diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/bindfs.c | 75 |
1 files changed, 54 insertions, 21 deletions
diff --git a/src/bindfs.c b/src/bindfs.c index fff3a16..3c430a1 100644 --- a/src/bindfs.c +++ b/src/bindfs.c @@ -72,11 +72,14 @@ #include <sys/xattr.h> #endif +#ifdef __linux__ #include <sys/mman.h> #include <fcntl.h> - -#ifdef __LINUX__ #include <linux/fs.h> // For BLKGETSIZE64 + +#ifndef O_DIRECT +#define O_DIRECT 00040000 /* direct disk access hint */ +#endif #endif #include <fuse.h> @@ -99,10 +102,6 @@ #define XATTR_APPLE_PREFIX "com.apple." #endif -#ifndef O_DIRECT -#define O_DIRECT 00040000 /* direct disk access hint */ -#endif - /* We pessimistically assume signed uid_t and gid_t in our overflow checks, mostly because supporting both cases would require a bunch more code. */ static const uid_t UID_T_MAX = ((1LL << (sizeof(uid_t)*8-1)) - 1); @@ -194,10 +193,14 @@ static struct Settings { int enable_lock_forwarding; int enable_ioctl; - + uid_t uid_offset; gid_t gid_offset; +#ifdef __linux__ + size_t linux_page_size; +#endif + } settings; @@ -227,6 +230,10 @@ static int apply_gid_offset(gid_t *gid); static int unapply_uid_offset(uid_t *uid); static int unapply_gid_offset(gid_t *gid); +#ifdef __linux__ +static size_t round_up_buffer_size_for_direct_io(size_t size); +#endif + /* FUSE callbacks */ static void *bindfs_init(); static void bindfs_destroy(void *private_data); @@ -388,15 +395,15 @@ static int getattr_common(const char *procpath, struct stat *stbuf) /* Block files as regular files. */ if (settings.block_devices_as_files && S_ISBLK(stbuf->st_mode)) { stbuf->st_mode ^= S_IFBLK | S_IFREG; // Flip both bits -#ifdef __LINUX__ + int fd = open(procpath, O_RDONLY); +#ifdef __linux__ uint64_t size; - ioctl(file, BLKGETSIZE64, &size); + ioctl(fd, BLKGETSIZE64, &size); stbuf->st_size = (off_t)size; if (stbuf->st_size < 0) { // Underflow return -EOVERFLOW; } #else - int fd = open(procpath, O_RDONLY); if (fd == -1) { return -errno; } @@ -592,6 +599,21 @@ static int unapply_gid_offset(gid_t *gid) { return 1; } +#ifdef __linux__ +static size_t round_up_buffer_size_for_direct_io(size_t size) +{ + // `man 2 open` says this should be block-size aligned and that there's no + // general way to determine this. Empirically the page size should be good enough. + // See also: Pull Request #74 + size_t page_size = settings.linux_page_size; + size_t rem = size % page_size; + if (rem == 0) { + return size; + } + return size - rem + page_size; +} +#endif + static void *bindfs_init() { @@ -1105,29 +1127,33 @@ static int bindfs_read(const char *path, char *buf, size_t size, off_t offset, int res; (void) path; - char * target_buf = buf; + char *target_buf = buf; if (settings.read_limiter) { rate_limiter_wait(settings.read_limiter, size); } - unsigned int page_size = sysconf(_SC_PAGESIZE); +#ifdef __linux__ + size_t mmap_size = 0; if (fi->flags & O_DIRECT) { - // allocate 512 bytes aligned buffer for direct io to work - target_buf = mmap(NULL, ((page_size - 1 + size) / page_size) * page_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + mmap_size = round_up_buffer_size_for_direct_io(size); + target_buf = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); if (target_buf == MAP_FAILED) { return -ENOMEM; } } +#endif res = pread(fi->fh, target_buf, size, offset); if (res == -1) res = -errno; +#ifdef __linux__ if (target_buf != buf) { memcpy(buf, target_buf, size); - munmap(target_buf, ((page_size - 1 + size) / page_size) * page_size); + munmap(target_buf, mmap_size); } +#endif return res; } @@ -1137,29 +1163,33 @@ static int bindfs_write(const char *path, const char *buf, size_t size, { int res; (void) path; - char * source_buf = buf; + char *source_buf = (char*)buf; if (settings.write_limiter) { rate_limiter_wait(settings.write_limiter, size); } - unsigned int page_size = sysconf(_SC_PAGESIZE); +#ifdef __linux__ + size_t mmap_size = 0; if (fi->flags & O_DIRECT) { - // allocate 512 bytes aligned buffer for direct io to work - source_buf = mmap(NULL, ((page_size - 1 + size) / page_size) * page_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); + mmap_size = round_up_buffer_size_for_direct_io(size); + source_buf = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_ANONYMOUS | MAP_PRIVATE, 0, 0); if (source_buf == MAP_FAILED) { return -ENOMEM; } memcpy(source_buf, buf, size); } +#endif res = pwrite(fi->fh, source_buf, size, offset); if (res == -1) res = -errno; - if (source_buf != buf) { - munmap(source_buf, ((page_size - 1 + size) / page_size) * page_size); +#ifdef __linux__ + if (source_buf != buf) { + munmap(source_buf, mmap_size); } +#endif return res; } @@ -2076,6 +2106,9 @@ int main(int argc, char *argv[]) settings.enable_ioctl = 0; settings.uid_offset = 0; settings.gid_offset = 0; +#ifdef __linux__ + settings.linux_page_size = sysconf(_SC_PAGESIZE); +#endif atexit(&atexit_func); |