diff options
Diffstat (limited to 'fs/nilfs2/alloc.c')
| -rw-r--r-- | fs/nilfs2/alloc.c | 234 |
1 files changed, 164 insertions, 70 deletions
diff --git a/fs/nilfs2/alloc.c b/fs/nilfs2/alloc.c index 89caef7513db..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) @@ -177,12 +197,14 @@ nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr) * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block * @inode: inode of metadata file * @bh: buffer head of the buffer to be initialized - * @kaddr: kernel address mapped for the page including the buffer + * @from: kernel address mapped for a chunk of the block + * + * This function does not yet support the case where block size > PAGE_SIZE. */ static void nilfs_palloc_desc_block_init(struct inode *inode, - struct buffer_head *bh, void *kaddr) + struct buffer_head *bh, void *from) { - struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh); + struct nilfs_palloc_group_desc *desc = from; unsigned long n = nilfs_palloc_groups_per_desc_block(inode); __le32 nfrees; @@ -236,6 +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, @@ -256,6 +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, @@ -275,6 +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, @@ -292,6 +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) @@ -310,6 +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) @@ -326,6 +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) { @@ -337,38 +375,55 @@ static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr) } /** - * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor + * nilfs_palloc_group_desc_offset - calculate the byte offset of a group + * descriptor in the folio containing it * @inode: inode of metadata file using this allocator * @group: group number - * @bh: buffer head of the buffer storing the group descriptor block - * @kaddr: kernel address mapped for the page including the buffer + * @bh: buffer head of the group descriptor block + * + * Return: Byte offset in the folio of the group descriptor for @group. */ -static struct nilfs_palloc_group_desc * -nilfs_palloc_block_get_group_desc(const struct inode *inode, - unsigned long group, - const struct buffer_head *bh, void *kaddr) +static size_t nilfs_palloc_group_desc_offset(const struct inode *inode, + unsigned long group, + const struct buffer_head *bh) { - return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) + - group % nilfs_palloc_groups_per_desc_block(inode); + return offset_in_folio(bh->b_folio, bh->b_data) + + sizeof(struct nilfs_palloc_group_desc) * + (group % nilfs_palloc_groups_per_desc_block(inode)); } /** - * nilfs_palloc_block_get_entry - get kernel address of an entry + * nilfs_palloc_bitmap_offset - calculate the byte offset of a bitmap block + * in the folio containing it + * @bh: buffer head of the bitmap block + * + * Return: Byte offset in the folio of the bitmap block for @bh. + */ +static size_t nilfs_palloc_bitmap_offset(const struct buffer_head *bh) +{ + return offset_in_folio(bh->b_folio, bh->b_data); +} + +/** + * nilfs_palloc_entry_offset - calculate the byte offset of an entry in the + * folio containing it * @inode: inode of metadata file using this allocator - * @nr: serial number of the entry (e.g. inode number) - * @bh: buffer head of the buffer storing the entry block - * @kaddr: kernel address mapped for the page including the buffer + * @nr: serial number of the entry (e.g. inode number) + * @bh: buffer head of the entry block + * + * Return: Byte offset in the folio of the entry @nr. */ -void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr, - const struct buffer_head *bh, void *kaddr) +size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr, + const struct buffer_head *bh) { - unsigned long entry_offset, group_offset; + unsigned long entry_index_in_group, entry_index_in_block; - nilfs_palloc_group(inode, nr, &group_offset); - entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block; + nilfs_palloc_group(inode, nr, &entry_index_in_group); + entry_index_in_block = entry_index_in_group % + NILFS_MDT(inode)->mi_entries_per_block; - return kaddr + bh_offset(bh) + - entry_offset * NILFS_MDT(inode)->mi_entry_size; + return offset_in_folio(bh->b_folio, bh->b_data) + + entry_index_in_block * NILFS_MDT(inode)->mi_entry_size; } /** @@ -377,11 +432,15 @@ void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr, * @target: offset number of an entry in the group (start point) * @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, unsigned int bsize, - spinlock_t *lock) + spinlock_t *lock, bool wrap) { int pos, end = bsize; @@ -397,6 +456,8 @@ static int nilfs_palloc_find_available_slot(unsigned char *bitmap, end = target; } + if (!wrap) + return -ENOSPC; /* wrap around */ for (pos = 0; pos < end; pos++) { @@ -416,6 +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, @@ -431,6 +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) @@ -451,6 +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) @@ -465,6 +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) { @@ -495,14 +569,22 @@ int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp) * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object * @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) + struct nilfs_palloc_req *req, bool wrap) { struct buffer_head *desc_bh, *bitmap_bh; struct nilfs_palloc_group_desc *desc; unsigned char *bitmap; - void *desc_kaddr, *bitmap_kaddr; + size_t doff, boff; unsigned long group, maxgroup, ngroups; unsigned long group_offset, maxgroup_offset; unsigned long n, entries_per_group; @@ -516,7 +598,7 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, entries_per_group = nilfs_palloc_entries_per_group(inode); for (i = 0; i < ngroups; i += n) { - if (group >= ngroups) { + if (group >= ngroups && wrap) { /* wrap around */ group = 0; maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr, @@ -525,17 +607,17 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh); if (ret < 0) return ret; - desc_kaddr = kmap_local_page(desc_bh->b_page); - desc = nilfs_palloc_block_get_group_desc( - inode, group, desc_bh, desc_kaddr); + + doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh); + desc = kmap_local_folio(desc_bh->b_folio, doff); n = nilfs_palloc_rest_groups_in_desc_block(inode, group, maxgroup); - for (j = 0; j < n; j++, desc++, group++, group_offset = 0) { + for (j = 0; j < n; j++, group++, group_offset = 0) { lock = nilfs_mdt_bgl_lock(inode, group); - if (nilfs_palloc_group_desc_nfrees(desc, lock) == 0) + if (nilfs_palloc_group_desc_nfrees(&desc[j], lock) == 0) continue; - kunmap_local(desc_kaddr); + kunmap_local(desc); ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh); if (unlikely(ret < 0)) { @@ -543,22 +625,31 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, return ret; } - desc_kaddr = kmap_local_page(desc_bh->b_page); - desc = nilfs_palloc_block_get_group_desc( - inode, group, desc_bh, desc_kaddr); + /* + * Re-kmap the folio containing the first (and + * subsequent) group descriptors. + */ + desc = kmap_local_folio(desc_bh->b_folio, doff); - bitmap_kaddr = kmap_local_page(bitmap_bh->b_page); - bitmap = bitmap_kaddr + bh_offset(bitmap_bh); + boff = nilfs_palloc_bitmap_offset(bitmap_bh); + bitmap = kmap_local_folio(bitmap_bh->b_folio, boff); pos = nilfs_palloc_find_available_slot( - bitmap, group_offset, entries_per_group, lock); - kunmap_local(bitmap_kaddr); + bitmap, group_offset, entries_per_group, lock, + wrap); + /* + * Since the search for a free slot in the second and + * subsequent bitmap blocks always starts from the + * beginning, the wrap flag only has an effect on the + * first search. + */ + kunmap_local(bitmap); if (pos >= 0) goto found; brelse(bitmap_bh); } - kunmap_local(desc_kaddr); + kunmap_local(desc); brelse(desc_bh); } @@ -567,9 +658,9 @@ int nilfs_palloc_prepare_alloc_entry(struct inode *inode, found: /* found a free entry */ - nilfs_palloc_group_desc_add_entries(desc, lock, -1); + nilfs_palloc_group_desc_add_entries(&desc[j], lock, -1); req->pr_entry_nr = entries_per_group * group + pos; - kunmap_local(desc_kaddr); + kunmap_local(desc); req->pr_desc_bh = desc_bh; req->pr_bitmap_bh = bitmap_bh; @@ -600,18 +691,18 @@ void nilfs_palloc_commit_alloc_entry(struct inode *inode, void nilfs_palloc_commit_free_entry(struct