fs: fat: Initialize filesystem timestamp ranges (c0da64f6) · Commits · 戴 / test

Fill in the appropriate limits to avoid inconsistencies in the vfs cached inode times when timestamps are outside the permitted range. Some FAT variants indicate that the years after 2099 are not supported. Since commit ("fat: Fix and cleanup timestamp conversion") we support the full range of years that can be represented, up to 2107. Signed-off-by:

Deepa Dinamani <deepa.kernel@gmail.com> Acked-by:

Jeff Layton <jlayton@kernel.org> Cc: hirofumi@mail.parknet.co.jp

fs/fat/inode.c

+12 −0

Original line number	Diff line number	Diff line
		@@ -31,6 +31,11 @@

		#define KB_IN_SECTORS 2

		/* DOS dates from 1980/1/1 through 2107/12/31 */
		#define FAT_DATE_MIN (0<<9 \| 1<<5 \| 1)
		#define FAT_DATE_MAX (127<<9 \| 12<<5 \| 31)
		#define FAT_TIME_MAX (23<<11 \| 59<<5 \| 29)

		/*
		* A deserialized copy of the on-disk structure laid out in struct
		* fat_boot_sector.
		@@ -1605,6 +1610,7 @@ int fat_fill_super(struct super_block sb, void data, int silent, int isvfat,
		int debug;
		long error;
		char buf[50];
		struct timespec64 ts;

		/*
		* GFP_KERNEL is ok here, because while we do hold the
		@@ -1698,6 +1704,12 @@ int fat_fill_super(struct super_block sb, void data, int silent, int isvfat,
		sbi->free_clus_valid = 0;
		sbi->prev_free = FAT_START_ENT;
		sb->s_maxbytes = 0xffffffff;
		fat_time_fat2unix(sbi, &ts, 0, cpu_to_le16(FAT_DATE_MIN), 0);
		sb->s_time_min = ts.tv_sec;

		fat_time_fat2unix(sbi, &ts, cpu_to_le16(FAT_TIME_MAX),
		cpu_to_le16(FAT_DATE_MAX), 0);
		sb->s_time_max = ts.tv_sec;

		if (!sbi->fat_length && bpb.fat32_length) {
		struct fat_boot_fsinfo *fsinfo;

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