From 82b9ccd651eb90f28b4336554d82ea0ab9067c63 Mon Sep 17 00:00:00 2001 From: Sebastian Andrzej Siewior Date: Wed, 5 Dec 2012 12:08:29 +0100 Subject: 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 Signed-off-by: Nicholas Bellinger [bwh: Backported to 3.2: use task->task_sg{,_nents} for iteration] Signed-off-by: Ben Hutchings Cc: Rui Xiang Signed-off-by: Greg Kroah-Hartman --- drivers/target/target_core_file.c | 9 +++++++-- 1 file 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) { -- cgit v1.2.3