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author | Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> | 2008-01-29 04:58:26 (GMT) |
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committer | Theodore Ts'o <tytso@mit.edu> | 2008-01-29 04:58:26 (GMT) |
commit | 0fc1b451471dfc3cabd6e99ef441df9804616e63 (patch) | |
tree | b018b6ddc5bb5f02b985b06c11f0c01adb38167a /fs/ext4/super.c | |
parent | a48380f769dfed6163fb82a68b13bd562ea1e027 (diff) | |
download | linux-fsl-qoriq-0fc1b451471dfc3cabd6e99ef441df9804616e63.tar.xz |
ext4: Add support for 48 bit inode i_blocks.
Use the __le16 l_i_reserved1 field of the linux2 struct of ext4_inode
to represet the higher 16 bits for i_blocks. With this change max_file
size becomes (2**48 -1 )* 512 bytes.
We add a RO_COMPAT feature to the super block to indicate that inode
have i_blocks represented as a split 48 bits. Super block with this
feature set cannot be mounted read write on a kernel with CONFIG_LSF
disabled.
Super block flag EXT4_FEATURE_RO_COMPAT_HUGE_FILE
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Diffstat (limited to 'fs/ext4/super.c')
-rw-r--r-- | fs/ext4/super.c | 62 |
1 files changed, 56 insertions, 6 deletions
diff --git a/fs/ext4/super.c b/fs/ext4/super.c index 7be27db..2b9dc96 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -1603,17 +1603,50 @@ static void ext4_orphan_cleanup (struct super_block * sb, /* * Maximal file size. There is a direct, and {,double-,triple-}indirect - * block limit, and also a limit of (2^32 - 1) 512-byte sectors in i_blocks. - * We need to be 1 filesystem block less than the 2^32 sector limit. + * block limit, and also a limit of (2^48 - 1) 512-byte sectors in i_blocks. + * We need to be 1 filesystem block less than the 2^48 sector limit. */ static loff_t ext4_max_size(int bits) { loff_t res = EXT4_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 2^48 -1 + * __u32 i_blocks_lo and _u16 i_blocks_high representing the + * total number of 512 bytes blocks of the file + */ + + if (sizeof(blkcnt_t) < sizeof(u64)) { + /* + * CONFIG_LSF is not enabled implies the inode + * i_block represent total blocks in 512 bytes + * 32 == size of vfs inode i_blocks * 8 + */ + upper_limit = (1LL << 32) - 1; + + /* total blocks in file system block size */ + upper_limit >>= (bits - 9); + + } else { + /* We use 48 bit ext4_inode i_blocks */ + upper_limit = (1LL << 48) - 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)); @@ -1621,6 +1654,10 @@ static loff_t ext4_max_size(int bits) res <<= bits; if (res > upper_limit) res = upper_limit; + + if (res > MAX_LFS_FILESIZE) + res = MAX_LFS_FILESIZE; + return res; } @@ -1789,6 +1826,19 @@ static int ext4_fill_super (struct super_block *sb, void *data, int silent) sb->s_id, le32_to_cpu(features)); goto failed_mount; } + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, EXT4_FEATURE_RO_COMPAT_HUGE_FILE)) { + /* + * Large file size enabled file system can only be + * mount if kernel is build with CONFIG_LSF + */ + if (sizeof(root->i_blocks) < sizeof(u64) && + !(sb->s_flags & MS_RDONLY)) { + printk(KERN_ERR "EXT4-fs: %s: Filesystem with huge " + "files cannot be mounted read-write " + "without CONFIG_LSF.\n", sb->s_id); + goto failed_mount; + } + } blocksize = BLOCK_SIZE << le32_to_cpu(es->s_log_block_size); if (blocksize < EXT4_MIN_BLOCK_SIZE || |