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Commit 0ba902eb authored by Wang Di's avatar Wang Di
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some minor fix in copy_back_pages

parent 9382ed8f
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with 37 additions and 70 deletions
lustre/snapfs/file.c
+ 37
− 70
View file @ 0ba902eb
......@@ -21,28 +21,37 @@ static int has_pages(struct inode *inode, int index)
{
unsigned long offset = index << PAGE_CACHE_SHIFT;
unsigned long blk_start = offset >> inode->i_sb->s_blocksize_bits;
unsigned long blk_end = (offset + PAGE_CACHE_SIZE) >> inode->i_sb->s_blocksize_bits;
int inside = 0;
unsigned long blk_end = (offset + PAGE_CACHE_SIZE) >>
inode->i_sb->s_blocksize_bits;
while (blk_start <= blk_end) {
if (inode->i_mapping && inode->i_mapping->a_ops) {
inside = inode->i_mapping->a_ops->bmap(inode->i_mapping, blk_start);
if (inode->i_mapping->a_ops->bmap(inode->i_mapping,
blk_start))
return 1;
}
blk_start++;
}
return inside;
return 0;
}
static int copy_back_page(struct inode *dst, struct inode *src,
int index)
static int copy_back_page(struct inode *dst,
struct inode *src,
unsigned long start,
unsigned long end)
{
char *kaddr_src, *kaddr_dst;
struct snap_cache *cache;
struct address_space_operations *c_aops;
struct page *src_page, *dst_page;
unsigned long index, offset, bytes;
int err = 0;
ENTRY;
index = start >> PAGE_CACHE_SHIFT;
bytes = end - start;
offset = start & PAGE_CACHE_MASK;
if (!has_pages(src, index))
RETURN(0);
......@@ -56,7 +65,7 @@ static int copy_back_page(struct inode *dst, struct inode *src,
src_page = grab_cache_page(src->i_mapping, index);
if (!src_page) {
CERROR("copy block %d from %lu to %lu ENOMEM \n",
CERROR("copy block %lu from %lu to %lu ENOMEM \n",
index, src->i_ino, dst->i_ino);
RETURN(-ENOMEM);
}
......@@ -66,27 +75,27 @@ static int copy_back_page(struct inode *dst, struct inode *src,
kaddr_src = kmap(src_page);
if (!Page_Uptodate(src_page)) {
CERROR("Can not read page index %d of inode %lu\n",
CERROR("Can not read page index %lu of inode %lu\n",
index, src->i_ino);
err = -EIO;
goto unlock_src_page;
}
dst_page = grab_cache_page(dst->i_mapping, index);
if (!dst_page) {
CERROR("copy block %d from %lu to %lu ENOMEM \n",
CERROR("copy block %lu from %lu to %lu ENOMEM \n",
index, src->i_ino, dst->i_ino);
err = -ENOMEM;
goto unlock_src_page;
}
kaddr_dst = kmap(dst_page);
err = c_aops->prepare_write(NULL, dst_page, 0, PAGE_CACHE_SIZE);
err = c_aops->prepare_write(NULL, dst_page, offset, bytes);
if (err)
goto unlock_dst_page;
memcpy(kaddr_dst, kaddr_src, PAGE_CACHE_SIZE);
flush_dcache_page(dst_page);
err = c_aops->commit_write(NULL, dst_page, 0, PAGE_CACHE_SIZE);
err = c_aops->commit_write(NULL, dst_page, offset, bytes);
if (err)
goto unlock_dst_page;
err = 1;
......@@ -106,7 +115,7 @@ static ssize_t currentfs_write (struct file *filp, const char *buf,
struct snap_cache *cache;
struct inode *inode = filp->f_dentry->d_inode;
struct file_operations *fops;
long page[2]={-1,-1};
long start[2]={-1,-1}, end[2]={-1,-1};
struct snap_table *table;
struct inode *cache_inode = NULL;
int slot = 0, index = 0, result = 0;
......@@ -139,65 +148,22 @@ static ssize_t currentfs_write (struct file *filp, const char *buf,
if (pos != *ppos)
RETURN(-EINVAL);
}
/*
* we only need to copy back the first and last blocks
*/
#if 0
mask = inode->i_sb->s_blocksize-1;
if( pos & mask )
block[0] = pos >> inode->i_sb->s_blocksize_bits;
pos += count - 1;
if( (pos+1) & mask )
block[1] = pos >> inode->i_sb->s_blocksize_bits;
if( block[0] == block[1] )
block[1] = -1;
snapops = filter_c2csnapops(cache->cache_filter);
for (i = 0; i < 2; i++) {
if (block[i] == -1)
continue;
table = &snap_tables[cache->cache_snap_tableno];
/*Find the nearest block in snaptable and copy back it*/
for (slot = table->tbl_count - 1; slot >= 1; slot--) {
cache_inode = NULL;
index = table->snap_items[slot].index;
cache_inode = snap_get_indirect(inode, NULL, index);
if (!cache_inode) continue;
CDEBUG(D_SNAP, "find cache_ino %lu\n", cache_inode->i_ino);
if (snapops && snapops->copy_block) {
result = snapops->copy_block(inode, cache_inode, block[i]);
if (result == 1) {
CDEBUG(D_SNAP, "copy block %lu back from ind %lu to %lu\n",
block[i], cache_inode->i_ino, inode->i_ino);
iput(cache_inode);
result = 0;
break;
}
if (result < 0) {
iput(cache_inode);
rc = result;
goto exit;
}
}
iput(cache_inode);
}
if (pos & PAGE_CACHE_MASK) {
start[0] = pos & PAGE_CACHE_MASK;
end[0] = pos;
}
#else
if (pos & PAGE_CACHE_MASK)
page[0] = pos >> PAGE_CACHE_SHIFT;
pos += count - 1;
if ((pos+1) & PAGE_CACHE_MASK)
page[1] = pos >> PAGE_CACHE_SHIFT;
if (page[0] == page[1])
page[1] = -1;
if ((pos+1) & PAGE_CACHE_MASK) {
start[1] = pos;
end[1] = PAGE_CACHE_ALIGN(pos);
}
if (((start[0] >> PAGE_CACHE_SHIFT) == (start[1] >> PAGE_CACHE_SHIFT)) ||
pos > inode->i_size)
start[1] = -1;
for (i = 0; i < 2; i++) {
if (page[i] == -1)
if (start[i] == -1)
continue;
table = &snap_tables[cache->cache_snap_tableno];
/*Find the nearest page in snaptable and copy back it*/
......@@ -210,10 +176,12 @@ static ssize_t currentfs_write (struct file *filp, const char *buf,
CDEBUG(D_SNAP, "find cache_ino %lu\n", cache_inode->i_ino);
result = copy_back_page(inode, cache_inode, page[i]);
result = copy_back_page(inode, cache_inode, start[i], end[i]);
if (result == 1) {
CDEBUG(D_SNAP, "copy page%lu back from ind %lu to %lu\n",
page[i], cache_inode->i_ino, inode->i_ino);
(start[i] >> PAGE_CACHE_SHIFT),
cache_inode->i_ino,
inode->i_ino);
iput(cache_inode);
result = 0;
break;
......@@ -226,7 +194,6 @@ static ssize_t currentfs_write (struct file *filp, const char *buf,
iput(cache_inode);
}
}
#endif
rc = fops->write(filp, buf, count, ppos);
exit:
RETURN(rc);
......
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