Make git read the index file version 5 without complaining. This version of the reader doesn't read neither the cache-tree nor the resolve undo data, but doesn't choke on an index that includes such data.
Helped-by: Junio C Hamano <gits...@pobox.com> Helped-by: Nguyen Thai Ngoc Duy <pclo...@gmail.com> Helped-by: Thomas Rast <tr...@student.ethz.ch> Signed-off-by: Thomas Gummerer <t.gumme...@gmail.com> --- Makefile | 1 + cache.h | 73 ++++++++ read-cache-v5.c | 556 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 630 insertions(+) create mode 100644 read-cache-v5.c diff --git a/Makefile b/Makefile index 3ccd3a8..ef55509 100644 --- a/Makefile +++ b/Makefile @@ -770,6 +770,7 @@ LIB_OBJS += quote.o LIB_OBJS += reachable.o LIB_OBJS += read-cache.o LIB_OBJS += read-cache-v2.o +LIB_OBJS += read-cache-v5.o LIB_OBJS += reflog-walk.o LIB_OBJS += refs.o LIB_OBJS += remote.o diff --git a/cache.h b/cache.h index bfe3099..bec9402 100644 --- a/cache.h +++ b/cache.h @@ -110,6 +110,15 @@ struct cache_time { unsigned int nsec; }; +/* + * The *next pointer is used in read_entries_v5 for holding + * all the elements of a directory, and points to the next + * cache_entry in a directory. + * + * It is reset by the add_name_hash call in set_index_entry + * to set it to point to the next cache_entry in the + * correct in-memory format ordering. + */ struct cache_entry { struct cache_time ce_ctime; struct cache_time ce_mtime; @@ -128,11 +137,59 @@ struct cache_entry { char name[FLEX_ARRAY]; /* more */ }; +struct directory_entry { + struct directory_entry *next; + struct directory_entry *next_hash; + struct cache_entry *ce; + struct cache_entry *ce_last; + struct conflict_entry *conflict; + struct conflict_entry *conflict_last; + unsigned int conflict_size; + unsigned int de_foffset; + unsigned int de_cr; + unsigned int de_ncr; + unsigned int de_nsubtrees; + unsigned int de_nfiles; + unsigned int de_nentries; + unsigned char sha1[20]; + unsigned short de_flags; + unsigned int de_pathlen; + char pathname[FLEX_ARRAY]; +}; + +struct conflict_part { + struct conflict_part *next; + unsigned short flags; + unsigned short entry_mode; + unsigned char sha1[20]; +}; + +struct conflict_entry { + struct conflict_entry *next; + unsigned int nfileconflicts; + struct conflict_part *entries; + unsigned int namelen; + unsigned int pathlen; + char name[FLEX_ARRAY]; +}; + +struct ondisk_conflict_part { + unsigned short flags; + unsigned short entry_mode; + unsigned char sha1[20]; +}; + +#define CE_NAMEMASK (0x0fff) #define CE_STAGEMASK (0x3000) #define CE_EXTENDED (0x4000) #define CE_VALID (0x8000) +#define CE_SMUDGED (0x0400) /* index v5 only flag */ #define CE_STAGESHIFT 12 +#define CONFLICT_CONFLICTED (0x8000) +#define CONFLICT_STAGESHIFT 13 +#define CONFLICT_STAGEMASK (0x6000) + /* * Range 0xFFFF0000 in ce_flags is divided into * two parts: in-memory flags and on-disk ones. @@ -166,6 +223,18 @@ struct cache_entry { #define CE_EXTENDED_FLAGS (CE_INTENT_TO_ADD | CE_SKIP_WORKTREE) /* + * Representation of the extended on-disk flags in the v5 format. + * They must not collide with the ordinary on-disk flags, and need to + * fit in 16 bits. Note however that v5 does not save the name + * length. + */ +#define CE_INTENT_TO_ADD_V5 (0x4000) +#define