diff options
Diffstat (limited to 'ANDROID_3.4.5/fs/ubifs/io.c')
| -rw-r--r-- | ANDROID_3.4.5/fs/ubifs/io.c | 1156 |
1 files changed, 0 insertions, 1156 deletions
diff --git a/ANDROID_3.4.5/fs/ubifs/io.c b/ANDROID_3.4.5/fs/ubifs/io.c deleted file mode 100644 index 21780502..00000000 --- a/ANDROID_3.4.5/fs/ubifs/io.c +++ /dev/null @@ -1,1156 +0,0 @@ -/* - * This file is part of UBIFS. - * - * Copyright (C) 2006-2008 Nokia Corporation. - * Copyright (C) 2006, 2007 University of Szeged, Hungary - * - * 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 - * Zoltan Sogor - */ - -/* - * This file implements UBIFS I/O subsystem which provides various I/O-related - * helper functions (reading/writing/checking/validating nodes) and implements - * write-buffering support. Write buffers help to save space which otherwise - * would have been wasted for padding to the nearest minimal I/O unit boundary. - * Instead, data first goes to the write-buffer and is flushed when the - * buffer is full or when it is not used for some time (by timer). This is - * similar to the mechanism is used by JFFS2. - * - * UBIFS distinguishes between minimum write size (@c->min_io_size) and maximum - * write size (@c->max_write_size). The latter is the maximum amount of bytes - * the underlying flash is able to program at a time, and writing in - * @c->max_write_size units should presumably be faster. Obviously, - * @c->min_io_size <= @c->max_write_size. Write-buffers are of - * @c->max_write_size bytes in size for maximum performance. However, when a - * write-buffer is flushed, only the portion of it (aligned to @c->min_io_size - * boundary) which contains data is written, not the whole write-buffer, - * because this is more space-efficient. - * - * This optimization adds few complications to the code. Indeed, on the one - * hand, we want to write in optimal @c->max_write_size bytes chunks, which - * also means aligning writes at the @c->max_write_size bytes offsets. On the - * other hand, we do not want to waste space when synchronizing the write - * buffer, so during synchronization we writes in smaller chunks. And this makes - * the next write offset to be not aligned to @c->max_write_size bytes. So the - * have to make sure that the write-buffer offset (@wbuf->offs) becomes aligned - * to @c->max_write_size bytes again. We do this by temporarily shrinking - * write-buffer size (@wbuf->size). - * - * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by - * mutexes defined inside these objects. Since sometimes upper-level code - * has to lock the write-buffer (e.g. journal space reservation code), many - * functions related to write-buffers have "nolock" suffix which means that the - * caller has to lock the write-buffer before calling this function. - * - * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not - * aligned, UBIFS starts the next node from the aligned address, and the padded - * bytes may contain any rubbish. In other words, UBIFS does not put padding - * bytes in those small gaps. Common headers of nodes store real node lengths, - * not aligned lengths. Indexing nodes also store real lengths in branches. - * - * UBIFS uses padding when it pads to the next min. I/O unit. In this case it - * uses padding nodes or padding bytes, if the padding node does not fit. - * - * All UBIFS nodes are protected by CRC checksums and UBIFS checks CRC when - * they are read from the flash media. - */ - -#include <linux/crc32.h> -#include <linux/slab.h> -#include "ubifs.h" - -/** - * 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 - */ -void ubifs_ro_mode(struct ubifs_info *c, int err) -{ - if (!c->ro_error) { - c->ro_error = 1; - c->no_chk_data_crc = 0; - c->vfs_sb->s_flags |= MS_RDONLY; - ubifs_warn("switched to read-only mode, error %d", err); - dump_stack(); - } -} - -/* - * Below are simple wrappers over UBI I/O functions which include some - * additional checks and UBIFS debugging stuff. See corresponding UBI function - * for more information. - */ - -int ubifs_leb_read(const struct ubifs_info *c, int lnum, void *buf, int offs, - int len, int even_ebadmsg) -{ - int err; - - err = ubi_read(c->ubi, lnum, buf, offs, len); - /* - * In case of %-EBADMSG print the error message only if the - * @even_ebadmsg is true. - */ - if (err && (err != -EBADMSG || even_ebadmsg)) { - ubifs_err("reading %d bytes from LEB %d:%d failed, error %d", - len, lnum, offs, err); - dbg_dump_stack(); - } - return err; -} - -int ubifs_leb_write(struct ubifs_info *c, int lnum, const void *buf, int offs, - int len, int dtype) -{ - int err; - - ubifs_assert(!c->ro_media && !c->ro_mount); - if (c->ro_error) - return -EROFS; - if (!dbg_is_tst_rcvry(c)) - err = ubi_leb_write(c->ubi, lnum, buf, offs, len); - else - err = dbg_leb_write(c, lnum, buf, offs, len, dtype); - if (err) { - ubifs_err("writing %d bytes to LEB %d:%d failed, error %d", - len, lnum, offs, err); - ubifs_ro_mode(c, err); - dbg_dump_stack(); - } - return err; -} - -int ubifs_leb_change(struct ubifs_info *c, int lnum, const void *buf, int len, - int dtype) -{ - int err; - - ubifs_assert(!c->ro_media && !c->ro_mount); - if (c->ro_error) - return -EROFS; - if (!dbg_is_tst_rcvry(c)) - err = ubi_leb_change(c->ubi, lnum, buf, len); - else - err = dbg_leb_change(c, lnum, buf, len, dtype); - if (err) { - ubifs_err("changing %d bytes in LEB %d failed, error %d", - len, lnum, err); - ubifs_ro_mode(c, err); - dbg_dump_stack(); - } - return err; -} - -int ubifs_leb_unmap(struct ubifs_info *c, int lnum) -{ - int err; - - ubifs_assert(!c->ro_media && !c->ro_mount); - if (c->ro_error) - return -EROFS; - if (!dbg_is_tst_rcvry(c)) - err = ubi_leb_unmap(c->ubi, lnum); - else - err = dbg_leb_unmap(c, lnum); - if (err) { - ubifs_err("unmap LEB %d failed, error %d", lnum, err); - ubifs_ro_mode(c, err); - dbg_dump_stack(); - } - return err; -} - -int ubifs_leb_map(struct ubifs_info *c, int lnum, int dtype) -{ - int err; - - ubifs_assert(!c->ro_media && !c->ro_mount); - if (c->ro_error) - return -EROFS; - if (!dbg_is_tst_rcvry(c)) - err = ubi_leb_map(c->ubi, lnum); - else - err = dbg_leb_map(c, lnum, dtype); - if (err) { - ubifs_err("mapping LEB %d failed, error %d", lnum, err); - ubifs_ro_mode(c, err); - dbg_dump_stack(); - } - return err; -} - -int ubifs_is_mapped(const struct ubifs_info *c, int lnum) -{ - int err; - - err = ubi_is_mapped(c->ubi, lnum); - if (err < 0) { - ubifs_err("ubi_is_mapped failed for LEB %d, error %d", - lnum, err); - dbg_dump_stack(); - } - return err; -} - -/** - * ubifs_check_node - check node. - * @c: UBIFS file-system description object - * @buf: node to check - * @lnum: logical eraseblock number - * @offs: offset within the logical eraseblock - * @quiet: print no messages - * @must_chk_crc: indicates whether to always check the CRC - * - * This function checks node magic number and CRC checksum. This function also - * validates node length to prevent UBIFS from becoming crazy when an attacker - * feeds it a file-system image with incorrect nodes. For example, too large - * node length in the common header could cause UBIFS to read memory outside of - * allocated buffer when checking the CRC checksum. - * - * This function may skip data nodes CRC checking if @c->no_chk_data_crc is - * true, which is controlled by corresponding UBIFS mount option. However, if - * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is - * checked. Similarly, if @c->mounting or @c->remounting_rw is true (we are - * mounting or re-mounting to R/W mode), @c->no_chk_data_crc is ignored and CRC - * is checked. This is because during mounting or re-mounting from R/O mode to - * R/W mode we may read journal nodes (when replying the journal or doing the - * recovery) and the journal nodes may potentially be corrupted, so checking is - * required. - * - * This function returns zero in case of success and %-EUCLEAN in case of bad - * CRC or magic. - */ -int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum, - int offs, int quiet, int must_chk_crc) -{ - int err = -EINVAL, type, node_len; - uint32_t crc, node_crc, magic; - struct ubifs_ch *ch = (struct ubifs_ch*)buf; - - ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); - ubifs_assert(!