FAT: remove ifdefs to make the code more readable

ifdefs in the code are making it harder to read. The use of simple if(vfat_enabled) makes no more code and is cleaner. (the code is discarded by the compiler instead of the preprocessor.) NB: if -O0 is used, the code won't be discarded and bonus, now the code compiles even if CONFIG_SUPPORT_VFAT is not defined. Signed-off-by: Richard Genoud <richard.genoud@gmail.com>

FAT: remove ifdefs to make the code more readable
ifdefs in the code are making it harder to read. The use of simple if(vfat_enabled) makes no more code and is cleaner. (the code is discarded by the compiler instead of the preprocessor.) NB: if -O0 is used, the code won't be discarded and bonus, now the code compiles even if CONFIG_SUPPORT_VFAT is not defined. Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
Richard Genoud · Tom Rini
1 parent fb7e16cc1c
Showing 2 changed files with 32 additions and 34 deletions Side-by-side Diff
fs/fat/fat.c
fs/fat/fat_write.c
@@ -35,6 +35,12 @@
 #include <linux/compiler.h>
 #include <linux/ctype.h>
  
+#ifdef CONFIG_SUPPORT_VFAT
+static const int vfat_enabled = 1;
+#else
+static const int vfat_enabled = 0;
+#endif
+
 /*
  * Convert a string to lowercase.
  */
@@ -442,7 +448,6 @@
 	} while (1);
 }
  
-#ifdef CONFIG_SUPPORT_VFAT
 /*
  * Extract the file name information from 'slotptr' into 'l_name',
  * starting at l_name[*idx].
@@ -577,7 +582,6 @@
  
 	return ret;
 }
-#endif	/* CONFIG_SUPPORT_VFAT */
  
 /*
  * Get the directory entry associated with 'filename' from the directory
@@ -618,8 +622,8 @@
 				continue;
 			}
 			if ((dentptr->attr & ATTR_VOLUME)) {
-#ifdef CONFIG_SUPPORT_VFAT
-				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
+				if (vfat_enabled &&
+				    (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 					prevcksum = ((dir_slot *)dentptr)->alias_checksum;
 					get_vfatname(mydata, curclust,
@@ -659,9 +663,7 @@
 						continue;
 					}
 					debug("vfatname: |%s|\n", l_name);
-				} else
-#endif
-				{
+				} else {
 					/* Volume label or VFAT entry */
 					dentptr++;
 					continue;
  
@@ -675,14 +677,15 @@
 				debug("Dentname == NULL - %d\n", i);
 				return NULL;
 			}
-#ifdef CONFIG_SUPPORT_VFAT
-			__u8 csum = mkcksum(dentptr->name, dentptr->ext);
-			if (dols && csum == prevcksum) {
-				prevcksum = 0xffff;
-				dentptr++;
-				continue;
+			if (vfat_enabled) {
+				__u8 csum = mkcksum(dentptr->name, dentptr->ext);
+				if (dols && csum == prevcksum) {
+					prevcksum = 0xffff;
+					dentptr++;
+					continue;
+				}
 			}
-#endif
+
 			get_name(dentptr, s_name);
 			if (dols) {
 				int isdir = (dentptr->attr & ATTR_DIR);
@@ -885,9 +888,9 @@
 		return -1;
 	}
  
-#ifdef CONFIG_SUPPORT_VFAT
-	debug("VFAT Support enabled\n");
-#endif
+	if (vfat_enabled)
+		debug("VFAT Support enabled\n");
+
 	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
 	       mydata->fatsize, mydata->fat_sect, mydata->fatlength);
 	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
  
@@ -953,10 +956,12 @@
 				continue;
 			}
  
-			csum = mkcksum(dentptr->name, dentptr->ext);
+			if (vfat_enabled)
+				csum = mkcksum(dentptr->name, dentptr->ext);
+
 			if (dentptr->attr & ATTR_VOLUME) {
-#ifdef CONFIG_SUPPORT_VFAT
-				if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
+				if (vfat_enabled &&
+				    (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 					prevcksum =
 						((dir_slot *)dentptr)->alias_checksum;
@@ -1000,9 +1005,7 @@
 					}
 					debug("Rootvfatname: |%s|\n",
 					       l_name);
-				} else
-#endif
-				{
+				} else {
 					/* Volume label or VFAT entry */
 					dentptr++;
 					continue;
  
