smp8671/android上yaffs2文件莫名丢失有关问题分析2
smp8671/android下yaffs2文件莫名丢失问题分析2
解决了前一篇文章中说的问题后，当时以为真的解决问题了。周五晚升级软件，继续测试，下周一看运行状况。结果很不幸，问题又出现了，还是丢失文件的问题。看了上一篇改的代码，看来改的另外一个问题，yaffs多进程会挂起。这次出现的问题才是真正的丢失文件问题。看来这个版本里yaffs有好多问题啊。真不知道sigma-design怎么搞的，难道都没测出来这些问题么？
继续调试问题，根据打印发现经常有so库找不到，libui.so，libdvm.so，libmedia_jni.so都可能找不到，有时甚至找不到2个库。
yaffs_get_obj_name中相关代码如下，与yaffs_check_obj_details_loaded类似，都是申请一块缓存，然后调用yaffs_rd_chunk_tags_nand()，不同的是yaffs_get_obj_name中多了memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
printk ("windsome%d: %d mtd read error! why???? len=%d, dummy_len=%d, nand_chunk=%d, addr=0x%llx, retval=%d\n",
windsome_path, windsome_read_twice, dev->param.total_bytes_per_chunk, dummy, nand_chunk, addr, retval);
根据如上调试信息，通过修改nandmtd2_ReadChunkWithTagsFromNAND函数暂时解决此问题。
可能有另外的解决办法，修改yaffs_rd_chunk_tags_nand，在里面增加memset()，可以试试。
最终的原因，我并没有查出来，是板子稳定性问题导致驱动不正常？或者smp8xxx_nand驱动本身有问题，有待继续调试。
解决了前一篇文章中说的问题后，当时以为真的解决问题了。周五晚升级软件，继续测试，下周一看运行状况。结果很不幸，问题又出现了，还是丢失文件的问题。看了上一篇改的代码，看来改的另外一个问题，yaffs多进程会挂起。这次出现的问题才是真正的丢失文件问题。看来这个版本里yaffs有好多问题啊。真不知道sigma-design怎么搞的，难道都没测出来这些问题么？
继续调试问题，根据打印发现经常有so库找不到，libui.so，libdvm.so，libmedia_jni.so都可能找不到，有时甚至找不到2个库。
bionic/linker/linker.c:2239| ERROR: 1817 could not load needed library 'libui.so' for 'libmedia.so' (load_library[1229]: Library 'libui.so' not found)查找一个文件，首先会运行yaffs_lookup()，在fs/yaffs2中增加打印信息，yaffs_vfs_glue.c中增加log级别，修改如下：
unsigned int yaffs_trace_mask =YAFFS_TRACE_BAD_BLOCKS | YAFFS_TRACE_ALWAYS | YAFFS_TRACE_OS | YAFFS_TRACE_TRACING | YAFFS_TRACE_SCAN;得到新的日志信息：
[ 32.700000] yaffs_lookup dentry [ 32.704000] yaffs_lookup for dev=90ccf000, 740:libui.so [ 32.732000] yaffs_lookup not found [ 32.736000] yaffs_lookup for dev=90c53000, 297:libui.so [ 32.768000] yaffs_lookup not found从上面的打印可以看到libui.so没有找到。继续跟踪yaffs_lookup函数，发现yaffs_find_by_name返回的是空。修改此函数，在此函数中多进行一次查找。结果发现，第二次查找却找到了此文件。说明flash初始化是正确的，但偶尔却找不到文件。修改函数如下：
yaffs_obj_t *yaffs_find_by_name(yaffs_obj_t *directory,
const YCHAR *name)
{
int sum;
struct ylist_head *i;
YCHAR buffer[YAFFS_MAX_NAME_LENGTH + 1];
yaffs_obj_t *l;
int windsome_obj_name_len = 0;
if (!name)
return NULL;
if (!directory) {
T(YAFFS_TRACE_ALWAYS,
(TSTR
("tragedy: yaffs_find_by_name: null pointer directory"
TENDSTR)));
YBUG();
return NULL;
}
if (directory->variant_type != YAFFS_OBJECT_TYPE_DIRECTORY) {
T(YAFFS_TRACE_ALWAYS,
(TSTR
("tragedy: yaffs_find_by_name: non-directory" TENDSTR)));
YBUG();
}
sum = yaffs_calc_name_sum(name);
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name to find: name=%s, len=%d, sum=%u\n"), name, yaffs_strnlen(name, YAFFS_MAX_NAME_LENGTH), sum));
ylist_for_each(i, &directory->variant.dir_variant.children) {
if (i) {
l = ylist_entry(i, yaffs_obj_t, siblings);
if (l->parent != directory) {
T(YAFFS_TRACE_ALWAYS,
(TSTR
("tragedy: yaffs_find_by_name1: parent diff" TENDSTR)));
YBUG();
}
yaffs_check_obj_details_loaded(l);
/* Special case for lost-n-found */
if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
if (yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME) == 0) {
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name1: name=%s\n"), name));
return l;
}
} else if (yaffs_sum_cmp(l->sum, sum) || l->hdr_chunk <= 0) {
/* LostnFound chunk called Objxxx
* Do a real check
*/
