提交 589dc260 编写于 作者: T Tao Ma 提交者: Mark Fasheh

ocfs2: Add xattr lookup code xattr btrees

Add code to lookup a given extended attribute in the xattr btree. Lookup
follows this general scheme:

1. Use ocfs2_xattr_get_rec to find the xattr extent record

2. Find the xattr bucket within the extent which may contain this xattr

3. Iterate the bucket to find the xattr. In ocfs2_xattr_block_get(), we need
   to recalcuate the block offset and name offset for the right position of
   name/value.
Signed-off-by: NTao Ma <tao.ma@oracle.com>
Signed-off-by: NMark Fasheh <mfasheh@suse.com>
上级 0c044f0b
......@@ -99,12 +99,25 @@ struct ocfs2_xattr_search {
*/
struct buffer_head *xattr_bh;
struct ocfs2_xattr_header *header;
struct ocfs2_xattr_bucket bucket;
void *base;
void *end;
struct ocfs2_xattr_entry *here;
int not_found;
};
static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
struct ocfs2_xattr_header *xh,
int index,
int *block_off,
int *new_offset);
static int ocfs2_xattr_index_block_find(struct inode *inode,
struct buffer_head *root_bh,
int name_index,
const char *name,
struct ocfs2_xattr_search *xs);
static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
struct ocfs2_xattr_tree_root *xt,
char *buffer,
......@@ -604,7 +617,7 @@ static int ocfs2_xattr_find_entry(int name_index,
}
static int ocfs2_xattr_get_value_outside(struct inode *inode,
struct ocfs2_xattr_search *xs,
struct ocfs2_xattr_value_root *xv,
void *buffer,
size_t len)
{
......@@ -613,12 +626,8 @@ static int ocfs2_xattr_get_value_outside(struct inode *inode,
int i, ret = 0;
size_t cplen, blocksize;
struct buffer_head *bh = NULL;
struct ocfs2_xattr_value_root *xv;
struct ocfs2_extent_list *el;
xv = (struct ocfs2_xattr_value_root *)
(xs->base + le16_to_cpu(xs->here->xe_name_offset) +
OCFS2_XATTR_SIZE(xs->here->xe_name_len));
el = &xv->xr_list;
clusters = le32_to_cpu(xv->xr_clusters);
bpc = ocfs2_clusters_to_blocks(inode->i_sb, 1);
......@@ -668,6 +677,7 @@ static int ocfs2_xattr_ibody_get(struct inode *inode,
{
struct ocfs2_inode_info *oi = OCFS2_I(inode);
struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
struct ocfs2_xattr_value_root *xv;
size_t size;
int ret = 0;
......@@ -692,7 +702,11 @@ static int ocfs2_xattr_ibody_get(struct inode *inode,
le16_to_cpu(xs->here->xe_name_offset) +
OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
} else {
ret = ocfs2_xattr_get_value_outside(inode, xs,
xv = (struct ocfs2_xattr_value_root *)
(xs->base + le16_to_cpu(
xs->here->xe_name_offset) +
OCFS2_XATTR_SIZE(xs->here->xe_name_len));
ret = ocfs2_xattr_get_value_outside(inode, xv,
buffer, size);
if (ret < 0) {
mlog_errno(ret);
......@@ -714,12 +728,15 @@ static int ocfs2_xattr_block_get(struct inode *inode,
struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
struct buffer_head *blk_bh = NULL;
struct ocfs2_xattr_block *xb;
struct ocfs2_xattr_value_root *xv;
size_t size;
int ret = -ENODATA;
int ret = -ENODATA, name_offset, name_len, block_off, i;
if (!di->i_xattr_loc)
return ret;
memset(&xs->bucket, 0, sizeof(xs->bucket));
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
le64_to_cpu(di->i_xattr_loc),
&blk_bh, OCFS2_BH_CACHED, inode);
......@@ -736,12 +753,19 @@ static int ocfs2_xattr_block_get(struct inode *inode,
xs->xattr_bh = blk_bh;
xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
xs->header = &xb->xb_attrs.xb_header;
xs->base = (void *)xs->header;
xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
xs->here = xs->header->xh_entries;
ret = ocfs2_xattr_find_entry(name_index, name, xs);
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
xs->header = &xb->xb_attrs.xb_header;
xs->base = (void *)xs->header;
xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
xs->here = xs->header->xh_entries;
ret = ocfs2_xattr_find_entry(name_index, name, xs);
} else
ret = ocfs2_xattr_index_block_find(inode, blk_bh,
name_index,
name, xs);
if (ret)
goto cleanup;
size = le64_to_cpu(xs->here->xe_value_size);
......@@ -749,12 +773,26 @@ static int ocfs2_xattr_block_get(struct inode *inode,
ret = -ERANGE;
if (size > buffer_size)
goto cleanup;
name_offset = le16_to_cpu(xs->here->xe_name_offset);
name_len = OCFS2_XATTR_SIZE(xs->here->xe_name_len);
i = xs->here - xs->header->xh_entries;