(offs & 7) && offs < c->leb_size); - - magic = le32_to_cpu(ch->magic); - if (magic != UBIFS_NODE_MAGIC) { - if (!quiet) - ubifs_err("bad magic %#08x, expected %#08x", - magic, UBIFS_NODE_MAGIC); - err = -EUCLEAN; - goto out; - } - - type = ch->node_type; - if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) { - if (!quiet) - ubifs_err("bad node type %d", type); - goto out; - } - - node_len = le32_to_cpu(ch->len); - if (node_len + offs > c->leb_size) - goto out_len; - - if (c->ranges[type].max_len == 0) { - if (node_len != c->ranges[type].len) - goto out_len; - } else if (node_len < c->ranges[type].min_len || - node_len > c->ranges[type].max_len) - goto out_len; - - if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->mounting && - !c->remounting_rw && c->no_chk_data_crc) - return 0; - - crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8); - node_crc = le32_to_cpu(ch->crc); - if (crc != node_crc) { - if (!quiet) - ubifs_err("bad CRC: calculated %#08x, read %#08x", - crc, node_crc); - err = -EUCLEAN; - goto out; - } - - return 0; - -out_len: - if (!quiet) - ubifs_err("bad node length %d", node_len); -out: - if (!quiet) { - ubifs_err("bad node at LEB %d:%d", lnum, offs); - dbg_dump_node(c, buf); - dbg_dump_stack(); - } - return err; -} - -/** - * ubifs_pad - pad flash space. - * @c: UBIFS file-system description object - * @buf: buffer to put padding to - * @pad: how many bytes to pad - * - * The flash media obliges us to write only in chunks of %c->min_io_size and - * when we have to write less data we add padding node to the write-buffer and - * pad it to the next minimal I/O unit's boundary. Padding nodes help when the - * media is being scanned. If the amount of wasted space is not enough to fit a - * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes - * pattern (%UBIFS_PADDING_BYTE). - * - * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is - * used. - */ -void ubifs_pad(const struct ubifs_info *c, void *buf, int pad) -{ - uint32_t crc; - - ubifs_assert(pad >= 0 && !(pad & 7)); - - if (pad >= UBIFS_PAD_NODE_SZ) { - struct ubifs_ch *ch = buf; - struct ubifs_pad_node *pad_node = buf; - - ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); - ch->node_type = UBIFS_PAD_NODE; - ch->group_type = UBIFS_NO_NODE_GROUP; - ch->padding[0] = ch->padding[1] = 0; - ch->sqnum = 0; - ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ); - pad -= UBIFS_PAD_NODE_SZ; - pad_node->pad_len = cpu_to_le32(pad); - crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8); - ch->crc = cpu_to_le32(crc); - memset(buf + UBIFS_PAD_NODE_SZ, 0, pad); - } else if (pad > 0) - /* Too little space, padding node won't fit */ - memset(buf, UBIFS_PADDING_BYTE, pad); -} - -/** - * next_sqnum - get next sequence number. - * @c: UBIFS file-system description object - */ -static unsigned long long next_sqnum(struct ubifs_info *c) -{ - unsigned long long sqnum; - - spin_lock(&c->cnt_lock); - sqnum = ++c->max_sqnum; - spin_unlock(&c->cnt_lock); - - if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) { - if (sqnum >= SQNUM_WATERMARK) { - ubifs_err("sequence number overflow %llu, end of life", - sqnum); - ubifs_ro_mode(c, -EINVAL); - } - ubifs_warn("running out of sequence numbers, end of life soon"); - } - - return sqnum; -} - -/** - * ubifs_prepare_node - prepare node to be written to flash. - * @c: UBIFS file-system description object - * @node: the node to pad - * @len: node length - * @pad: if the buffer has to be padded - * - * This function prepares node at @node to be written to the media - it - * calculates node CRC, fills the common header, and adds proper padding up to - * the next minimum I/O unit if @pad is not zero. - */ -void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad) -{ - uint32_t crc; - struct ubifs_ch *ch = node; - unsigned long long sqnum = next_sqnum(c); - - ubifs_assert(len >= UBIFS_CH_SZ); - - ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); - ch->len = cpu_to_le32(len); - ch->group_type = UBIFS_NO_NODE_GROUP; - ch->sqnum = cpu_to_le64(sqnum); - ch->padding[0] = ch->padding[1] = 0; - crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); - ch->crc = cpu_to_le32(crc); - - if (pad) { - len = ALIGN(len, 8); - pad = ALIGN(len, c->min_io_size) - len; - ubifs_pad(c, node + len, pad); - } -} - -/** - * ubifs_prep_grp_node - prepare node of a group to be written to flash. - * @c: UBIFS file-system description object - * @node: the node to pad - * @len: node length - * @last: indicates the last node of the group - * - * This function prepares node at @node to be written to the media - it - * calculates node CRC and fills the common header. - */ -void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last) -{ - uint32_t crc; - struct ubifs_ch *ch = node; - unsigned long long sqnum = next_sqnum(c); - - ubifs_assert(len >= UBIFS_CH_SZ); - - ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC); - ch->len = cpu_to_le32(len); - if (last) - ch->group_type = UBIFS_LAST_OF_NODE_GROUP; - else - ch->group_type = UBIFS_IN_NODE_GROUP; - ch->sqnum = cpu_to_le64(sqnum); - ch->padding[0] = ch->padding[1] = 0; - crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8); - ch->crc = cpu_to_le32(crc); -} - -/** - * wbuf_timer_callback - write-buffer timer callback function. - * @data: timer data (write-buffer descriptor) - * - * This function is called when the write-buffer timer expires. - */ -static enum hrtimer_restart wbuf_timer_callback_nolock(struct hrtimer *timer) -{ - struct ubifs_wbuf *wbuf = container_of(timer, struct ubifs_wbuf, timer); - - dbg_io("jhead %s", dbg_jhead(wbuf->jhead)); - wbuf->need_sync = 1; - wbuf->c->need_wbuf_sync = 1; - ubifs_wake_up_bgt(wbuf->c); - return HRTIMER_NORESTART; -} - -/** - * new_wbuf_timer - start new write-buffer timer. - * @wbuf: write-buffer descriptor - */ -static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) -{ - ubifs_assert(!hrtimer_active(&wbuf->timer)); - - if (wbuf->no_timer) - return; - dbg_io("set timer for jhead %s, %llu-%llu millisecs", - dbg_jhead(wbuf->jhead), - div_u64(ktime_to_ns(wbuf->softlimit), USEC_PER_SEC), - div_u64(ktime_to_ns(wbuf->softlimit) + wbuf->delta, - USEC_PER_SEC)); - hrtimer_start_range_ns(&wbuf->timer, wbuf->softlimit, wbuf->delta, - HRTIMER_MODE_REL); -} - -/** - * cancel_wbuf_timer - cancel write-buffer timer. - * @wbuf: write-buffer descriptor - */ -static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf) -{ - if (wbuf->no_timer) - return; - wbuf->need_sync = 0; - hrtimer_cancel(&wbuf->timer); -} - -/** - * ubifs_wbuf_sync_nolock - synchronize write-buffer. - * @wbuf: write-buffer to synchronize - * - * This function synchronizes write-buffer @buf and returns zero in case of - * success or a negative error code in case of failure. - * - * Note, although write-buffers are of @c->max_write_size, this function does - * not necessarily writes all @c->max_write_size bytes to the flash. Instead, - * if the write-buffer is only partially filled with data, only the used part - * of the write-buffer (aligned on @c->min_io_size boundary) is synchronized. - * This way we waste less space. - */ -int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) -{ - struct ubifs_info *c = wbuf->c; - int err, dirt, sync_len; - - cancel_wbuf_timer_nolock(wbuf); - if (!wbuf->used || wbuf->lnum == -1) - /* Write-buffer is empty or not seeked */ - return 0; - - dbg_io("LEB %d:%d, %d bytes, jhead %s", - wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead)); - ubifs_assert(!(wbuf->avail & 7)); - ubifs_assert(wbuf->offs + wbuf->size <= c->leb_size); - ubifs_assert(wbuf->size >= c->min_io_size); - ubifs_assert(wbuf->size <= c->max_write_size); - ubifs_assert(wbuf->size % c->min_io_size == 0); - ubifs_assert(!c->ro_media && !c->ro_mount); - if (c->leb_size - wbuf->offs >= c->max_write_size) - ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); - - if (c->ro_error) - return -EROFS; - - /* - * Do not write whole write buffer but write only the minimum necessary - * amount of min. I/O units. - */ - sync_len = ALIGN(wbuf->used, c->min_io_size); - dirt = sync_len - wbuf->used; - if (dirt) - ubifs_pad(c, wbuf->buf + wbuf->used, dirt); - err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, sync_len, - wbuf->dtype); - if (err) - return err; - - spin_lock(&wbuf->lock); - wbuf->offs += sync_len; - /* - * Now @wbuf->offs is not necessarily aligned to @c->max_write_size. - * But our goal is to optimize writes and make sure we write in - * @c->max_write_size chunks and to @c->max_write_size-aligned offset. - * Thus, if @wbuf->offs is not aligned to @c->max_write_size now, make - * sure that @wbuf->offs + @wbuf->size is aligned to - * @c->max_write_size. This way we make sure that after next - * write-buffer flush we are again at the optimal offset (aligned to - * @c->max_write_size). - */ - if (c->leb_size - wbuf->offs < c->max_write_size) - wbuf->size = c->leb_size - wbuf->offs; - else if (wbuf->offs & (c->max_write_size - 