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Rearranged flags a bit

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Mainly to make space for more shared open/mount flags that are future
planned.

The nice thing about our flags is they don't live on-disk, so we can
always change them whenever we need to.

It gets a bit messy, but this is what the current layout looks like:

              8     8     8     8
            .----++----++----++----.
            .----..-..-..----------.
  o_flags:  |type||f||t||    o     |
            |----||-|:-:'--.-.-----'
            |----||-|:-:---:-:-----.
  d_flags:  |type||f|: :   : :     |
            |----||-|:-:---:-:-----'
            |----||-|:-'--..-..----.
  t_flags:  |type||f|| t  ||f||tstt|
            '----''-'|----|'-''----'
            .--------|----|:-:-----.
  gc_flags: |        | t  |: :     |
            '--------|----|:-:-----'
            .----..-.|----|:-:.----.
  f_flags:  | f  ||m|| t  |: :| f  |
            '----'|-||----|:-:'----'
            .----.|-||----||-|.----.
  m_flags:  | i  ||m|| t  ||o|| m  |
            |----||-|'----'|-||----|
            |----||-|------|-||----|
  i_flags:  | i  ||m|      |o|| m  |
            '----''-'------'-''----'

The main downside of this layout is that some of the traversal flags,
LFS_T_DIRTY/MUTATED, now risk ambiguity with open/mount flags. But I
don't think this is really avoidable as traversals are already using
almost the entire 32-bit encoding space...

No code changes:

