diff options
Diffstat (limited to 'lib/littlefs/lfs2.h')
| -rw-r--r-- | lib/littlefs/lfs2.h | 100 |
1 files changed, 65 insertions, 35 deletions
diff --git a/lib/littlefs/lfs2.h b/lib/littlefs/lfs2.h index 4c426fc4c7..77477aaff8 100644 --- a/lib/littlefs/lfs2.h +++ b/lib/littlefs/lfs2.h @@ -21,7 +21,7 @@ extern "C" // Software library version // Major (top-nibble), incremented on backwards incompatible changes // Minor (bottom-nibble), incremented on feature additions -#define LFS2_VERSION 0x00020008 +#define LFS2_VERSION 0x0002000b #define LFS2_VERSION_MAJOR (0xffff & (LFS2_VERSION >> 16)) #define LFS2_VERSION_MINOR (0xffff & (LFS2_VERSION >> 0)) @@ -52,16 +52,15 @@ typedef uint32_t lfs2_block_t; #endif // Maximum size of a file in bytes, may be redefined to limit to support other -// drivers. Limited on disk to <= 4294967296. However, above 2147483647 the -// functions lfs2_file_seek, lfs2_file_size, and lfs2_file_tell will return -// incorrect values due to using signed integers. Stored in superblock and -// must be respected by other littlefs drivers. +// drivers. Limited on disk to <= 2147483647. Stored in superblock and must be +// respected by other littlefs drivers. #ifndef LFS2_FILE_MAX #define LFS2_FILE_MAX 2147483647 #endif // Maximum size of custom attributes in bytes, may be redefined, but there is -// no real benefit to using a smaller LFS2_ATTR_MAX. Limited to <= 1022. +// no real benefit to using a smaller LFS2_ATTR_MAX. Limited to <= 1022. Stored +// in superblock and must be respected by other littlefs drivers. #ifndef LFS2_ATTR_MAX #define LFS2_ATTR_MAX 1022 #endif @@ -205,7 +204,8 @@ struct lfs2_config { // program sizes. lfs2_size_t block_size; - // Number of erasable blocks on the device. + // Number of erasable blocks on the device. Defaults to block_count stored + // on disk when zero. lfs2_size_t block_count; // Number of erase cycles before littlefs evicts metadata logs and moves @@ -226,9 +226,20 @@ struct lfs2_config { // Size of the lookahead buffer in bytes. A larger lookahead buffer // increases the number of blocks found during an allocation pass. The // lookahead buffer is stored as a compact bitmap, so each byte of RAM - // can track 8 blocks. Must be a multiple of 8. + // can track 8 blocks. lfs2_size_t lookahead_size; + // Threshold for metadata compaction during lfs2_fs_gc in bytes. Metadata + // pairs that exceed this threshold will be compacted during lfs2_fs_gc. + // Defaults to ~88% block_size when zero, though the default may change + // in the future. + // + // Note this only affects lfs2_fs_gc. Normal compactions still only occur + // when full. + // + // Set to -1 to disable metadata compaction during lfs2_fs_gc. + lfs2_size_t compact_thresh; + // Optional statically allocated read buffer. Must be cache_size. // By default lfs2_malloc is used to allocate this buffer. void *read_buffer; @@ -237,25 +248,24 @@ struct lfs2_config { // By default lfs2_malloc is used to allocate this buffer. void *prog_buffer; - // Optional statically allocated lookahead buffer. Must be lookahead_size - // and aligned to a 32-bit boundary. By default lfs2_malloc is used to - // allocate this buffer. + // Optional statically allocated lookahead buffer. Must be lookahead_size. + // By default lfs2_malloc is used to allocate this buffer. void *lookahead_buffer; // Optional upper limit on length of file names in bytes. No downside for // larger names except the size of the info struct which is controlled by - // the LFS2_NAME_MAX define. Defaults to LFS2_NAME_MAX when zero. Stored in - // superblock and must be respected by other littlefs drivers. + // the LFS2_NAME_MAX define. Defaults to LFS2_NAME_MAX or name_max stored on + // disk when zero. lfs2_size_t name_max; // Optional upper limit