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| author | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-22 21:26:58 +0200 |
|---|---|---|
| committer | Wolfgang Wiedmeyer <wolfgit@wiedmeyer.de> | 2015-10-22 21:26:58 +0200 |
| commit | 786208aedd8f75b0720e36b2ca66b3a411417301 (patch) | |
| tree | e6e902ab383ca94842c8691a9e28e1a6aefc5695 /fs/fat | |
| parent | b99374450c03bf5081b88995d91d34fb9b2fd040 (diff) | |
| download | kernel_samsung_smdk4412-786208aedd8f75b0720e36b2ca66b3a411417301.zip kernel_samsung_smdk4412-786208aedd8f75b0720e36b2ca66b3a411417301.tar.gz kernel_samsung_smdk4412-786208aedd8f75b0720e36b2ca66b3a411417301.tar.bz2 | |
merged 3.0.101 tag
Diffstat (limited to 'fs/fat')
| -rw-r--r-- | fs/fat/inode.c | 15 |
1 files changed, 14 insertions, 1 deletions
diff --git a/fs/fat/inode.c b/fs/fat/inode.c index d7136bd..869dae3 100644 --- a/fs/fat/inode.c +++ b/fs/fat/inode.c @@ -1301,6 +1301,19 @@ static int fat_read_root(struct inode *inode) return 0; } +static unsigned long calc_fat_clusters(struct super_block *sb) +{ + struct msdos_sb_info *sbi = MSDOS_SB(sb); + + /* Divide first to avoid overflow */ + if (sbi->fat_bits != 12) { + unsigned long ent_per_sec = sb->s_blocksize * 8 / sbi->fat_bits; + return ent_per_sec * sbi->fat_length; + } + + return sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; +} + /* * Read the super block of an MS-DOS FS. */ @@ -1507,7 +1520,7 @@ int fat_fill_super(struct super_block *sb, void *data, int silent, int isvfat, sbi->fat_bits = (total_clusters > MAX_FAT12) ? 16 : 12; /* check that FAT table does not overflow */ - fat_clusters = sbi->fat_length * sb->s_blocksize * 8 / sbi->fat_bits; + fat_clusters = calc_fat_clusters(sb); total_clusters = min(total_clusters, fat_clusters - FAT_START_ENT); if (total_clusters > MAX_FAT(sb)) { if (!silent) |