           code          stack
  before: 36480           2680
  after:  36480 (+0.0%)   2680 (+0.0%)
This commit is contained in:
Christopher Haster
2024-08-12 16:54:10 -05:00
parent 80ef963bec
commit e536300606
2 changed files with 40 additions and 40 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+4 -4
View File
@@ -6672,8 +6672,8 @@ static inline bool lfsr_t_ismutated(uint32_t flags) {
}
static inline uint32_t lfsr_t_swapdirty(uint32_t flags) {
uint32_t x = ((flags >> 19) ^ (flags >> 18)) & 0x1;
return flags ^ (x << 19) ^ (x << 18);
uint32_t x = ((flags >> 9) ^ (flags >> 8)) & 0x1;
return flags ^ (x << 9) ^ (x << 8);
}
// mount flags
@@ -13831,7 +13831,7 @@ int lfsr_fs_gc(lfs_t *lfs, lfs_soff_t steps, uint32_t flags) {
uint32_t pending = flags & (
((lfs->flags & (
LFS_I_HASORPHANS
| LFS_I_UNCOMPACTED)) >> 16)
| LFS_I_UNCOMPACTED)) >> 12)
| ((lfsr_fs_canlookahead(lfs)) ? LFS_GC_LOOKAHEAD : 0)
| LFS_GC_CKMETA
| LFS_GC_CKDATA);
@@ -13896,7 +13896,7 @@ int lfsr_fs_gc(lfs_t *lfs, lfs_soff_t steps, uint32_t flags) {
pending &= (
((lfs->flags & (
LFS_I_HASORPHANS
| LFS_I_UNCOMPACTED)) >> 16)
| LFS_I_UNCOMPACTED)) >> 12)
| ((lfsr_fs_canlookahead(lfs)) ? LFS_GC_LOOKAHEAD : 0)
// only consider our filesystem checked if we
// weren't mutated
lfs.h
+36 -36
View File
@@ -136,8 +136,8 @@ enum lfs_type {
#define LFS_O_FLUSH 0x00000040 // Flush data on every write
#define LFS_O_SYNC 0x00000080 // Sync metadata on every write
#define LFS_O_DESYNC 0x00000100 // Do not sync or recieve file updates
#define LFS_O_CKMETA 0x00001000 // Check metadata checksums
#define LFS_O_CKDATA 0x00002000 // Check metadata + data checksums
#define LFS_O_CKMETA 0x00010000 // Check metadata checksums
#define LFS_O_CKDATA 0x00020000 // Check metadata + data checksums
// internally used flags, don't use these
#define LFS_O_TYPE 0xff000000 // The file's type
@@ -153,42 +153,42 @@ enum lfs_type {
// Filesystem format flags
#define LFS_F_RDWR 0 // Format the filesystem as read and write
#define LFS_F_CKPROGS 0x00000010 // Check progs by reading back progged data
#define LFS_F_CKPROGS 0x00100000 // Check progs by reading back progged data
#ifdef LFS_CKREADS
#define LFS_F_CKREADS 0x00000020 // Check reads via parity bits/checksums
#define LFS_F_CKREADS 0x00200000 // Check reads via parity bits/checksums
#endif
#define LFS_F_MTREEONLY 0x00010000 // Only traverse the mtree
#define LFS_F_COMPACT 0x00000800 // Compact metadata logs
#define LFS_F_CKMETA 0x00001000 // Check metadata checksums
#define LFS_F_CKDATA 0x00002000 // Check metadata + data checksums
#define LFS_F_MTREEONLY 0x00000800 // Only traverse the mtree
#define LFS_F_COMPACT 0x00008000 // Compact metadata logs
#define LFS_F_CKMETA 0x00010000 // Check metadata checksums
#define LFS_F_CKDATA 0x00020000 // Check metadata + data checksums
// Filesystem mount flags
#define LFS_M_RDWR 0 // Mount the filesystem as read and write
#define LFS_M_RDONLY 1 // Mount the filesystem as read only
#define LFS_M_CKPROGS 0x00000010 // Check progs by reading back progged data
#ifdef LFS_CKREADS
#define LFS_M_CKREADS 0x00000020 // Check reads via parity bits/checksums
#endif
#define LFS_M_FLUSH 0x00000040 // Open all files with LFS_O_FLUSH
#define LFS_M_SYNC 0x00000080 // Open all files with LFS_O_SYNC
#define LFS_M_CKPROGS 0x00100000 // Check progs by reading back progged data
#ifdef LFS_CKREADS
#define LFS_M_CKREADS 0x00200000 // Check reads via parity bits/checksums
#endif
#define LFS_M_MTREEONLY 0x00010000 // Only traverse the mtree
#define LFS_M_MTREEONLY 0x00000800 // Only traverse the mtree
#define LFS_M_MKCONSISTENT \
0x00000100 // Make the filesystem consistent
#define LFS_M_LOOKAHEAD 0x00000200 // Populate lookahead buffer
#define LFS_M_COMPACT 0x00000800 // Compact metadata logs
#define LFS_M_CKMETA 0x00001000 // Check metadata checksums
#define LFS_M_CKDATA 0x00002000 // Check metadata + data checksums
0x00001000 // Make the filesystem consistent
#define LFS_M_LOOKAHEAD 0x00002000 // Populate lookahead buffer
#define LFS_M_COMPACT 0x00008000 // Compact metadata logs
#define LFS_M_CKMETA 0x00010000 // Check metadata checksums
#define LFS_M_CKDATA 0x00020000 // Check metadata + data checksums
// Filesystem info flags
#define LFS_I_RDONLY 0x00000001 // Filesystem mounted read only
#define LFS_I_CKPROGS 0x00000010 // Filesystem mounted with LFS_M_CKPROGS
#ifdef LFS_CKREADS
#define LFS_I_CKREADS 0x00000020 // Filesystem mounted with LFS_M_CKREADS
#endif
#define LFS_I_FLUSH 0x00000040 // Filesystem mounted with LFS_M_FLUSH
#define LFS_I_SYNC 0x00000080 // Filesystem mounted with LFS_M_SYNC
#define LFS_I_CKPROGS 0x00100000 // Filesystem mounted with LFS_M_CKPROGS
#ifdef LFS_CKREADS
#define LFS_I_CKREADS 0x00200000 // Filesystem mounted with LFS_M_CKREADS
#endif
#define LFS_I_INCONSISTENT \
0x01000000 // Filesystem needs mkconsistent to write
@@ -210,30 +210,30 @@ enum lfs_btype {
};
// Traversal flags
#define LFS_T_MTREEONLY 0x00010000 // Only traverse the mtree
#define LFS_T_MTREEONLY 0x00000800 // Only traverse the mtree
#define LFS_T_MKCONSISTENT \
0x00000100 // Make the filesystem consistent
#define LFS_T_LOOKAHEAD 0x00000200 // Populate lookahead buffer
#define LFS_T_COMPACT 0x00000800 // Compact metadata logs
#define LFS_T_CKMETA 0x00001000 // Check metadata checksums
#define LFS_T_CKDATA 0x00002000 // Check metadata + data checksums
0x00001000 // Make the filesystem consistent
#define LFS_T_LOOKAHEAD 0x00002000 // Populate lookahead buffer
#define LFS_T_COMPACT 0x00008000 // Compact metadata logs
#define LFS_T_CKMETA 0x00010000 // Check metadata checksums
#define LFS_T_CKDATA 0x00020000 // Check metadata + data checksums
// internally used flags, don't use these
#define LFS_T_TSTATE 0x0000000f // The current traversal state
#define LFS_T_BTYPE 0x000000f0 // The current traversal btype
#define LFS_T_DIRTY 0x00040000 // Filesystem modified during traversal
#define LFS_T_MUTATED 0x00080000 // Filesystem modified by traversal
#define LFS_T_DIRTY 0x00000100 // Filesystem modified during traversal
#define LFS_T_MUTATED 0x00000200 // Filesystem modified by traversal
// GC flags
#define LFS_GC_MTREEONLY \
0x00010000 // Only traverse the mtree
0x00000800 // Only traverse the mtree
#define LFS_GC_MKCONSISTENT \
0x00000100 // Make the filesystem consistent
0x00001000 // Make the filesystem consistent
#define LFS_GC_LOOKAHEAD \
0x00000200 // Populate lookahead buffer
#define LFS_GC_COMPACT 0x00000800 // Compact metadata logs
#define LFS_GC_CKMETA 0x00001000 // Check metadata checksums
#define LFS_GC_CKDATA 0x00002000 // Check metadata + data checksums
0x00002000 // Populate lookahead buffer
#define LFS_GC_COMPACT 0x00008000 // Compact metadata logs
#define LFS_GC_CKMETA 0x00010000 // Check metadata checksums
#define LFS_GC_CKDATA 0x00020000 // Check metadata + data checksums
// Configuration provided during initialization of the littlefs