diff options
Diffstat (limited to 'sha1_file.c')
| -rw-r--r-- | sha1_file.c | 381 |
1 files changed, 272 insertions, 109 deletions
diff --git a/sha1_file.c b/sha1_file.c index 0926643..df0edba 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -13,6 +13,7 @@ #include "commit.h" #include "tag.h" #include "tree.h" +#include "tree-walk.h" #include "refs.h" #include "pack-revindex.h" #include "sha1-lookup.h" @@ -25,21 +26,46 @@ #endif #endif -#ifdef NO_C99_FORMAT -#define SZ_FMT "lu" -static unsigned long sz_fmt(size_t s) { return (unsigned long)s; } -#else -#define SZ_FMT "zu" -static size_t sz_fmt(size_t s) { return s; } -#endif +#define SZ_FMT PRIuMAX +static inline uintmax_t sz_fmt(size_t s) { return s; } const unsigned char null_sha1[20]; -static inline int offset_1st_component(const char *path) +static int git_open_noatime(const char *name, struct packed_git *p); + +/* + * This is meant to hold a *small* number of objects that you would + * want read_sha1_file() to be able to return, but yet you do not want + * to write them into the object store (e.g. a browse-only + * application). + */ +static struct cached_object { + unsigned char sha1[20]; + enum object_type type; + void *buf; + unsigned long size; +} *cached_objects; +static int cached_object_nr, cached_object_alloc; + +static struct cached_object empty_tree = { + EMPTY_TREE_SHA1_BIN_LITERAL, + OBJ_TREE, + "", + 0 +}; + +static struct cached_object *find_cached_object(const unsigned char *sha1) { - if (has_dos_drive_prefix(path)) - return 2 + (path[2] == '/'); - return *path == '/'; + int i; + struct cached_object *co = cached_objects; + + for (i = 0; i < cached_object_nr; i++, co++) { + if (!hashcmp(co->sha1, sha1)) + return co; + } + if (!hashcmp(sha1, empty_tree.sha1)) + return &empty_tree; + return NULL; } int mkdir_in_gitdir(const char *path) @@ -138,20 +164,22 @@ static void fill_sha1_path(char *pathbuf, const unsigned char *sha1) */ char *sha1_file_name(const unsigned char *sha1) { - static char *name, *base; + static char buf[PATH_MAX]; + const char *objdir; + int len; - if (!base) { - const char *sha1_file_directory = get_object_directory(); - int len = strlen(sha1_file_directory); - base = xmalloc(len + 60); - memcpy(base, sha1_file_directory, len); - memset(base+len, 0, 60); - base[len] = '/'; - base[len+3] = '/'; - name = base + len + 1; - } - fill_sha1_path(name, sha1); - return base; + objdir = get_object_directory(); + len = strlen(objdir); + + /* '/' + sha1(2) + '/' + sha1(38) + '\0' */ + if (len + 43 > PATH_MAX) + die("insanely long object directory %s", objdir); + memcpy(buf, objdir, len); + buf[len] = '/'; + buf[len+3] = '/'; + buf[len+42] = '\0'; + fill_sha1_path(buf + len + 1, sha1); + return buf; } static char *sha1_get_pack_name(const unsigned char *sha1, @@ -332,7 +360,7 @@ static void read_info_alternates(const char * relative_base, int depth) int fd; sprintf(path, "%s/%s", relative_base, alt_file_name); - fd = open(path, O_RDONLY); + fd = git_open_noatime(path, NULL); if (fd < 0) return; if (fstat(fd, &st) || (st.st_size == 0)) { @@ -414,6 +442,8 @@ static unsigned int pack_used_ctr; static unsigned int pack_mmap_calls; static unsigned int peak_pack_open_windows; static unsigned int pack_open_windows; +static unsigned int pack_open_fds; +static unsigned int pack_max_fds; static size_t peak_pack_mapped; static size_t pack_mapped; struct packed_git *packed_git; @@ -445,7 +475,7 @@ static int check_packed_git_idx(const char *path, struct packed_git *p) struct pack_idx_header *hdr; size_t idx_size; uint32_t version, nr, i, *index; - int fd = open(path, O_RDONLY); + int fd = git_open_noatime(path, p); struct stat st; if (fd < 0) @@ -591,8 +621,10 @@ static int unuse_one_window(struct packed_git *current, int keep_fd) lru_l->next = lru_w->next; else { lru_p->windows = lru_w->next; - if (!lru_p->windows && lru_p->pack_fd != keep_fd) { + if (!lru_p->windows && lru_p->pack_fd != -1 + && lru_p->pack_fd != keep_fd) { close(lru_p->pack_fd); + pack_open_fds--; lru_p->pack_fd = -1; } } @@ -610,6 +642,21 @@ void release_pack_memory(size_t need, int fd) ; /* nothing */ } +void *xmmap(void *start, size_t length, + int prot, int flags, int fd, off_t offset) +{ + void *ret = mmap(start, length, prot, flags, fd, offset); + if (ret == MAP_FAILED) { + if (!length) + return NULL; + release_pack_memory(length, fd); + ret = mmap(start, length, prot, flags, fd, offset); + if (ret == MAP_FAILED) + die_errno("Out of memory? mmap failed"); + } + return ret; +} + void close_pack_windows(struct packed_git *p) { while (p->windows) { @@ -635,6 +682,14 @@ void unuse_pack(struct pack_window **w_cursor) } } +void close_pack_index(struct packed_git *p) +{ + if (p->index_data) { + munmap((void *)p->index_data, p->index_size); + p->index_data = NULL; + } +} + /* * This is used by git-repack in case a newly created pack happens to * contain the same set of objects as an existing one. In that case @@ -654,10 +709,11 @@ void free_pack_by_name(const char *pack_name) if (strcmp(pack_name, p->pack_name) == 0) { clear_delta_base_cache(); close_pack_windows(p); - if (p->pack_fd != -1) + if (p->pack_fd != -1) { close(p->pack_fd); - if (p->index_data) - munmap((void *)p->index_data, p->index_size); + pack_open_fds--; + } + close_pack_index(p); free(p->bad_object_sha1); *pp = p->next; free(p); @@ -682,11 +738,29 @@ static int open_packed_git_1(struct packed_git *p) if (!p->index_data && open_pack_index(p)) return error("packfile %s index unavailable", p->pack_name); - p->pack_fd = open(p->pack_name, O_RDONLY); - while (p->pack_fd < 0 && errno == EMFILE && unuse_one_window(p, -1)) - p->pack_fd = open(p->pack_name, O_RDONLY); + if (!pack_max_fds) { + struct rlimit lim; + unsigned int max_fds; + + if (getrlimit(RLIMIT_NOFILE, &lim)) + die_errno("cannot get RLIMIT_NOFILE"); + + max_fds = lim.rlim_cur; + + /* Save 3 for stdin/stdout/stderr, 22 for work */ + if (25 < max_fds) + pack_max_fds = max_fds - 25; + else + pack_max_fds = 1; + } + + while (pack_max_fds <= pack_open_fds && unuse_one_window(NULL, -1)) + ; /* nothing */ + + p->pack_fd = git_open_noatime(p->pack_name, p); if (p->pack_fd < 0 || fstat(p->pack_fd, &st)) return -1; + pack_open_fds++; /* If we created the struct before we had the pack we lack size. */ if (!p->pack_size) { @@ -738,6 +812,7 @@ static int open_packed_git(struct packed_git *p) return 0; if (p->pack_fd != -1) { close(p->pack_fd); + pack_open_fds--; p->pack_fd = -1; } return -1; @@ -763,14 +838,13 @@ unsigned char *use_pack(struct packed_git *p, { struct pack_window *win = *w_cursor; - if (p->pack_fd == -1 && open_packed_git(p)) - die("packfile %s cannot be accessed", p->pack_name); - /* Since packfiles end in a hash of their content and it's * pointless to ask for an offset into the middle of that * hash, and the in_window function above wouldn't match * don't allow an offset too close to the end of the file. */ + if (!p->pack_size && p->pack_fd == -1 && open_packed_git(p)) + die("packfile %s cannot be accessed", p->pack_name); if (offset > (p->pack_size - 20)) die("offset beyond end of packfile (truncated pack?)"); @@ -784,6 +858,10 @@ unsigned char *use_pack(struct packed_git *p, if (!win) { size_t window_align = packed_git_window_size / 2; off_t len; + + if (p->pack_fd == -1 && open_packed_git(p)) + die("packfile %s cannot be accessed", p->pack_name); + win = xcalloc(1, sizeof(*win)); win->offset = (offset / window_align) * window_align; len = p->pack_size - win->offset; @@ -801,6 +879,12 @@ unsigned char *use_pack(struct packed_git *p, die("packfile %s cannot be mapped: %s", p->pack_name, strerror(errno)); + if (!win->offset && win->len == p->pack_size + && !p->do_not_close) { + close(p->pack_fd); + pack_open_fds--; + p->pack_fd = -1; + } pack_mmap_calls++; pack_open_windows++; if (pack_mapped > peak_pack_mapped) @@ -830,11 +914,22 @@ static struct packed_git *alloc_packed_git(int extra) return p; } +static void try_to_free_pack_memory(size_t size) +{ + release_pack_memory(size, -1); +} + struct packed_git *add_packed_git(const char *path, int path_len, int local) { + static int