From: Long Li <longli@xxxxxxxxxxxxx>
Introduce a function rqst_page_get_length to return the page offset and
length for a given page in smb_rqst. This function is to be used by
following patches.
Signed-off-by: Long Li <longli@xxxxxxxxxxxxx>
---
fs/cifs/cifsproto.h | 3 +++
fs/cifs/misc.c | 17 +++++++++++++++++
2 files changed, 20 insertions(+)
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7933c5f..89dda14 100644
--- a/fs/cifs/cifsproto.h
+++ b/fs/cifs/cifsproto.h
@@ -557,4 +557,7 @@ int cifs_alloc_hash(const char *name, struct crypto_shash **shash,
struct sdesc **sdesc);
void cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc);
+extern void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
+ unsigned int *len, unsigned int *offset);
+
#endif /* _CIFSPROTO_H */
diff --git a/fs/cifs/misc.c b/fs/cifs/misc.c
index 96849b5..e951417 100644
--- a/fs/cifs/misc.c
+++ b/fs/cifs/misc.c
@@ -905,3 +905,20 @@ cifs_free_hash(struct crypto_shash **shash, struct sdesc **sdesc)
crypto_free_shash(*shash);
*shash = NULL;
}
+
+/**
+ * rqst_page_get_length - obtain the length and offset for a page in smb_rqst
+ * Input: rqst - a smb_rqst, page - a page index for rqst
+ * Output: *len - the length for this page, *offset - the offset for this page
+ */
+void rqst_page_get_length(struct smb_rqst *rqst, unsigned int page,
+ unsigned int *len, unsigned int *offset)
+{
+ *len = rqst->rq_pagesz;
+ *offset = (page == 0) ? rqst->rq_offset : 0;
+
+ if (rqst->rq_npages == 1 || page == rqst->rq_npages-1)
+ *len = rqst->rq_tailsz;
+ else if (page == 0)
+ *len = rqst->rq_pagesz - rqst->rq_offset;
+}
--
2.7.4
