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![Artem Bityutskiy](/assets/img/avatar_default.png)
The R/O state may have various reasons: 1. The UBI volume is R/O 2. The FS is mounted R/O 3. The FS switched to R/O mode because of an error However, in UBIFS we have only one variable which represents cases 1 and 3 - 'c->ro_media'. Indeed, we set this to 1 if we switch to R/O mode due to an error, and then we test it in many places to make sure that we stop writing as soon as the error happens. But this is very unclean. One consequence of this, for example, is that in 'ubifs_remount_fs()' we use 'c->ro_media' to check whether we are in R/O mode because on an error, and we print a message in this case. However, if we are in R/O mode because the media is R/O, our message is bogus. This patch introduces new flag - 'c->ro_error' which is set when we switch to R/O mode because of an error. It also changes all "if (c->ro_media)" checks to "if (c->ro_error)" checks, because this is what the checks actually mean. We do not need to check for 'c->ro_media' because if the UBI volume is in R/O mode, we do not allow R/W mounting, and now writes can happen. This is guaranteed by VFS. But it is good to double-check this, so this patch also adds many "ubifs_assert(!c->ro_media)" checks. In the 'ubifs_remount_fs()' function this patch makes a bit more changes - it fixes the error messages as well. Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
343 lines
9.1 KiB
C
343 lines
9.1 KiB
C
/*
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* This file is part of UBIFS.
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*
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* Copyright (C) 2006-2008 Nokia Corporation
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published by
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* the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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* more details.
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*
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* You should have received a copy of the GNU General Public License along with
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* this program; if not, write to the Free Software Foundation, Inc., 51
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* Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Authors: Artem Bityutskiy (Битюцкий Артём)
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* Adrian Hunter
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*/
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/*
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* This file contains miscellaneous helper functions.
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*/
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#ifndef __UBIFS_MISC_H__
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#define __UBIFS_MISC_H__
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/**
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* ubifs_zn_dirty - check if znode is dirty.
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* @znode: znode to check
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*
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* This helper function returns %1 if @znode is dirty and %0 otherwise.
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*/
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static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
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{
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return !!test_bit(DIRTY_ZNODE, &znode->flags);
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}
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/**
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* ubifs_wake_up_bgt - wake up background thread.
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* @c: UBIFS file-system description object
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*/
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static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
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{
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if (c->bgt && !c->need_bgt) {
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c->need_bgt = 1;
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wake_up_process(c->bgt);
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}
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}
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/**
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* ubifs_tnc_find_child - find next child in znode.
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* @znode: znode to search at
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* @start: the zbranch index to start at
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*
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* This helper function looks for znode child starting at index @start. Returns
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* the child or %NULL if no children were found.
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*/
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static inline struct ubifs_znode *
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ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
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{
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while (start < znode->child_cnt) {
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if (znode->zbranch[start].znode)
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return znode->zbranch[start].znode;
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start += 1;
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}
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return NULL;
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}
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/**
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* ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
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* @inode: the VFS 'struct inode' pointer
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*/
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static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
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{
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return container_of(inode, struct ubifs_inode, vfs_inode);
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}
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/**
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* ubifs_compr_present - check if compressor was compiled in.
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* @compr_type: compressor type to check
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*
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* This function returns %1 of compressor of type @compr_type is present, and
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* %0 if not.
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*/
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static inline int ubifs_compr_present(int compr_type)
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{
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ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
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return !!ubifs_compressors[compr_type]->capi_name;
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}
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/**
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* ubifs_compr_name - get compressor name string by its type.
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* @compr_type: compressor type
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*
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* This function returns compressor type string.
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*/
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static inline const char *ubifs_compr_name(int compr_type)
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{
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ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
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return ubifs_compressors[compr_type]->name;
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}
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/**
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* ubifs_wbuf_sync - synchronize write-buffer.
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* @wbuf: write-buffer to synchronize
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*
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* This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
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* that the write-buffer is already locked.
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*/
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static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
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{
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int err;
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mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
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err = ubifs_wbuf_sync_nolock(wbuf);
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mutex_unlock(&wbuf->io_mutex);
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return err;
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}
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/**
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* ubifs_leb_unmap - unmap an LEB.
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* @c: UBIFS file-system description object
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* @lnum: LEB number to unmap
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
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{
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int err;
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ubifs_assert(!c->ro_media);
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if (c->ro_error)
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return -EROFS;
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err = ubi_leb_unmap(c->ubi, lnum);
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if (err) {
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ubifs_err("unmap LEB %d failed, error %d", lnum, err);
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return err;
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}
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return 0;
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}
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/**
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* ubifs_leb_write - write to a LEB.
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* @c: UBIFS file-system description object
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* @lnum: LEB number to write
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* @buf: buffer to write from
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* @offs: offset within LEB to write to
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* @len: length to write
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* @dtype: data type
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
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const void *buf, int offs, int len, int dtype)
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{
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int err;
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ubifs_assert(!c->ro_media);
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if (c->ro_error)
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return -EROFS;
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err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
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if (err) {
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ubifs_err("writing %d bytes at %d:%d, error %d",
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len, lnum, offs, err);
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return err;
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}
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return 0;
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}
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/**
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* ubifs_leb_change - atomic LEB change.
