Commit 28ec039c authored by OGAWA Hirofumi's avatar OGAWA Hirofumi Committed by Linus Torvalds
Browse files

fat: don't use free_clusters for fat32 



It seems that the recent Windows changed specification, and it's
undocumented.  Windows doesn't update ->free_clusters correctly.

This patch doesn't use ->free_clusters by default.  (instead, add "usefree"
for forcing to use it)

Signed-off-by: default avatarOGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Cc: Juergen Beisert <juergen127@kreuzholzen.de>
Cc: Andreas Schwab <schwab@suse.de>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 4ff773bb

Documentation/filesystems/vfat.txt

+7 −0
Original line number Diff line number Diff line
@@ -57,6 +57,13 @@ nonumtail=<bool> -- When creating 8.3 aliases, normally the alias will 
                 currently exist in the directory, 'longfile.txt' will

                 be the short alias instead of 'longfi~1.txt'. 

                  

usefree       -- Use the "free clusters" value stored on FSINFO. It'll

                 be used to determine number of free clusters without

                 scanning disk. But it's not used by default, because

                 recent Windows don't update it correctly in some

                 case. If you are sure the "free clusters" on FSINFO is

                 correct, by this option you can avoid scanning disk.



quiet         -- Stops printing certain warning messages.



check=s|r|n   -- Case sensitivity checking setting.

fs/fat/inode.c

+11 −3
Original line number Diff line number Diff line
@@ -825,6 +825,8 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt) 
	}

	if (opts->name_check != 'n')

		seq_printf(m, ",check=%c", opts->name_check);

	if (opts->usefree)

		seq_puts(m, ",usefree");

	if (opts->quiet)

		seq_puts(m, ",quiet");

	if (opts->showexec)
@@ -850,7 +852,7 @@ static int fat_show_options(struct seq_file *m, struct vfsmount *mnt) 


enum {

	Opt_check_n, Opt_check_r, Opt_check_s, Opt_uid, Opt_gid,

	Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_nocase,

	Opt_umask, Opt_dmask, Opt_fmask, Opt_codepage, Opt_usefree, Opt_nocase,

	Opt_quiet, Opt_showexec, Opt_debug, Opt_immutable,

	Opt_dots, Opt_nodots,

	Opt_charset, Opt_shortname_lower, Opt_shortname_win95,
@@ -872,6 +874,7 @@ static match_table_t fat_tokens = { 
	{Opt_dmask, "dmask=%o"},

	{Opt_fmask, "fmask=%o"},

	{Opt_codepage, "codepage=%u"},

	{Opt_usefree, "usefree"},

	{Opt_nocase, "nocase"},

	{Opt_quiet, "quiet"},

	{Opt_showexec, "showexec"},
@@ -951,7 +954,7 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug, 
	opts->quiet = opts->showexec = opts->sys_immutable = opts->dotsOK =  0;

	opts->utf8 = opts->unicode_xlate = 0;

	opts->numtail = 1;

	opts->nocase = 0;

	opts->usefree = opts->nocase = 0;

	*debug = 0;



	if (!options)
@@ -979,6 +982,9 @@ static int parse_options(char *options, int is_vfat, int silent, int *debug, 
		case Opt_check_n:

			opts->name_check = 'n';

			break;

		case Opt_usefree:

			opts->usefree = 1;

			break;

		case Opt_nocase:

			if (!is_vfat)

				opts->nocase = 1;
@@ -1304,7 +1310,9 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, 
			       le32_to_cpu(fsinfo->signature2),

			       sbi->fsinfo_sector);

		} else {

			sbi->free_clusters = le32_to_cpu(fsinfo->free_clusters);

			if (sbi->options.usefree)

				sbi->free_clusters =

					le32_to_cpu(fsinfo->free_clusters);

			sbi->prev_free = le32_to_cpu(fsinfo->next_cluster);

		}

include/linux/msdos_fs.h

+2 −1
Original line number Diff line number Diff line
@@ -205,7 +205,8 @@ struct fat_mount_options { 
		 numtail:1,       /* Does first alias have a numeric '~1' type tail? */

		 atari:1,         /* Use Atari GEMDOS variation of MS-DOS fs */

		 flush:1,	  /* write things quickly */

		 nocase:1;	  /* Does this need case conversion? 0=need case conversion*/

		 nocase:1,	  /* Does this need case conversion? 0=need case conversion*/

		 usefree:1;	  /* Use free_clusters for FAT32 */

};



#define FAT_HASH_BITS	8

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