Mercurial > dovecot > core-2.2
view src/lib/file-set-size.c @ 19604:c996bc091c6b
master: Do not close stdout if going foreground
This lets one to use /dev/stdout for logging. Mainly
useful for testing purposes where we can generate
log output to stdout and use tee to write it to a
file for later examination.
author | Aki Tuomi <aki.tuomi@dovecot.fi> |
---|---|
date | Mon, 18 Jan 2016 15:50:23 +0200 |
parents | 0f22db71df7a |
children | 59437f8764c6 |
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/* Copyright (c) 2002-2016 Dovecot authors, see the included COPYING file */ #ifdef HAVE_CONFIG_H # include "config.h" #endif #ifdef HAVE_POSIX_FALLOCATE # define _XOPEN_SOURCE 600 /* Required by glibc, breaks Solaris 9 */ #endif #define _GNU_SOURCE /* for fallocate() */ #include "lib.h" #include "file-set-size.h" #include <unistd.h> #include <fcntl.h> #include <sys/stat.h> #if defined(HAVE_LINUX_FALLOC_H) && !defined(FALLOC_FL_KEEP_SIZE) /* Legacy Linux does not have the FALLOC_FL_* flags under fcntl.h */ # include <linux/falloc.h> #endif int file_set_size(int fd, off_t size) { #ifdef HAVE_POSIX_FALLOCATE static bool posix_fallocate_supported = TRUE; #endif char block[IO_BLOCK_SIZE]; off_t offset; ssize_t ret; struct stat st; i_assert(size >= 0); if (fstat(fd, &st) < 0) { i_error("fstat() failed: %m"); return -1; } if (size < st.st_size) { if (ftruncate(fd, size) < 0) { i_error("ftruncate() failed: %m"); return -1; } return 0; } if (size == st.st_size) return 0; #ifdef HAVE_POSIX_FALLOCATE if (posix_fallocate_supported) { int err; err = posix_fallocate(fd, st.st_size, size - st.st_size); if (err == 0) return 0; if (err != EINVAL /* Solaris */ && err != EOPNOTSUPP /* AOX */) { if (!ENOSPACE(err)) i_error("posix_fallocate() failed: %m"); return -1; } /* Not supported by kernel, fallback to writing. */ posix_fallocate_supported = FALSE; } #endif /* start growing the file */ offset = st.st_size; memset(block, 0, I_MIN((ssize_t)sizeof(block), size - offset)); while (offset < size) { ret = pwrite(fd, block, I_MIN((ssize_t)sizeof(block), size - offset), offset); if (ret < 0) { if (!ENOSPACE(errno)) i_error("pwrite() failed: %m"); return -1; } offset += ret; } return 0; } int file_preallocate(int fd ATTR_UNUSED, off_t size ATTR_UNUSED) { #if defined(HAVE_FALLOCATE) && defined(FALLOC_FL_KEEP_SIZE) /* Linux */ if (fallocate(fd, FALLOC_FL_KEEP_SIZE, 0, size) < 0) return errno == ENOSYS ? 0 : -1; return 1; #elif defined (F_PREALLOCATE) /* OSX */ fstore_t fs; memset(&fs, 0, sizeof(fs)); fs.fst_flags = F_ALLOCATECONTIG; fs.fst_posmode = F_PEOFPOSMODE; fs.fst_offset = 0; fs.fst_length = size; fs.fst_bytesalloc = 0; if (fcntl(fd, F_PREALLOCATE, &fs) < 0) return -1; return fs.fst_bytesalloc > 0 ? 1 : 0; #else return 0; #endif }