Move the logic for determining if we should support split directories
into a helper function.  This permits compiled outputs that do not
utilize this to drop this code easily at the linker level.

Additionally, drop the default behavior.
This commit is contained in:
Tim Nordell
2021-06-13 21:38:35 -05:00
parent a3ea209503
commit 2612ef130b

113
lfs.c
View File

@@ -3190,11 +3190,61 @@ static int lfs_rawstat(lfs_t *lfs, const char *path, struct lfs_info *info) {
}
#ifndef LFS_READONLY
static int lfs_dir_prep_removal(lfs_t *lfs, struct lfs_mlist *dir,
lfs_mdir_t *newcwd, uint16_t newid, lfs_block_t *pair,
lfs_gstate_t *tmp_gstate, bool allow_nonempty_folder)
typedef int (*lfs_dir_prep_helper_t)(lfs_t *, struct lfs_mlist *, lfs_gstate_t *);
static int lfs_dir_prep_remove_nonempty_folders(lfs_t *lfs, struct lfs_mlist *dir,
lfs_gstate_t *tmp_gstate)
{
lfs_gstate_t split_gstate;
uint16_t id = 0;
// Walk tags stored in this directory and check for any directory
// tags. Removal of directories with a directory in them can lead
// to additional orphans in the filesystem, so we return
// LFS_ERR_NOTEMPTY in this case. Otherwise, leave the loaded
// directory for the tail end of the directory split to leave a proper
// view of the filesystem after removal.
while (true) {
if (dir->m.count == id) {
if (!dir->m.split) {
// We have iterated through the folder to the last
// tag.
break;
}
// Before we fetch the next block, update our fetched gstate xor
lfs_dir_getgstate(lfs, &dir->m, &split_gstate);
lfs_gstate_xor(tmp_gstate, &split_gstate);
int err = lfs_dir_fetch(lfs, &dir->m, dir->m.tail);
if (err) {
return err;
}
id = 0;
}
lfs_stag_t tag = lfs_dir_get(lfs, &dir->m, LFS_MKTAG(0x780, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_NAME, id, 0), NULL);
if (tag < 0) {
return tag;
}
if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
return LFS_ERR_NOTEMPTY;
}
id += 1;
}
return 0;
}
static int lfs_dir_prep_removal(lfs_t *lfs, struct lfs_mlist *dir,
lfs_mdir_t *newcwd, uint16_t newid, lfs_block_t *pair,
lfs_gstate_t *tmp_gstate, lfs_dir_prep_helper_t helper)
{
lfs_stag_t res = lfs_dir_get(lfs, newcwd, LFS_MKTAG(0x700, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_STRUCT, newid, 8), pair);
if (res < 0) {
@@ -3212,50 +3262,13 @@ static int lfs_dir_prep_removal(lfs_t *lfs, struct lfs_mlist *dir,
if (dir->m.count > 0 || dir->m.split) {
// Normal POSIX behavior wouldn't allow a non-empty
// folder to be removed/renamed into in this manner
if (!allow_nonempty_folder) {
if (NULL == helper) {
return LFS_ERR_NOTEMPTY;
}
uint16_t id = 0;
// Walk tags stored in this directory and check for any directory
// tags. Removal of directories with a directory in them can lead
// to additional orphans in the filesystem, so we return
// LFS_ERR_NOTEMPTY in this case. Otherwise, leave the loaded
// directory for the tail end of the directory split to leave a proper
// view of the filesystem after removal.
while (true) {
if (dir->m.count == id) {
if (!dir->m.split) {
// We have iterated through the folder to the last
// tag.
break;
}
// Before we fetch the next block, update our fetched gstate xor
lfs_dir_getgstate(lfs, &dir->m, &split_gstate);
lfs_gstate_xor(tmp_gstate, &split_gstate);
err = lfs_dir_fetch(lfs, &dir->m, dir->m.tail);
if (err) {
return err;
}
id = 0;
}
lfs_stag_t tag = lfs_dir_get(lfs, &dir->m, LFS_MKTAG(0x780, 0x3ff, 0),
LFS_MKTAG(LFS_TYPE_NAME, id, 0), NULL);
if (tag < 0) {
return tag;
}
if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
return LFS_ERR_NOTEMPTY;
}
id += 1;
err = helper(lfs, dir, tmp_gstate);
if (err) {
return err;
}
}
@@ -3276,7 +3289,7 @@ static int lfs_dir_prep_removal(lfs_t *lfs, struct lfs_mlist *dir,
#endif
#ifndef LFS_READONLY
static int lfs_rawremove(lfs_t *lfs, const char *path, bool allow_nonempty_folder) {
static int lfs_rawremove(lfs_t *lfs, const char *path, lfs_dir_prep_helper_t helper) {
// deorphan if we haven't yet, needed at most once after poweron
int err = lfs_fs_forceconsistency(lfs);
if (err) {
@@ -3296,7 +3309,7 @@ static int lfs_rawremove(lfs_t *lfs, const char *path, bool allow_nonempty_folde
if (lfs_tag_type3(tag) == LFS_TYPE_DIR) {
// must be empty before removal to prevent orphans
err = lfs_dir_prep_removal(lfs, &dir, &cwd, lfs_tag_id(tag),
pair, &tmp_gstate, allow_nonempty_folder);
pair, &tmp_gstate, helper);
if (err < 0) {
return err;
}
@@ -3339,7 +3352,7 @@ static int lfs_rawremove(lfs_t *lfs, const char *path, bool allow_nonempty_folde
#ifndef LFS_READONLY
static int lfs_rawrename(lfs_t *lfs, const char *oldpath,
const char *newpath, bool allow_nonempty_folder) {
const char *newpath, lfs_dir_prep_helper_t helper) {
// deorphan if we haven't yet, needed at most once after poweron
int err = lfs_fs_forceconsistency(lfs);
if (err) {
@@ -3391,7 +3404,7 @@ static int lfs_rawrename(lfs_t *lfs, const char *oldpath,
} else if (lfs_tag_type3(prevtag) == LFS_TYPE_DIR) {
// must be empty before removal to prevent orphans
err = lfs_dir_prep_removal(lfs, &prevdir, &newcwd, newid,
dir_pair, &tmp_gstate, allow_nonempty_folder);
dir_pair, &tmp_gstate, helper);
if (err) {
return err;
}
@@ -5046,7 +5059,7 @@ int lfs_remove(lfs_t *lfs, const char *path) {
}
LFS_TRACE("lfs_remove(%p, \"%s\")", (void*)lfs, path);
err = lfs_rawremove(lfs, path, false);
err = lfs_rawremove(lfs, path, NULL);
LFS_TRACE("lfs_remove -> %d", err);
LFS_UNLOCK(lfs->cfg);
@@ -5062,7 +5075,7 @@ int lfs_rename(lfs_t *lfs, const char *oldpath, const char *newpath) {
}
LFS_TRACE("lfs_rename(%p, \"%s\", \"%s\")", (void*)lfs, oldpath, newpath);
err = lfs_rawrename(lfs, oldpath, newpath);
err = lfs_rawrename(lfs, oldpath, newpath, NULL);
LFS_TRACE("lfs_rename -> %d", err);
LFS_UNLOCK(lfs->cfg);