Gang He
2018-Jan-03 05:14 UTC
[Ocfs2-devel] [PATCH v3 2/3] ocfs2: add ocfs2_overwrite_io function
Hi Alex,>>> > Hi Gang, > > On 2017/12/28 18:07, Gang He wrote: >> Add ocfs2_overwrite_io function, which is used to judge if >> overwrite allocated blocks, otherwise, the write will bring extra >> block allocation overhead. >> >> Signed-off-by: Gang He <ghe at suse.com> >> --- >> fs/ocfs2/extent_map.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ >> fs/ocfs2/extent_map.h | 3 +++ >> 2 files changed, 48 insertions(+) >> >> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c >> index e4719e0..06cb964 100644 >> --- a/fs/ocfs2/extent_map.c >> +++ b/fs/ocfs2/extent_map.c >> @@ -38,6 +38,7 @@ >> #include "inode.h" >> #include "super.h" >> #include "symlink.h" >> +#include "aops.h" >> #include "ocfs2_trace.h" >> >> #include "buffer_head_io.h" >> @@ -832,6 +833,50 @@ int ocfs2_fiemap(struct inode *inode, struct > fiemap_extent_info *fieinfo, >> 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) > Here can the type of 'map_start' is struct loff_t and map_len is struct > size_t?I prefer to use the detailed types for file start address and length in ocfs2_overwrite_io() function declaration, then here will be a potential type conversion (loff_t -> u64, size_t -> u64), I think this conversion should be considered as expectation. Since our OCFS2 is a 64 bit file system, the related data types do not change, but loff_t and size_t type can change under different architectures (e.g. x86_32, x86_64, etc.). Thanks Gang> > Thanks, > Alex >> +{ >> + 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) { >> + if (ocfs2_size_fits_inline_data(di_bh, map_start + map_len)) >> + return ret; >> + else >> + return -EAGAIN; >> + } >> + >> + 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 --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h >> index 67ea57d..1057586 100644 >> --- a/fs/ocfs2/extent_map.h >> +++ b/fs/ocfs2/extent_map.h >> @@ -53,6 +53,9 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 > v_blkno, u64 *p_blkno, >> 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, >>
alex chen
2018-Jan-04 01:10 UTC
[Ocfs2-devel] [PATCH v3 2/3] ocfs2: add ocfs2_overwrite_io function
Hi Gang, On 2018/1/3 13:14, Gang He wrote:> Hi Alex, > > >>>> >> Hi Gang, >> >> On 2017/12/28 18:07, Gang He wrote: >>> Add ocfs2_overwrite_io function, which is used to judge if >>> overwrite allocated blocks, otherwise, the write will bring extra >>> block allocation overhead. >>> >>> Signed-off-by: Gang He <ghe at suse.com> >>> --- >>> fs/ocfs2/extent_map.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ >>> fs/ocfs2/extent_map.h | 3 +++ >>> 2 files changed, 48 insertions(+) >>> >>> diff --git a/fs/ocfs2/extent_map.c b/fs/ocfs2/extent_map.c >>> index e4719e0..06cb964 100644 >>> --- a/fs/ocfs2/extent_map.c >>> +++ b/fs/ocfs2/extent_map.c >>> @@ -38,6 +38,7 @@ >>> #include "inode.h" >>> #include "super.h" >>> #include "symlink.h" >>> +#include "aops.h" >>> #include "ocfs2_trace.h" >>> >>> #include "buffer_head_io.h" >>> @@ -832,6 +833,50 @@ int ocfs2_fiemap(struct inode *inode, struct >> fiemap_extent_info *fieinfo, >>> 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) >> Here can the type of 'map_start' is struct loff_t and map_len is struct >> size_t? > I prefer to use the detailed types for file start address and length in ocfs2_overwrite_io() function declaration, > then here will be a potential type conversion (loff_t -> u64, size_t -> u64), I think this conversion should be considered as expectation. > Since our OCFS2 is a 64 bit file system, the related data types do not change, but loff_t and size_t type can change under different architectures (e.g. x86_32, x86_64, etc.). >The type conversion (loff_t -> u64, size_t -> u64) has been made before calling the function ocfs2_overwrite_io(). So it doesn't matter which type we use for file start address and length in ocfs2_overwrite_io(), Right? To be consistent with the context, is it better to use struct loff_t for 'map_start' and struct size_t for 'map_len'? Thanks, Alex> Thanks > Gang > >> >> Thanks, >> Alex >>> +{ >>> + 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) { >>> + if (ocfs2_size_fits_inline_data(di_bh, map_start + map_len)) >>> + return ret; >>> + else >>> + return -EAGAIN; >>> + } >>> + >>> + 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 --git a/fs/ocfs2/extent_map.h b/fs/ocfs2/extent_map.h >>> index 67ea57d..1057586 100644 >>> --- a/fs/ocfs2/extent_map.h >>> +++ b/fs/ocfs2/extent_map.h >>> @@ -53,6 +53,9 @@ int ocfs2_extent_map_get_blocks(struct inode *inode, u64 >> v_blkno, u64 *p_blkno, >>> 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, >>> > > > . >