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Extended lfsr_mount to accept mount flags

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This has been a long-time coming, mount flags are just too useful for
configuring a filesystem at runtime.

Currently this is limited to LFS_M_RDONLY and LFS_M_CKPROGS, but there
are a few more planned in the future:

  LFS_M_RDWR     = 0x0000, // Mount the filesystem as read and write
  LFS_M_RDONLY   = 0x0001, // Mount the filesystem as readonly
  LFS_M_STRICT*  = 0x0002, // Error if on-disk config does not match
  LFS_M_FORCE*   = 0x0004, // Ignore compat flags, mount readonly
  LFS_M_FORCEWITHRECKLESSABANDON*
                 = 0x0008, // Ignore compat flags, mount read write

  LFS_M_CKPROGS  = 0x0010, // Check progs by reading back progged data
  LFS_M_CKREADS* = 0x0020, // Check reads via checksums

  * Hypothetical

As a convenience, we also return mount flags in the struct lfs_fsinfo's
flags field as their relevant LFS_I_* variants. Though only to match
statvfs, and only because it's cheap, littlefs's API is low-level and we
should expect users to know what flags they passed to lfsr_mount.

As for the new mount flags:

- LFS_M_RDONLY - For consistency with existing APIs, this just asserts
  on write operations, which makes it a bit useless... But the info flag
  LFS_I_RDONLY may be useful for falling back to a readonly mode if
  we encounter on-disk compat issues.

  At least if implement the theoretical LFS_UNTRUSTED_USER mode
  LFS_M_RDONLY could become a runtime error.

- LFS_M_RDWR - This really just exists to compliment LFS_M_RDONLY and to
  match LFS_O_RDONLY/LFS_O_RDWR. It's just an alias for 0, and I don't
  think there will ever be a reason to make it non-0 (but I can always
  be wrong!).

- LFS_M_CKPROGS - This replaces the check_progs config option and avoids
  using a full byte to store a bool.

  We should probably also have a compile-time option to compile this out
  (LFS_NO_CKPROGS?), but that's a future thing to do.

This ended up adding a surprising bit of code, considering we're just
moving flags around, and noise in lfs_alloc added a bit of stack again:

           code          stack
  before: 35880           2672
  after:  35932 (+0.1%)   2680 (+0.3%)
This commit is contained in:
Christopher Haster
2024-07-15 01:48:37 -05:00
parent 0a3cb2dd3a
commit acfae9e072
25 changed files with 1322 additions and 1126 deletions
Download Patch File Download Diff File Expand all files Collapse all files
tests/test_incompat.toml
+33 -33
View File
@@ -19,7 +19,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_RM | LFSR_TAG_MAGIC, 0,
@@ -27,7 +27,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_CORRUPT;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_CORRUPT;
'''
# test that we fail if we find bad magic
@@ -42,7 +42,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_MAGIC, 0,
@@ -50,7 +50,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_CORRUPT;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_CORRUPT;
'''
# test that we fail to mount after a major version bump
@@ -65,7 +65,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_VERSION, 0,
@@ -75,7 +75,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount after a minor version bump
@@ -90,7 +90,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_VERSION, 0,
@@ -100,7 +100,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount incompatible rcompat flags
@@ -116,7 +116,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_RCOMPAT, 0,
@@ -126,7 +126,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount incompatible wcompat flags
@@ -142,7 +142,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_WCOMPAT, 0,
@@ -152,7 +152,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that an incompatible ocompat flag is a noop
@@ -168,7 +168,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_OCOMPAT, 0,
@@ -178,7 +178,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should _not_ fail, ocompat should always be ignored
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_unmount(&lfs) => 0;
'''
@@ -194,7 +194,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR_CAT(
LFSR_TAG_RCOMPAT, 0,
@@ -203,7 +203,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
[cases.test_incompat_wcompat_overflow]
@@ -217,7 +217,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR_CAT(
LFSR_TAG_WCOMPAT, 0,
@@ -226,7 +226,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
[cases.test_incompat_ocompat_overflow]
@@ -240,7 +240,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR_CAT(
LFSR_TAG_OCOMPAT, 0,
@@ -249,7 +249,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should _not_ fail, ocompat should always be ignored
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_unmount(&lfs) => 0;
'''
@@ -266,7 +266,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_GEOMETRY, 0,
@@ -276,7 +276,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount after incompatible block counts
@@ -292,7 +292,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_GEOMETRY, 0,
@@ -302,7 +302,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount after incompatible name limit
@@ -318,7 +318,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_NAMELIMIT, 0,
@@ -326,7 +326,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test that we fail to mount after incompatible file limit
@@ -341,7 +341,7 @@ code = '''
//
// note we're messing around with internals to do this! this
// is not a user API
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR_CAT(
LFSR_TAG_FILELIMIT, 0,
@@ -354,7 +354,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test what happens if we find an unknown config
@@ -366,7 +366,7 @@ code = '''
lfsr_format(&lfs, CFG) => 0;
// create an unknown config
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_commit(&lfs, &lfs.mroot, LFSR_ATTRS(
LFSR_ATTR(
LFSR_TAG_CONFIG + 0x13, 0,
@@ -374,7 +374,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''
# test what happens if we find an unknown file type
@@ -386,7 +386,7 @@ code = '''
lfsr_format(&lfs, CFG) => 0;
// create some files
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_file_t file;
lfsr_file_open(&lfs, &file, "a",
LFS_O_WRONLY | LFS_O_CREAT | LFS_O_EXCL) => 0;
@@ -406,7 +406,7 @@ code = '''
lfsr_unmount(&lfs) => 0;
// change a file's type to something unknown
lfsr_mount(&lfs, CFG) => 0;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => 0;
lfsr_mdir_t mdir;
lfsr_did_t did;
const char *name;
@@ -421,5 +421,5 @@ code = '''
lfsr_unmount(&lfs) => 0;
// mount should now fail
lfsr_mount(&lfs, CFG) => LFS_ERR_NOTSUP;
lfsr_mount(&lfs, LFS_M_RDWR, CFG) => LFS_ERR_NOTSUP;
'''