Mercurial > dovecot > core-2.2
view src/lib-fs/fs-sis.c @ 12479:5e82c5b1b4a9
fs-sis: Memory leak fix.
author | Timo Sirainen <tss@iki.fi> |
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date | Mon, 29 Nov 2010 19:13:37 +0000 |
parents | e3fe87b855ef |
children | 447bce266022 |
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/* Copyright (c) 2010 Dovecot authors, see the included COPYING file */ #include "lib.h" #include "str.h" #include "istream.h" #include "ostream-cmp.h" #include "fs-sis-common.h" struct sis_fs { struct fs fs; struct fs *super; }; struct sis_fs_file { struct fs_file file; struct fs_file *super; enum fs_open_mode open_mode; struct fs_file *hash_file; struct istream *hash_input; struct ostream *fs_output; char *hash, *hash_path; }; static void fs_sis_copy_error(struct sis_fs *fs) { fs_set_error(&fs->fs, "%s", fs_last_error(fs->super)); } static void fs_sis_file_copy_error(struct sis_fs_file *file) { struct sis_fs *fs = (struct sis_fs *)file->file.fs; fs_sis_copy_error(fs); } static struct fs * fs_sis_init(const char *args, const struct fs_settings *set) { struct sis_fs *fs; const char *p; fs = i_new(struct sis_fs, 1); fs->fs = fs_class_sis; if (*args == '\0') i_fatal("fs-sis: Parent filesystem not given as parameter"); p = strchr(args, ':'); if (p == NULL) fs->super = fs_init(args, "", set); else fs->super = fs_init(t_strdup_until(args, p), p+1, set); return &fs->fs; } static void fs_sis_deinit(struct fs *_fs) { struct sis_fs *fs = (struct sis_fs *)_fs; fs_deinit(&fs->super); i_free(fs); } static int fs_sis_open(struct fs *_fs, const char *path, enum fs_open_mode mode, enum fs_open_flags flags, struct fs_file **file_r) { struct sis_fs *fs = (struct sis_fs *)_fs; struct sis_fs_file *file; struct fs_file *super; const char *dir, *hash; if (mode == FS_OPEN_MODE_APPEND) { fs_set_error(_fs, "APPEND mode not supported"); return -1; } if (fs_open(fs->super, path, mode | flags, &super) < 0) { fs_sis_copy_error(fs); return -1; } switch (mode) { case FS_OPEN_MODE_RDONLY: *file_r = super; return 0; case FS_OPEN_MODE_CREATE: case FS_OPEN_MODE_REPLACE: break; case FS_OPEN_MODE_APPEND: i_unreached(); } if (fs_sis_path_parse(_fs, path, &dir, &hash) < 0) return -1; file = i_new(struct sis_fs_file, 1); file->file.fs = _fs; file->file.path = i_strdup(fs_file_path(super)); file->super = super; file->open_mode = mode; file->hash = i_strdup(hash); /* if hashes/<hash> already exists, open it */ file->hash_path = i_strdup_printf("%s/"HASH_DIR_NAME"/%s", dir, hash); if (fs_open(fs->super, file->hash_path, FS_OPEN_MODE_RDONLY, &file->hash_file) < 0 && errno != ENOENT) { i_error("fs-sis: Couldn't open hash file: %s", fs_last_error(fs->super)); } if (file->hash_file != NULL) { file->hash_input = fs_read_stream(file->hash_file, IO_BLOCK_SIZE); } *file_r = &file->file; return 0; } static void fs_sis_close(struct fs_file *_file) { struct sis_fs_file *file = (struct sis_fs_file *)_file; if (file->hash_file != NULL) { i_stream_unref(&file->hash_input); fs_close(&file->hash_file); } fs_close(&file->super); i_free(file->hash); i_free(file->hash_path); i_free(file->file.path); i_free(file); } static ssize_t fs_sis_read(struct fs_file *_file, void *buf, size_t size) { struct sis_fs_file *file = (struct sis_fs_file *)_file; ssize_t ret; if ((ret = fs_read(file->super, buf, size)) < 0) fs_sis_file_copy_error(file); return ret; } static struct istream * fs_sis_read_stream(struct fs_file *_file, size_t max_buffer_size) { struct sis_fs_file *file = (struct sis_fs_file *)_file; return fs_read_stream(file->super, max_buffer_size); } static bool fs_sis_try_link(struct sis_fs_file *file) { const char *path = fs_file_path(&file->file); const struct stat *st; struct stat st2; st = i_stream_stat(file->hash_input, FALSE); /* we can use the existing file */ if (fs_link(file->super->fs, file->hash_path, path) < 0) { if (errno != ENOENT && errno != EMLINK) i_error("fs-sis: %s", fs_last_error(file->super->fs)); /* failed to use link(), continue as if it hadn't been equal */ return FALSE; } if (fs_stat(file->super->fs, path, &st2) < 0) { i_error("fs-sis: %s", fs_last_error(file->super->fs)); if (fs_unlink(file->super->fs, path) < 0) i_error("fs-sis: %s", fs_last_error(file->super->fs)); return FALSE; } if (st->st_ino != st2.st_ino) { /* the hashes/ file was already replaced with something else */ if (fs_unlink(file->super->fs, path) < 0) i_error("fs-sis: %s", fs_last_error(file->super->fs)); return FALSE; } return TRUE; } static void fs_sis_replace_hash_file(struct sis_fs_file *file) { const char *hash_fname, *path = fs_file_path(&file->file); struct fs *super_fs = file->super->fs; string_t *temp_path; int ret; if (file->hash_input == NULL) { /* hash file didn't exist previously. we should be able to create it with link() */ if (fs_link(super_fs, path, file->hash_path) < 