Namjae Jeon <namjae.jeon@xxxxxxxxxxx> writes:
> Adding i_disksize to represent uninitialized allocated size.
> And mmu_private represent initialized allocated size.
> i_disksize - is always kept cluster size aligned
> mmu_private - is normally block size aligned
Hi,
While reading this with fresh mind, I've now noticed i_disksize is
lesser i_blocks in fatfs?
Well, if fallocate inode, what number should we return? I.e. it returns
really allocated blocks, or fake blocks in i_size?
If we can use i_blocks (fatfs doesn't have hole), maybe, this patch
become simpler. If not, I think we should add i_disksize changes more
like i_blocks does.
What do you think?
Thanks.
> Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
> Signed-off-by: Amit Sahrawat <a.sahrawat@xxxxxxxxxxx>
> ---
> fs/fat/fat.h | 3 ++-
> fs/fat/file.c | 5 ++++-
> fs/fat/inode.c | 11 +++++++++--
> 3 files changed, 15 insertions(+), 4 deletions(-)
>
> diff --git a/fs/fat/fat.h b/fs/fat/fat.h
> index e0c4ba3..f6bcaa7 100644
> --- a/fs/fat/fat.h
> +++ b/fs/fat/fat.h
> @@ -119,7 +119,8 @@ struct msdos_inode_info {
> unsigned int cache_valid_id;
>
> /* NOTE: mmu_private is 64bits, so must hold ->i_mutex to access */
> - loff_t mmu_private; /* physically allocated size */
> + loff_t mmu_private; /* physically allocated size (initialized) */
> + loff_t i_disksize; /* physically allocated size (uninitialized) */
>
> int i_start; /* first cluster or 0 */
> int i_logstart; /* logical first cluster */
> diff --git a/fs/fat/file.c b/fs/fat/file.c
> index 85f79a8..288cf1f 100644
> --- a/fs/fat/file.c
> +++ b/fs/fat/file.c
> @@ -300,8 +300,11 @@ void fat_truncate_blocks(struct inode *inode, loff_t offset)
> * This protects against truncating a file bigger than it was then
> * trying to write into the hole.
> */
> - if (MSDOS_I(inode)->mmu_private > offset)
> + if (MSDOS_I(inode)->mmu_private > offset) {
> MSDOS_I(inode)->mmu_private = offset;
> + MSDOS_I(inode)->i_disksize = round_up(offset,
> + sbi->cluster_size);
> + }
>
> nr_clusters = (offset + (cluster_size - 1)) >> sbi->cluster_bits;
>
> diff --git a/fs/fat/inode.c b/fs/fat/inode.c
> index 756aead..21c2442 100644
> --- a/fs/fat/inode.c
> +++ b/fs/fat/inode.c
> @@ -104,6 +104,7 @@ static struct fat_floppy_defaults {
> static int fat_add_cluster(struct inode *inode)
> {
> int err, cluster;
> + struct msdos_sb_info *sbi = MSDOS_SB(inode->i_sb);
>
> err = fat_alloc_clusters(inode, &cluster, 1);
> if (err)
> @@ -113,6 +114,9 @@ static int fat_add_cluster(struct inode *inode)
> err = fat_chain_add(inode, cluster, 1);
> if (err)
> fat_free_clusters(inode, cluster);
> + else
> + MSDOS_I(inode)->i_disksize += sbi->cluster_size;
> +
> return err;
> }
>
> @@ -469,7 +473,6 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
> error = fat_calc_dir_size(inode);
> if (error < 0)
> return error;
> - MSDOS_I(inode)->mmu_private = inode->i_size;
>
> set_nlink(inode, fat_subdirs(inode));
> } else { /* not a directory */
> @@ -484,8 +487,11 @@ int fat_fill_inode(struct inode *inode, struct msdos_dir_entry *de)
> inode->i_op = &fat_file_inode_operations;
> inode->i_fop = &fat_file_operations;
> inode->i_mapping->a_ops = &fat_aops;
> - MSDOS_I(inode)->mmu_private = inode->i_size;
> }
> +
> + MSDOS_I(inode)->mmu_private = inode->i_size;
> + MSDOS_I(inode)->i_disksize = round_up(inode->i_size, sbi->cluster_size);
> +
> if (de->attr & ATTR_SYS) {
> if (sbi->options.sys_immutable)
> inode->i_flags |= S_IMMUTABLE;
> @@ -1293,6 +1299,7 @@ static int fat_read_root(struct inode *inode)
> & ~((loff_t)sbi->cluster_size - 1)) >> 9;
> MSDOS_I(inode)->i_logstart = 0;
> MSDOS_I(inode)->mmu_private = inode->i_size;
> + MSDOS_I(inode)->i_disksize = round_up(inode->i_size, sbi->cluster_size);
>
> fat_save_attrs(inode, ATTR_DIR);
> inode->i_mtime.tv_sec = inode->i_atime.tv_sec = inode->i_ctime.tv_sec = 0;
--
OGAWA Hirofumi <hirofumi@xxxxxxxxxxxxxxxxxx>
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