: LEB to return + * + * This helper function cleans the "taken" flag of a logical eraseblock in the + * lprops. Returns zero in case of success and a negative error code in case of + * failure. + */ +static inline int ubifs_return_leb(struct ubifs_info *c, int lnum) +{ + return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0, + LPROPS_TAKEN, 0); +} + +/** + * ubifs_idx_node_sz - return index node size. + * @c: the UBIFS file-system description object + * @child_cnt: number of children of this index node + */ +static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt) +{ + return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt; +} + +/** + * ubifs_idx_branch - return pointer to an index branch. + * @c: the UBIFS file-system description object + * @idx: index node + * @bnum: branch number + */ +static inline +struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c, + const struct ubifs_idx_node *idx, + int bnum) +{ + return (struct ubifs_branch *)((void *)idx->branches + + (UBIFS_BRANCH_SZ + c->key_len) * bnum); +} + +/** + * ubifs_idx_key - return pointer to an index key. + * @c: the UBIFS file-system description object + * @idx: index node + */ +static inline void *ubifs_idx_key(const struct ubifs_info *c, + const struct ubifs_idx_node *idx) +{ + return (void *)((struct ubifs_branch *)idx->branches)->key; +} + +/** + * ubifs_reported_space - calculate reported free space. + * @c: the UBIFS file-system description object + * @free: amount of free space + * + * This function calculates amount of free space which will be reported to + * user-space. User-space application tend to expect that if the file-system + * (e.g., via the 'statfs()' call) reports that it has N bytes available, they + * are able to write a file of size N. UBIFS attaches node headers to each data + * node and it has to write indexind nodes as well. This introduces additional + * overhead, and UBIFS it has to report sligtly less free space to meet the + * above expectetion. + * + * This function assumes free space is made up of uncompressed data nodes and + * full index nodes (one per data node, doubled because we always allow enough + * space to write the index twice). + * + * Note, the calculation is pessimistic, which means that most of the time + * UBIFS reports less space than it actually has. + */ +static inline long long ubifs_reported_space(const struct ubifs_info *c, + uint64_t free) +{ + int divisor, factor; + + divisor = UBIFS_MAX_DATA_NODE_SZ + (c->max_idx_node_sz << 1); + factor = UBIFS_MAX_DATA_NODE_SZ - UBIFS_DATA_NODE_SZ; + do_div(free, divisor); + + return free * factor; +} + +/** + * ubifs_current_time - round current time to time granularity. + * @inode: inode + */ +static inline struct timespec ubifs_current_time(struct inode *inode) +{ + return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ? + current_fs_time(inode->i_sb) : CURRENT_TIME_SEC; +} + +#endif /* __UBIFS_MISC_H__ */ -- cgit v1.2.3