Skip to content

Commit

Permalink
ocfs2: Add xattr bucket iteration for large numbers of EAs
Browse files Browse the repository at this point in the history 
Ocfs2 breaks up xattr index tree leaves into 4k regions, called buckets.
Attributes are stored within a given bucket, depending on hash value.

After a discussion with Mark, we decided that the per-bucket index
(xe_entry[]) would only exist in the 1st block of a bucket. Likewise,
name/value pairs will not straddle more than one block. This allows the
majority of operations to work directly on the buffer heads in a leaf block.

This patch adds code to iterate the buckets in an EA. A new abstration of
ocfs2_xattr_bucket is added. It records the bhs in this bucket and
ocfs2_xattr_header. This keeps the code neat, improving readibility.

Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
  • Loading branch information
Tao Ma authored and Mark Fasheh committed Oct 13, 2008
1 parent ba49261 commit 0c044f0
Show file tree
Hide file tree
Showing 3 changed files with 293 additions and 6 deletions.
35 changes: 33 additions & 2 deletions fs/ocfs2/ocfs2_fs.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -755,8 +755,13 @@ struct ocfs2_xattr_header {
__le16 xh_count; /* contains the count of how
many records are in the
local xattr storage. */
__le16 xh_reserved1;
__le32 xh_reserved2;
__le16 xh_free_start; /* current offset for storing
xattr. */
__le16 xh_name_value_len; /* total length of name/value
length in this bucket. */
__le16 xh_num_buckets; /* bucket nums in one extent
record, only valid in the
first bucket. */
__le64 xh_csum;
struct ocfs2_xattr_entry xh_entries[0]; /* xattr entry list. */
};
Expand Down Expand Up @@ -793,6 +798,10 @@ struct ocfs2_xattr_tree_root {
#define OCFS2_XATTR_SIZE(size) (((size) + OCFS2_XATTR_ROUND) & \
~(OCFS2_XATTR_ROUND))

#define OCFS2_XATTR_BUCKET_SIZE 4096
#define OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET (OCFS2_XATTR_BUCKET_SIZE \
/ OCFS2_MIN_BLOCKSIZE)

/*
* On disk structure for xattr block.
*/
Expand Down Expand Up @@ -963,6 +972,17 @@ static inline u64 ocfs2_backup_super_blkno(struct super_block *sb, int index)
return 0;

}

static inline u16 ocfs2_xattr_recs_per_xb(struct super_block *sb)
{
int size;

size = sb->s_blocksize -
offsetof(struct ocfs2_xattr_block,
xb_attrs.xb_root.xt_list.l_recs);

return size / sizeof(struct ocfs2_extent_rec);
}
#else
static inline int ocfs2_fast_symlink_chars(int blocksize)
{
Expand Down Expand Up @@ -1046,6 +1066,17 @@ static inline uint64_t ocfs2_backup_super_blkno(int blocksize, int index)

return 0;
}

static inline int ocfs2_xattr_recs_per_xb(int blocksize)
{
int size;

size = blocksize -
offsetof(struct ocfs2_xattr_block,
xb_attrs.xb_root.xt_list.l_recs);

return size / sizeof(struct ocfs2_extent_rec);
}
#endif /* __KERNEL__ */


Expand Down
255 changes: 251 additions & 4 deletions fs/ocfs2/xattr.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,7 @@
#include "suballoc.h"
#include "uptodate.h"
#include "buffer_head_io.h"
#include "super.h"
#include "xattr.h"


Expand All @@ -60,6 +61,11 @@ struct ocfs2_xattr_def_value_root {
struct ocfs2_extent_rec er;
};

struct ocfs2_xattr_bucket {
struct buffer_head *bhs[OCFS2_XATTR_MAX_BLOCKS_PER_BUCKET];
struct ocfs2_xattr_header *xh;
};

#define OCFS2_XATTR_ROOT_SIZE (sizeof(struct ocfs2_xattr_def_value_root))
#define OCFS2_XATTR_INLINE_SIZE 80

Expand Down Expand Up @@ -99,6 +105,11 @@ struct ocfs2_xattr_search {
int not_found;
};

