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: OGAWA Hirofumi --- fs/fat/inode.c | 14 +++++++++++--- include/linux/msdos_fs.h | 3 ++- 2 files changed, 13 insertions(+), 4 deletions(-) diff -puN fs/fat/inode.c~fat_dont-use_free_clusters-for-fat32 fs/fat/inode.c --- linux-2.6/fs/fat/inode.c~fat_dont-use_free_clusters-for-fat32 2007-04-22 13:07:05.000000000 +0900 +++ linux-2.6-hirofumi/fs/fat/inode.c 2007-04-22 13:18:07.000000000 +0900 @@ -825,6 +825,8 @@ static int fat_show_options(struct seq_f } 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_f 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, 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, 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; @@ -1306,7 +1312,9 @@ int fat_fill_super(struct super_block *s 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); } diff -puN include/linux/msdos_fs.h~fat_dont-use_free_clusters-for-fat32 include/linux/msdos_fs.h --- linux-2.6/include/linux/msdos_fs.h~fat_dont-use_free_clusters-for-fat32 2007-04-22 13:07:05.000000000 +0900 +++ linux-2.6-hirofumi/include/linux/msdos_fs.h 2007-04-22 13:09:14.000000000 +0900 @@ -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 _