| From | Herton Ronaldo Krzesinski <> | Subject | [PATCH 081/222] target/file: Fix 32-bit highmem breakage for SGL -> iovec mapping | Date | Wed, 16 Jan 2013 13:54:41 -0200 |
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3.5.7.3 -stable review patch. If anyone has any objections, please let me know.
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From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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> Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com> --- 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 c0d6e6d..d2414e9 100644 --- a/drivers/target/target_core_file.c +++ b/drivers/target/target_core_file.c @@ -279,7 +279,7 @@ static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl, for_each_sg(sgl, sg, sgl_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(); @@ -287,6 +287,8 @@ static int fd_do_readv(struct se_cmd *cmd, struct scatterlist *sgl, ret = vfs_readv(fd, &iov[0], sgl_nents, &pos); set_fs(old_fs); + for_each_sg(sgl, sg, sgl_nents, i) + kunmap(sg_page(sg)); kfree(iov); /* * Return zeros and GOOD status even if the READ did not return @@ -332,7 +334,7 @@ static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl, for_each_sg(sgl, sg, sgl_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(); @@ -340,6 +342,9 @@ static int fd_do_writev(struct se_cmd *cmd, struct scatterlist *sgl, ret = vfs_writev(fd, &iov[0], sgl_nents, &pos); set_fs(old_fs); + for_each_sg(sgl, sg, sgl_nents, i) + kunmap(sg_page(sg)); + kfree(iov); if (ret < 0 || ret != cmd->data_length) { -- 1.7.9.5
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