nfsd: last_byte_offset

refactor the nfs4 server lock code to use last_byte_offset to compute the last byte covered by the lock. Check for overflow so that the last byte is set to NFS4_MAX_UINT64 if offset + len wraps around. Also, use NFS4_MAX_UINT64 for ~(u64)0 where appropriate. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>

nfsd: last_byte_offset
refactor the nfs4 server lock code to use last_byte_offset to compute the last byte covered by the lock. Check for overflow so that the last byte is set to NFS4_MAX_UINT64 if offset + len wraps around. Also, use NFS4_MAX_UINT64 for ~(u64)0 where appropriate. Signed-off-by: Benny Halevy <bhalevy@panasas.com> Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Benny Halevy · J. Bruce Fields
1 parent 4e65ebf089
Showing 2 changed files with 28 additions and 16 deletions Side-by-side Diff
fs/nfsd/nfs4state.c
include/linux/nfs4.h
@@ -2416,6 +2416,26 @@
 #define LOCK_HASH_SIZE             (1 << LOCK_HASH_BITS)
 #define LOCK_HASH_MASK             (LOCK_HASH_SIZE - 1)
  
+static inline u64
+end_offset(u64 start, u64 len)
+{
+	u64 end;
+
+	end = start + len;
+	return end >= start ? end: NFS4_MAX_UINT64;
+}
+
+/* last octet in a range */
+static inline u64
+last_byte_offset(u64 start, u64 len)
+{
+	u64 end;
+
+	BUG_ON(!len);
+	end = start + len;
+	return end > start ? end - 1: NFS4_MAX_UINT64;
+}
+
 #define lockownerid_hashval(id) \
         ((id) & LOCK_HASH_MASK)
  
@@ -2519,8 +2539,8 @@
 		deny->ld_clientid.cl_id = 0;
 	}
 	deny->ld_start = fl->fl_start;
-	deny->ld_length = ~(u64)0;
-	if (fl->fl_end != ~(u64)0)
+	deny->ld_length = NFS4_MAX_UINT64;
+	if (fl->fl_end != NFS4_MAX_UINT64)
 		deny->ld_length = fl->fl_end - fl->fl_start + 1;        
 	deny->ld_type = NFS4_READ_LT;
 	if (fl->fl_type != F_RDLCK)
@@ -2617,7 +2637,7 @@
 static int
 check_lock_length(u64 offset, u64 length)
 {
-	return ((length == 0)  || ((length != ~(u64)0) &&
+	return ((length == 0)  || ((length != NFS4_MAX_UINT64) &&
 	     LOFF_OVERFLOW(offset, length)));
 }
  
@@ -2737,11 +2757,7 @@
 	file_lock.fl_lmops = &nfsd_posix_mng_ops;
  
 	file_lock.fl_start = lock->lk_offset;
-	if ((lock->lk_length == ~(u64)0) || 
-			LOFF_OVERFLOW(lock->lk_offset, lock->lk_length))
-		file_lock.fl_end = ~(u64)0;
-	else
-		file_lock.fl_end = lock->lk_offset + lock->lk_length - 1;
+	file_lock.fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
 	nfs4_transform_lock_offset(&file_lock);
  
 	/*
@@ -2858,10 +2874,7 @@
 	file_lock.fl_lmops = &nfsd_posix_mng_ops;
  
 	file_lock.fl_start = lockt->lt_offset;
-	if ((lockt->lt_length == ~(u64)0) || LOFF_OVERFLOW(lockt->lt_offset, lockt->lt_length))
-		file_lock.fl_end = ~(u64)0;
-	else
-		file_lock.fl_end = lockt->lt_offset + lockt->lt_length - 1;
+	file_lock.fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
  
 	nfs4_transform_lock_offset(&file_lock);
  
@@ -2917,10 +2930,7 @@
 	file_lock.fl_lmops = &nfsd_posix_mng_ops;
 	file_lock.fl_start = locku->lu_offset;
  
-	if ((locku->lu_length == ~(u64)0) || LOFF_OVERFLOW(locku->lu_offset, locku->lu_length))
-		file_lock.fl_end = ~(u64)0;
-	else
-		file_lock.fl_end = locku->lu_offset + locku->lu_length - 1;
+	file_lock.fl_end = last_byte_offset(locku->lu_offset, locku->lu_length);
 	nfs4_transform_lock_offset(&file_lock);
  
 	/*
@@ -88,6 +88,8 @@
 #define NFS4_ACE_GENERIC_EXECUTE              0x001200A0
 #define NFS4_ACE_MASK_ALL                     0x001F01FF
  