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name1: sum=%u, hdr_chunk=%d, short_name=%s\n"), l->sum, l->hdr_chunk, l->short_name?:""));
windsome_obj_name_len = yaffs_get_obj_name(l, buffer, YAFFS_MAX_NAME_LENGTH + 1);
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name1: obj_name=%s, windsome_obj_name_len=%d\n"), buffer, windsome_obj_name_len));
if (yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH) == 0) {
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name1: name=%s, obj_name=%s\n"), name, buffer));
return l;
}
}
}
}
T(YAFFS_TRACE_OS, (TSTR("yaffs_find_by_name: sum=%d, ret=NULL, try again! only for print\n"), sum));
ylist_for_each(i, &directory->variant.dir_variant.children) {
if (i) {
l = ylist_entry(i, yaffs_obj_t, siblings);
if (l->parent != directory) {
T(YAFFS_TRACE_ALWAYS,
(TSTR
("tragedy: yaffs_find_by_name2: parent diff" TENDSTR)));
YBUG();
}
yaffs_check_obj_details_loaded(l);
/* Special case for lost-n-found */
if (l->obj_id == YAFFS_OBJECTID_LOSTNFOUND) {
if (yaffs_strcmp(name, YAFFS_LOSTNFOUND_NAME) == 0) {
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name2: name=%s\n"), name));
return NULL;
}
} else if (yaffs_sum_cmp(l->sum, sum) || l->hdr_chunk <= 0) {
/* LostnFound chunk called Objxxx
* Do a real check
*/
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name2: sum=%u, hdr_chunk=%d, short_name=%s\n"), l->sum, l->hdr_chunk, l->short_name?:""));
windsome_obj_name_len = yaffs_get_obj_name(l, buffer, YAFFS_MAX_NAME_LENGTH + 1);
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name2: obj_name=%s, windsome_obj_name_len=%d\n"), buffer, windsome_obj_name_len));
if (yaffs_strncmp(name, buffer, YAFFS_MAX_NAME_LENGTH) == 0) {
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_find_by_name1: name=%s, obj_name=%s\n"), name, buffer));
return NULL;
}
}
}
}
T(YAFFS_TRACE_OS, (TSTR("yaffs_find_by_name: final ret=NULL\n")));
return NULL;
}
为了确定丢失的文件inode是否真的存在，在yaffs_add_obj_to_dir中加入打印+ T(YAFFS_TRACE_TRACING, (TSTR("yaffs_add_obj_to_dir: sum=%u, obj_id=%u, short_name=%s, parent:(%u,%u,%s)\n"), obj->sum, obj->obj_id, obj->short_name, directory->sum, directory->obj_id, directory->short_name));
/* Now add it */
ylist_add(&obj->siblings, &directory->variant.dir_variant.children);
obj->parent = directory;
从得到的日志中发现libui.so的obj_id=879确实存在，通过看代码感觉与short_name有莫大关系。[ 17.552000] yaffs_add_obj_to_dir: sum=0, obj_id=0, short_name=, parent:(0,2,) [ 17.560000] yaffs_add_obj_to_dir: sum=0, obj_id=879, short_name=, parent:(0,740,) [ 17.568000] yaffs_add_obj_to_dir: sum=0, obj_id=0, short_name=, parent:(0,2,) [ 17.576000] yaffs_add_obj_to_dir: sum=0, obj_id=368, short_name=, parent:(0,298,) [ 17.584000] yaffs_add_obj_to_dir: sum=0, obj_id=0, short_name=, parent:(0,2,) [ 17.588000] yaffs_add_obj_to_dir: sum=0, obj_id=624, short_name=, parent:(0,610,) [ 17.596000] yaffs_add_obj_to_dir: sum=0, obj_id=0, short_name=, parent:(0,2,)查看short_name相关代码后在set_obj_name()中加入打印，如下：
void yaffs_set_obj_name(yaffs_obj_t *obj, const YCHAR *name)
{
#ifdef CONFIG_YAFFS_SHORT_NAMES_IN_RAM
memset(obj->short_name, 0, sizeof(YCHAR) * (YAFFS_SHORT_NAME_LENGTH+1));
if (name && yaffs_strnlen(name,YAFFS_SHORT_NAME_LENGTH+1) <= YAFFS_SHORT_NAME_LENGTH)
yaffs_strcpy(obj->short_name, name);
else
obj->short_name[0] = _Y('\0');
#endif
obj->sum = yaffs_calc_name_sum(name);
