From 144bde78e9ff22d53682ef46b3d9845b83e70f54 Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 23 Apr 2005 11:09:32 -0700 Subject: Use O_NOATIME when opening the sha1 files. We really don't care about atime, and it sucks to dirty the inode cache just for it. This is more than a one-liner only because we need to be able to clear the O_NOATIME flag in case some of the objects are owned by others (in which case open will return EPERM), and because not everybody has the O_NOATIME flag. --- sha1_file.c | 29 ++++++++++++++++++++++++++--- 1 file changed, 26 insertions(+), 3 deletions(-) (limited to 'sha1_file.c') diff --git a/sha1_file.c b/sha1_file.c index 6f7228e106..66308ede85 100644 --- a/sha1_file.c +++ b/sha1_file.c @@ -11,6 +11,16 @@ const char *sha1_file_directory = NULL; +#ifndef O_NOATIME +#if defined(__linux__) && (defined(__i386__) || defined(__PPC__)) +#define O_NOATIME 01000000 +#else +#define O_NOATIME 0 +#endif +#endif + +static unsigned int sha1_file_open_flag = O_NOATIME; + static unsigned hexval(char c) { if (c >= '0' && c <= '9') @@ -96,13 +106,26 @@ int check_sha1_signature(unsigned char *sha1, void *map, unsigned long size, con void *map_sha1_file(const unsigned char *sha1, unsigned long *size) { char *filename = sha1_file_name(sha1); - int fd = open(filename, O_RDONLY); struct stat st; void *map; + int fd; + fd = open(filename, O_RDONLY | sha1_file_open_flag); if (fd < 0) { - perror(filename); - return NULL; + /* See if it works without O_NOATIME */ + switch (sha1_file_open_flag) { + default: + fd = open(filename, O_RDONLY); + if (fd >= 0) + break; + /* Fallthrough */ + case 0: + perror(filename); + return NULL; + } + + /* If it failed once, it will probably fail again. Stop using O_NOATIME */ + sha1_file_open_flag = 0; } if (fstat(fd, &st) < 0) { close(fd); -- cgit v1.2.3