| Message ID | 4DC5DB9A.3030001@linux.vnet.ibm.com |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Sat, 2011-05-07 at 16:54 -0700, Allison Henderson wrote: > This patch adds routines needed to zero out the > unblock aligned data of the hole. > > The existing ext4_block_truncate_page routine that > is used to zero out unblock aligned data from truncate > has been modified to accept a length parameter, and > renamed to ext4_block_zero_page_range. > > The function can now be used to zero out the > head of a block, the tail of a block, or the middle > of a block. The existing ext4_block_truncate_page > has now become a wrapper to this function > > Signed-off-by: Allison Henderson <achender@us.ibm.com> I have looked at this patch before, so you could add my reviewed-by here too. > --- > :100644 100644 3ba6c31... 95efb4e... M fs/ext4/ext4.h > :100644 100644 f92c58b... 8ce382d... M fs/ext4/inode.c > fs/ext4/ext4.h | 2 ++ > fs/ext4/inode.c | 33 +++++++++++++++++++++++++++++++-- > 2 files changed, 33 insertions(+), 2 deletions(-) > > diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h > index 3ba6c31..95efb4e 100644 > --- a/fs/ext4/ext4.h > +++ b/fs/ext4/ext4.h > @@ -1758,6 +1758,8 @@ extern int ext4_writepage_trans_blocks(struct inode *); > extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks); > extern int ext4_block_truncate_page(handle_t *handle, > struct address_space *mapping, loff_t from); > +extern int ext4_block_zero_page_range(handle_t *handle, > + struct address_space *mapping, loff_t from, loff_t length); > extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf); > extern qsize_t *ext4_get_reserved_space(struct inode *inode); > extern void ext4_da_update_reserve_space(struct inode *inode, > diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c > index f92c58b..8ce382d 100644 > --- a/fs/ext4/inode.c > +++ b/fs/ext4/inode.c > @@ -3916,9 +3916,30 @@ void ext4_set_aops(struct inode *inode) > int ext4_block_truncate_page(handle_t *handle, > struct address_space *mapping, loff_t from) > { > + unsigned offset = from & (PAGE_CACHE_SIZE-1); > + unsigned length; > + unsigned blocksize; > + struct inode *inode = mapping->host; > + > + blocksize = inode->i_sb->s_blocksize; > + length = blocksize - (offset & (blocksize - 1)); > + > + return ext4_block_zero_page_range(handle, mapping, from, length); > +} > + > +/* > + * ext4_block_zero_page_range() zeros out a mapping of length 'length' > + * starting from file offset 'from'. The range to be zero'd must > + * be contained with in one block. If the specified range exceeds > + * the end of the block it will be shortened to end of the block > + * that cooresponds to 'from' > + */ > +int ext4_block_zero_page_range(handle_t *handle, > + struct address_space *mapping, loff_t from, loff_t length) > +{ > ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; > unsigned offset = from & (PAGE_CACHE_SIZE-1); > - unsigned blocksize, length, pos; > + unsigned blocksize, max, pos; > ext4_lblk_t iblock; > struct inode *inode = mapping->host; > struct buffer_head *bh; > @@ -3931,7 +3952,15 @@ int ext4_block_truncate_page(handle_t *handle, > return -EINVAL; > > blocksize = inode->i_sb->s_blocksize; > - length = blocksize - (offset & (blocksize - 1)); > + max = blocksize - (offset & (blocksize - 1)); > + > + /* > + * correct length if it does not fall between > + * 'from' and the end of the block > + */ > + if (length > max || length < 0) > + length = max; > + > iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); > > if (!page_has_buffers(page)) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index 3ba6c31..95efb4e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1758,6 +1758,8 @@ extern int ext4_writepage_trans_blocks(struct inode *); extern int ext4_chunk_trans_blocks(struct inode *, int nrblocks); extern int ext4_block_truncate_page(handle_t *handle, struct address_space *mapping, loff_t from); +extern int ext4_block_zero_page_range(handle_t *handle, + struct address_space *mapping, loff_t from, loff_t length); extern int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf); extern qsize_t *ext4_get_reserved_space(struct inode *inode); extern void ext4_da_update_reserve_space(struct inode *inode, diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index f92c58b..8ce382d 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3916,9 +3916,30 @@ void ext4_set_aops(struct inode *inode) int ext4_block_truncate_page(handle_t *handle, struct address_space *mapping, loff_t from) { + unsigned offset = from & (PAGE_CACHE_SIZE-1); + unsigned length; + unsigned blocksize; + struct inode *inode = mapping->host; + + blocksize = inode->i_sb->s_blocksize; + length = blocksize - (offset & (blocksize - 1)); + + return ext4_block_zero_page_range(handle, mapping, from, length); +} + +/* + * ext4_block_zero_page_range() zeros out a mapping of length 'length' + * starting from file offset 'from'. The range to be zero'd must + * be contained with in one block. If the specified range exceeds + * the end of the block it will be shortened to end of the block + * that cooresponds to 'from' + */ +int ext4_block_zero_page_range(handle_t *handle, + struct address_space *mapping, loff_t from, loff_t length) +{ ext4_fsblk_t index = from >> PAGE_CACHE_SHIFT; unsigned offset = from & (PAGE_CACHE_SIZE-1); - unsigned blocksize, length, pos; + unsigned blocksize, max, pos; ext4_lblk_t iblock; struct inode *inode = mapping->host; struct buffer_head *bh; @@ -3931,7 +3952,15 @@ int ext4_block_truncate_page(handle_t *handle, return -EINVAL; blocksize = inode->i_sb->s_blocksize; - length = blocksize - (offset & (blocksize - 1)); + max = blocksize - (offset & (blocksize - 1)); + + /* + * correct length if it does not fall between + * 'from' and the end of the block + */ + if (length > max || length < 0) + length = max; + iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits); if (!page_has_buffers(page))
This patch adds routines needed to zero out the unblock aligned data of the hole. The existing ext4_block_truncate_page routine that is used to zero out unblock aligned data from truncate has been modified to accept a length parameter, and renamed to ext4_block_zero_page_range. The function can now be used to zero out the head of a block, the tail of a block, or the middle of a block. The existing ext4_block_truncate_page has now become a wrapper to this function Signed-off-by: Allison Henderson <achender@us.ibm.com> --- :100644 100644 3ba6c31... 95efb4e... M fs/ext4/ext4.h :100644 100644 f92c58b... 8ce382d... M fs/ext4/inode.c fs/ext4/ext4.h | 2 ++ fs/ext4/inode.c | 33 +++++++++++++++++++++++++++++++-- 2 files changed, 33 insertions(+), 2 deletions(-)