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Removing zeroing of trailing space in attribute buffers

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This was provided as a courtesy to hopefully make custom attributes more
easy to use, however the zeroing turned out to be a bit complicated when
syncing custom attributes across multiple open files.

Implicitly zeroing trailing buffer space is also inconsistent with the
other APIs in the filesystem, such as lfs_file_read, so this commit
removes the behavior.

If you need to handle differently sized custom attributes, you can
either pre-zero the custom attribute buffers, or use lfs_getattr to find
the on-disk size of custom attributes explicitly.
This commit is contained in:
Christopher Haster
2020-12-16 21:30:12 -06:00
parent b19a51c044
commit 026833214a
4 changed files with 40 additions and 56 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+8 -15
View File
@@ -638,8 +638,6 @@ static lfs_stag_t lfs_dir_getslice(lfs_t *lfs, const lfs_mdir_t *dir,
return err;
}
memset((uint8_t*)gbuffer + diff, 0, gsize - diff);
return tag + gdiff;
}
}
@@ -1088,7 +1086,7 @@ static int lfs_dir_fetch(lfs_t *lfs,
static int lfs_dir_getgstate(lfs_t *lfs, const lfs_mdir_t *dir,
lfs_gstate_t *gstate) {
lfs_gstate_t temp;
lfs_gstate_t temp = {0};
lfs_stag_t res = lfs_dir_get(lfs, dir, LFS_MKTAG(0x7ff, 0, 0),
LFS_MKTAG(LFS_TYPE_MOVESTATE, 0, sizeof(temp)), &temp);
if (res < 0 && res != LFS_ERR_NOENT) {
@@ -1114,10 +1112,11 @@ static int lfs_dir_getinfo(lfs_t *lfs, lfs_mdir_t *dir,
}
lfs_stag_t tag = lfs_dir_get(lfs, dir, LFS_MKTAG(0x780, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max+1), info->name);
LFS_MKTAG(LFS_TYPE_NAME, id, lfs->name_max), info->name);
if (tag < 0) {
return (int)tag;
}
info->name[lfs_tag_size(tag)] = '\0';
info->type = lfs_tag_type3(tag);
@@ -2870,14 +2869,11 @@ static int lfs_file_rawsync(lfs_t *lfs, lfs_file_t *file) {
for (lfs_size_t i = 0; i < f->cfg->attr_count; i++) {
for (lfs_size_t j = 0; j < file->cfg->attr_count; j++) {
if (f->cfg->attrs[i].type == file->cfg->attrs[i].type) {
lfs_size_t diff = lfs_min(
f->cfg->attrs[i].size,
file->cfg->attrs[i].size);
memcpy(f->cfg->attrs[i].buffer,
file->cfg->attrs[i].buffer,
diff);
memset((uint8_t*)f->cfg->attrs[i].buffer + diff,
0, f->cfg->attrs[i].size - diff);
lfs_min(
f->cfg->attrs[i].size,
file->cfg->attrs[i].size));
}
}
}
@@ -3484,11 +3480,8 @@ static int lfs_commitattr(lfs_t *lfs, const char *path,
// sync attrs
for (lfs_size_t i = 0; i < f->cfg->attr_count; i++) {
if (f->cfg->attrs[i].type == type) {
// TODO should this zero trailing bytes?
lfs_size_t diff = lfs_min(f->cfg->attrs[i].size, size);
memcpy(f->cfg->attrs[i].buffer, buffer, diff);
memset((uint8_t*)f->cfg->attrs[i].buffer + diff,
0, f->cfg->attrs[i].size - diff);
memcpy(f->cfg->attrs[i].buffer, buffer,
lfs_min(f->cfg->attrs[i].size, size));
}
}
}
lfs.h
+6 -8
View File
@@ -300,10 +300,9 @@ struct lfs_file_config {
// write occurs atomically with update to the file's contents.
