linux/fs/ubifs/io.c

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/*
* 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.
*
* 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 all nodes
* every time they are read from the flash media.
*/
#include <linux/crc32.h>
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 08:04:11 +00:00
#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_media) {
c->ro_media = 1;
c->no_chk_data_crc = 0;
c->vfs_sb->s_flags |= MS_RDONLY;
ubifs_warn("switched to read-only mode, error %d", err);
dbg_dump_stack();
}
}
/**
* 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->always_chk_crc is true, @c->no_chk_data_crc is
* ignored and CRC is checked.
*
* 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;
const struct ubifs_ch *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->always_chk_crc &&
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.
*/
int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
{
struct ubifs_info *c = wbuf->c;
int err, dirt;
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(!(c->vfs_sb->s_flags & MS_RDONLY));
ubifs_assert(!(wbuf->avail & 7));
ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);
if (c->ro_media)
return -EROFS;
ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail);
err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
c->min_io_size, wbuf->dtype);
if (err) {
ubifs_err("cannot write %d bytes to LEB %d:%d",
c->min_io_size, wbuf->lnum, wbuf->offs);
dbg_dump_stack();
return err;
}
dirt = wbuf->avail;
spin_lock(&wbuf->lock);
wbuf->offs += c->min_io_size;
wbuf->avail = c->min_io_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 is synchronized if it is not 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);
if (wbuf->used > 0) {
int err = ubifs_wbuf_sync_nolock(wbuf);
if (err)
return err;
}
spin_lock(&wbuf->lock);
wbuf->lnum = lnum;
wbuf->offs = offs;
wbuf->avail = c->min_io_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;
if (!c->need_wbuf_sync)
return 0;
c->need_wbuf_sync = 0;
if (c->ro_media) {
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 minimal I/O unit. Instead, the node will sit in RAM
* until the write-buffer is synchronized (e.g., by timer).
*
* 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), offs;
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 <= c->min_io_size);
ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
err = -ENOSPC;
goto out;
}
cancel_wbuf_timer_nolock(wbuf);
if (c->ro_media)
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 = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf,
wbuf->offs, c->min_io_size,
wbuf->dtype);
if (err)
goto out;
spin_lock(&wbuf->lock);
wbuf->offs += c->min_io_size;
wbuf->avail = c->min_io_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;
}
/*
* The node is large enough and does not fit entirely within current
* minimal I/O unit. We have to fill and flush write-buffer and switch
* to the next min. I/O 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 = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
c->min_io_size, wbuf->dtype);
if (err)
goto out;
offs = wbuf->offs + c->min_io_size;
len -= wbuf->avail;
aligned_len -= wbuf->avail;
written = wbuf->avail;
/*
* The remaining data may take more whole min. I/O units, so write the
* remains multiple to min. I/O 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->min_io_shift;
if (n) {
n <<= c->min_io_shift;
dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs);
err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n,
wbuf->dtype);
if (err)
goto out;
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
* min. I/O unit, so write it to the write-buffer and we are
* done.
*/
memcpy(wbuf->buf, buf + written, len);
wbuf->offs = offs;
wbuf->used = aligned_len;
wbuf->avail = c->min_io_size - 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);
if (c->ro_media)
return -EROFS;
ubifs_prepare_node(c, buf, len, 1);
err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype);
if (err) {
ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
buf_len, lnum, offs, err);
dbg_dump_node(c, buf);
dbg_dump_stack();
}
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 = ubi_read(c->ubi, lnum, buf, offs, rlen);
if (err && err != -EBADMSG) {
ubifs_err("failed to read node %d from LEB %d:%d, "
"error %d", type, lnum, offs, err);
dbg_dump_stack();
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 = ubi_read(c->ubi, lnum, buf, offs, len);
if (err && err != -EBADMSG) {
ubifs_err("cannot read node %d from LEB %d:%d, error %d",
type, lnum, offs, err);
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", lnum, offs);
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->min_io_size, GFP_KERNEL);
if (!wbuf->buf)
return -ENOMEM;
size = (c->min_io_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;
wbuf->avail = c->min_io_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;
}