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authorFrédéric Danis <frederic.danis@collabora.com>2022-01-25 20:14:05 +0300
committerRichard Weinberger <richard@nod.at>2022-03-11 12:46:34 +0300
commitd2a0a616ab2246aab9527eeacf86a033679c8b22 (patch)
treef20757bf5efbfacc01c905f417b35fadc9eaf9fe /arch/um
parentb35507a4cfb26b7fcc0c97de6367828d5902bbba (diff)
downloadlinux-d2a0a616ab2246aab9527eeacf86a033679c8b22.tar.xz
um: Fix WRITE_ZEROES in the UBD Driver
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 <frederic.danis@collabora.com> Acked-by: Anton Ivanov <anton.ivanov@cambridgegreys.com> Signed-off-by: Richard Weinberger <richard@nod.at>
Diffstat (limited to 'arch/um')
-rw-r--r--arch/um/drivers/ubd_kern.c8
-rw-r--r--arch/um/include/shared/os.h1
-rw-r--r--arch/um/os-Linux/file.c9
3 files changed, 17 insertions, 1 deletions
diff --git a/arch/um/drivers/ubd_kern.c b/arch/um/drivers/ubd_kern.c
index 69d2d0049a61..b03269faef71 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 00214059d9ec..fafde1d5416e 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 e4421dbc4c36..fc4450db59bd 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);