Hi Gang,
On 2017/12/1 6:24, a...@linux-foundation.org wrote:
> From: Gang He <g...@suse.com>
> Subject: ocfs2: add ocfs2_overwrite_io()
>
> Add ocfs2_overwrite_io(), which is used to judge if overwrite allocated
> blocks, otherwise, the write will bring extra block allocation overhead.
>
> [g...@suse.com: v2]
> Link:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__lkml.kernel.org_r_1511944612-2D9629-2D3-2Dgit-2Dsend-2Demail-2Dghe-40suse.com&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=C7gAd4uDxlAvTdc0vmU6X8CMk6L2iDY8-HD0qT6Fo7Y&m=C4AZ7lGI2-gfFtbla8puNvYIA3a9Cr_XOH6oyx94oGo&s=QhxdPyP9gdEJZTa2UhuSk0x7ENXyGXUOIBV_LyP8oZw&e=
> Link:
> https://urldefense.proofpoint.com/v2/url?u=http-3A__lkml.kernel.org_r_1511775987-2D841-2D3-2Dgit-2Dsend-2Demail-2Dghe-40suse.com&d=DwICAg&c=RoP1YumCXCgaWHvlZYR8PZh8Bv7qIrMUB65eapI_JnE&r=C7gAd4uDxlAvTdc0vmU6X8CMk6L2iDY8-HD0qT6Fo7Y&m=C4AZ7lGI2-gfFtbla8puNvYIA3a9Cr_XOH6oyx94oGo&s=T9Ljku-nipBqCaeXWukY2hAwcHQL95gtlU7pS3l1fgs&e=
> Signed-off-by: Gang He <g...@suse.com>
> Cc: Mark Fasheh <mfas...@versity.com>
> Cc: Joel Becker <jl...@evilplan.org>
> Cc: Junxiao Bi <junxiao...@oracle.com>
> Cc: Joseph Qi <jiangqi...@gmail.com>
> Cc: Changwei Ge <ge.chang...@h3c.com>
> Signed-off-by: Andrew Morton <a...@linux-foundation.org>
> ---
>
> fs/ocfs2/extent_map.c | 41 ++++++++++++++++++++++++++++++++++++++++
> fs/ocfs2/extent_map.h | 3 ++
> 2 files changed, 44 insertions(+)
>
> diff -puN fs/ocfs2/extent_map.c~ocfs2-add-ocfs2_overwrite_io-function
> fs/ocfs2/extent_map.c
> --- a/fs/ocfs2/extent_map.c~ocfs2-add-ocfs2_overwrite_io-function
> +++ a/fs/ocfs2/extent_map.c
> @@ -832,6 +832,47 @@ out:
> return ret;
> }
>
> +/* Is IO overwriting allocated blocks? */
> +int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
> + u64 map_start, u64 map_len)
> +{
> + int ret = 0, is_last;
> + u32 mapping_end, cpos;
> + struct ocfs2_super *osb = OCFS2_SB(inode->i_sb);
> + struct ocfs2_extent_rec rec;
> +
> + if ((OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) &&
> + ((map_start + map_len) <= i_size_read(inode)))
> + goto out;
> +
Should we return -EAGAIN directly when the condition
((OCFS2_I(inode)->ip_dyn_features & OCFS2_INLINE_DATA_FL) && ((map_start +
map_len) > i_size_read(inode)))
is true?
Thanks,
Alex
> + cpos = map_start >> osb->s_clustersize_bits;
> + mapping_end = ocfs2_clusters_for_bytes(inode->i_sb,
> + map_start + map_len);
> + is_last = 0;
> + while (cpos < mapping_end && !is_last) {
> + ret = ocfs2_get_clusters_nocache(inode, di_bh, cpos,
> + NULL, &rec, &is_last);
> + if (ret) {
> + mlog_errno(ret);
> + goto out;
> + }
> +
> + if (rec.e_blkno == 0ULL)
> + break;
> +
> + if (rec.e_flags & OCFS2_EXT_REFCOUNTED)
> + break;
> +
> + cpos = le32_to_cpu(rec.e_cpos) +
> + le16_to_cpu(rec.e_leaf_clusters);
> + }
> +
> + if (cpos < mapping_end)
> + ret = -EAGAIN;
> +out:
> + return ret;
> +}
> +
> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int
> whence)
> {
> struct inode *inode = file->f_mapping->host;
> diff -puN fs/ocfs2/extent_map.h~ocfs2-add-ocfs2_overwrite_io-function
> fs/ocfs2/extent_map.h
> --- a/fs/ocfs2/extent_map.h~ocfs2-add-ocfs2_overwrite_io-function
> +++ a/fs/ocfs2/extent_map.h
> @@ -53,6 +53,9 @@ int ocfs2_extent_map_get_blocks(struct i
> int ocfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
> u64 map_start, u64 map_len);
>
> +int ocfs2_overwrite_io(struct inode *inode, struct buffer_head *di_bh,
> + u64 map_start, u64 map_len);
> +
> int ocfs2_seek_data_hole_offset(struct file *file, loff_t *offset, int
> origin);
>
> int ocfs2_xattr_get_clusters(struct inode *inode, u32 v_cluster,
> _
>
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> Ocfs2-devel@oss.oracle.com
> https://oss.oracle.com/mailman/listinfo/ocfs2-devel
>
> .
>
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