1)) - wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; - else - wbuf->size = c->max_write_size; - wbuf->avail = wbuf->size; - wbuf->used = 0; - wbuf->next_ino = 0; - spin_unlock(&wbuf->lock); - - if (wbuf->sync_callback) - err = wbuf->sync_callback(c, wbuf->lnum, - c->leb_size - wbuf->offs, dirt); - return err; -} - -/** - * ubifs_wbuf_seek_nolock - seek write-buffer. - * @wbuf: write-buffer - * @lnum: logical eraseblock number to seek to - * @offs: logical eraseblock offset to seek to - * @dtype: data type - * - * This function targets the write-buffer to logical eraseblock @lnum:@offs. - * The write-buffer has to be empty. Returns zero in case of success and a - * negative error code in case of failure. - */ -int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs, - int dtype) -{ - const struct ubifs_info *c = wbuf->c; - - dbg_io("LEB %d:%d, jhead %s", lnum, offs, dbg_jhead(wbuf->jhead)); - ubifs_assert(lnum >= 0 && lnum < c->leb_cnt); - ubifs_assert(offs >= 0 && offs <= c->leb_size); - ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7)); - ubifs_assert(lnum != wbuf->lnum); - ubifs_assert(wbuf->used == 0); - - spin_lock(&wbuf->lock); - wbuf->lnum = lnum; - wbuf->offs = offs; - if (c->leb_size - wbuf->offs < c->max_write_size) - wbuf->size = c->leb_size - wbuf->offs; - else if (wbuf->offs & (c->max_write_size - 1)) - wbuf->size = ALIGN(wbuf->offs, c->max_write_size) - wbuf->offs; - else - wbuf->size = c->max_write_size; - wbuf->avail = wbuf->size; - wbuf->used = 0; - spin_unlock(&wbuf->lock); - wbuf->dtype = dtype; - - return 0; -} - -/** - * ubifs_bg_wbufs_sync - synchronize write-buffers. - * @c: UBIFS file-system description object - * - * This function is called by background thread to synchronize write-buffers. - * Returns zero in case of success and a negative error code in case of - * failure. - */ -int ubifs_bg_wbufs_sync(struct ubifs_info *c) -{ - int err, i; - - ubifs_assert(!c->ro_media && !c->ro_mount); - if (!c->need_wbuf_sync) - return 0; - c->need_wbuf_sync = 0; - - if (c->ro_error) { - err = -EROFS; - goto out_timers; - } - - dbg_io("synchronize"); - for (i = 0; i < c->jhead_cnt; i++) { - struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; - - cond_resched(); - - /* - * If the mutex is locked then wbuf is being changed, so - * synchronization is not necessary. - */ - if (mutex_is_locked(&wbuf->io_mutex)) - continue; - - mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); - if (!wbuf->need_sync) { - mutex_unlock(&wbuf->io_mutex); - continue; - } - - err = ubifs_wbuf_sync_nolock(wbuf); - mutex_unlock(&wbuf->io_mutex); - if (err) { - ubifs_err("cannot sync write-buffer, error %d", err); - ubifs_ro_mode(c, err); - goto out_timers; - } - } - - return 0; - -out_timers: - /* Cancel all timers to prevent repeated errors */ - for (i = 0; i < c->jhead_cnt; i++) { - struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; - - mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); - cancel_wbuf_timer_nolock(wbuf); - mutex_unlock(&wbuf->io_mutex); - } - return err; -} - -/** - * ubifs_wbuf_write_nolock - write data to flash via write-buffer. - * @wbuf: write-buffer - * @buf: node to write - * @len: node length - * - * This function writes data to flash via write-buffer @wbuf. This means that - * the last piece of the node won't reach the flash media immediately if it - * does not take whole max. write unit (@c->max_write_size). Instead, the node - * will sit in RAM until the write-buffer is synchronized (e.g., by timer, or - * because more data are appended to the write-buffer). - * - * This function returns zero in case of success and a negative error code in - * case of failure. If the node cannot be written because there is no more - * space in this logical eraseblock, %-ENOSPC is returned. - */ -int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) -{ - struct ubifs_info *c = wbuf->c; - int err, written, n, aligned_len = ALIGN(len, 8); - - dbg_io("%d bytes (%s) to jhead %s wbuf at LEB %d:%d", len, - dbg_ntype(((struct ubifs_ch *)buf)->node_type), - dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs + wbuf->used); - ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt); - ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0); - ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size); - ubifs_assert(wbuf->avail > 0 && wbuf->avail <= wbuf->size); - ubifs_assert(wbuf->size >= c->min_io_size); - ubifs_assert(wbuf->size <= c->max_write_size); - ubifs_assert(wbuf->size % c->min_io_size == 0); - ubifs_assert(mutex_is_locked(&wbuf->io_mutex)); - ubifs_assert(!c->ro_media && !c->ro_mount); - ubifs_assert(!c->space_fixup); - if (c->leb_size - wbuf->offs >= c->max_write_size) - ubifs_assert(!