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-rw-r--r--fs/nilfs2/alloc.c67
1 files changed, 65 insertions, 2 deletions
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c
index ba3e1f591f36..6b506995818d 100644
--- a/fs/nilfs2/alloc.c
+++ b/fs/nilfs2/alloc.c
@@ -21,6 +21,8 @@
* nilfs_palloc_groups_per_desc_block - get the number of groups that a group
* descriptor block can maintain
* @inode: inode of metadata file using this allocator
+ *
+ * Return: Number of groups that a group descriptor block can maintain.
*/
static inline unsigned long
nilfs_palloc_groups_per_desc_block(const struct inode *inode)
@@ -32,6 +34,8 @@ nilfs_palloc_groups_per_desc_block(const struct inode *inode)
/**
* nilfs_palloc_groups_count - get maximum number of groups
* @inode: inode of metadata file using this allocator
+ *
+ * Return: Maximum number of groups.
*/
static inline unsigned long
nilfs_palloc_groups_count(const struct inode *inode)
@@ -43,6 +47,8 @@ nilfs_palloc_groups_count(const struct inode *inode)
* nilfs_palloc_init_blockgroup - initialize private variables for allocator
* @inode: inode of metadata file using this allocator
* @entry_size: size of the persistent object
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
{
@@ -78,6 +84,9 @@ int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
* @offset: pointer to store offset number in the group
+ *
+ * Return: Number of the group that contains the entry with the index
+ * specified by @nr.
*/
static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
unsigned long *offset)
@@ -93,8 +102,8 @@ static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
* @inode: inode of metadata file using this allocator
* @group: group number
*
- * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
- * block which contains a descriptor of the specified group.
+ * Return: Index number in the metadata file of the descriptor block of
+ * the group specified by @group.
*/
static unsigned long
nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
@@ -111,6 +120,9 @@ nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
*
* nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
* block used to allocate/deallocate entries in the specified group.
+ *
+ * Return: Index number in the metadata file of the bitmap block of
+ * the group specified by @group.
*/
static unsigned long
nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
@@ -125,6 +137,8 @@ nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
* nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
* @desc: pointer to descriptor structure for the group
* @lock: spin lock protecting @desc
+ *
+ * Return: Number of free entries written in the group descriptor @desc.
*/
static unsigned long
nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
@@ -143,6 +157,9 @@ nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
* @desc: pointer to descriptor structure for the group
* @lock: spin lock protecting @desc
* @n: delta to be added
+ *
+ * Return: Number of free entries after adjusting the group descriptor
+ * @desc.
*/
static u32
nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
@@ -161,6 +178,9 @@ nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
* nilfs_palloc_entry_blkoff - get block offset of an entry block
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry (e.g. inode number)
+ *
+ * Return: Index number in the metadata file of the block containing
+ * the entry specified by @nr.
*/
static unsigned long
nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
@@ -238,6 +258,12 @@ static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
* @blkoff: block offset
* @prev: nilfs_bh_assoc struct of the last used buffer
* @lock: spin lock protecting @prev
+ *
+ * Return: 0 on success, or one of the following negative error codes on
+ * failure:
+ * * %-EIO - I/O error (including metadata corruption).
+ * * %-ENOENT - Non-existent block.
+ * * %-ENOMEM - Insufficient memory available.
*/
static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
struct nilfs_bh_assoc *prev,
@@ -258,6 +284,8 @@ static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
* @group: group number
* @create: create flag
* @bhp: pointer to store the resultant buffer head
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
static int nilfs_palloc_get_desc_block(struct inode *inode,
unsigned long group,
@@ -277,6 +305,8 @@ static int nilfs_palloc_get_desc_block(struct inode *inode,
* @group: group number
* @create: create flag
* @bhp: pointer to store the resultant buffer head
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
static int nilfs_palloc_get_bitmap_block(struct inode *inode,
unsigned long group,
@@ -294,6 +324,8 @@ static int nilfs_palloc_get_bitmap_block(struct inode *inode,
* nilfs_palloc_delete_bitmap_block - delete a bitmap block
* @inode: inode of metadata file using this allocator
* @group: group number
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
unsigned long group)
@@ -312,6 +344,8 @@ static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
* @nr: serial number of the entry (e.g. inode number)
* @create: create flag
* @bhp: pointer to store the resultant buffer head
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
int create, struct buffer_head **bhp)
@@ -328,6 +362,8 @@ int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
* nilfs_palloc_delete_entry_block - delete an entry block
* @inode: inode of metadata file using this allocator
* @nr: serial number of the entry
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
{
@@ -397,6 +433,9 @@ size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr,
* @bsize: size in bits
* @lock: spin lock protecting @bitmap
* @wrap: whether to wrap around
+ *
+ * Return: Offset number within the group of the found free entry, or
+ * %-ENOSPC if not found.
*/
static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
unsigned long target,
@@ -438,6 +477,9 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
* @inode: inode of metadata file using this allocator
* @curr: current group number
* @max: maximum number of groups
+ *
+ * Return: Number of remaining descriptors (= groups) managed by the descriptor
+ * block.
*/
static unsigned long
nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
@@ -453,6 +495,8 @@ nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
* nilfs_palloc_count_desc_blocks - count descriptor blocks number
* @inode: inode of metadata file using this allocator
* @desc_blocks: descriptor blocks number [out]
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
static int nilfs_palloc_count_desc_blocks(struct inode *inode,
unsigned long *desc_blocks)
@@ -473,6 +517,8 @@ static int nilfs_palloc_count_desc_blocks(struct inode *inode,
* MDT file growing
* @inode: inode of metadata file using this allocator
* @desc_blocks: known current descriptor blocks count
+ *
+ * Return: true if a group can be added in the metadata file, false if not.
*/
static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
unsigned long desc_blocks)
@@ -487,6 +533,12 @@ static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
* @inode: inode of metadata file using this allocator
* @nused: current number of used entries
* @nmaxp: max number of entries [out]
+ *
+ * Return: 0 on success, or one of the following negative error codes on
+ * failure:
+ * * %-EIO - I/O error (including metadata corruption).
+ * * %-ENOMEM - Insufficient memory available.
+ * * %-ERANGE - Number of entries in use is out of range.
*/
int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
{
@@ -518,6 +570,13 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the allocation
* @wrap: whether to wrap around
+ *
+ * Return: 0 on success, or one of the following negative error codes on
+ * failure:
+ * * %-EIO - I/O error (including metadata corruption).
+ * * %-ENOMEM - Insufficient memory available.
+ * * %-ENOSPC - Entries exhausted (No entries available for allocation).
+ * * %-EROFS - Read only filesystem
*/
int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
struct nilfs_palloc_req *req, bool wrap)
@@ -710,6 +769,8 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode,
* nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
* @inode: inode of metadata file using this allocator
* @req: nilfs_palloc_req structure exchanged for the removal
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
int nilfs_palloc_prepare_free_entry(struct inode *inode,
struct nilfs_palloc_req *req)
@@ -754,6 +815,8 @@ void nilfs_palloc_abort_free_entry(struct inode *inode,
* @inode: inode of metadata file using this allocator
* @entry_nrs: array of entry numbers to be deallocated
* @nitems: number of entries stored in @entry_nrs
+ *
+ * Return: 0 on success, or a negative error code on failure.
*/
int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
{