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
struct ocfs2_xattr_tree_root *xt,
char *buffer,
size_t buffer_size);

static inline struct xattr_handler *ocfs2_xattr_handler(int name_index)
{
struct xattr_handler *handler = NULL;
Expand Down Expand Up @@ -483,7 +494,7 @@ static int ocfs2_xattr_block_list(struct inode *inode,
size_t buffer_size)
{
struct buffer_head *blk_bh = NULL;
struct ocfs2_xattr_header *header = NULL;
struct ocfs2_xattr_block *xb;
int ret = 0;

if (!di->i_xattr_loc)
Expand All @@ -503,10 +514,17 @@ static int ocfs2_xattr_block_list(struct inode *inode,
goto cleanup;
}

header = &((struct ocfs2_xattr_block *)blk_bh->b_data)->
xb_attrs.xb_header;
xb = (struct ocfs2_xattr_block *)blk_bh->b_data;

ret = ocfs2_xattr_list_entries(inode, header, buffer, buffer_size);
if (!(le16_to_cpu(xb->xb_flags) & OCFS2_XATTR_INDEXED)) {
struct ocfs2_xattr_header *header = &xb->xb_attrs.xb_header;
ret = ocfs2_xattr_list_entries(inode, header,
buffer, buffer_size);
} else {
struct ocfs2_xattr_tree_root *xt = &xb->xb_attrs.xb_root;
ret = ocfs2_xattr_tree_list_index_block(inode, xt,
buffer, buffer_size);
}
cleanup:
brelse(blk_bh);

Expand Down Expand Up @@ -1923,3 +1941,232 @@ int ocfs2_xattr_set(struct inode *inode,
return ret;
}

/*
* Find the xattr extent rec which may contains name_hash.
* e_cpos will be the first name hash of the xattr rec.
* el must be the ocfs2_xattr_header.xb_attrs.xb_root.xt_list.
*/
static int ocfs2_xattr_get_rec(struct inode *inode,
u32 name_hash,
u64 *p_blkno,
u32 *e_cpos,
u32 *num_clusters,
struct ocfs2_extent_list *el)
{
int ret = 0, i;
struct buffer_head *eb_bh = NULL;
struct ocfs2_extent_block *eb;
struct ocfs2_extent_rec *rec = NULL;
u64 e_blkno = 0;

if (el->l_tree_depth) {
ret = ocfs2_find_leaf(inode, el, name_hash, &eb_bh);
if (ret) {
mlog_errno(ret);
goto out;
}

eb = (struct ocfs2_extent_block *) eb_bh->b_data;
el = &eb->h_list;

if (el->l_tree_depth) {
ocfs2_error(inode->i_sb,
"Inode %lu has non zero tree depth in "
"xattr tree block %llu\n", inode->i_ino,
(unsigned long long)eb_bh->b_blocknr);
ret = -EROFS;
goto out;
}
}

for (i = le16_to_cpu(el->l_next_free_rec) - 1; i >= 0; i--) {
rec = &el->l_recs[i];

if (le32_to_cpu(rec->e_cpos) <= name_hash) {
e_blkno = le64_to_cpu(rec->e_blkno);
break;
}
}

if (!e_blkno) {
ocfs2_error(inode->i_sb, "Inode %lu has bad extent "
"record (%u, %u, 0) in xattr", inode->i_ino,
le32_to_cpu(rec->e_cpos),
ocfs2_rec_clusters(el, rec));
ret = -EROFS;
goto out;
}

*p_blkno = le64_to_cpu(rec->e_blkno);
*num_clusters = le16_to_cpu(rec->e_leaf_clusters);
if (e_cpos)
*e_cpos = le32_to_cpu(rec->e_cpos);
out:
brelse(eb_bh);
return ret;
}

typedef int (xattr_bucket_func)(struct inode *inode,
struct ocfs2_xattr_bucket *bucket,
void *para);

static int ocfs2_iterate_xattr_buckets(struct inode *inode,
u64 blkno,
u32 clusters,
xattr_bucket_func *func,
void *para)
{
int i, j, ret = 0;
int blk_per_bucket = ocfs2_blocks_per_xattr_bucket(inode->i_sb);
u32 bpc = ocfs2_xattr_buckets_per_cluster(OCFS2_SB(inode->i_sb));
u32 num_buckets = clusters * bpc;
struct ocfs2_xattr_bucket bucket;

memset(&bucket, 0, sizeof(bucket));

mlog(0, "iterating xattr buckets in %u clusters starting from %llu\n",
clusters, blkno);

for (i = 0; i < num_buckets; i++, blkno += blk_per_bucket) {
ret = ocfs2_read_blocks(OCFS2_SB(inode->i_sb),
blkno, blk_per_bucket,
bucket.bhs, OCFS2_BH_CACHED, inode);
if (ret) {
mlog_errno(ret);
goto out;
}

