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authorJeff Layton <jlayton@redhat.com>2018-01-30 15:32:21 -0500
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 08:43:35 -0800
commitc0cef30e4ff0dc025f4a1660b8f0ba43ed58426e (patch)
tree8be4d90a4eb4f64bf0569e7b9e9bf88112722776
parent3da90b159b146672f830bcd2489dd3a1f4e9e089 (diff)
iversion: make inode_cmp_iversion{+raw} return bool instead of s64
As Linus points out: The inode_cmp_iversion{+raw}() functions are pure and utter crap. Why? You say that they return 0/negative/positive, but they do so in a completely broken manner. They return that ternary value as the sequence number difference in a 's64', which means that if you actually care about that ternary value, and do the *sane* thing that the kernel-doc of the function implies is the right thing, you would do int cmp = inode_cmp_iversion(inode, old); if (cmp < 0 ... and as a result you get code that looks sane, but that doesn't actually *WORK* right. Since none of the callers actually care about the ternary value here, convert the inode_cmp_iversion{+raw} functions to just return a boolean value (false for matching, true for non-matching). This matches the existing use of these functions just fine, and makes it simple to convert them to return a ternary value in the future if we grow callers that need it. With this change we can also reimplement inode_cmp_iversion in a simpler way using inode_peek_iversion. Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--include/linux/iversion.h20
1 files changed, 8 insertions, 12 deletions
diff --git a/include/linux/iversion.h b/include/linux/iversion.h
index 858463fca249..3d2fd06495ec 100644
--- a/include/linux/iversion.h
+++ b/include/linux/iversion.h
@@ -309,13 +309,13 @@ inode_query_iversion(struct inode *inode)
* @inode: inode to check
* @old: old value to check against its i_version
*
- * Compare the current raw i_version counter with a previous one. Returns 0 if
- * they are the same or non-zero if they are different.
+ * Compare the current raw i_version counter with a previous one. Returns false
+ * if they are the same or true if they are different.
*/
-static inline s64
+static inline bool
inode_cmp_iversion_raw(const struct inode *inode, u64 old)
{
- return (s64)inode_peek_iversion_raw(inode) - (s64)old;
+ return inode_peek_iversion_raw(inode) != old;
}
/**
@@ -323,19 +323,15 @@ inode_cmp_iversion_raw(const struct inode *inode, u64 old)
* @inode: inode to check
* @old: old value to check against its i_version
*
- * Compare an i_version counter with a previous one. Returns 0 if they are
- * the same, a positive value if the one in the inode appears newer than @old,
- * and a negative value if @old appears to be newer than the one in the
- * inode.
+ * Compare an i_version counter with a previous one. Returns false if they are
+ * the same, and true if they are different.
*
* Note that we don't need to set the QUERIED flag in this case, as the value
* in the inode is not being recorded for later use.
*/
-
-static inline s64
+static inline bool
inode_cmp_iversion(const struct inode *inode, u64 old)
{
- return (s64)(inode_peek_iversion_raw(inode) & ~I_VERSION_QUERIED) -
- (s64)(old << I_VERSION_QUERIED_SHIFT);
+ return inode_peek_iversion(inode) != old;
}
#endif