The max file size for ext2 file system is now calculated
with hardcoded 4K block size. The patch fixes it to be
calculated with the right block size.
Signed-off-by: Aneesh Kumar K.V <[email protected]>
---
fs/ext2/super.c | 32 ++++++++++++++++++++++++++++----
1 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 639a32c..a433a53 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -603,11 +603,31 @@ static int ext2_check_descriptors (struct super_block * sb)
static loff_t ext2_max_size(int bits)
{
loff_t res = EXT2_NDIR_BLOCKS;
- /* This constant is calculated to be the largest file size for a
- * dense, 4k-blocksize file such that the total number of
+ int meta_blocks;
+ loff_t upper_limit;
+
+ /* This is calculated to be the largest file size for a
+ * dense, file such that the total number of
* sectors in the file, including data and all indirect blocks,
- * does not exceed 2^32. */
- const loff_t upper_limit = 0x1ff7fffd000LL;
+ * does not exceed 2^32 -1
+ * __u32 i_blocks representing the total number of
+ * 512 bytes blocks of the file
+ */
+ upper_limit = (1LL << 32) - 1;
+
+ /* total blocks in file system block size */
+ upper_limit >>= (bits - 9);
+
+
+ /* indirect blocks */
+ meta_blocks = 1;
+ /* double indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2));
+ /* tripple indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+ upper_limit -= meta_blocks;
+ upper_limit <<= bits;
res += 1LL << (bits-2);
res += 1LL << (2*(bits-2));
@@ -615,6 +635,10 @@ static loff_t ext2_max_size(int bits)
res <<= bits;
if (res > upper_limit)
res = upper_limit;
+
+ if (res > MAX_LFS_FILESIZE)
+ res = MAX_LFS_FILESIZE;
+
return res;
}
--
1.5.3.4.206.g58ba4-dirty
The max file size for ext3 file system is now calculated
with hardcoded 4K block size. The patch fixes it to be
calculated with the right block size.
Signed-off-by: Aneesh Kumar K.V <[email protected]>
---
fs/ext3/super.c | 32 ++++++++++++++++++++++++++++----
1 files changed, 28 insertions(+), 4 deletions(-)
diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index 9537316..4f0de11 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -1362,11 +1362,31 @@ static void ext3_orphan_cleanup (struct super_block * sb,
static loff_t ext3_max_size(int bits)
{
loff_t res = EXT3_NDIR_BLOCKS;
- /* This constant is calculated to be the largest file size for a
- * dense, 4k-blocksize file such that the total number of
+ int meta_blocks;
+ loff_t upper_limit;
+
+ /* This is calculated to be the largest file size for a
+ * dense, file such that the total number of
* sectors in the file, including data and all indirect blocks,
- * does not exceed 2^32. */
- const loff_t upper_limit = 0x1ff7fffd000LL;
+ * does not exceed 2^32 -1
+ * __u32 i_blocks representing the total number of
+ * 512 bytes blocks of the file
+ */
+ upper_limit = (1LL << 32) - 1;
+
+ /* total blocks in file system block size */
+ upper_limit >>= (bits - 9);
+
+
+ /* indirect blocks */
+ meta_blocks = 1;
+ /* double indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2));
+ /* tripple indirect blocks */
+ meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
+
+ upper_limit -= meta_blocks;
+ upper_limit <<= bits;
res += 1LL << (bits-2);
res += 1LL << (2*(bits-2));
@@ -1374,6 +1394,10 @@ static loff_t ext3_max_size(int bits)
res <<= bits;
if (res > upper_limit)
res = upper_limit;
+
+ if (res > MAX_LFS_FILESIZE)
+ res = MAX_LFS_FILESIZE;
+
return res;
}
--
1.5.3.4.206.g58ba4-dirty
On Oct 11, 2007 20:20 +0530, Aneesh Kumar K.V wrote:
> + /* indirect blocks */
> + meta_blocks = 1;
> + /* double indirect blocks */
> + meta_blocks += 1 + (1LL << (bits-2));
> + /* tripple indirect blocks */
> + meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
It may be worthwhile calculating how many indirect blocks there actually
are in a file that size. Also note that your comments are backward -
there is at most a single triple indirect block per file.
Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.
Andreas Dilger wrote:
> On Oct 11, 2007 20:20 +0530, Aneesh Kumar K.V wrote:
>> + /* indirect blocks */
>> + meta_blocks = 1;
>> + /* double indirect blocks */
>> + meta_blocks += 1 + (1LL << (bits-2));
>> + /* tripple indirect blocks */
>> + meta_blocks += 1 + (1LL << (bits-2)) + (1LL << (2*(bits-2)));
>
> It may be worthwhile calculating how many indirect blocks there actually
> are in a file that size.
The math become more confusing for that right ?. I am not sure we need to be that specific.
>Also note that your comments are backward -
> there is at most a single triple indirect block per file.
What i meant by those comment was, the count of meta data blocks taken for
different type of indirect blocks.
-aneesh