* [PATCH] reject too-large filesystems on 32-bit kernels
@ 2009-08-12 22:06 Eric Sandeen
2009-08-12 22:30 ` [PATCH V2] " Eric Sandeen
0 siblings, 1 reply; 3+ messages in thread
From: Eric Sandeen @ 2009-08-12 22:06 UTC (permalink / raw)
To: ext4 development
ext4 will happily mount a > 16T filesystem on a 32-bit box, but
this is not safe; writes to the block device will wrap past 16T
and the page cache can't index past 16T (2^32 index * 4k pages).
Adding another test to the existing "too many sectors" test
should do the trick.
Add a comment, a relevant return value, and fix the reference
to the CONFIG_LBD(AF) option as well.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
Index: linux-2.6.29.noarch/fs/ext4/super.c
===================================================================
--- linux-2.6.29.noarch.orig/fs/ext4/super.c
+++ linux-2.6.29.noarch/fs/ext4/super.c
@@ -2274,13 +2274,20 @@ static int ext4_fill_super(struct super_
goto failed_mount;
}
+ /*
+ * Test whether we have more sectors than will fit in sector_t,
+ * and whether the max offset is addressable by the page cache.
+ */
if (ext4_blocks_count(es) >
- (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
+ (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9) ||
+ ext4_blocks_count(es) >
+ (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits)) {
printk(KERN_ERR "EXT4-fs: filesystem on %s:"
- " too large to mount safely\n", sb->s_id);
+ " too large to mount safely on this system\n", sb->s_id);
if (sizeof(sector_t) < 8)
- printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
+ printk(KERN_WARNING "EXT4-fs: CONFIG_LBDAF not "
"enabled\n");
+ ret = EFBIG;
goto failed_mount;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH V2] reject too-large filesystems on 32-bit kernels
2009-08-12 22:06 [PATCH] reject too-large filesystems on 32-bit kernels Eric Sandeen
@ 2009-08-12 22:30 ` Eric Sandeen
2009-08-18 3:47 ` Theodore Tso
0 siblings, 1 reply; 3+ messages in thread
From: Eric Sandeen @ 2009-08-12 22:30 UTC (permalink / raw)
To: ext4 development
ext4 will happily mount a > 16T filesystem on a 32-bit box, but
this is not safe; writes to the block device will wrap past 16T
and the page cache can't index past 16T (232 index * 4k pages).
Adding another test to the existing "too many sectors" test
should do the trick.
Add a comment, a relevant return value, and fix the reference
to the CONFIG_LBD(AF) option as well.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
---
V2: Get error sign right, too much userspace today :)
Index: linux-2.6.29.noarch/fs/ext4/super.c
===================================================================
--- linux-2.6.29.noarch.orig/fs/ext4/super.c
+++ linux-2.6.29.noarch/fs/ext4/super.c
@@ -2274,13 +2274,20 @@ static int ext4_fill_super(struct super_
goto failed_mount;
}
+ /*
+ * Test whether we have more sectors than will fit in sector_t,
+ * and whether the max offset is addressable by the page cache.
+ */
if (ext4_blocks_count(es) >
- (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9)) {
+ (sector_t)(~0ULL) >> (sb->s_blocksize_bits - 9) ||
+ ext4_blocks_count(es) >
+ (pgoff_t)(~0ULL) >> (PAGE_CACHE_SHIFT - sb->s_blocksize_bits)) {
printk(KERN_ERR "EXT4-fs: filesystem on %s:"
- " too large to mount safely\n", sb->s_id);
+ " too large to mount safely on this system\n", sb->s_id);
if (sizeof(sector_t) < 8)
- printk(KERN_WARNING "EXT4-fs: CONFIG_LBD not "
+ printk(KERN_WARNING "EXT4-fs: CONFIG_LBDAF not "
"enabled\n");
+ ret = -EFBIG;
goto failed_mount;
}
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^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH V2] reject too-large filesystems on 32-bit kernels
2009-08-12 22:30 ` [PATCH V2] " Eric Sandeen
@ 2009-08-18 3:47 ` Theodore Tso
0 siblings, 0 replies; 3+ messages in thread
From: Theodore Tso @ 2009-08-18 3:47 UTC (permalink / raw)
To: Eric Sandeen; +Cc: ext4 development
On Wed, Aug 12, 2009 at 05:30:23PM -0500, Eric Sandeen wrote:
> ext4 will happily mount a > 16T filesystem on a 32-bit box, but
> this is not safe; writes to the block device will wrap past 16T
> and the page cache can't index past 16T (232 index * 4k pages).
Applied in the ext4 patch queue, with minor changes to take into
account the use of ext4_msg().
- Ted
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2009-08-18 3:47 UTC | newest]
Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed)
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2009-08-12 22:06 [PATCH] reject too-large filesystems on 32-bit kernels Eric Sandeen
2009-08-12 22:30 ` [PATCH V2] " Eric Sandeen
2009-08-18 3:47 ` Theodore Tso
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