@@ -1016,13 +1019,13 @@
 				}
 				goto exit;
 			}
-#ifdef CONFIG_SUPPORT_VFAT
-			else if (dols == LS_ROOT && csum == prevcksum) {
+			else if (vfat_enabled &&
+				 dols == LS_ROOT && csum == prevcksum) {
 				prevcksum = 0xffff;
 				dentptr++;
 				continue;
 			}
-#endif
+
 			get_name(dentptr, s_name);
  
 			if (dols == LS_ROOT) {
@@ -249,7 +249,6 @@
 	return ret;
 }
  
-#ifdef CONFIG_SUPPORT_VFAT
 /*
  * Set the file name information from 'name' into 'slotptr',
  */
@@ -469,8 +468,6 @@
 	return 0;
 }
  
-#endif
-
 /*
  * Set the entry at index 'entry' in a FAT (16/32) table.
  */
  
@@ -854,16 +851,14 @@
 				continue;
 			}
 			if ((dentptr->attr & ATTR_VOLUME)) {
-#ifdef CONFIG_SUPPORT_VFAT
-				if ((dentptr->attr & ATTR_VFAT) &&
+				if (vfat_enabled &&
+				    (dentptr->attr & ATTR_VFAT) &&
 				    (dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
 					get_long_file_name(mydata, curclust,
 						     get_dentfromdir_block,
 						     &dentptr, l_name);
 					debug("vfatname: |%s|\n", l_name);
-				} else
-#endif
-				{
+				} else {
 					/* Volume label or VFAT entry */
 					dentptr++;
 					if (is_next_clust(mydata, dentptr))
...	...	@@ -35,6 +35,12 @@
35	35	#include <linux/compiler.h>
36	36	#include <linux/ctype.h>
37	37
	38	+#ifdef CONFIG_SUPPORT_VFAT
	39	+static const int vfat_enabled = 1;
	40	+#else
	41	+static const int vfat_enabled = 0;
	42	+#endif
	43	+
38	44	/*
39	45	* Convert a string to lowercase.
40	46	*/
...	...	@@ -442,7 +448,6 @@
442	448	} while (1);
443	449	}
444	450
445		-#ifdef CONFIG_SUPPORT_VFAT
446	451	/*
447	452	* Extract the file name information from 'slotptr' into 'l_name',
448	453	* starting at l_name[*idx].
...	...	@@ -577,7 +582,6 @@
577	582
578	583	return ret;
579	584	}
580		-#endif /* CONFIG_SUPPORT_VFAT */
581	585
582	586	/*
583	587	* Get the directory entry associated with 'filename' from the directory
...	...	@@ -618,8 +622,8 @@
618	622	continue;
619	623	}
620	624	if ((dentptr->attr & ATTR_VOLUME)) {
621		-#ifdef CONFIG_SUPPORT_VFAT
622		- if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
	625	+ if (vfat_enabled &&
	626	+ (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
623	627	(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
624	628	prevcksum = ((dir_slot *)dentptr)->alias_checksum;
625	629	get_vfatname(mydata, curclust,
...	...	@@ -659,9 +663,7 @@
659	663	continue;
660	664	}
661	665	debug("vfatname: \|%s\|\n", l_name);
662		- } else
663		-#endif
664		- {
	666	+ } else {
665	667	/* Volume label or VFAT entry */
666	668	dentptr++;
667	669	continue;
668	670
...	...	@@ -675,14 +677,15 @@
675	677	debug("Dentname == NULL - %d\n", i);
676	678	return NULL;
677	679	}
678		-#ifdef CONFIG_SUPPORT_VFAT
679		- __u8 csum = mkcksum(dentptr->name, dentptr->ext);
680		- if (dols && csum == prevcksum) {
681		- prevcksum = 0xffff;
682		- dentptr++;
683		- continue;
	680	+ if (vfat_enabled) {