if (le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED) {
ret = ocfs2_xattr_bucket_get_name_value(inode,
xs->bucket.xh,
i,
&block_off,
&name_offset);
xs->base = xs->bucket.bhs[block_off]->b_data;
}
if (ocfs2_xattr_is_local(xs->here)) {
memcpy(buffer, (void *)xs->base +
le16_to_cpu(xs->here->xe_name_offset) +
OCFS2_XATTR_SIZE(xs->here->xe_name_len), size);
name_offset + name_len, size);
} else {
ret = ocfs2_xattr_get_value_outside(inode, xs,
xv = (struct ocfs2_xattr_value_root *)
(xs->base + name_offset + name_len);
ret = ocfs2_xattr_get_value_outside(inode, xv,
buffer, size);
if (ret < 0) {
mlog_errno(ret);
......@@ -764,8 +802,11 @@ static int ocfs2_xattr_block_get(struct inode *inode,
}
ret = size;
cleanup:
brelse(blk_bh);
for (i = 0; i < OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET; i++)
brelse(xs->bucket.bhs[i]);
memset(&xs->bucket, 0, sizeof(xs->bucket));
brelse(blk_bh);
return ret;
}
......@@ -1679,6 +1720,7 @@ static int ocfs2_xattr_block_find(struct inode *inode,
{
struct ocfs2_dinode *di = (struct ocfs2_dinode *)xs->inode_bh->b_data;
struct buffer_head *blk_bh = NULL;
struct ocfs2_xattr_block *xb;
int ret = 0;
if (!di->i_xattr_loc)
......@@ -1699,20 +1741,26 @@ static int ocfs2_xattr_block_find(struct inode *inode,
}
xs->xattr_bh = blk_bh;
xs->header = &((struct ocfs2_xattr_block *)blk_bh->b_data)->
xb_attrs.xb_header;
xs->base = (void *)xs->header;
xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
xs->here = xs->header->xh_entries;
xb = (struct ocfs2_xattr_block *)blk_bh->b_data;
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
xs->header = &xb->xb_attrs.xb_header;
xs->base = (void *)xs->header;
xs->end = (void *)(blk_bh->b_data) + blk_bh->b_size;
xs->here = xs->header->xh_entries;
ret = ocfs2_xattr_find_entry(name_index, name, xs);
} else
ret = ocfs2_xattr_index_block_find(inode, blk_bh,
name_index,
name, xs);
ret = ocfs2_xattr_find_entry(name_index, name, xs);
if (ret && ret != -ENODATA) {
xs->xattr_bh = NULL;
goto cleanup;
}
xs->not_found = ret;
return 0;
cleanup:
brelse(blk_bh);
......@@ -1941,6 +1989,18 @@ int ocfs2_xattr_set(struct inode *inode,
return ret;
}
static inline u32 ocfs2_xattr_hash_by_name(struct inode *inode,
int name_index,
const char *suffix_name)
{
struct xattr_handler *handler = ocfs2_xattr_handler(name_index);
char *prefix = handler->prefix;
int prefix_len = strlen(handler->prefix);
return ocfs2_xattr_name_hash(inode, prefix, prefix_len,
(char *)suffix_name, strlen(suffix_name));
}
/*
* Find the xattr extent rec which may contains name_hash.
* e_cpos will be the first name hash of the xattr rec.
......@@ -2010,6 +2070,251 @@ typedef int (xattr_bucket_func)(struct inode *inode,
struct ocfs2_xattr_bucket *bucket,
void *para);
static int ocfs2_find_xe_in_bucket(struct inode *inode,
struct buffer_head *header_bh,
int name_index,
const char *name,
u32 name_hash,
u16 *xe_index,
int *found)
{
int i, ret = 0, cmp = 1, block_off, new_offset;
struct ocfs2_xattr_header *xh =
(struct ocfs2_xattr_header *)header_bh->b_data;
size_t name_len = strlen(name);
struct ocfs2_xattr_entry *xe = NULL;
struct buffer_head *name_bh = NULL;
char *xe_name;
/*
* We don't use binary search in the bucket because there
* may be multiple entries with the same name hash.
*/
for (i = 0; i < le16_to_cpu(xh->xh_count); i++) {
xe = &xh->xh_entries[i];
if (name_hash > le32_to_cpu(xe->xe_name_hash))
continue;
else if (name_hash < le32_to_cpu(xe->xe_name_hash))
break;
cmp = name_index - ocfs2_xattr_get_type(xe);
if (!cmp)
cmp = name_len - xe->xe_name_len;
if (cmp)
continue;
ret = ocfs2_xattr_bucket_get_name_value(inode,
xh,
i,
&block_off,
&new_offset);
if (ret) {
mlog_errno(ret);
break;
}
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb),
header_bh->b_blocknr + block_off,
&name_bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
break;
}
xe_name = name_bh->b_data + new_offset;
cmp = memcmp(name, xe_name, name_len);
brelse(name_bh);
name_bh = NULL;
if (cmp == 0) {
*xe_index = i;
*found = 1;
ret = 0;
break;
}
}
return ret;
}
/*
* Find the specified xattr entry in a series of buckets.
* This series start from p_blkno and last for num_clusters.
* The ocfs2_xattr_header.xh_num_buckets of the first bucket contains