inode *inode, struct nilfs_palloc_req *req) { - struct nilfs_palloc_group_desc *desc; unsigned long group, group_offset; + size_t doff, boff; + struct nilfs_palloc_group_desc *desc; unsigned char *bitmap; - void *desc_kaddr, *bitmap_kaddr; spinlock_t *lock; group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset); - desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page); - desc = nilfs_palloc_block_get_group_desc(inode, group, - req->pr_desc_bh, desc_kaddr); - bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page); - bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh); + doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh); + desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff); + + boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh); + bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff); lock = nilfs_mdt_bgl_lock(inode, group); if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap)) @@ -622,8 +713,8 @@ void nilfs_palloc_commit_free_entry(struct inode *inode, else nilfs_palloc_group_desc_add_entries(desc, lock, 1); - kunmap_local(bitmap_kaddr); - kunmap_local(desc_kaddr); + kunmap_local(bitmap); + kunmap_local(desc); mark_buffer_dirty(req->pr_desc_bh); mark_buffer_dirty(req->pr_bitmap_bh); @@ -642,17 +733,17 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode, struct nilfs_palloc_req *req) { struct nilfs_palloc_group_desc *desc; - void *desc_kaddr, *bitmap_kaddr; + size_t doff, boff; unsigned char *bitmap; unsigned long group, group_offset; spinlock_t *lock; group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset); - desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page); - desc = nilfs_palloc_block_get_group_desc(inode, group, - req->pr_desc_bh, desc_kaddr); - bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page); - bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh); + doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh); + desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff); + + boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh); + bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff); lock = nilfs_mdt_bgl_lock(inode, group); if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap)) @@ -663,8 +754,8 @@ void nilfs_palloc_abort_alloc_entry(struct inode *inode, else nilfs_palloc_group_desc_add_entries(desc, lock, 1); - kunmap_local(bitmap_kaddr); - kunmap_local(desc_kaddr); + kunmap_local(bitmap); + kunmap_local(desc); brelse(req->pr_bitmap_bh); brelse(req->pr_desc_bh); @@ -678,6 +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) @@ -722,13 +815,15 @@ 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) { struct buffer_head *desc_bh, *bitmap_bh; struct nilfs_palloc_group_desc *desc; unsigned char *bitmap; - void *desc_kaddr, *bitmap_kaddr; + size_t doff, boff; unsigned long group, group_offset; __u64 group_min_nr, last_nrs[8]; const unsigned long epg = nilfs_palloc_entries_per_group(inode); @@ -756,8 +851,8 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) /* Get the first entry number of the group */ group_min_nr = (__u64)group * epg; - bitmap_kaddr = kmap_local_page(bitmap_bh->b_page); - bitmap = bitmap_kaddr + bh_offset(bitmap_bh); + boff = nilfs_palloc_bitmap_offset(bitmap_bh); + bitmap = kmap_local_folio(bitmap_bh->b_folio, boff); lock = nilfs_mdt_bgl_lock(inode, group); j = i; @@ -802,7 +897,7 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) entry_start = rounddown(group_offset, epb); } while (true); - kunmap_local(bitmap_kaddr); + kunmap_local(bitmap); mark_buffer_dirty(bitmap_bh); brelse(bitmap_bh); @@ -816,11 +911,10 @@ int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems) inode->i_ino); } - desc_kaddr = kmap_local_page(desc_bh->b_page); - desc = nilfs_palloc_block_get_group_desc( - inode, group, desc_bh, desc_kaddr); + doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh); + desc = kmap_local_folio(desc_bh->b_folio, doff); nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n); - kunmap_local(desc_kaddr); + kunmap_local(desc); mark_buffer_dirty(desc_bh); nilfs_mdt_mark_dirty(inode); brelse(desc_bh); |