+#define NFS4_MAX_UINT64	(~(u64)0)
+
 enum nfs4_acl_whotype {
 	NFS4_ACL_WHO_NAMED = 0,
 	NFS4_ACL_WHO_OWNER,
...	...	@@ -2416,6 +2416,26 @@
2416	2416	#define LOCK_HASH_SIZE (1 << LOCK_HASH_BITS)
2417	2417	#define LOCK_HASH_MASK (LOCK_HASH_SIZE - 1)
2418	2418
	2419	+static inline u64
	2420	+end_offset(u64 start, u64 len)
	2421	+{
	2422	+ u64 end;
	2423	+
	2424	+ end = start + len;
	2425	+ return end >= start ? end: NFS4_MAX_UINT64;
	2426	+}
	2427	+
	2428	+/* last octet in a range */
	2429	+static inline u64
	2430	+last_byte_offset(u64 start, u64 len)
	2431	+{
	2432	+ u64 end;
	2433	+
	2434	+ BUG_ON(!len);
	2435	+ end = start + len;
	2436	+ return end > start ? end - 1: NFS4_MAX_UINT64;
	2437	+}
	2438	+
2419	2439	#define lockownerid_hashval(id) \
2420	2440	((id) & LOCK_HASH_MASK)
2421	2441
...	...	@@ -2519,8 +2539,8 @@
2519	2539	deny->ld_clientid.cl_id = 0;
2520	2540	}
2521	2541	deny->ld_start = fl->fl_start;
2522		- deny->ld_length = ~(u64)0;
2523		- if (fl->fl_end != ~(u64)0)
	2542	+ deny->ld_length = NFS4_MAX_UINT64;
	2543	+ if (fl->fl_end != NFS4_MAX_UINT64)
2524	2544	deny->ld_length = fl->fl_end - fl->fl_start + 1;
2525	2545	deny->ld_type = NFS4_READ_LT;
2526	2546	if (fl->fl_type != F_RDLCK)
...	...	@@ -2617,7 +2637,7 @@
2617	2637	static int
2618	2638	check_lock_length(u64 offset, u64 length)
2619	2639	{
2620		- return ((length == 0) \|\| ((length != ~(u64)0) &&
	2640	+ return ((length == 0) \|\| ((length != NFS4_MAX_UINT64) &&
2621	2641	LOFF_OVERFLOW(offset, length)));
2622	2642	}
2623	2643
...	...	@@ -2737,11 +2757,7 @@
2737	2757	file_lock.fl_lmops = &nfsd_posix_mng_ops;
2738	2758
2739	2759	file_lock.fl_start = lock->lk_offset;
2740		- if ((lock->lk_length == ~(u64)0) \|\|
2741		- LOFF_OVERFLOW(lock->lk_offset, lock->lk_length))
2742		- file_lock.fl_end = ~(u64)0;
2743		- else
2744		- file_lock.fl_end = lock->lk_offset + lock->lk_length - 1;
	2760	+ file_lock.fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
2745	2761	nfs4_transform_lock_offset(&file_lock);
2746	2762
2747	2763	/*
...	...	@@ -2858,10 +2874,7 @@
2858	2874	file_lock.fl_lmops = &nfsd_posix_mng_ops;
2859	2875
2860	2876	file_lock.fl_start = lockt->lt_offset;
2861		- if ((lockt->lt_length == ~(u64)0) \|\| LOFF_OVERFLOW(lockt->lt_offset, lockt->lt_length))
2862		- file_lock.fl_end = ~(u64)0;
2863		- else
2864		- file_lock.fl_end = lockt->lt_offset + lockt->lt_length - 1;
	2877	+ file_lock.fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
2865	2878
2866	2879	nfs4_transform_lock_offset(&file_lock);
2867	2880
...	...	@@ -2917,10 +2930,7 @@
2917	2930	file_lock.fl_lmops = &nfsd_posix_mng_ops;
2918	2931	file_lock.fl_start = locku->lu_offset;
2919	2932
2920		- if ((locku->lu_length == ~(u64)0) \|\| LOFF_OVERFLOW(locku->lu_offset, locku->lu_length))
2921		- file_lock.fl_end = ~(u64)0;
2922		- else
2923		- file_lock.fl_end = locku->lu_offset + locku->lu_length - 1;
	2933	+ file_lock.fl_end = last_byte_offset(locku->lu_offset, locku->lu_length);
2924	2934	nfs4_transform_lock_offset(&file_lock);
2925	2935
2926	2936	/*
...	...	@@ -88,6 +88,8 @@
88	88	#define NFS4_ACE_GENERIC_EXECUTE 0x001200A0
89	89	#define NFS4_ACE_MASK_ALL 0x001F01FF
90	90
	91	+#define NFS4_MAX_UINT64 (~(u64)0)
	92	+
91	93	enum nfs4_acl_whotype {
92	94	NFS4_ACL_WHO_NAMED = 0,
93	95	NFS4_ACL_WHO_OWNER,