0) { if (errno == EEXIST) { /* the file was just created. it's probably a duplicate, but it's too much trouble trying to deduplicate it anymore */ } else { i_error("fs-sis: %s", fs_last_error(super_fs)); } } return; } temp_path = t_str_new(256); hash_fname = strrchr(file->hash_path, '/'); if (hash_fname == NULL) hash_fname = file->hash_path; else { str_append_n(temp_path, file->hash_path, (hash_fname-file->hash_path) + 1); hash_fname++; } str_printfa(temp_path, "%s%s.tmp", super_fs->set.temp_file_prefix, hash_fname); /* replace existing hash file atomically */ ret = fs_link(super_fs, path, str_c(temp_path)); if (ret < 0 && errno == EEXIST) { /* either someone's racing us or it's a stale file. try to continue. */ if (fs_unlink(super_fs, str_c(temp_path)) < 0 && errno != ENOENT) i_error("fs-sis: %s", fs_last_error(super_fs)); ret = fs_link(super_fs, path, str_c(temp_path)); } if (ret < 0) { i_error("fs-sis: %s", fs_last_error(super_fs)); return; } if (fs_rename(super_fs, str_c(temp_path), file->hash_path) < 0) { if (errno == ENOENT) { /* apparently someone else just renamed it. ignore. */ } else { i_error("fs-sis: %s", fs_last_error(super_fs)); } (void)fs_unlink(super_fs, str_c(temp_path)); } } static int fs_sis_write(struct fs_file *_file, const void *data, size_t size) { struct sis_fs_file *file = (struct sis_fs_file *)_file; if (file->hash_input != NULL && stream_cmp_block(file->hash_input, data, size) && i_stream_is_eof(file->hash_input)) { /* try to use existing file */ if (fs_sis_try_link(file)) return 0; } if (fs_write(file->super, data, size) < 0) { fs_sis_file_copy_error(file); return -1; } T_BEGIN { fs_sis_replace_hash_file(file); } T_END; return 0; } static void fs_sis_write_stream(struct fs_file *_file) { struct sis_fs_file *file = (struct sis_fs_file *)_file; i_assert(_file->output == NULL); file->fs_output = fs_write_stream(file->super); if (file->hash_input == NULL) _file->output = file->fs_output; else { /* compare if files are equal */ _file->output = o_stream_create_cmp(file->fs_output, file->hash_input); } } static int fs_sis_write_stream_finish(struct fs_file *_file, bool success) { struct sis_fs_file *file = (struct sis_fs_file *)_file; if (!success) { fs_write_stream_abort(file->super, &file->fs_output); fs_sis_file_copy_error(file); return -1; } if (file->hash_input != NULL && o_stream_cmp_equals(_file->output) && i_stream_is_eof(file->hash_input)) { if (fs_sis_try_link(file)) { fs_write_stream_abort(file->super, &file->fs_output); return 0; } } if (fs_write_stream_finish(file->super, &file->fs_output) < 0) { fs_sis_file_copy_error(file); return -1; } T_BEGIN { fs_sis_replace_hash_file(file); } T_END; return 0; } static int fs_sis_lock(struct fs_file *_file, unsigned int secs, struct fs_lock **lock_r) { struct sis_fs_file *file = (struct sis_fs_file *)_file; if (fs_lock(file->super, secs, lock_r) < 0) { fs_sis_file_copy_error(file); return -1; } return 0; } static void fs_sis_unlock(struct fs_lock *_lock ATTR_UNUSED) { i_unreached(); } static int fs_sis_fdatasync(struct fs_file *_file) { struct sis_fs_file *file = (struct sis_fs_file *)_file; if (fs_fdatasync(file->super) < 0) { fs_sis_file_copy_error(file); return -1; } return 0; } static int fs_sis_exists(struct fs *_fs, const char *path) { struct sis_fs *fs = (struct sis_fs *)_fs; if (fs_exists(fs->super, path) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } static int fs_sis_stat(struct fs *_fs, const char *path, struct stat *st_r) { struct sis_fs *fs = (struct sis_fs *)_fs; if (fs_stat(fs->super, path, st_r) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } static int fs_sis_link(struct fs *_fs, const char *src, const char *dest) { struct sis_fs *fs = (struct sis_fs *)_fs; if (fs_link(fs->super, src, dest) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } static int fs_sis_rename(struct fs *_fs, const char *src, const char *dest) { struct sis_fs *fs = (struct sis_fs *)_fs; if (fs_rename(fs->super, src, dest) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } static int fs_sis_unlink(struct fs *_fs, const char *path) { struct sis_fs *fs = (struct sis_fs *)_fs; T_BEGIN { fs_sis_try_unlink_hash_file(&fs->fs, fs->super, path); } T_END; if (fs_unlink(fs->super, path) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } static int fs_sis_rmdir(struct fs *_fs, const char *path) { struct sis_fs *fs = (struct sis_fs *)_fs; if (fs_rmdir(fs->super, path) < 0) { fs_sis_copy_error(fs); return -1; } return 0; } struct fs fs_class_sis = { .name = "sis", .v = { fs_sis_init, fs_sis_deinit, fs_sis_open, fs_sis_close, fs_sis_read, fs_sis_read_stream, fs_sis_write, fs_sis_write_stream, fs_sis_write_stream_finish, fs_sis_lock, fs_sis_unlock, fs_sis_fdatasync, fs_sis_exists, fs_sis_stat, fs_sis_link, fs_sis_rename, fs_sis_unlink, fs_sis_rmdir } };