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_set_obj_name: sum=%u, obj_id=%d, hdr_chunk=%d, short_name=%s (%s)\n"), obj->sum, obj->obj_id, obj->hdr_chunk, obj->short_name, name?:""));
}
加入打印后得到一个日志如下，正常情况下obj_id=764是指libdvm.so，但这里却是libmedia_jni.so，为何会如此？？[ 38.796000] yaffs_set_obj_name: sum=6787, obj_id=767, hdr_chunk=54162, short_name=librmomx.so (librmomx.so) [ 38.804000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.816000] yaffs_set_obj_name: sum=62483, obj_id=766, hdr_chunk=54156, short_name= (libstagefright_color_conversion.so) [ 38.824000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.840000] yaffs_set_obj_name: sum=11922, obj_id=765, hdr_chunk=54114, short_name=libmedia_jni.so (libmedia_jni.so) [ 38.848000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.860000] yaffs_set_obj_name: sum=11922, obj_id=764, hdr_chunk=53515, short_name=libmedia_jni.so (libmedia_jni.so) [ 38.868000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.884000] yaffs_set_obj_name: sum=4566, obj_id=763, hdr_chunk=53507, short_name=libETC1.so (libETC1.so) [ 38.892000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.904000] yaffs_set_obj_name: sum=7769, obj_id=762, hdr_chunk=53481, short_name=libskiagl.so (libskiagl.so) [ 38.912000] yaffs_check_obj_details_loaded: chunkData=0x92c73000 [ 38.920000] yaffs_set_obj_name: sum=18559, obj_id=761, hdr_chunk=53462, short_name= (libreference-ril.so) [ 38.928000] yaffs_check_obj_details_loaded: chunkData=0x92c73000查看代码中调用yaffs_set_obj_name的地方，发现yaffs_get_obj_name和yaffs_check_obj_details_loaded调用了yaffs_set_obj_name()
yaffs_get_obj_name中相关代码如下，与yaffs_check_obj_details_loaded类似，都是申请一块缓存，然后调用yaffs_rd_chunk_tags_nand()，不同的是yaffs_get_obj_name中多了memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
int result;
__u8 *buffer = yaffs_get_temp_buffer(obj->my_dev, __LINE__);
yaffs_obj_header *oh = (yaffs_obj_header *) buffer;
memset(buffer, 0, obj->my_dev->data_bytes_per_chunk);
if (obj->hdr_chunk > 0) {
result = yaffs_rd_chunk_tags_nand(obj->my_dev,
obj->hdr_chunk, buffer,
NULL);
}
yaffs_load_name_from_oh(obj->my_dev,name,oh->name,buffer_size);
回忆之前的日志，发现对于同一个文件，先调用yaffs_get_obj_name与先调用yaffs_check_obj_details_loaded效果是不同的。先调用yaffs_get_obj_name的，在find /system/lib/ -name lib*的时候能打印奇怪的信息（libui.so not find），而如果先调用yaffs_check_obj_details_loaded，则find的时候无异常打印，在ls -l时，发现完全一样的两个文件（大小，日期，名字）。全在于memset()对结果的影响。yaffs_rd_chunk_tags_nand的相关代码如下： if (in->lazy_loaded && in->hdr_chunk > 0) {
in->lazy_loaded = 0;
chunkData = yaffs_get_temp_buffer(dev, __LINE__);
T(YAFFS_TRACE_TRACING, (TSTR("yaffs_check_obj_details_loaded: chunkData=0x%p" TENDSTR),chunkData));
result = yaffs_rd_chunk_tags_nand(dev, in->hdr_chunk, chunkData, &tags);
oh = (yaffs_obj_header *) chunkData;
继续分析，根据日志看出问题出在yaffs_rd_chunk_tags_nand()函数内部，接下来运行 result = dev->param.read_chunk_tags_fn(dev, realignedChunkInNAND, buffer,tags);继续运行到nandmtd2_ReadChunkWithTagsFromNAND(yaffs_dev_t *dev, int nand_chunk,__u8 *data, yaffs_ext_tags *tags)
，修改此函数代码如下：int nandmtd2_ReadChunkWithTagsFromNAND(yaffs_dev_t *dev, int nand_chunk,
__u8 *data, yaffs_ext_tags *tags)
{
struct mtd_info *mtd = yaffs_dev_to_mtd(dev);
#if (MTD_VERSION_CODE > MTD_VERSION(2, 6, 17))
struct mtd_oob_ops ops;
#endif
size_t dummy;
int retval = 0;
int localData = 0;
