diff options
Diffstat (limited to 'kernel/fs/nilfs2/segment.c')
| -rw-r--r-- | kernel/fs/nilfs2/segment.c | 2758 |
1 files changed, 2758 insertions, 0 deletions
diff --git a/kernel/fs/nilfs2/segment.c b/kernel/fs/nilfs2/segment.c new file mode 100644 index 000000000..c6abbad9b --- /dev/null +++ b/kernel/fs/nilfs2/segment.c @@ -0,0 +1,2758 @@ +/* + * segment.c - NILFS segment constructor. + * + * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA + * + * Written by Ryusuke Konishi <ryusuke@osrg.net> + * + */ + +#include <linux/pagemap.h> +#include <linux/buffer_head.h> +#include <linux/writeback.h> +#include <linux/bitops.h> +#include <linux/bio.h> +#include <linux/completion.h> +#include <linux/blkdev.h> +#include <linux/backing-dev.h> +#include <linux/freezer.h> +#include <linux/kthread.h> +#include <linux/crc32.h> +#include <linux/pagevec.h> +#include <linux/slab.h> +#include "nilfs.h" +#include "btnode.h" +#include "page.h" +#include "segment.h" +#include "sufile.h" +#include "cpfile.h" +#include "ifile.h" +#include "segbuf.h" + + +/* + * Segment constructor + */ +#define SC_N_INODEVEC 16 /* Size of locally allocated inode vector */ + +#define SC_MAX_SEGDELTA 64 /* Upper limit of the number of segments + appended in collection retry loop */ + +/* Construction mode */ +enum { + SC_LSEG_SR = 1, /* Make a logical segment having a super root */ + SC_LSEG_DSYNC, /* Flush data blocks of a given file and make + a logical segment without a super root */ + SC_FLUSH_FILE, /* Flush data files, leads to segment writes without + creating a checkpoint */ + SC_FLUSH_DAT, /* Flush DAT file. This also creates segments without + a checkpoint */ +}; + +/* Stage numbers of dirty block collection */ +enum { + NILFS_ST_INIT = 0, + NILFS_ST_GC, /* Collecting dirty blocks for GC */ + NILFS_ST_FILE, + NILFS_ST_IFILE, + NILFS_ST_CPFILE, + NILFS_ST_SUFILE, + NILFS_ST_DAT, + NILFS_ST_SR, /* Super root */ + NILFS_ST_DSYNC, /* Data sync blocks */ + NILFS_ST_DONE, +}; + +/* State flags of collection */ +#define NILFS_CF_NODE 0x0001 /* Collecting node blocks */ +#define NILFS_CF_IFILE_STARTED 0x0002 /* IFILE stage has started */ +#define NILFS_CF_SUFREED 0x0004 /* segment usages has been freed */ +#define NILFS_CF_HISTORY_MASK (NILFS_CF_IFILE_STARTED | NILFS_CF_SUFREED) + +/* Operations depending on the construction mode and file type */ +struct nilfs_sc_operations { + int (*collect_data)(struct nilfs_sc_info *, struct buffer_head *, + struct inode *); + int (*collect_node)(struct nilfs_sc_info *, struct buffer_head *, + struct inode *); + int (*collect_bmap)(struct nilfs_sc_info *, struct buffer_head *, + struct inode *); + void (*write_data_binfo)(struct nilfs_sc_info *, + struct nilfs_segsum_pointer *, + union nilfs_binfo *); + void (*write_node_binfo)(struct nilfs_sc_info *, + struct nilfs_segsum_pointer *, + union nilfs_binfo *); +}; + +/* + * Other definitions + */ +static void nilfs_segctor_start_timer(struct nilfs_sc_info *); +static void nilfs_segctor_do_flush(struct nilfs_sc_info *, int); +static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *); +static void nilfs_dispose_list(struct the_nilfs *, struct list_head *, int); + +#define nilfs_cnt32_gt(a, b) \ + (typecheck(__u32, a) && typecheck(__u32, b) && \ + ((__s32)(b) - (__s32)(a) < 0)) +#define nilfs_cnt32_ge(a, b) \ + (typecheck(__u32, a) && typecheck(__u32, b) && \ + ((__s32)(a) - (__s32)(b) >= 0)) +#define nilfs_cnt32_lt(a, b) nilfs_cnt32_gt(b, a) +#define nilfs_cnt32_le(a, b) nilfs_cnt32_ge(b, a) + +static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti) +{ + struct nilfs_transaction_info *cur_ti = current->journal_info; + void *save = NULL; + + if (cur_ti) { + if (cur_ti->ti_magic == NILFS_TI_MAGIC) + return ++cur_ti->ti_count; + else { + /* + * If journal_info field is occupied by other FS, + * it is saved and will be restored on + * nilfs_transaction_commit(). + */ + printk(KERN_WARNING + "NILFS warning: journal info from a different " + "FS\n"); + save = current->journal_info; + } + } + if (!ti) { + ti = kmem_cache_alloc(nilfs_transaction_cachep, GFP_NOFS); + if (!ti) + return -ENOMEM; + ti->ti_flags = NILFS_TI_DYNAMIC_ALLOC; + } else { + ti->ti_flags = 0; + } + ti->ti_count = 0; + ti->ti_save = save; + ti->ti_magic = NILFS_TI_MAGIC; + current->journal_info = ti; + return 0; +} + +/** + * nilfs_transaction_begin - start indivisible file operations. + * @sb: super block + * @ti: nilfs_transaction_info + * @vacancy_check: flags for vacancy rate checks + * + * nilfs_transaction_begin() acquires a reader/writer semaphore, called + * the segment semaphore, to make a segment construction and write tasks + * exclusive. The function is used with nilfs_transaction_commit() in pairs. + * The region enclosed by these two functions can be nested. To avoid a + * deadlock, the semaphore is only acquired or released in the outermost call. + * + * This function allocates a nilfs_transaction_info struct to keep context + * information on it. It is initialized and hooked onto the current task in + * the outermost call. If a pre-allocated struct is given to @ti, it is used + * instead; otherwise a new struct is assigned from a slab. + * + * When @vacancy_check flag is set, this function will check the amount of + * free space, and will wait for the GC to reclaim disk space if low capacity. + * + * Return Value: On success, 0 is returned. On error, one of the following + * negative error code is returned. + * + * %-ENOMEM - Insufficient memory available. + * + * %-ENOSPC - No space left on device + */ +int nilfs_transaction_begin(struct super_block *sb, + struct nilfs_transaction_info *ti, + int vacancy_check) +{ + struct the_nilfs *nilfs; + int ret = nilfs_prepare_segment_lock(ti); + + if (unlikely(ret < 0)) + return ret; + if (ret > 0) + return 0; + + sb_start_intwrite(sb); + + nilfs = sb->s_fs_info; + down_read(&nilfs->ns_segctor_sem); + if (vacancy_check && nilfs_near_disk_full(nilfs)) { + up_read(&nilfs->ns_segctor_sem); + ret = -ENOSPC; + goto failed; + } + return 0; + + failed: + ti = current->journal_info; + current->journal_info = ti->ti_save; + if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) + kmem_cache_free(nilfs_transaction_cachep, ti); + sb_end_intwrite(sb); + return ret; +} + +/** + * nilfs_transaction_commit - commit indivisible file operations. + * @sb: super block + * + * nilfs_transaction_commit() releases the read semaphore which is + * acquired by nilfs_transaction_begin(). This is only performed + * in outermost call of this function. If a commit flag is set, + * nilfs_transaction_commit() sets a timer to start the segment + * constructor. If a sync flag is set, it starts construction + * directly. + */ +int nilfs_transaction_commit(struct super_block *sb) +{ + struct nilfs_transaction_info *ti = current->journal_info; + struct the_nilfs *nilfs = sb->s_fs_info; + int err = 0; + + BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); + ti->ti_flags |= NILFS_TI_COMMIT; + if (ti->ti_count > 0) { + ti->ti_count--; + return 0; + } + if (nilfs->ns_writer) { + struct nilfs_sc_info *sci = nilfs->ns_writer; + + if (ti->ti_flags & NILFS_TI_COMMIT) + nilfs_segctor_start_timer(sci); + if (atomic_read(&nilfs->ns_ndirtyblks) > sci->sc_watermark) + nilfs_segctor_do_flush(sci, 0); + } + up_read(&nilfs->ns_segctor_sem); + current->journal_info = ti->ti_save; + + if (ti->ti_flags & NILFS_TI_SYNC) + err = nilfs_construct_segment(sb); + if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) + kmem_cache_free(nilfs_transaction_cachep, ti); + sb_end_intwrite(sb); + return err; +} + +void nilfs_transaction_abort(struct super_block *sb) +{ + struct nilfs_transaction_info *ti = current->journal_info; + struct the_nilfs *nilfs = sb->s_fs_info; + + BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); + if (ti->ti_count > 0) { + ti->ti_count--; + return; + } + up_read(&nilfs->ns_segctor_sem); + + current->journal_info = ti->ti_save; + if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC) + kmem_cache_free(nilfs_transaction_cachep, ti); + sb_end_intwrite(sb); +} + +void nilfs_relax_pressure_in_lock(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + + if (!sci || !sci->sc_flush_request) + return; + + set_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); + up_read(&nilfs->ns_segctor_sem); + + down_write(&nilfs->ns_segctor_sem); + if (sci->sc_flush_request && + test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) { + struct nilfs_transaction_info *ti = current->journal_info; + + ti->ti_flags |= NILFS_TI_WRITER; + nilfs_segctor_do_immediate_flush(sci); + ti->ti_flags &= ~NILFS_TI_WRITER; + } + downgrade_write(&nilfs->ns_segctor_sem); +} + +static void nilfs_transaction_lock(struct super_block *sb, + struct nilfs_transaction_info *ti, + int gcflag) +{ + struct nilfs_transaction_info *cur_ti = current->journal_info; + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + + WARN_ON(cur_ti); + ti->ti_flags = NILFS_TI_WRITER; + ti->ti_count = 0; + ti->ti_save = cur_ti; + ti->ti_magic = NILFS_TI_MAGIC; + current->journal_info = ti; + + for (;;) { + down_write(&nilfs->ns_segctor_sem); + if (!test_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags)) + break; + + nilfs_segctor_do_immediate_flush(sci); + + up_write(&nilfs->ns_segctor_sem); + yield(); + } + if (gcflag) + ti->ti_flags |= NILFS_TI_GC; +} + +static void nilfs_transaction_unlock(struct super_block *sb) +{ + struct nilfs_transaction_info *ti = current->journal_info; + struct the_nilfs *nilfs = sb->s_fs_info; + + BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC); + BUG_ON(ti->ti_count > 0); + + up_write(&nilfs->ns_segctor_sem); + current->journal_info = ti->ti_save; +} + +static void *nilfs_segctor_map_segsum_entry(struct nilfs_sc_info *sci, + struct nilfs_segsum_pointer *ssp, + unsigned bytes) +{ + struct nilfs_segment_buffer *segbuf = sci->sc_curseg; + unsigned blocksize = sci->sc_super->s_blocksize; + void *p; + + if (unlikely(ssp->offset + bytes > blocksize)) { + ssp->offset = 0; + BUG_ON(NILFS_SEGBUF_BH_IS_LAST(ssp->bh, + &segbuf->sb_segsum_buffers)); + ssp->bh = NILFS_SEGBUF_NEXT_BH(ssp->bh); + } + p = ssp->bh->b_data + ssp->offset; + ssp->offset += bytes; + return p; +} + +/** + * nilfs_segctor_reset_segment_buffer - reset the current segment buffer + * @sci: nilfs_sc_info + */ +static int nilfs_segctor_reset_segment_buffer(struct nilfs_sc_info *sci) +{ + struct nilfs_segment_buffer *segbuf = sci->sc_curseg; + struct buffer_head *sumbh; + unsigned sumbytes; + unsigned flags = 0; + int err; + + if (nilfs_doing_gc()) + flags = NILFS_SS_GC; + err = nilfs_segbuf_reset(segbuf, flags, sci->sc_seg_ctime, sci->sc_cno); + if (unlikely(err)) + return err; + + sumbh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); + sumbytes = segbuf->sb_sum.sumbytes; + sci->sc_finfo_ptr.bh = sumbh; sci->sc_finfo_ptr.offset = sumbytes; + sci->sc_binfo_ptr.bh = sumbh; sci->sc_binfo_ptr.offset = sumbytes; + sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; + return 