bucket.xh = (struct ocfs2_xattr_header *)bucket.bhs[0]->b_data;
/*
* The real bucket num in this series of blocks is stored
* in the 1st bucket.
*/
if (i == 0)
num_buckets = le16_to_cpu(bucket.xh->xh_num_buckets);

mlog(0, "iterating xattr bucket %llu\n", blkno);
if (func) {
ret = func(inode, &bucket, para);
if (ret) {
mlog_errno(ret);
break;
}
}

for (j = 0; j < blk_per_bucket; j++)
brelse(bucket.bhs[j]);
memset(&bucket, 0, sizeof(bucket));
}

out:
for (j = 0; j < blk_per_bucket; j++)
brelse(bucket.bhs[j]);

return ret;
}

struct ocfs2_xattr_tree_list {
char *buffer;
size_t buffer_size;
};

static int ocfs2_xattr_bucket_get_name_value(struct inode *inode,
struct ocfs2_xattr_header *xh,
int index,
int *block_off,
int *new_offset)
{
u16 name_offset;

if (index < 0 || index >= le16_to_cpu(xh->xh_count))
return -EINVAL;

name_offset = le16_to_cpu(xh->xh_entries[index].xe_name_offset);

*block_off = name_offset >> inode->i_sb->s_blocksize_bits;
*new_offset = name_offset % inode->i_sb->s_blocksize;

return 0;
}

static int ocfs2_list_xattr_bucket(struct inode *inode,
struct ocfs2_xattr_bucket *bucket,
void *para)
{
int ret = 0;
struct ocfs2_xattr_tree_list *xl = (struct ocfs2_xattr_tree_list *)para;
size_t size;
int i, block_off, new_offset;

for (i = 0 ; i < le16_to_cpu(bucket->xh->xh_count); i++) {
struct ocfs2_xattr_entry *entry = &bucket->xh->xh_entries[i];
struct xattr_handler *handler =
ocfs2_xattr_handler(ocfs2_xattr_get_type(entry));

if (handler) {
ret = ocfs2_xattr_bucket_get_name_value(inode,
bucket->xh,
i,
&block_off,
&new_offset);
if (ret)
break;
size = handler->list(inode, xl->buffer, xl->buffer_size,
bucket->bhs[block_off]->b_data +
new_offset,
entry->xe_name_len);
if (xl->buffer) {
if (size > xl->buffer_size)
return -ERANGE;
xl->buffer += size;
}
xl->buffer_size -= size;
}
}

return ret;
}

static int ocfs2_xattr_tree_list_index_block(struct inode *inode,
struct ocfs2_xattr_tree_root *xt,
char *buffer,
size_t buffer_size)
{
struct ocfs2_extent_list *el = &xt->xt_list;
int ret = 0;
u32 name_hash = UINT_MAX, e_cpos = 0, num_clusters = 0;
u64 p_blkno = 0;
struct ocfs2_xattr_tree_list xl = {
.buffer = buffer,
.buffer_size = buffer_size,
};

if (le16_to_cpu(el->l_next_free_rec) == 0)
return 0;

while (name_hash > 0) {
ret = ocfs2_xattr_get_rec(inode, name_hash, &p_blkno,
&e_cpos, &num_clusters, el);
if (ret) {
mlog_errno(ret);
goto out;
}

ret = ocfs2_iterate_xattr_buckets(inode, p_blkno, num_clusters,
ocfs2_list_xattr_bucket,
&xl);
if (ret) {
mlog_errno(ret);
goto out;
}

if (e_cpos == 0)
break;

name_hash = e_cpos - 1;
}

ret = buffer_size - xl.buffer_size;
out:
return ret;
}
9 changes: 9 additions & 0 deletions fs/ocfs2/xattr.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -48,4 +48,13 @@ extern int ocfs2_xattr_set(struct inode *, int, const char *, const void *,
extern int ocfs2_xattr_remove(struct inode *inode, struct buffer_head *di_bh);
extern struct xattr_handler *ocfs2_xattr_handlers[];

static inline u16 ocfs2_xattr_buckets_per_cluster(struct ocfs2_super *osb)
{
return (1 << osb->s_clustersize_bits) / OCFS2_XATTR_BUCKET_SIZE;
}

static inline u16 ocfs2_blocks_per_xattr_bucket(struct super_block *sb)
{
return OCFS2_XATTR_BUCKET_SIZE / (1 << sb->s_blocksize_bits);
}
#endif /* OCFS2_XATTR_H */

0 comments on commit 0c044f0

Please sign in to comment.