((wbuf->offs + wbuf->size) % c->max_write_size)); - - if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) { - err = -ENOSPC; - goto out; - } - - cancel_wbuf_timer_nolock(wbuf); - - if (c->ro_error) - return -EROFS; - - if (aligned_len <= wbuf->avail) { - /* - * The node is not very large and fits entirely within - * write-buffer. - */ - memcpy(wbuf->buf + wbuf->used, buf, len); - - if (aligned_len == wbuf->avail) { - dbg_io("flush jhead %s wbuf to LEB %d:%d", - dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); - err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, - wbuf->offs, wbuf->size, - wbuf->dtype); - if (err) - goto out; - - spin_lock(&wbuf->lock); - wbuf->offs += wbuf->size; - if (c->leb_size - wbuf->offs >= c->max_write_size) - wbuf->size = c->max_write_size; - else - wbuf->size = c->leb_size - wbuf->offs; - wbuf->avail = wbuf->size; - wbuf->used = 0; - wbuf->next_ino = 0; - spin_unlock(&wbuf->lock); - } else { - spin_lock(&wbuf->lock); - wbuf->avail -= aligned_len; - wbuf->used += aligned_len; - spin_unlock(&wbuf->lock); - } - - goto exit; - } - - written = 0; - - if (wbuf->used) { - /* - * The node is large enough and does not fit entirely within - * current available space. We have to fill and flush - * write-buffer and switch to the next max. write unit. - */ - dbg_io("flush jhead %s wbuf to LEB %d:%d", - dbg_jhead(wbuf->jhead), wbuf->lnum, wbuf->offs); - memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail); - err = ubifs_leb_write(c, wbuf->lnum, wbuf->buf, wbuf->offs, - wbuf->size, wbuf->dtype); - if (err) - goto out; - - wbuf->offs += wbuf->size; - len -= wbuf->avail; - aligned_len -= wbuf->avail; - written += wbuf->avail; - } else if (wbuf->offs & (c->max_write_size - 1)) { - /* - * The write-buffer offset is not aligned to - * @c->max_write_size and @wbuf->size is less than - * @c->max_write_size. Write @wbuf->size bytes to make sure the - * following writes are done in optimal @c->max_write_size - * chunks. - */ - dbg_io("write %d bytes to LEB %d:%d", - wbuf->size, wbuf->lnum, wbuf->offs); - err = ubifs_leb_write(c, wbuf->lnum, buf, wbuf->offs, - wbuf->size, wbuf->dtype); - if (err) - goto out; - - wbuf->offs += wbuf->size; - len -= wbuf->size; - aligned_len -= wbuf->size; - written += wbuf->size; - } - - /* - * The remaining data may take more whole max. write units, so write the - * remains multiple to max. write unit size directly to the flash media. - * We align node length to 8-byte boundary because we anyway flash wbuf - * if the remaining space is less than 8 bytes. - */ - n = aligned_len >> c->max_write_shift; - if (n) { - n <<= c->max_write_shift; - dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, - wbuf->offs); - err = ubifs_leb_write(c, wbuf->lnum, buf + written, - wbuf->offs, n, wbuf->dtype); - if (err) - goto out; - wbuf->offs += n; - aligned_len -= n; - len -= n; - written += n; - } - - spin_lock(&wbuf->lock); - if (aligned_len) - /* - * And now we have what's left and what does not take whole - * max. write unit, so write it to the write-buffer and we are - * done. - */ - memcpy(wbuf->buf, buf + written, len); - - if (c->leb_size - wbuf->offs >= c->max_write_size) - wbuf->size = c->max_write_size; - else - wbuf->size = c->leb_size - wbuf->offs; - wbuf->avail = wbuf->size - aligned_len; - wbuf->used = aligned_len; - wbuf->next_ino = 0; - spin_unlock(&wbuf->lock); - -exit: - if (wbuf->sync_callback) { - int free = c->leb_size - wbuf->offs - wbuf->used; - - err = wbuf->sync_callback(c, wbuf->lnum, free, 0); - if (err) - goto out; - } - - if (wbuf->used) - new_wbuf_timer_nolock(wbuf); - - return 0; - -out: - ubifs_err("cannot write %d bytes to LEB %d:%d, error %d", - len, wbuf->lnum, wbuf->offs, err); - dbg_dump_node(c, buf); - dbg_dump_stack(); - dbg_dump_leb(c, wbuf->lnum); - return err; -} - -/** - * ubifs_write_node - write node to the media. - * @c: UBIFS file-system