diff options
author | Anton Ivanov <aivanov@brocade.com> | 2015-12-21 21:54:00 +0300 |
---|---|---|
committer | Richard Weinberger <richard@nod.at> | 2016-01-10 23:49:48 +0300 |
commit | 8c6157b6b30a765ec233a1be5f9446f24a5283de (patch) | |
tree | 81128a9f0252bd4075b6093cf5408eab19d45ce4 /arch | |
parent | 470a166e8c5a4da4be88545b1c4dde308abac5b2 (diff) | |
download | linux-8c6157b6b30a765ec233a1be5f9446f24a5283de.tar.xz |
um: Update UBD to use pread/pwrite family of functions
This decreases the number of syscalls per read/write by half.
Signed-off-by: Anton Ivanov <aivanov@brocade.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch')
-rw-r--r-- | arch/um/drivers/ubd_kern.c | 27 | ||||
-rw-r--r-- | arch/um/include/shared/os.h | 2 | ||||
-rw-r--r-- | arch/um/os-Linux/file.c | 19 |
3 files changed, 26 insertions, 22 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index e8ab93c3e638..39ba20755e03 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -535,11 +535,7 @@ static int read_cow_bitmap(int fd, void *buf, int offset, int len) { int err; - err = os_seek_file(fd, offset); - if (err < 0) - return err; - - err = os_read_file(fd, buf, len); + err = os_pread_file(fd, buf, len, offset); if (err < 0) return err; @@ -1377,14 +1373,8 @@ static int update_bitmap(struct io_thread_req *req) if(req->cow_offset == -1) return 0; - n = os_seek_file(req->fds[1], req->cow_offset); - if(n < 0){ - printk("do_io - bitmap lseek failed : err = %d\n", -n); - return 1; - } - - n = os_write_file(req->fds[1], &req->bitmap_words, - sizeof(req->bitmap_words)); + n = os_pwrite_file(req->fds[1], &req->bitmap_words, + sizeof(req->bitmap_words), req->cow_offset); if(n != sizeof(req->bitmap_words)){ printk("do_io - bitmap update failed, err = %d fd = %d\n", -n, req->fds[1]); @@ -1399,7 +1389,6 @@ static void do_io(struct io_thread_req *req) char *buf; unsigned long len; int n, nsectors, start, end, bit; - int err; __u64 off; if (req->op == UBD_FLUSH) { @@ -1428,18 +1417,12 @@ static void do_io(struct io_thread_req *req) len = (end - start) * req->sectorsize; buf = &req->buffer[start * req->sectorsize]; - err = os_seek_file(req->fds[bit], off); - if(err < 0){ - printk("do_io - lseek failed : err = %d\n", -err); - req->error = 1; - return; - } if(req->op == UBD_READ){ n = 0; do { buf = &buf[n]; len -= n; - n = os_read_file(req->fds[bit], buf, len); + n = os_pread_file(req->fds[bit], buf, len, off); if (n < 0) { printk("do_io - read failed, err = %d " "fd = %d\n", -n, req->fds[bit]); @@ -1449,7 +1432,7 @@ static void do_io(struct io_thread_req *req) } while((n < len) && (n != 0)); if (n < len) memset(&buf[n], 0, len - n); } else { - n = os_write_file(req->fds[bit], buf, len); + n = os_pwrite_file(req->fds[bit], buf, len, off); if(n != len){ printk("do_io - write failed err = %d " "fd = %d\n", -n, req->fds[bit]); diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 868e6c3f83dd..7a04ddd85334 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -146,6 +146,8 @@ extern int os_read_file(int fd, void *buf, int len); extern int os_write_file(int fd, const void *buf, int count); extern int os_sync_file(int fd); extern int os_file_size(const char *file, unsigned long long *size_out); +extern int os_pread_file(int fd, void *buf, int len, unsigned long long offset); +extern int os_pwrite_file(int fd, const void *buf, int count, unsigned long long offset); extern int os_file_modtime(const char *file, unsigned long *modtime); extern int os_pipe(int *fd, int stream, int close_on_exec); extern int os_set_fd_async(int fd); diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c index 26e0164895e4..2db18cbbb0ea 100644 --- a/arch/um/os-Linux/file.c +++ b/arch/um/os-Linux/file.c @@ -264,6 +264,15 @@ int os_read_file(int fd, void *buf, int len) return n; } +int os_pread_file(int fd, void *buf, int len, unsigned long long offset) +{ + int n = pread(fd, buf, len, offset); + + if (n < 0) + return -errno; + return n; +} + int os_write_file(int fd, const void *buf, int len) { int n = write(fd, (void *) buf, len); @@ -282,6 +291,16 @@ int os_sync_file(int fd) return n; } +int os_pwrite_file(int fd, const void *buf, int len, unsigned long long offset) +{ + int n = pwrite(fd, (void *) buf, len, offset); + + if (n < 0) + return -errno; + return n; +} + + int os_file_size(const char *file, unsigned long long *size_out) { struct uml_stat buf; |