//
// Custom attributes are uniquely identified by an 8-bit type and limited
// to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller
// than the buffer, it will be padded with zeros. If the stored attribute
// is larger, then it will be silently truncated. If the attribute is not
// found, it will be created implicitly.
// to LFS_ATTR_MAX bytes. If the stored attribute is larger than the
// provided buffer, it will be silently truncated. If no attribute is
// found, and the file is open for writing, it will be created implicitly.
struct lfs_attr *attrs;
// Number of custom attributes in the list
@@ -471,10 +470,9 @@ int lfs_stat(lfs_t *lfs, const char *path, struct lfs_info *info);
// Get a custom attribute
//
// Custom attributes are uniquely identified by an 8-bit type and limited
// to LFS_ATTR_MAX bytes. When read, if the stored attribute is smaller than
// the buffer, it will be padded with zeros. If the stored attribute is larger,
// then it will be silently truncated. If no attribute is found, the error
// LFS_ERR_NOATTR is returned and the buffer is filled with zeros.
// to LFS_ATTR_MAX bytes. If the stored attribute is larger than the
// provided buffer, it will be silently truncated. If no attribute is found,
// the error LFS_ERR_NOATTR is returned and the buffer is filled with zeros.
//
// Returns the size of the attribute, or a negative error code on failure.
// Note, the returned size is the size of the attribute on disk, irrespective
tests/test_attrs.toml
+19 -26
View File
@@ -25,7 +25,6 @@ code = '''
lfs_getattr(&lfs, "hello", 'B', buffer+4, 6) => 0;
lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "\0\0\0\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_removeattr(&lfs, "hello", 'B') => 0;
@@ -33,7 +32,6 @@ code = '''
lfs_getattr(&lfs, "hello", 'B', buffer+4, 6) => LFS_ERR_NOATTR;
lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "\0\0\0\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_setattr(&lfs, "hello", 'B', "dddddd", 6) => 0;
@@ -48,9 +46,9 @@ code = '''
lfs_getattr(&lfs, "hello", 'A', buffer, 4) => 4;
lfs_getattr(&lfs, "hello", 'B', buffer+4, 6) => 3;
lfs_getattr(&lfs, "hello", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee", 3) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_setattr(&lfs, "hello", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
lfs_setattr(&lfs, "hello", 'B', "fffffffff", 9) => 0;
@@ -102,17 +100,15 @@ code = '''
lfs_getattr(&lfs, "/", 'A', buffer, 4) => 4;
lfs_getattr(&lfs, "/", 'B', buffer+4, 6) => 0;
lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "\0\0\0\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_removeattr(&lfs, "/", 'B') => 0;
lfs_getattr(&lfs, "/", 'A', buffer, 4) => 4;
lfs_getattr(&lfs, "/", 'B', buffer+4, 6) => LFS_ERR_NOATTR;
lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "\0\0\0\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_setattr(&lfs, "/", 'B', "dddddd", 6) => 0;
lfs_getattr(&lfs, "/", 'A', buffer, 4) => 4;
@@ -126,9 +122,9 @@ code = '''
lfs_getattr(&lfs, "/", 'A', buffer, 4) => 4;
lfs_getattr(&lfs, "/", 'B', buffer+4, 6) => 3;