description object - * @buf: the node to write - * @len: node length - * @lnum: logical eraseblock number - * @offs: offset within the logical eraseblock - * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN) - * - * This function automatically fills node magic number, assigns sequence - * number, and calculates node CRC checksum. The length of the @buf buffer has - * to be aligned to the minimal I/O unit size. This function automatically - * appends padding node and padding bytes if needed. Returns zero in case of - * success and a negative error code in case of failure. - */ -int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, - int offs, int dtype) -{ - int err, buf_len = ALIGN(len, c->min_io_size); - - dbg_io("LEB %d:%d, %s, length %d (aligned %d)", - lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len, - buf_len); - ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); - ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size); - ubifs_assert(!c->ro_media && !c->ro_mount); - ubifs_assert(!c->space_fixup); - - if (c->ro_error) - return -EROFS; - - ubifs_prepare_node(c, buf, len, 1); - err = ubifs_leb_write(c, lnum, buf, offs, buf_len, dtype); - if (err) - dbg_dump_node(c, buf); - - return err; -} - -/** - * ubifs_read_node_wbuf - read node from the media or write-buffer. - * @wbuf: wbuf to check for un-written data - * @buf: buffer to read to - * @type: node type - * @len: node length - * @lnum: logical eraseblock number - * @offs: offset within the logical eraseblock - * - * This function reads a node of known type and length, checks it and stores - * in @buf. If the node partially or fully sits in the write-buffer, this - * function takes data from the buffer, otherwise it reads the flash media. - * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative - * error code in case of failure. - */ -int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len, - int lnum, int offs) -{ - const struct ubifs_info *c = wbuf->c; - int err, rlen, overlap; - struct ubifs_ch *ch = buf; - - dbg_io("LEB %d:%d, %s, length %d, jhead %s", lnum, offs, - dbg_ntype(type), len, dbg_jhead(wbuf->jhead)); - ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0); - ubifs_assert(!(offs & 7) && offs < c->leb_size); - ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); - - spin_lock(&wbuf->lock); - overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs); - if (!overlap) { - /* We may safely unlock the write-buffer and read the data */ - spin_unlock(&wbuf->lock); - return ubifs_read_node(c, buf, type, len, lnum, offs); - } - - /* Don't read under wbuf */ - rlen = wbuf->offs - offs; - if (rlen < 0) - rlen = 0; - - /* Copy the rest from the write-buffer */ - memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen); - spin_unlock(&wbuf->lock); - - if (rlen > 0) { - /* Read everything that goes before write-buffer */ - err = ubifs_leb_read(c, lnum, buf, offs, rlen, 0); - if (err && err != -EBADMSG) - return err; - } - - if (type != ch->node_type) { - ubifs_err("bad node type (%d but expected %d)", - ch->node_type, type); - goto out; - } - - err = ubifs_check_node(c, buf, lnum, offs, 0, 0); - if (err) { - ubifs_err("expected node type %d", type); - return err; - } - - rlen = le32_to_cpu(ch->len); - if (rlen != len) { - ubifs_err("bad node length %d, expected %d", rlen, len); - goto out; - } - - return 0; - -out: - ubifs_err("bad node at LEB %d:%d", lnum, offs); - dbg_dump_node(c, buf); - dbg_dump_stack(); - return -EINVAL; -} - -/** - * ubifs_read_node - read node. - * @c: UBIFS file-system description object - * @buf: buffer to read to - * @type: node type - * @len: node length (not aligned) - * @lnum: logical eraseblock number - * @offs: offset within the logical eraseblock - * - * This function reads a node of known type and and length, checks it and - * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched - * and a negative error code in case of failure. - */ -int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len, - int lnum, int offs) -{ - int err, l; - struct ubifs_ch *ch = buf; - - dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len); - ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0); - ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size); - ubifs_assert(!