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authorSebastian Andrzej Siewior <bigeasy@linutronix.de>2012-12-05 12:08:29 +0100
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-11 12:04:21 -0700
commit82b9ccd651eb90f28b4336554d82ea0ab9067c63 (patch)
tree297a05c4eaff132a27645ef59f35f9736321fdb7
parent2b102fcef6a89e1bc0b7116125a82b3b03d57d89 (diff)
downloadlinux-linaro-stable-82b9ccd651eb90f28b4336554d82ea0ab9067c63.tar.gz
target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping
commit 40ff2c3b3da35dd3a00ac6722056a59b4b3f2caf upstream. This patch changes vectored file I/O to use kmap + kunmap when mapping incoming SGL memory -> struct iovec in order to properly support 32-bit highmem configurations. This is because an extra bounce buffer may be required when processing scatterlist pages allocated with GFP_KERNEL. Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org> [bwh: Backported to 3.2: use task->task_sg{,_nents} for iteration] Signed-off-by: Ben Hutchings <ben@decadent.org.uk> Cc: Rui Xiang <rui.xiang@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--drivers/target/target_core_file.c9
1 files changed, 7 insertions, 2 deletions
diff --git a/drivers/target/target_core_file.c b/drivers/target/target_core_file.c
index a251efd783de..f44459a2a7c5 100644
--- a/drivers/target/target_core_file.c
+++ b/drivers/target/target_core_file.c
@@ -299,7 +299,7 @@ static int fd_do_readv(struct se_task *task)
for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
iov[i].iov_len = sg->length;
- iov[i].iov_base = sg_virt(sg);
+ iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
}
old_fs = get_fs();
@@ -307,6 +307,8 @@ static int fd_do_readv(struct se_task *task)
ret = vfs_readv(fd, &iov[0], task->task_sg_nents, &pos);
set_fs(old_fs);
+ for_each_sg(task->task_sg, sg, task->task_sg_nents, i)
+ kunmap(sg_page(sg));
kfree(iov);
/*
* Return zeros and GOOD status even if the READ did not return
@@ -352,7 +354,7 @@ static int fd_do_writev(struct se_task *task)
for_each_sg(task->task_sg, sg, task->task_sg_nents, i) {
iov[i].iov_len = sg->length;
- iov[i].iov_base = sg_virt(sg);
+ iov[i].iov_base = kmap(sg_page(sg)) + sg->offset;
}
old_fs = get_fs();
@@ -360,6 +362,9 @@ static int fd_do_writev(struct se_task *task)
ret = vfs_writev(fd, &iov[0], task->task_sg_nents, &pos);
set_fs(old_fs);
+ for_each_sg(task->task_sg, sg, task->task_sg_nents, i)
+ kunmap(sg_page(sg));
+
kfree(iov);
if (ret < 0 || ret != task->task_size) {