From d2a0a616ab2246aab9527eeacf86a033679c8b22 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Fr=C3=A9d=C3=A9ric=20Danis?= Date: Tue, 25 Jan 2022 18:14:05 +0100 Subject: [PATCH] um: Fix WRITE_ZEROES in the UBD Driver MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Call to fallocate with FALLOC_FL_PUNCH_HOLE on a device backed by a sparse file can end up by missing data, zeroes data range, if the underlying file is used with a tool like bmaptool which will referenced only used spaces. Signed-off-by: Frédéric Danis Acked-by: Anton Ivanov Signed-off-by: Richard Weinberger --- arch/um/drivers/ubd_kern.c | 8 +++++++- arch/um/include/shared/os.h | 1 + arch/um/os-Linux/file.c | 9 +++++++++ 3 files changed, 17 insertions(+), 1 deletion(-) diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c index 69d2d00..b03269f 100644 --- a/arch/um/drivers/ubd_kern.c +++ b/arch/um/drivers/ubd_kern.c @@ -1526,13 +1526,19 @@ static void do_io(struct io_thread_req *req, struct io_desc *desc) } break; case REQ_OP_DISCARD: - case REQ_OP_WRITE_ZEROES: n = os_falloc_punch(req->fds[bit], off, len); if (n) { req->error = map_error(-n); return; } break; + case REQ_OP_WRITE_ZEROES: + n = os_falloc_zeroes(req->fds[bit], off, len); + if (n) { + req->error = map_error(-n); + return; + } + break; default: WARN_ON_ONCE(1); req->error = BLK_STS_NOTSUPP; diff --git a/arch/um/include/shared/os.h b/arch/um/include/shared/os.h index 0021405..fafde1d 100644 --- a/arch/um/include/shared/os.h +++ b/arch/um/include/shared/os.h @@ -168,6 +168,7 @@ extern unsigned os_major(unsigned long long dev); extern unsigned os_minor(unsigned long long dev); extern unsigned long long os_makedev(unsigned major, unsigned minor); extern int os_falloc_punch(int fd, unsigned long long offset, int count); +extern int os_falloc_zeroes(int fd, unsigned long long offset, int count); extern int os_eventfd(unsigned int initval, int flags); extern int os_sendmsg_fds(int fd, const void *buf, unsigned int len, const int *fds, unsigned int fds_num); diff --git a/arch/um/os-Linux/file.c b/arch/um/os-Linux/file.c index e4421db..fc4450d 100644 --- a/arch/um/os-Linux/file.c +++ b/arch/um/os-Linux/file.c @@ -625,6 +625,15 @@ int os_falloc_punch(int fd, unsigned long long offset, int len) return n; } +int os_falloc_zeroes(int fd, unsigned long long offset, int len) +{ + int n = fallocate(fd, FALLOC_FL_ZERO_RANGE|FALLOC_FL_KEEP_SIZE, offset, len); + + if (n < 0) + return -errno; + return n; +} + int os_eventfd(unsigned int initval, int flags) { int fd = eventfd(initval, flags); -- 2.7.4