	681	+ __u8 csum = mkcksum(dentptr->name, dentptr->ext);
	682	+ if (dols && csum == prevcksum) {
	683	+ prevcksum = 0xffff;
	684	+ dentptr++;
	685	+ continue;
	686	+ }
684	687	}
685		-#endif
	688	+
686	689	get_name(dentptr, s_name);
687	690	if (dols) {
688	691	int isdir = (dentptr->attr & ATTR_DIR);
...	...	@@ -885,9 +888,9 @@
885	888	return -1;
886	889	}
887	890
888		-#ifdef CONFIG_SUPPORT_VFAT
889		- debug("VFAT Support enabled\n");
890		-#endif
	891	+ if (vfat_enabled)
	892	+ debug("VFAT Support enabled\n");
	893	+
891	894	debug("FAT%d, fat_sect: %d, fatlength: %d\n",
892	895	mydata->fatsize, mydata->fat_sect, mydata->fatlength);
893	896	debug("Rootdir begins at cluster: %d, sector: %d, offset: %x\n"
894	897
...	...	@@ -953,10 +956,12 @@
953	956	continue;
954	957	}
955	958
956		- csum = mkcksum(dentptr->name, dentptr->ext);
	959	+ if (vfat_enabled)
	960	+ csum = mkcksum(dentptr->name, dentptr->ext);
	961	+
957	962	if (dentptr->attr & ATTR_VOLUME) {
958		-#ifdef CONFIG_SUPPORT_VFAT
959		- if ((dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
	963	+ if (vfat_enabled &&
	964	+ (dentptr->attr & ATTR_VFAT) == ATTR_VFAT &&
960	965	(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
961	966	prevcksum =
962	967	((dir_slot *)dentptr)->alias_checksum;
...	...	@@ -1000,9 +1005,7 @@
1000	1005	}
1001	1006	debug("Rootvfatname: \|%s\|\n",
1002	1007	l_name);
1003		- } else
1004		-#endif
1005		- {
	1008	+ } else {
1006	1009	/* Volume label or VFAT entry */
1007	1010	dentptr++;
1008	1011	continue;
1009	1012
...	...	@@ -1016,13 +1019,13 @@
1016	1019	}
1017	1020	goto exit;
1018	1021	}
1019		-#ifdef CONFIG_SUPPORT_VFAT
1020		- else if (dols == LS_ROOT && csum == prevcksum) {
	1022	+ else if (vfat_enabled &&
	1023	+ dols == LS_ROOT && csum == prevcksum) {
1021	1024	prevcksum = 0xffff;
1022	1025	dentptr++;
1023	1026	continue;
1024	1027	}
1025		-#endif
	1028	+
1026	1029	get_name(dentptr, s_name);
1027	1030
1028	1031	if (dols == LS_ROOT) {
...	...	@@ -249,7 +249,6 @@
249	249	return ret;
250	250	}
251	251
252		-#ifdef CONFIG_SUPPORT_VFAT
253	252	/*
254	253	* Set the file name information from 'name' into 'slotptr',
255	254	*/
...	...	@@ -469,8 +468,6 @@
469	468	return 0;
470	469	}
471	470
472		-#endif
473		-
474	471	/*
475	472	* Set the entry at index 'entry' in a FAT (16/32) table.
476	473	*/
477	474
...	...	@@ -854,16 +851,14 @@
854	851	continue;
855	852	}
856	853	if ((dentptr->attr & ATTR_VOLUME)) {
857		-#ifdef CONFIG_SUPPORT_VFAT
858		- if ((dentptr->attr & ATTR_VFAT) &&
	854	+ if (vfat_enabled &&
	855	+ (dentptr->attr & ATTR_VFAT) &&
859	856	(dentptr->name[0] & LAST_LONG_ENTRY_MASK)) {
860	857	get_long_file_name(mydata, curclust,
861	858	get_dentfromdir_block,
862	859	&dentptr, l_name);
863	860	debug("vfatname: \|%s\|\n", l_name);
864		- } else
865		-#endif
866		- {
	861	+ } else {
867	862	/* Volume label or VFAT entry */
868	863	dentptr++;
869	864	if (is_next_clust(mydata, dentptr))