int windsome_read_twice = 1;
int windsome_path = 0;
loff_t addr = ((loff_t) nand_chunk) * dev->param.total_bytes_per_chunk;
yaffs_PackedTags2 pt;
int packed_tags_size = dev->param.no_tags_ecc ? sizeof(pt.t) : sizeof(pt);
void * packed_tags_ptr = dev->param.no_tags_ecc ? (void *) &pt.t: (void *)&pt;
T(YAFFS_TRACE_MTD,
(TSTR
("nandmtd2_ReadChunkWithTagsFromNAND chunk %d data %p tags %p"
TENDSTR), nand_chunk, data, tags));
if (dev->param.inband_tags) {
if (!data) {
localData = 1;
data = yaffs_get_temp_buffer(dev, __LINE__);
}
}
#if (LINUX_VERSION_CODE > KERNEL_VERSION(2, 6, 17))
windsome_read_twice_pos:
data[0]='w';data[1]='\5';data[2]='n';data[3]='d';data[4]='s';data[5]='o';data[6]='m';data[7]='e';
if (dev->param.inband_tags || (data && !tags)) {
retval = mtd->read(mtd, addr, dev->param.total_bytes_per_chunk, &dummy, data);
windsome_path = 0;
} else if (tags) {
ops.mode = MTD_OOB_AUTO;
ops.ooblen = packed_tags_size;
ops.len = data ? dev->data_bytes_per_chunk : packed_tags_size;
ops.ooboffs = 0;
ops.datbuf = data;
ops.oobbuf = yaffs_dev_to_lc(dev)->spareBuffer;
retval = mtd->read_oob(mtd, addr, &ops);
windsome_path = 1;
}
if (data[0]=='w' && data[1]=='\5' && data[2]=='n' && data[3]=='d' && data[4]=='s' && data[5]=='o' && data[6]=='m' && data[7]=='e') {
printk ("windsome%d: %d mtd read error! why???? len=%d, dummy_len=%d, nand_chunk=%d, addr=0x%llx, retval=%d\n",
windsome_path, windsome_read_twice, dev->param.total_bytes_per_chunk, dummy, nand_chunk, addr, retval);
if (windsome_read_twice > 0) {
printk ("windsome: try again!\n");
windsome_read_twice--;
goto windsome_read_twice_pos;
}
}
#else
if (!dev->param.inband_tags && data && tags) {
retval = mtd->read_ecc(mtd, addr, dev->data_bytes_per_chunk,
&dummy, data, dev->spareBuffer,
NULL);
} else {
if (data)
retval =
mtd->read(mtd, addr, dev->data_bytes_per_chunk, &dummy,
data);
if (!dev->param.inband_tags && tags)
retval =
mtd->read_oob(mtd, addr, mtd->oobsize, &dummy,
dev->spareBuffer);
}
#endif
if (dev->param.inband_tags) {
if (tags) {
yaffs_PackedTags2TagsPart *pt2tp;
pt2tp = (yaffs_PackedTags2TagsPart *)&data[dev->data_bytes_per_chunk];
yaffs_unpack_tags2tags_part(tags, pt2tp);
}
} else {
if (tags) {
memcpy(packed_tags_ptr, yaffs_dev_to_lc(dev)->spareBuffer, packed_tags_size);
yaffs_unpack_tags2(tags, &pt, !dev->param.no_tags_ecc);
}
}
if (localData)
yaffs_release_temp_buffer(dev, data, __LINE__);
if (tags && retval == -EBADMSG && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
tags->ecc_result = YAFFS_ECC_RESULT_UNFIXED;
dev->n_ecc_unfixed++;
}
if(tags && retval == -EUCLEAN && tags->ecc_result == YAFFS_ECC_RESULT_NO_ERROR) {
tags->ecc_result = YAFFS_ECC_RESULT_FIXED;
dev->n_ecc_fixed++;
}
if (retval == 0)
return YAFFS_OK;
else {
T(YAFFS_TRACE_TRACING, (TSTR("nandmtd2_ReadChunkWithTagsFromNAND:retval=%d\n"), retval));
return YAFFS_FAIL;
}
}
根据此函数的日志，发现确实有mtd read error!的打印，重新读一次能够正常。printk ("windsome%d: %d mtd read error! why???? len=%d, dummy_len=%d, nand_chunk=%d, addr=0x%llx, retval=%d\n",
windsome_path, windsome_read_twice, dev->param.total_bytes_per_chunk, dummy, nand_chunk, addr, retval);
根据如上调试信息，通过修改nandmtd2_ReadChunkWithTagsFromNAND函数暂时解决此问题。
可能有另外的解决办法，修改yaffs_rd_chunk_tags_nand，在里面增加memset()，可以试试。
最终的原因，我并没有查出来，是板子稳定性问题导致驱动不正常？或者smp8xxx_nand驱动本身有问题，有待继续调试。