CE_SKIP_WORKTREE_V5 (0x0800) +#if (CE_VALID|CE_STAGEMASK) & (CE_INTENTTOADD_V5|CE_SKIPWORKTREE_V5) +#error "v5 on-disk flags collide with ordinary on-disk flags" +#endif + +/* * Safeguard to avoid saving wrong flags: * - CE_EXTENDED2 won't get saved until its semantic is known * - Bits in 0x0000FFFF have been saved in ce_flags already @@ -203,6 +272,8 @@ static inline unsigned create_ce_flags(unsigned stage) #define ce_skip_worktree(ce) ((ce)->ce_flags & CE_SKIP_WORKTREE) #define ce_mark_uptodate(ce) ((ce)->ce_flags |= CE_UPTODATE) +#define conflict_stage(c) ((CONFLICT_STAGEMASK & (c)->flags) >> CONFLICT_STAGESHIFT) + #define ce_permissions(mode) (((mode) & 0100) ? 0755 : 0644) static inline unsigned int create_ce_mode(unsigned int mode) { @@ -249,6 +320,8 @@ static inline unsigned int canon_mode(unsigned int mode) } #define cache_entry_size(len) (offsetof(struct cache_entry,name) + (len) + 1) +#define directory_entry_size(len) (offsetof(struct directory_entry,pathname) + (len) + 1) +#define conflict_entry_size(len) (offsetof(struct conflict_entry,name) + (len) + 1) struct index_state { struct cache_entry **cache; diff --git a/read-cache-v5.c b/read-cache-v5.c new file mode 100644 index 0000000..2031969 --- /dev/null +++ b/read-cache-v5.c @@ -0,0 +1,556 @@ +#include "cache.h" +#include "read-cache.h" +#include "resolve-undo.h" +#include "cache-tree.h" + +#define ptr_add(x,y) ((void *)(((char *)(x)) + (y))) + +struct cache_header { + unsigned int hdr_ndir; + unsigned int hdr_nfile; + unsigned int hdr_fblockoffset; + unsigned int hdr_nextension; +}; + +/***************************************************************** + * Index File I/O + *****************************************************************/ + +struct ondisk_cache_entry { + unsigned short flags; + unsigned short mode; + struct cache_time mtime; + unsigned int size; + int stat_crc; + unsigned char sha1[20]; +}; + +struct ondisk_directory_entry { + unsigned int foffset; + unsigned int cr; + unsigned int ncr; + unsigned int nsubtrees; + unsigned int nfiles; + unsigned int nentries; + unsigned char sha1[20]; + unsigned short flags; +}; + +static int check_crc32(int initialcrc, + void *data, + size_t len, + unsigned int expected_crc) +{ + int crc; + + crc = crc32(initialcrc, (Bytef*)data, len); + return crc == expected_crc; +} + +static int match_stat_crc(struct stat *st, uint32_t expected_crc) +{ + uint32_t data, stat_crc = 0; + unsigned int ctimens = 0; + + data = htonl(st->st_ctime); + stat_crc = crc32(0, (Bytef*)&data, 4); +#ifdef USE_NSEC + ctimens = ST_CTIME_NSEC(*st); +#endif + data = htonl(ctimens); + stat_crc = crc32(stat_crc, (Bytef*)&data, 4); + data = htonl(st->st_ino); + stat_crc = crc32(stat_crc, (Bytef*)&data, 4); + data = htonl(st->st_dev); + stat_crc = crc32(stat_crc, (Bytef*)&data, 4); + data = htonl(st->st_uid); + stat_crc = crc32(stat_crc, (Bytef*)&data, 4); + data = htonl(st->st_gid); + stat_crc = crc32(stat_crc, (Bytef*)&data, 4); + + return stat_crc == expected_crc; +} + +static int match_stat_basic(struct cache_entry *ce, + struct stat *st, + int changed) +{ + + if (ce->ce_mtime.sec != (unsigned int)st->st_mtime) + changed |= MTIME_CHANGED; +#ifdef USE_NSEC + if (ce->ce_mtime.nsec != ST_MTIME_NSEC(*st)) + changed |= MTIME_CHANGED; +#endif + if (ce->ce_size != (unsigned int)st->st_size) + changed |= DATA_CHANGED; + + if (trust_ctime && ce->ce_stat_crc != 0 && !match_stat_crc(st, ce->ce_stat_crc)) { + changed |= OWNER_CHANGED; + changed |= INODE_CHANGED; + } + /* Racily smudged entry? */ + if (ce->ce_flags & CE_SMUDGED) { + if (!changed && !is_empty_blob_sha1(ce->sha1) && ce_modified_check_fs(ce, st)) + changed |= DATA_CHANGED; + } + return changed; +} + +static int verify_hdr(void *mmap, unsigned long size) +{ + uint32_t *filecrc; + unsigned int header_size; + struct cache_version_header *hdr; + struct cache_header *hdr_v5; + + if (size < sizeof(struct cache_version_header) + + sizeof (struct cache_header) + 4) + die("index file smaller than expected"); + + hdr = mmap; + hdr_v5 = ptr_add(mmap, sizeof(*hdr)); + /* Size of the header + the size of the extensionoffsets */ + header_size = sizeof(*hdr) + sizeof(*hdr_v5) + hdr_v5->hdr_nextension * 4; + /* Initialize crc */ + filecrc = ptr_add(mmap, header_size); + if (!check_crc32(0, hdr, header_size, ntohl(*filecrc))) + return error("bad index file header crc signature"); + return 0; +} + +static struct cache_entry *cache_entry_from_ondisk(struct ondisk_cache_entry *ondisk, + struct directory_entry *de, + char *name, + size_t len, + size_t prefix_len) +{ + struct cache_entry *ce = xmalloc(cache_entry_size(len + de->de_pathlen)); + int flags; + + flags = ntoh_s(ondisk->flags); + ce->ce_ctime.sec = 0; + ce->ce_mtime.sec = ntoh_l(ondisk->mtime.sec); + ce->ce_ctime.nsec = 0; + ce->ce_mtime.nsec = ntoh_l(ondisk->mtime.nsec); + ce->ce_dev = 0; + ce->ce_ino = 0; + ce->ce_mode = ntoh_s(ondisk->mode); + ce->ce_uid = 0; + ce->ce_gid = 0; + ce->ce_size = ntoh_l(ondisk->size); + ce->ce_flags = flags & CE_STAGEMASK; + ce->ce_flags |= flags & CE_VALID; + ce->ce_flags |= flags & CE_SMUDGED; + if (flags & CE_INTENT_TO_ADD_V5) + ce->ce_flags |= CE_INTENT_TO_ADD; + if (flags & CE_SKIP_WORKTREE_V5) + ce->ce_flags |= CE_SKIP_WORKTREE; + ce->ce_stat_crc = ntoh_l(ondisk->stat_crc); + ce->ce_namelen = len + de->de_pathlen; + hashcpy(ce->sha1, ondisk->sha1); + memcpy(ce->name, de->pathname, de->de_pathlen); + memcpy(ce->name + de->de_pathlen, name, len); + ce->name[len + de->de_pathlen] = '\0'; + return ce; +} + +static struct directory_entry *directory_entry_from_ondisk(struct ondisk_directory_entry *ondisk, + const char *name, + size_t len) +{ + struct directory_entry *de = xmalloc(directory_entry_size(len)); + + + memcpy(de->pathname, name, len); + de->pathname[len] = '\0'; + de->de_flags = ntoh_s(ondisk->flags); + de->de_foffset = ntoh_l(ondisk->foffset); + de->de_cr = ntoh_l(ondisk->cr); + de->de_ncr = ntoh_l(ondisk->ncr); + de->de_nsubtrees = ntoh_l(ondisk->nsubtrees); + de->de_nfiles = ntoh_l(ondisk->nfiles); + de->de_nentries = ntoh_l(ondisk->nentries); + de->de_pathlen = len; + hashcpy(de->sha1, ondisk->sha1); + return de; +} + +static struct conflict_part *conflict_part_from_ondisk(struct ondisk_conflict_part *ondisk) +{ + struct conflict_part *cp = xmalloc(sizeof(struct conflict_part)); + + cp->flags = ntoh_s(ondisk->flags); + cp->entry_mode = ntoh_s(ondisk->entry_mode); + hashcpy(cp->sha1, ondisk->sha1); + return cp; +} + +static struct cache_entry *convert_conflict_part(struct conflict_part *cp, + char * name, + unsigned int len) +{ + + struct cache_entry *ce = xmalloc(cache_entry_size(len)); + + ce->ce_ctime.sec = 0; + ce->ce_mtime.sec = 0; + ce->ce_ctime.nsec = 0; + ce->ce_mtime.nsec = 0; + ce->ce_dev = 0; + ce->ce_ino = 0; + ce->ce_mode = cp->entry_mode; + ce->ce_uid = 0; + ce->ce_gid = 0; + ce->ce_size = 0; + ce->ce_flags = conflict_stage(cp) << CE_STAGESHIFT; + ce->ce_stat_crc = 0; + ce->ce_namelen = len; + hashcpy(ce->sha1, cp->sha1); + memcpy(ce->name, name, len); + ce->name[len] = '\0'; + return ce; +} + +static struct directory_entry *read_directories(unsigned int *dir_offset, + unsigned int *dir_table_offset, + void *mmap, + int mmap_size) +{ + int i, ondisk_directory_size; + uint32_t *filecrc, *beginning, *end; + struct directory_entry *current = NULL; + struct ondisk_directory_entry *disk_de; + struct directory_entry *de; + unsigned int data_len, len; + char *name; + + ondisk_directory_size = sizeof(disk_de->flags) + + sizeof(disk_de->foffset) + + sizeof(disk_de->cr) + + sizeof(disk_de->ncr) + + sizeof(disk_de->nsubtrees) + + sizeof(disk_de->nfiles) + + sizeof(disk_de->nentries) + + sizeof(disk_de->sha1); + name = ptr_add(mmap, *dir_offset); + beginning = ptr_add(mmap, *dir_table_offset); + end = ptr_add(mmap, *dir_table_offset + 4); + len = ntoh_l(*end) - ntoh_l(*beginning) - ondisk_directory_size - 5; + disk_de = ptr_add(mmap, *dir_offset + len + 1); + de = directory_entry_from_ondisk(disk_de, name, len); + de->next = NULL; + + /* Length of pathname + nul byte for termination + size of + * members of ondisk_directory_entry. (Just using the size + * of the stuct doesn't work, because there may be padding + * bytes for the struct) + */ + data_len = len + 1 + ondisk_directory_size; + + filecrc = ptr_add(mmap, *dir_offset + data_len); + if (!check_crc32(0, ptr_add(mmap, *dir_offset), data_len, ntoh_l(*filecrc))) + goto unmap; + + *dir_table_offset += 4; + *dir_offset += data_len + 4; /* crc code */ + + current = de; + for (i = 0; i < de->de_nsubtrees; i++) { + current->next = read_directories(dir_offset, dir_table_offset, + mmap, mmap_size); + while (current->next) + current = current->next; + } + + return de; +unmap: + munmap(mmap, mmap_size); + die("directory crc doesn't match for '%s'", de->pathname); +} + +static int read_entry(struct cache_entry **ce, struct directory_entry *de, + unsigned long *entry_offset, + void **mmap, unsigned long mmap_size, + unsigned int *foffsetblock) +{ + int len, offset_to_offset; + char *name; + uint32_t foffsetblockcrc; + uint32_t *filecrc, *beginning, *end; + struct ondisk_cache_entry *disk_ce; + + name = ptr_add(*mmap, *entry_offset); + beginning = ptr_add(*mmap, *foffsetblock); + end = ptr_add(*mmap, *foffsetblock + 4); + len = ntoh_l(*end) - ntoh_l(*beginning) - sizeof(struct ondisk_cache_entry) - 5; + disk_ce = ptr_add(*mmap, *entry_offset + len + 1); + *ce = cache_entry_from_ondisk(disk_ce, de, name, len, de->de_pathlen); + filecrc = ptr_add(*mmap, *entry_offset + len + 1 + sizeof(*disk_ce)); + offset_to_offset = htonl(*foffsetblock); + foffsetblockcrc = crc32(0, (Bytef*)&offset_to_offset, 4); + if (!check_crc32(foffsetblockcrc, + ptr_add(*mmap, *entry_offset), len + 1 + sizeof(*disk_ce), + ntoh_l(*filecrc))) + return -1; + + /* TODO: return error if crc code is wrong */ + *entry_offset += len + 1 + sizeof(*disk_ce) + 4; + return 0; +} + +static void ce_queue_push(struct cache_entry **head, + struct cache_entry **tail, + struct cache_entry *ce) +{ + if (!