(offs & 7) && offs < c->leb_size); - ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT); - - err = ubifs_leb_read(c, lnum, buf, offs, len, 0); - if (err && err != -EBADMSG) - return err; - - if (type != ch->node_type) { - ubifs_err("bad node type (%d but expected %d)", - ch->node_type, type); - goto out; - } - - err = ubifs_check_node(c, buf, lnum, offs, 0, 0); - if (err) { - ubifs_err("expected node type %d", type); - return err; - } - - l = le32_to_cpu(ch->len); - if (l != len) { - ubifs_err("bad node length %d, expected %d", l, len); - goto out; - } - - return 0; - -out: - ubifs_err("bad node at LEB %d:%d, LEB mapping status %d", lnum, offs, - ubi_is_mapped(c->ubi, lnum)); - dbg_dump_node(c, buf); - dbg_dump_stack(); - return -EINVAL; -} - -/** - * ubifs_wbuf_init - initialize write-buffer. - * @c: UBIFS file-system description object - * @wbuf: write-buffer to initialize - * - * This function initializes write-buffer. Returns zero in case of success - * %-ENOMEM in case of failure. - */ -int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf) -{ - size_t size; - - wbuf->buf = kmalloc(c->max_write_size, GFP_KERNEL); - if (!wbuf->buf) - return -ENOMEM; - - size = (c->max_write_size / UBIFS_CH_SZ + 1) * sizeof(ino_t); - wbuf->inodes = kmalloc(size, GFP_KERNEL); - if (!wbuf->inodes) { - kfree(wbuf->buf); - wbuf->buf = NULL; - return -ENOMEM; - } - - wbuf->used = 0; - wbuf->lnum = wbuf->offs = -1; - /* - * If the LEB starts at the max. write size aligned address, then - * write-buffer size has to be set to @c->max_write_size. Otherwise, - * set it to something smaller so that it ends at the closest max. - * write size boundary. - */ - size = c->max_write_size - (c->leb_start % c->max_write_size); - wbuf->avail = wbuf->size = size; - wbuf->dtype = UBI_UNKNOWN; - wbuf->sync_callback = NULL; - mutex_init(&wbuf->io_mutex); - spin_lock_init(&wbuf->lock); - wbuf->c = c; - wbuf->next_ino = 0; - - hrtimer_init(&wbuf->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); - wbuf->timer.function = wbuf_timer_callback_nolock; - wbuf->softlimit = ktime_set(WBUF_TIMEOUT_SOFTLIMIT, 0); - wbuf->delta = WBUF_TIMEOUT_HARDLIMIT - WBUF_TIMEOUT_SOFTLIMIT; - wbuf->delta *= 1000000000ULL; - ubifs_assert(wbuf->delta <= ULONG_MAX); - return 0; -} - -/** - * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array. - * @wbuf: the write-buffer where to add - * @inum: the inode number - * - * This function adds an inode number to the inode array of the write-buffer. - */ -void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum) -{ - if (!wbuf->buf) - /* NOR flash or something similar */ - return; - - spin_lock(&wbuf->lock); - if (wbuf->used) - wbuf->inodes[wbuf->next_ino++] = inum; - spin_unlock(&wbuf->lock); -} - -/** - * wbuf_has_ino - returns if the wbuf contains data from the inode. - * @wbuf: the write-buffer - * @inum: the inode number - * - * This function returns with %1 if the write-buffer contains some data from the - * given inode otherwise it returns with %0. - */ -static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum) -{ - int i, ret = 0; - - spin_lock(&wbuf->lock); - for (i = 0; i < wbuf->next_ino; i++) - if (inum == wbuf->inodes[i]) { - ret = 1; - break; - } - spin_unlock(&wbuf->lock); - - return ret; -} - -/** - * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode. - * @c: UBIFS file-system description object - * @inode: inode to synchronize - * - * This function synchronizes write-buffers which contain nodes belonging to - * @inode. Returns zero in case of success and a negative error code in case of - * failure. - */ -int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode) -{ - int i, err = 0; - - for (i = 0; i < c->jhead_cnt; i++) { - struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf; - - if (i == GCHD) - /* - * GC head is special, do not look at it. Even if the - * head contains something related to this inode, it is - * a _copy_ of corresponding on-flash node which sits - * somewhere else. - */ - continue; - - if (!wbuf_has_ino(wbuf, inode->i_ino)) - continue; - - mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead); - if (wbuf_has_ino(wbuf, inode->i_ino)) - err = ubifs_wbuf_sync_nolock(wbuf); - mutex_unlock(&wbuf->io_mutex); - - if (err) { - ubifs_ro_mode(c, err); - return err; - } - } - return 0; -} |