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* @c: UBIFS file-system description object
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* @lnum: LEB number to write
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* @buf: buffer to write from
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* @len: length to write
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* @dtype: data type
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*
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* This function returns %0 on success and a negative error code on failure.
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*/
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static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
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const void *buf, int len, int dtype)
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{
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int err;
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ubifs_assert(!c->ro_media);
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if (c->ro_error)
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return -EROFS;
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err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
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if (err) {
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ubifs_err("changing %d bytes in LEB %d, error %d",
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len, lnum, err);
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return err;
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}
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return 0;
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}
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/**
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* ubifs_encode_dev - encode device node IDs.
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* @dev: UBIFS device node information
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* @rdev: device IDs to encode
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*
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* This is a helper function which encodes major/minor numbers of a device node
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* into UBIFS device node description. We use standard Linux "new" and "huge"
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* encodings.
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*/
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static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
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{
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if (new_valid_dev(rdev)) {
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dev->new = cpu_to_le32(new_encode_dev(rdev));
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return sizeof(dev->new);
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} else {
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dev->huge = cpu_to_le64(huge_encode_dev(rdev));
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return sizeof(dev->huge);
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}
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}
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/**
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* ubifs_add_dirt - add dirty space to LEB properties.
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* @c: the UBIFS file-system description object
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* @lnum: LEB to add dirty space for
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* @dirty: dirty space to add
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*
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* This is a helper function which increased amount of dirty LEB space. Returns
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* zero in case of success and a negative error code in case of failure.
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*/
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static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
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{
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return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
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}
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/**
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* ubifs_return_leb - return LEB to lprops.
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* @c: the UBIFS file-system description object
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* @lnum: LEB to return
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*
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* This helper function cleans the "taken" flag of a logical eraseblock in the
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* lprops. Returns zero in case of success and a negative error code in case of
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* failure.
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*/
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static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
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{
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return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
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LPROPS_TAKEN, 0);
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}
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/**
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* ubifs_idx_node_sz - return index node size.
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* @c: the UBIFS file-system description object
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* @child_cnt: number of children of this index node
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*/
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static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
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{
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return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
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}
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/**
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* ubifs_idx_branch - return pointer to an index branch.
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* @c: the UBIFS file-system description object
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* @idx: index node
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* @bnum: branch number
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*/
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static inline
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struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
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const struct ubifs_idx_node *idx,
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int bnum)
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{
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return (struct ubifs_branch *)((void *)idx->branches +
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(UBIFS_BRANCH_SZ + c->key_len) * bnum);
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}
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/**
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* ubifs_idx_key - return pointer to an index key.
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* @c: the UBIFS file-system description object
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* @idx: index node
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*/
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static inline void *ubifs_idx_key(const struct ubifs_info *c,
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const struct ubifs_idx_node *idx)
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{
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return (void *)((struct ubifs_branch *)idx->branches)->key;
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}
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/**
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* ubifs_current_time - round current time to time granularity.
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* @inode: inode
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*/
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static inline struct timespec ubifs_current_time(struct inode *inode)
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{
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return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
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current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
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}
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/**
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* ubifs_tnc_lookup - look up a file-system node.
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* @c: UBIFS file-system description object
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* @key: node key to lookup
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* @node: the node is returned here
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*
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* This function look up and reads node with key @key. The caller has to make
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* sure the @node buffer is large enough to fit the node. Returns zero in case
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* of success, %-ENOENT if the node was not found, and a negative error code in
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* case of failure.
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*/
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static inline int ubifs_tnc_lookup(struct ubifs_info *c,
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const union ubifs_key *key, void *node)
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{
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return ubifs_tnc_locate(c, key, node, NULL, NULL);
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}
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/**
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* ubifs_get_lprops - get reference to LEB properties.
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* @c: the UBIFS file-system description object
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*
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* This function locks lprops. Lprops have to be unlocked by
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* 'ubifs_release_lprops()'.
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*/
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static inline void ubifs_get_lprops(struct ubifs_info *c)
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{
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mutex_lock(&c->lp_mutex);
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}
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/**
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* ubifs_release_lprops - release lprops lock.
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* @c: the UBIFS file-system description object
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*
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* This function has to be called after each 'ubifs_get_lprops()' call to
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* unlock lprops.
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*/
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static inline void ubifs_release_lprops(struct ubifs_info *c)
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{
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ubifs_assert(mutex_is_locked(&c->lp_mutex));
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ubifs_assert(c->lst.empty_lebs >= 0 &&
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c->lst.empty_lebs <= c->main_lebs);
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mutex_unlock(&c->lp_mutex);
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}
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#endif /* __UBIFS_MISC_H__ */
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