libext2fs: extend xattr api to query number of attrs

Add another API to query the number of extended attributes.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index ff51c64..dd6404e 100644 (file)
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1180,6 +1180,7 @@ errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
 errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle);
 errcode_t ext2fs_free_ext_attr(ext2_filsys fs, ext2_ino_t ino,
                               struct ext2_inode_large *inode);
+size_t ext2fs_xattrs_count(struct ext2_xattr_handle *handle);
 
 /* extent.c */
 extern errcode_t ext2fs_extent_header_verify(void *ptr, int size);

diff --git a/lib/ext2fs/ext_attr.c b/lib/ext2fs/ext_attr.c
index 8101c7f..772bb07 100644 (file)
--- a/lib/ext2fs/ext_attr.c
+++ b/lib/ext2fs/ext_attr.c
@@ -197,7 +197,7 @@ struct ext2_xattr {
 struct ext2_xattr_handle {
        ext2_filsys fs;
        struct ext2_xattr *attrs;
-       size_t length;
+       size_t length, count;
        ext2_ino_t ino;
        int dirty;
 };
@@ -575,7 +575,8 @@ out:
 static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
                                         struct ext2_ext_attr_entry *entries,
                                         unsigned int storage_size,
-                                        void *value_start)
+                                        void *value_start,
+                                        size_t *nr_read)
 {
        struct ext2_xattr *x;
        struct ext2_ext_attr_entry *entry;
@@ -648,6 +649,7 @@ static errcode_t read_xattrs_from_buffer(struct ext2_xattr_handle *handle,
                memcpy(x->value, value_start + entry->e_value_offs,
                       entry->e_value_size);
                x++;
+               (*nr_read)++;
                entry = EXT2_EXT_ATTR_NEXT(entry);
        }
 
@@ -696,7 +698,7 @@ errcode_t ext2fs_xattrs_read(struct ext2_xattr_handle *handle)
                        inode->i_extra_isize + sizeof(__u32);
 
                err = read_xattrs_from_buffer(handle, start, storage_size,
-                                             start);
+                                             start, &handle->count);
                if (err)
                        goto out;
        }
@@ -736,7 +738,7 @@ read_ea_block:
                        sizeof(struct ext2_ext_attr_header);
                start = block_buf + sizeof(struct ext2_ext_attr_header);
                err = read_xattrs_from_buffer(handle, start, storage_size,
-                                             block_buf);
+                                             block_buf, &handle->count);
                if (err)
                        goto out3;
 
@@ -845,6 +847,7 @@ errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
                memcpy(last_empty->value, value, value_len);
                last_empty->value_len = value_len;
                handle->dirty = 1;
+               handle->count++;
                return 0;
        }
 
@@ -865,6 +868,7 @@ errcode_t ext2fs_xattr_set(struct ext2_xattr_handle *handle,
        memcpy(x->value, value, value_len);
        x->value_len = value_len;
        handle->dirty = 1;
+       handle->count++;
        return 0;
 }
 
@@ -883,6 +887,7 @@ errcode_t ext2fs_xattr_remove(struct ext2_xattr_handle *handle,
                        ext2fs_free_mem(&x->value);
                        x->value_len = 0;
                        handle->dirty = 1;
+                       handle->count--;
                        return 0;
                }
        }
@@ -913,6 +918,7 @@ errcode_t ext2fs_xattrs_open(ext2_filsys fs, ext2_ino_t ino,
                ext2fs_free_mem(&h);
                return err;
        }
+       h->count = 0;
        h->ino = ino;
        h->fs = fs;
        *handle = h;
@@ -943,3 +949,8 @@ errcode_t ext2fs_xattrs_close(struct ext2_xattr_handle **handle)
        ext2fs_free_mem(handle);
        return 0;
 }
+
+size_t ext2fs_xattrs_count(struct ext2_xattr_handle *handle)
+{
+       return handle->count;
+}