lfs_getattr(&lfs, "/", 'C', buffer+10, 5) => 5;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee", 3) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
lfs_setattr(&lfs, "/", 'A', buffer, LFS_ATTR_MAX+1) => LFS_ERR_NOSPC;
lfs_setattr(&lfs, "/", 'B', "fffffffff", 9) => 0;
@@ -193,9 +189,8 @@ code = '''
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file) => 0;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "\0\0\0\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1) => 0;
@@ -219,9 +214,9 @@ code = '''
attrs1[1].size = 6;
lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_RDONLY, &cfg1) => 0;
lfs_file_close(&lfs, &file) => 0;
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee\0\0\0", 6) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
assert(memcmp(buffer, "aaaa", 4) == 0);
assert(memcmp(buffer+4, "eee", 3) == 0);
assert(memcmp(buffer+10, "ccccc", 5) == 0);
attrs1[0].size = LFS_ATTR_MAX+1;
lfs_file_opencfg(&lfs, &file, "hello/hello", LFS_O_WRONLY, &cfg1)
@@ -292,18 +287,16 @@ code = '''
lfs_getattr(&lfs, "hello/hello", 'B', buffer, 9) => 9;
lfs_getattr(&lfs, "hello/hello", 'C', buffer+9, 9) => 5;
lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => LFS_ERR_NOATTR;
assert(memcmp(buffer, "fffffffff", 9) == 0);
assert(memcmp(buffer+9, "ccccc\0\0\0\0", 9) == 0);
assert(memcmp(buffer+18, "\0\0\0\0\0\0\0\0\0", 9) == 0);
assert(memcmp(buffer, "fffffffff", 9) == 0);
assert(memcmp(buffer+9, "ccccc", 5) == 0);
lfs_file_write(&lfs, &file, "hi", 2) => 2;
lfs_file_sync(&lfs, &file) => 0;
lfs_getattr(&lfs, "hello/hello", 'B', buffer, 9) => 4;
lfs_getattr(&lfs, "hello/hello", 'C', buffer+9, 9) => 0;
lfs_getattr(&lfs, "hello/hello", 'D', buffer+18, 9) => 4;
assert(memcmp(buffer, "gggg\0\0\0\0\0", 9) == 0);
assert(memcmp(buffer+9, "\0\0\0\0\0\0\0\0\0", 9) == 0);
assert(memcmp(buffer+18, "hhhh\0\0\0\0\0", 9) == 0);
assert(memcmp(buffer, "gggg", 4) == 0);
assert(memcmp(buffer+18, "hhhh", 4) == 0);
lfs_file_close(&lfs, &file) => 0;
lfs_unmount(&lfs) => 0;
tests/test_paths.toml
+7 -7
View File
@@ -95,9 +95,9 @@ code = '''
lfs_mkdir(&lfs, "coffee/../milk") => 0;
lfs_stat(&lfs, "coffee/../milk", &info) => 0;
strcmp(info.name, "milk") => 0;
assert(strcmp(info.name, "milk") == 0);
lfs_stat(&lfs, "milk", &info) => 0;
strcmp(info.name, "milk") => 0;
assert(strcmp(info.name, "milk") == 0);
lfs_unmount(&lfs) => 0;
'''
@@ -129,9 +129,9 @@ code = '''
lfs_mount(&lfs, &cfg) => 0;
lfs_mkdir(&lfs, ".milk") => 0;
lfs_stat(&lfs, ".milk", &info) => 0;
strcmp(info.name, ".milk") => 0;
assert(strcmp(info.name, ".milk") == 0);
lfs_stat(&lfs, "tea/.././.milk", &info) => 0;
strcmp(info.name, ".milk") => 0;
assert(strcmp(info.name, ".milk") == 0);
lfs_unmount(&lfs) => 0;
'''
@@ -149,13 +149,13 @@ code = '''
lfs_mkdir(&lfs, "coffee/coldcoffee") => 0;
lfs_stat(&lfs, "coffee/../../../../../../tea/hottea", &info) => 0;
strcmp(info.name, "hottea") => 0;
assert(strcmp(info.name, "hottea") == 0);
lfs_mkdir(&lfs, "coffee/../../../../../../milk") => 0;
lfs_stat(&lfs, "coffee/../../../../../../milk", &info) => 0;
strcmp(info.name, "milk") => 0;
assert(strcmp(info.name, "milk") == 0);
lfs_stat(&lfs, "milk", &info) => 0;
strcmp(info.name, "milk") => 0;
assert(strcmp(info.name, "milk") == 0);
lfs_unmount(&lfs) => 0;
'''