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author | Lennart Poettering <lennart@poettering.net> | 2022-02-14 17:18:32 +0100 |
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committer | Lennart Poettering <lennart@poettering.net> | 2022-02-14 17:27:09 +0100 |
commit | 38db6211b5aa6e2fb65883ae3353914e82f5bef1 (patch) | |
tree | 7d02b343b8d7d4ea05d78a0d3c16f00e963fd3a5 /src/basic/stat-util.c | |
parent | d74da762a3b1edbb7935c3b3a229db601f734125 (diff) | |
download | systemd-38db6211b5aa6e2fb65883ae3353914e82f5bef1.tar.gz |
stat-util: add helper stat_inode_same() for comparing stat's st_dev/st_ino in one
We do this all over the place, hence let's add a simple helper that does
this and particularly carefully and thoroughly.
Diffstat (limited to 'src/basic/stat-util.c')
-rw-r--r-- | src/basic/stat-util.c | 18 |
1 files changed, 13 insertions, 5 deletions
diff --git a/src/basic/stat-util.c b/src/basic/stat-util.c index c2269844f8..298f46440f 100644 --- a/src/basic/stat-util.c +++ b/src/basic/stat-util.c @@ -417,6 +417,18 @@ int proc_mounted(void) { return r; } +bool stat_inode_same(const struct stat *a, const struct stat *b) { + + /* Returns if the specified stat structure references the same (though possibly modified) inode. Does + * a thorough check, comparing inode nr, backing device and if the inode is still of the same type. */ + + return a && b && + (a->st_mode & S_IFMT) != 0 && /* We use the check for .st_mode if the structure was ever initialized */ + ((a->st_mode ^ b->st_mode) & S_IFMT) == 0 && /* same inode type */ + a->st_dev == b->st_dev && + a->st_ino == b->st_ino; +} + bool stat_inode_unmodified(const struct stat *a, const struct stat *b) { /* Returns if the specified stat structures reference the same, unmodified inode. This check tries to @@ -428,14 +440,10 @@ bool stat_inode_unmodified(const struct stat *a, const struct stat *b) { * about contents of the file. The purpose here is to detect file contents changes, and nothing * else. */ - return a && b && - (a->st_mode & S_IFMT) != 0 && /* We use the check for .st_mode if the structure was ever initialized */ - ((a->st_mode ^ b->st_mode) & S_IFMT) == 0 && /* same inode type */ + return stat_inode_same(a, b) && a->st_mtim.tv_sec == b->st_mtim.tv_sec && a->st_mtim.tv_nsec == b->st_mtim.tv_nsec && (!S_ISREG(a->st_mode) || a->st_size == b->st_size) && /* if regular file, compare file size */ - a->st_dev == b->st_dev && - a->st_ino == b->st_ino && (!(S_ISCHR(a->st_mode) || S_ISBLK(a->st_mode)) || a->st_rdev == b->st_rdev); /* if device node, also compare major/minor, because we can */ } |