on files in bytes. No downside for larger files - // but must be <= LFS2_FILE_MAX. Defaults to LFS2_FILE_MAX when zero. Stored - // in superblock and must be respected by other littlefs drivers. + // but must be <= LFS2_FILE_MAX. Defaults to LFS2_FILE_MAX or file_max stored + // on disk when zero. lfs2_size_t file_max; // Optional upper limit on custom attributes in bytes. No downside for // larger attributes size but must be <= LFS2_ATTR_MAX. Defaults to - // LFS2_ATTR_MAX when zero. + // LFS2_ATTR_MAX or attr_max stored on disk when zero. lfs2_size_t attr_max; // Optional upper limit on total space given to metadata pairs in bytes. On @@ -264,6 +274,15 @@ struct lfs2_config { // Defaults to block_size when zero. lfs2_size_t metadata_max; + // Optional upper limit on inlined files in bytes. Inlined files live in + // metadata and decrease storage requirements, but may be limited to + // improve metadata-related performance. Must be <= cache_size, <= + // attr_max, and <= block_size/8. Defaults to the largest possible + // inline_max when zero. + // + // Set to -1 to disable inlined files. + lfs2_size_t inline_max; + #ifdef LFS2_MULTIVERSION // On-disk version to use when writing in the form of 16-bit major version // + 16-bit minor version. This limiting metadata to what is supported by @@ -430,19 +449,20 @@ typedef struct lfs2 { lfs2_gstate_t gdisk; lfs2_gstate_t gdelta; - struct lfs2_free { - lfs2_block_t off; + struct lfs2_lookahead { + lfs2_block_t start; lfs2_block_t size; - lfs2_block_t i; - lfs2_block_t ack; - uint32_t *buffer; - } free; + lfs2_block_t next; + lfs2_block_t ckpoint; + uint8_t *buffer; + } lookahead; const struct lfs2_config *cfg; lfs2_size_t block_count; lfs2_size_t name_max; lfs2_size_t file_max; lfs2_size_t attr_max; + lfs2_size_t inline_max; #ifdef LFS2_MIGRATE struct lfs21 *lfs21; @@ -712,18 +732,6 @@ lfs2_ssize_t lfs2_fs_size(lfs2_t *lfs2); // Returns a negative error code on failure. int lfs2_fs_traverse(lfs2_t *lfs2, int (*cb)(void*, lfs2_block_t), void *data); -// Attempt to proactively find free blocks -// -// Calling this function is not required, but may allowing the offloading of -// the expensive block allocation scan to a less time-critical code path. -// -// Note: littlefs currently does not persist any found free blocks to disk. -// This may change in the future. -// -// Returns a negative error code on failure. Finding no free blocks is -// not an error. -int lfs2_fs_gc(lfs2_t *lfs2); - #ifndef LFS2_READONLY // Attempt to make the filesystem consistent and ready for writing // @@ -737,10 +745,32 @@ int lfs2_fs_mkconsistent(lfs2_t *lfs2); #endif #ifndef LFS2_READONLY +// Attempt any janitorial work +// +// This currently: +// 1. Calls mkconsistent if not already consistent +// 2. Compacts metadata > compact_thresh +// 3. Populates the block allocator +// +// Though additional janitorial work may be added in the future. +// +// Calling this function is not required, but may allow the offloading of +// expensive janitorial work to a less time-critical code path. +// +// Returns a negative error code on failure. Accomplishing nothing is not +// an error. +int lfs2_fs_gc(lfs2_t *lfs2); +#endif + +#ifndef LFS2_READONLY // Grows the filesystem to a new size, updating the superblock with the new // block count. // -// Note: This is irreversible. +// If LFS2_SHRINKNONRELOCATING is defined, this function will also accept +// block_counts smaller than the current configuration, after checking +// that none of the blocks that are being removed are in use. +// Note that littlefs's pseudorandom block allocation means that +// this is very unlikely to work in the general case. // // Returns a negative error code on failure. int lfs2_fs_grow(lfs2_t *lfs2, lfs2_size_t block_count); |