From bdd29249a882e599e5e365536372d08dee398cd4 Mon Sep 17 00:00:00 2001 From: Harald Hoyer Date: Fri, 19 Apr 2013 13:44:56 +0200 Subject: [PATCH] Reintroduce f_type comparison macro This reverts commit 4826f0b7b5c0aefa08b8cc7ef64d69027f84da2c. Because statfs.t_type can be int on some architecures, we have to cast the const magic to the type, otherwise the compiler warns about signed/unsigned comparison, because the magic can be 32 bit unsigned. statfs(2) man page is also wrong on some systems, because f_type is not __SWORD_TYPE on some architecures. The following program: int main(int argc, char**argv) { struct statfs s; statfs(argv[1], &s); printf("sizeof(f_type) = %d\n", sizeof(s.f_type)); printf("sizeof(__SWORD_TYPE) = %d\n", sizeof(__SWORD_TYPE)); printf("sizeof(long) = %d\n", sizeof(long)); printf("sizeof(int) = %d\n", sizeof(int)); if (sizeof(s.f_type) == sizeof(int)) { printf("f_type = 0x%x\n", s.f_type); } else { printf("f_type = 0x%lx\n", s.f_type); } return 0; } executed on s390x gives for a btrfs: sizeof(f_type) = 4 sizeof(__SWORD_TYPE) = 8 sizeof(long) = 8 sizeof(int) = 4 f_type = 0x9123683e --- src/journal/sd-journal.c | 10 +++++----- src/readahead/readahead-collect.c | 2 +- src/shared/macro.h | 7 +++++++ src/shared/util.c | 5 +++-- 4 files changed, 16 insertions(+), 8 deletions(-) diff --git a/src/journal/sd-journal.c b/src/journal/sd-journal.c index e021d9815..15239b568 100644 --- a/src/journal/sd-journal.c +++ b/src/journal/sd-journal.c @@ -1251,11 +1251,11 @@ static void check_network(sd_journal *j, int fd) { return; j->on_network = - sfs.f_type == (__SWORD_TYPE) CIFS_MAGIC_NUMBER || - sfs.f_type == (__SWORD_TYPE) CODA_SUPER_MAGIC || - sfs.f_type == (__SWORD_TYPE) NCP_SUPER_MAGIC || - sfs.f_type == (__SWORD_TYPE) NFS_SUPER_MAGIC || - sfs.f_type == (__SWORD_TYPE) SMB_SUPER_MAGIC; + F_TYPE_CMP(sfs.f_type, CIFS_MAGIC_NUMBER) || + F_TYPE_CMP(sfs.f_type, CODA_SUPER_MAGIC) || + F_TYPE_CMP(sfs.f_type, NCP_SUPER_MAGIC) || + F_TYPE_CMP(sfs.f_type, NFS_SUPER_MAGIC) || + F_TYPE_CMP(sfs.f_type, SMB_SUPER_MAGIC); } static int add_file(sd_journal *j, const char *prefix, const char *filename) { diff --git a/src/readahead/readahead-collect.c b/src/readahead/readahead-collect.c index 02ecbe56c..75ec5b70c 100644 --- a/src/readahead/readahead-collect.c +++ b/src/readahead/readahead-collect.c @@ -505,7 +505,7 @@ done: on_ssd = fs_on_ssd(root) > 0; log_debug("On SSD: %s", yes_no(on_ssd)); - on_btrfs = statfs(root, &sfs) >= 0 && sfs.f_type == (__SWORD_TYPE) BTRFS_SUPER_MAGIC; + on_btrfs = statfs(root, &sfs) >= 0 && F_TYPE_CMP(sfs.f_type, BTRFS_SUPER_MAGIC); log_debug("On btrfs: %s", yes_no(on_btrfs)); if (asprintf(&pack_fn_new, "%s/.readahead.new", root) < 0) { diff --git a/src/shared/macro.h b/src/shared/macro.h index 9bf81dc3c..ac61b4958 100644 --- a/src/shared/macro.h +++ b/src/shared/macro.h @@ -264,6 +264,13 @@ do { \ } \ } while(false) + /* Because statfs.t_type can be int on some architecures, we have to cast + * the const magic to the type, otherwise the compiler warns about + * signed/unsigned comparison, because the magic can be 32 bit unsigned. + */ +#define F_TYPE_CMP(a, b) (a == (typeof(a)) b) + + /* Returns the number of chars needed to format variables of the * specified type as a decimal string. Adds in extra space for a * negative '-' prefix. */ diff --git a/src/shared/util.c b/src/shared/util.c index 5d0327261..1fc6c5aa1 100644 --- a/src/shared/util.c +++ b/src/shared/util.c @@ -2779,8 +2779,9 @@ int rm_rf_children_dangerous(int fd, bool only_dirs, bool honour_sticky, struct static int is_temporary_fs(struct statfs *s) { assert(s); - return s->f_type == (__SWORD_TYPE) TMPFS_MAGIC || - s->f_type == (__SWORD_TYPE) RAMFS_MAGIC; + return + F_TYPE_CMP(s->f_type, TMPFS_MAGIC) || + F_TYPE_CMP(s->f_type, RAMFS_MAGIC); } int rm_rf_children(int fd, bool only_dirs, bool honour_sticky, struct stat *root_dev) { -- 2.30.2