*head) { + *head = *tail = ce; + (*tail)->next = NULL; + return; + } + + (*tail)->next = ce; + ce->next = NULL; + *tail = (*tail)->next; +} + +static void conflict_entry_push(struct conflict_entry **head, + struct conflict_entry **tail, + struct conflict_entry *conflict_entry) +{ + if (!*head) { + *head = *tail = conflict_entry; + (*tail)->next = NULL; + return; + } + + (*tail)->next = conflict_entry; + conflict_entry->next = NULL; + *tail = (*tail)->next; +} + +static struct cache_entry *ce_queue_pop(struct cache_entry **head) +{ + struct cache_entry *ce; + + ce = *head; + *head = (*head)->next; + return ce; +} + +static void conflict_part_head_remove(struct conflict_part **head) +{ + struct conflict_part *to_free; + + to_free = *head; + *head = (*head)->next; + free(to_free); +} + +static void conflict_entry_head_remove(struct conflict_entry **head) +{ + struct conflict_entry *to_free; + + to_free = *head; + *head = (*head)->next; + free(to_free); +} + +struct conflict_entry *create_new_conflict(char *name, int len, int pathlen) +{ + struct conflict_entry *conflict_entry; + + if (pathlen) + pathlen++; + conflict_entry = xmalloc(conflict_entry_size(len)); + conflict_entry->entries = NULL; + conflict_entry->nfileconflicts = 0; + conflict_entry->namelen = len; + memcpy(conflict_entry->name, name, len); + conflict_entry->name[len] = '\0'; + conflict_entry->pathlen = pathlen; + conflict_entry->next = NULL; + + return conflict_entry; +} + +void add_part_to_conflict_entry(struct directory_entry *de, + struct conflict_entry *entry, + struct conflict_part *conflict_part) +{ + + struct conflict_part *conflict_search; + + entry->nfileconflicts++; + de->conflict_size += sizeof(struct ondisk_conflict_part); + if (!entry->entries) + entry->entries = conflict_part; + else { + conflict_search = entry->entries; + while (conflict_search->next) + conflict_search = conflict_search->next; + conflict_search->next = conflict_part; + } +} + +static int read_conflicts(struct conflict_entry **head, + struct directory_entry *de, + void **mmap, unsigned long mmap_size) +{ + struct conflict_entry *tail; + unsigned int croffset, i; + char *full_name; + + croffset = de->de_cr; + tail = NULL; + for (i = 0; i < de->de_ncr; i++) { + struct conflict_entry *conflict_new; + unsigned int len, *nfileconflicts; + char *name; + void *crc_start; + int k, offset; + uint32_t *filecrc; + + offset = croffset; + crc_start = ptr_add(*mmap, offset); + name = ptr_add(*mmap, offset); + len = strlen(name); + offset += len + 1; + nfileconflicts = ptr_add(*mmap, offset); + offset += 4; + + full_name = xmalloc(sizeof(char) * (len + de->de_pathlen)); + memcpy(full_name, de->pathname, de->de_pathlen); + memcpy(full_name + de->de_pathlen, name, len); + conflict_new = create_new_conflict(full_name, + len + de->de_pathlen, de->de_pathlen); + for (k = 0; k < ntoh_l(*nfileconflicts); k++) { + struct ondisk_conflict_part *ondisk; + struct conflict_part *cp; + + ondisk = ptr_add(*mmap, offset); + cp = conflict_part_from_ondisk(ondisk); + cp->next = NULL; + add_part_to_conflict_entry(de, conflict_new, cp); + offset += sizeof(struct ondisk_conflict_part); + } + filecrc = ptr_add(*mmap, offset); + free(full_name); + if (!check_crc32(0, crc_start, + len + 1 + 4 + conflict_new->nfileconflicts + * sizeof(struct ondisk_conflict_part), + ntoh_l(*filecrc))) + return -1; + croffset = offset + 4; + conflict_entry_push(head, &tail, conflict_new); + } + return 0; +} + +static int read_entries(struct index_state *istate, struct directory_entry **de, + unsigned long *entry_offset, void **mmap, + unsigned long mmap_size, int *nr, + unsigned int *foffsetblock) +{ + struct cache_entry *head = NULL, *tail = NULL; + struct conflict_entry *conflict_queue; + struct cache_entry *ce; + int i; + + conflict_queue = NULL; + if (read_conflicts(&conflict_queue, *de, mmap, mmap_size) < 0) + return -1; + for (i = 0; i < (*de)->de_nfiles; i++) { + if (read_entry(&ce, + *de, + entry_offset, + mmap, + mmap_size, + foffsetblock) < 0) + return -1; + ce_queue_push(&head, &tail, ce); + *foffsetblock += 4; + + /* Add the conflicted entries at the end of the index file + * to the in memory format + */ + if (conflict_queue && + (conflict_queue->entries->flags & CONFLICT_CONFLICTED) != 0 && + !cache_name_compare(conflict_queue->name, conflict_queue->namelen, + ce->name, ce_namelen(ce))) { + struct conflict_part *cp; + cp = conflict_queue->entries; + cp = cp->next; + while (cp) { + ce = convert_conflict_part(cp, + conflict_queue->name, + conflict_queue->namelen); + ce_queue_push(&head, &tail, ce); + conflict_part_head_remove(&cp); + } + conflict_entry_head_remove(&conflict_queue); + } + } + + *de = (*de)->next; + + while (head) { + if (*de != NULL + && strcmp(head->name, (*de)->pathname) > 0) { + read_entries(istate, + de, + entry_offset, + mmap, + mmap_size, + nr, + foffsetblock); + } else { + ce = ce_queue_pop(&head); + set_index_entry(istate, *nr, ce); + (*nr)++; + } + } + return 0; +} + +static int read_index_v5(struct index_state *istate, void *mmap, int mmap_size) +{ + unsigned long entry_offset; + unsigned int dir_offset, dir_table_offset; + struct cache_version_header *hdr; + struct cache_header *hdr_v5; + struct directory_entry *root_directory, *de; + int nr; + unsigned int foffsetblock; + + hdr = mmap; + hdr_v5 = ptr_add(mmap, sizeof(*hdr)); + istate->version = ntohl(hdr->hdr_version); + istate->cache_nr = ntohl(hdr_v5->hdr_nfile); + istate->cache_alloc = alloc_nr(istate->cache_nr); + istate->cache = xcalloc(istate->cache_alloc, sizeof(struct cache_entry *)); + istate->initialized = 1; + + /* Skip size of the header + crc sum + size of offsets */ + dir_offset = sizeof(*hdr) + sizeof(*hdr_v5) + 4 + (ntohl(hdr_v5->hdr_ndir) + 1) * 4; + dir_table_offset = sizeof(*hdr) + sizeof(*hdr_v5) + 4; + root_directory = read_directories(&dir_offset, &dir_table_offset, mmap, mmap_size); + + entry_offset = ntohl(hdr_v5->hdr_fblockoffset); + + nr = 0; + foffsetblock = dir_offset; + de = root_directory; + while (de) + if (read_entries(istate, &de, &entry_offset, + &mmap, mmap_size, &nr, &foffsetblock) < 0) + return -1; + return 0; +} + +struct index_ops v5_ops = { + match_stat_basic, + verify_hdr, + read_index_v5, + NULL +}; -- 1.7.11.2 -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html