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authorLong Li <longli@microsoft.com>2018-05-30 12:47:58 -0700
committerSteve French <stfrench@microsoft.com>2018-06-05 17:41:00 -0500
commit7b7f2bdf829ecf21845c0a571847ea18c6934970 (patch)
tree216f146f9c716800d304ed0ac329fb2ad91977b0 /fs/cifs
parentc06a0f2dff704d9f734ff0d3d4812ccfc46ed8d0 (diff)
downloadlinux-7b7f2bdf829ecf21845c0a571847ea18c6934970.tar.bz2
CIFS: Introduce helper function to get page offset and length in smb_rqst
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@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/cifs')
-rw-r--r--fs/cifs/cifsproto.h3
-rw-r--r--fs/cifs/misc.c17
2 files changed, 20 insertions, 0 deletions
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h
index 7f0c773d5f6b..84765c8764bf 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 aba3fc3058da..f90d4ad6624c 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;
+}