* the num of the valid buckets.
*
* Return the buffer_head this xattr should reside in. And if the xattr's
* hash is in the gap of 2 buckets, return the lower bucket.
*/
static int ocfs2_xattr_bucket_find(struct inode *inode,
int name_index,
const char *name,
u32 name_hash,
u64 p_blkno,
u32 first_hash,
u32 num_clusters,
struct ocfs2_xattr_search *xs)
{
int ret, found = 0;
struct buffer_head *bh = NULL;
struct buffer_head *lower_bh = NULL;
struct ocfs2_xattr_header *xh = NULL;
struct ocfs2_xattr_entry *xe = NULL;
u16 index = 0;
u16 blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
int low_bucket = 0, bucket, high_bucket;
u32 last_hash;
u64 blkno;
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), p_blkno,
&bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
goto out;
}
xh = (struct ocfs2_xattr_header *)bh->b_data;
high_bucket = le16_to_cpu(xh->xh_num_buckets) - 1;
while (low_bucket <= high_bucket) {
brelse(bh);
bh = NULL;
bucket = (low_bucket + high_bucket) / 2;
blkno = p_blkno + bucket * blk_per_bucket;
ret = ocfs2_read_block(OCFS2_SB(inode->i_sb), blkno,
&bh, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
goto out;
}
xh = (struct ocfs2_xattr_header *)bh->b_data;
xe = &xh->xh_entries[0];
if (name_hash < le32_to_cpu(xe->xe_name_hash)) {
high_bucket = bucket - 1;
continue;
}
/*
* Check whether the hash of the last entry in our
* bucket is larger than the search one.
*/
xe = &xh->xh_entries[le16_to_cpu(xh->xh_count) - 1];
last_hash = le32_to_cpu(xe->xe_name_hash);
/* record lower_bh which may be the insert place. */
brelse(lower_bh);
lower_bh = bh;
bh = NULL;
if (name_hash > le32_to_cpu(xe->xe_name_hash)) {
low_bucket = bucket + 1;
continue;
}
/* the searched xattr should reside in this bucket if exists. */
ret = ocfs2_find_xe_in_bucket(inode, lower_bh,
name_index, name, name_hash,
&index, &found);
if (ret) {
mlog_errno(ret);
goto out;
}
break;
}
/*
* Record the bucket we have found.
* When the xattr's hash value is in the gap of 2 buckets, we will
* always set it to the previous bucket.
*/
if (!lower_bh) {
/*
* We can't find any bucket whose first name_hash is less
* than the find name_hash.
*/
BUG_ON(bh->b_blocknr != p_blkno);
lower_bh = bh;
bh = NULL;
}
xs->bucket.bhs[0] = lower_bh;
xs->bucket.xh = (struct ocfs2_xattr_header *)
xs->bucket.bhs[0]->b_data;
lower_bh = NULL;
xs->header = xs->bucket.xh;
xs->base = xs->bucket.bhs[0]->b_data;
xs->end = xs->base + inode->i_sb->s_blocksize;
if (found) {
/*
* If we have found the xattr enty, read all the blocks in
* this bucket.
*/
ret = ocfs2_read_blocks(OCFS2_SB(inode->i_sb),
xs->bucket.bhs[0]->b_blocknr + 1,
blk_per_bucket - 1, &xs->bucket.bhs[1],
OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
goto out;
}
xs->here = &xs->header->xh_entries[index];
mlog(0, "find xattr %s in bucket %llu, entry = %u\n", name,
(unsigned long long)xs->bucket.bhs[0]->b_blocknr, index);
} else
ret = -ENODATA;
out:
brelse(bh);
brelse(lower_bh);
return ret;
}
static int ocfs2_xattr_index_block_find(struct inode *inode,
struct buffer_head *root_bh,
int name_index,
const char *name,
struct ocfs2_xattr_search *xs)
{
int ret;
struct ocfs2_xattr_block *xb =
(struct ocfs2_xattr_block *)root_bh->b_data;
struct ocfs2_xattr_tree_root *xb_root = &xb->xb_attrs.xb_root;
struct ocfs2_extent_list *el = &xb_root->xt_list;
u64 p_blkno = 0;
u32 first_hash, num_clusters = 0;
u32 name_hash = ocfs2_xattr_hash_by_name(inode, name_index, name);
if (le16_to_cpu(el->l_next_free_rec) == 0)
return -ENODATA;
mlog(0, "find xattr %s, hash = %u, index = %d in xattr tree\n",
name, name_hash, name_index);
ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno, &first_hash,
&num_clusters, el);
if (ret) {
mlog_errno(ret);
goto out;
}
BUG_ON(p_blkno == 0 || num_clusters == 0 || first_hash > name_hash);
mlog(0, "find xattr extent rec %u clusters from %llu, the first hash "
"in the rec is %u\n", num_clusters, p_blkno, first_hash);
ret = ocfs2_xattr_bucket_find(inode, name_index, name, name_hash,
p_blkno, first_hash, num_clusters, xs);
out:
return ret;
}
static int ocfs2_iterate_xattr_buckets(struct inode *inode,
u64 blkno,
u32 clusters,
......
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