have_set_try_to_free_routine; struct stat st; struct packed_git *p = alloc_packed_git(path_len + 2); + if (!have_set_try_to_free_routine) { + have_set_try_to_free_routine = 1; + set_try_to_free_routine(try_to_free_pack_memory); + } + /* * Make sure a corresponding .pack file exists and that * the index looks sane. @@ -867,9 +962,8 @@ struct packed_git *add_packed_git(const char *path, int path_len, int local) return p; } -struct packed_git *parse_pack_index(unsigned char *sha1) +struct packed_git *parse_pack_index(unsigned char *sha1, const char *idx_path) { - const char *idx_path = sha1_pack_index_name(sha1); const char *path = sha1_pack_name(sha1); struct packed_git *p = alloc_packed_git(strlen(path) + 1); @@ -885,6 +979,9 @@ struct packed_git *parse_pack_index(unsigned char *sha1) void install_packed_git(struct packed_git *pack) { + if (pack->pack_fd != -1) + pack_open_fds++; + pack->next = packed_git; packed_git = pack; } @@ -902,8 +999,6 @@ static void prepare_packed_git_one(char *objdir, int local) sprintf(path, "%s/pack", objdir); len = strlen(path); dir = opendir(path); - while (!dir && errno == EMFILE && unuse_one_window(packed_git, -1)) - dir = opendir(path); if (!dir) { if (errno != ENOENT) error("unable to open object pack directory: %s: %s", @@ -1031,7 +1126,7 @@ static void mark_bad_packed_object(struct packed_git *p, p->num_bad_objects++; } -static int has_packed_and_bad(const unsigned char *sha1) +static const struct packed_git *has_packed_and_bad(const unsigned char *sha1) { struct packed_git *p; unsigned i; @@ -1039,8 +1134,8 @@ static int has_packed_and_bad(const unsigned char *sha1) for (p = packed_git; p; p = p->next) for (i = 0; i < p->num_bad_objects; i++) if (!hashcmp(sha1, p->bad_object_sha1 + 20 * i)) - return 1; - return 0; + return p; + return NULL; } int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long size, const char *type) @@ -1050,18 +1145,23 @@ int check_sha1_signature(const unsigned char *sha1, void *map, unsigned long siz return hashcmp(sha1, real_sha1) ? -1 : 0; } -static int git_open_noatime(const char *name) +static int git_open_noatime(const char *name, struct packed_git *p) { static int sha1_file_open_flag = O_NOATIME; - int fd = open(name, O_RDONLY | sha1_file_open_flag); - /* Might the failure be due to O_NOATIME? */ - if (fd < 0 && errno != ENOENT && sha1_file_open_flag) { - fd = open(name, O_RDONLY); + for (;;) { + int fd = open(name, O_RDONLY | sha1_file_open_flag); if (fd >= 0) + return fd; + + /* Might the failure be due to O_NOATIME? */ + if (errno != ENOENT && sha1_file_open_flag) { sha1_file_open_flag = 0; + continue; + } + + return -1; } - return fd; } static int open_sha1_file(const unsigned char *sha1) @@ -1070,7 +1170,7 @@ static int open_sha1_file(const unsigned char *sha1) char *name = sha1_file_name(sha1); struct alternate_object_database *alt; - fd = git_open_noatime(name); + fd = git_open_noatime(name, NULL); if (fd >= 0) return fd; @@ -1079,7 +1179,7 @@ static int open_sha1_file(const unsigned char *sha1) for (alt = alt_odb_list; alt; alt = alt->next) { name = alt->name; fill_sha1_path(name, sha1); - fd = git_open_noatime(alt->base); + fd = git_open_noatime(alt->base, NULL); if (fd >= 0) return fd; } @@ -1885,6 +1985,27 @@ off_t find_pack_entry_one(const unsigned char *sha1, return 0; } +static int is_pack_valid(struct packed_git *p) +{ + /* An already open pack is known to be valid. */ + if (p->pack_fd != -1) + return 1; + + /* If the pack has one window completely covering the + * file size, the pack is known to be valid even if + * the descriptor is not currently open. + */ + if (p->windows) { + struct pack_window *w = p->windows; + + if (!w->offset && w->len == p->pack_size) + return 1; + } + + /* Force the pack to open to prove its valid. */ + return !open_packed_git(p); +} + static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e) { static struct packed_git *last_found = (void *)1; @@ -1914,7 +2035,7 @@ static int find_pack_entry(const unsigned char *sha1, struct pack_entry *e) * it may have been deleted since the index * was loaded! */ - if (p->pack_fd == -1 && open_packed_git(p)) { + if (!is_pack_valid(p)) { error("packfile %s cannot be accessed", p->pack_name); goto next; } @@ -1974,9 +2095,17 @@ static int sha1_loose_object_info(const unsigned char *sha1, unsigned long *size int sha1_object_info(const unsigned char *sha1, unsigned long *sizep) { + struct cached_object *co; struct pack_entry e; int status; + co = find_cached_object(sha1); + if (co) { + if (sizep) + *sizep = co->size; + return co->type; + } + if (!find_pack_entry(sha1, &e)) { /* Most likely it's a loose object. */ status = sha1_loose_object_info(sha1, sizep); @@ -2022,41 +2151,6 @@ static void *read_packed_sha1(const unsigned char *sha1, return data; } -/* - * This is meant to hold a *small* number of objects that you would - * want read_sha1_file() to be able to return, but yet you do not want - * to write them into the object store (e.g. a browse-only - * application). - */ -static struct cached_object { - unsigned char sha1[20]; - enum object_type type; - void *buf; - unsigned long size; -} *cached_objects; -static int cached_object_nr, cached_object_alloc; - -static struct cached_object empty_tree = { - EMPTY_TREE_SHA1_BIN, - OBJ_TREE, - "", - 0 -}; - -static struct cached_object *find_cached_object(const unsigned char *sha1) -{ - int i; - struct cached_object *co = cached_objects; - - for (i = 0; i < cached_object_nr; i++, co++) { - if (!hashcmp(co->sha1, sha1)) - return co; - } - if (!hashcmp(sha1, empty_tree.sha1)) - return &empty_tree; - return NULL; -} - int pretend_sha1_file(void *buf, unsigned long len, enum object_type type, unsigned char *sha1) { @@ -2107,27 +2201,48 @@ static void *read_object(const unsigned char *sha1, enum object_type *type, return read_packed_sha1(sha1, type, size); } +/* + * This function dies on corrupt objects; the callers who want to + * deal with them should arrange to call read_object() and give error + * messages themselves. + */ void *read_sha1_file_repl(const unsigned char *sha1, enum object_type *type, unsigned long *size, const unsigned char **replacement) { const unsigned char *repl = lookup_replace_object(sha1); - void *data = read_object(repl, type, size); + void *data; + char *path; + const struct packed_git *p; + + errno = 0; + data = read_object(repl, type, size); + if (data) { + if (replacement) + *replacement = repl; + return data; + } + + if (errno && errno != ENOENT) + die_errno("failed to read object %s", sha1_to_hex(sha1)); /* die if we replaced an object with one that does not exist */ - if (!data && repl != sha1) + if (repl != sha1) die("replacement %s not found for %s", sha1_to_hex(repl), sha1_to_hex(sha1)); - /* legacy behavior is to die on corrupted objects */ - if (!data && (has_loose_object(repl) || has_packed_and_bad(repl))) - die("object %s is corrupted", sha1_to_hex(repl)); + if (has_loose_object(repl)) { + path = sha1_file_name(sha1); + die("loose object %s (stored in %s) is corrupt", + sha1_to_hex(repl), path); + } - if (replacement) - *replacement = repl; + if ((p = has_packed_and_bad(repl)) != NULL) + die("packed object %s (stored in %s) is corrupt", + sha1_to_hex(repl), p->pack_name); - return data; + return NULL; } void *read_object_with_reference(const unsigned char *sha1, @@ -2307,7 +2422,7 @@ static int create_tmpfile(char *buffer, size_t bufsiz, const char *filename) } static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, - void *buf, unsigned long len, time_t mtime) + const void *buf, unsigned long len, time_t mtime) { int fd, ret; unsigned char compressed[4096]; @@ -2319,8 +2434,6 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, filename = sha1_file_name(sha1); fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename); - while (fd < 0 && errno == EMFILE && unuse_one_window(packed_git, -1)) - fd = create_tmpfile(tmpfile, sizeof(tmpfile), filename); if (fd < 0) { if (errno == EACCES) return error("insufficient permission for adding an object to repository database %s\n", get_object_directory()); @@ -2343,7 +2456,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, git_SHA1_Update(&c, hdr, hdrlen); /* Then the data itself.. */ - stream.next_in = buf; + stream.next_in = (void *)buf; stream.avail_in = len; do { unsigned char *in0 = stream.next_in; @@ -2378,7 +2491,7 @@ static int write_loose_object(const unsigned char *sha1, char *hdr, int hdrlen, return move_temp_to_file(tmpfile, filename); } -int write_sha1_file(void *buf, unsigned long len, const char *type, unsigned char *returnsha1) +int write_sha1_file(const void *buf, unsigned long len, const char *type, unsigned char *returnsha1) { unsigned char sha1[20]; char hdr[32]; @@ -2439,8 +2552,37 @@ int has_sha1_file(const unsigned char *sha1) return has_loose_object(sha1); } +static void check_tree(const void *buf, size_t size) +{ + struct tree_desc desc; + struct name_entry entry; + + init_tree_desc(&desc, buf, size); + while (tree_entry(&desc, &entry)) + /* do nothing + * tree_entry() will die() on malformed entries */ + ; +} + +static void check_commit(const void *buf, size_t size) +{ + struct commit c; + memset(&c, 0, sizeof(c)); + if (parse_commit_buffer(&c, buf, size)) + die("corrupt commit"); +} + +static void check_tag(const void *buf, size_t size) +{ + struct tag t; + memset(&t, 0, sizeof(t)); + if (parse_tag_buffer(&t, buf, size)) + die("corrupt tag"); +} + static int index_mem(unsigned char *sha1, void *buf, size_t size, - int write_object, enum object_type type, const char *path) + int write_object, enum object_type type, + const char *path, int format_check) { int ret, re_allocated = 0; @@ -2458,6 +2600,14 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size, re_allocated = 1; } } + if (format_check) { + if (type == OBJ_TREE) + check_tree(buf, size); + if (type == OBJ_COMMIT) + check_commit(buf, size); + if (type == OBJ_TAG) + check_tag(buf, size); + } if (write_object) ret = write_sha1_file(buf, size, typename(type), sha1); @@ -2471,7 +2621,7 @@ static int index_mem(unsigned char *sha1, void *buf, size_t size, #define SMALL_FILE_SIZE (32*1024) int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, - enum object_type type, const char *path) + enum object_type type, const char *path, int format_check) { int ret; size_t size = xsize_t(st->st_size); @@ -2480,24 +2630,27 @@ int index_fd(unsigned char *sha1, int fd, struct stat *st, int write_object, struct strbuf sbuf = STRBUF_INIT; if (strbuf_read(&sbuf, fd, 4096) >= 0) ret = index_mem(sha1, sbuf.buf, sbuf.len, write_object, - type, path); + type, path, format_check); else ret = -1; strbuf_release(&sbuf); + } else if (!size) { + ret = index_mem(sha1, NULL, size, write_object, type, path, + format_check); } else if (size <= SMALL_FILE_SIZE) { char *buf = xmalloc(size); if (size == read_in_full(fd, buf, size)) ret = index_mem(sha1, buf, size, write_object, type, - path); + path, format_check); else ret = error("short read %s", strerror(errno)); free(buf); - } else if (size) { + } else { void *buf = xmmap(NULL, size, PROT_READ, MAP_PRIVATE, fd, 0); - ret = index_mem(sha1, buf, size, write_object, type, path); + ret = index_mem(sha1, buf, size, write_object, type, path, + format_check); munmap(buf, size); - } else - ret = index_mem(sha1, NULL, size, write_object, type, path); + } close(fd); return ret; } @@ -2513,7 +2666,7 @@ int index_path(unsigned char *sha1, const char *path, struct stat *st, int write if (fd < 0) return error("open(\"%s\"): %s", path, strerror(errno)); - if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path) < 0) + if (index_fd(sha1, fd, st, write_object, OBJ_BLOB, path, 0) < 0) return error("%s: failed to insert into database", path); break; @@ -2552,3 +2705,13 @@ int read_pack_header(int fd, struct pack_header *header) return PH_ERROR_PROTOCOL; return 0; } + +void assert_sha1_type(const unsigned char *sha1, enum object_type expect) +{ + enum object_type type = sha1_object_info(sha1, NULL); + if (type < 0) + die("%s is not a valid object", sha1_to_hex(sha1)); + if (type != expect) + die("%s is not a valid '%s' object", sha1_to_hex(sha1), + typename(expect)); +} |