0; +} + +static int nilfs_segctor_feed_segment(struct nilfs_sc_info *sci) +{ + sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; + if (NILFS_SEGBUF_IS_LAST(sci->sc_curseg, &sci->sc_segbufs)) + return -E2BIG; /* The current segment is filled up + (internal code) */ + sci->sc_curseg = NILFS_NEXT_SEGBUF(sci->sc_curseg); + return nilfs_segctor_reset_segment_buffer(sci); +} + +static int nilfs_segctor_add_super_root(struct nilfs_sc_info *sci) +{ + struct nilfs_segment_buffer *segbuf = sci->sc_curseg; + int err; + + if (segbuf->sb_sum.nblocks >= segbuf->sb_rest_blocks) { + err = nilfs_segctor_feed_segment(sci); + if (err) + return err; + segbuf = sci->sc_curseg; + } + err = nilfs_segbuf_extend_payload(segbuf, &segbuf->sb_super_root); + if (likely(!err)) + segbuf->sb_sum.flags |= NILFS_SS_SR; + return err; +} + +/* + * Functions for making segment summary and payloads + */ +static int nilfs_segctor_segsum_block_required( + struct nilfs_sc_info *sci, const struct nilfs_segsum_pointer *ssp, + unsigned binfo_size) +{ + unsigned blocksize = sci->sc_super->s_blocksize; + /* Size of finfo and binfo is enough small against blocksize */ + + return ssp->offset + binfo_size + + (!sci->sc_blk_cnt ? sizeof(struct nilfs_finfo) : 0) > + blocksize; +} + +static void nilfs_segctor_begin_finfo(struct nilfs_sc_info *sci, + struct inode *inode) +{ + sci->sc_curseg->sb_sum.nfinfo++; + sci->sc_binfo_ptr = sci->sc_finfo_ptr; + nilfs_segctor_map_segsum_entry( + sci, &sci->sc_binfo_ptr, sizeof(struct nilfs_finfo)); + + if (NILFS_I(inode)->i_root && + !test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) + set_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); + /* skip finfo */ +} + +static void nilfs_segctor_end_finfo(struct nilfs_sc_info *sci, + struct inode *inode) +{ + struct nilfs_finfo *finfo; + struct nilfs_inode_info *ii; + struct nilfs_segment_buffer *segbuf; + __u64 cno; + + if (sci->sc_blk_cnt == 0) + return; + + ii = NILFS_I(inode); + + if (test_bit(NILFS_I_GCINODE, &ii->i_state)) + cno = ii->i_cno; + else if (NILFS_ROOT_METADATA_FILE(inode->i_ino)) + cno = 0; + else + cno = sci->sc_cno; + + finfo = nilfs_segctor_map_segsum_entry(sci, &sci->sc_finfo_ptr, + sizeof(*finfo)); + finfo->fi_ino = cpu_to_le64(inode->i_ino); + finfo->fi_nblocks = cpu_to_le32(sci->sc_blk_cnt); + finfo->fi_ndatablk = cpu_to_le32(sci->sc_datablk_cnt); + finfo->fi_cno = cpu_to_le64(cno); + + segbuf = sci->sc_curseg; + segbuf->sb_sum.sumbytes = sci->sc_binfo_ptr.offset + + sci->sc_super->s_blocksize * (segbuf->sb_sum.nsumblk - 1); + sci->sc_finfo_ptr = sci->sc_binfo_ptr; + sci->sc_blk_cnt = sci->sc_datablk_cnt = 0; +} + +static int nilfs_segctor_add_file_block(struct nilfs_sc_info *sci, + struct buffer_head *bh, + struct inode *inode, + unsigned binfo_size) +{ + struct nilfs_segment_buffer *segbuf; + int required, err = 0; + + retry: + segbuf = sci->sc_curseg; + required = nilfs_segctor_segsum_block_required( + sci, &sci->sc_binfo_ptr, binfo_size); + if (segbuf->sb_sum.nblocks + required + 1 > segbuf->sb_rest_blocks) { + nilfs_segctor_end_finfo(sci, inode); + err = nilfs_segctor_feed_segment(sci); + if (err) + return err; + goto retry; + } + if (unlikely(required)) { + err = nilfs_segbuf_extend_segsum(segbuf); + if (unlikely(err)) + goto failed; + } + if (sci->sc_blk_cnt == 0) + nilfs_segctor_begin_finfo(sci, inode); + + nilfs_segctor_map_segsum_entry(sci, &sci->sc_binfo_ptr, binfo_size); + /* Substitution to vblocknr is delayed until update_blocknr() */ + nilfs_segbuf_add_file_buffer(segbuf, bh); + sci->sc_blk_cnt++; + failed: + return err; +} + +/* + * Callback functions that enumerate, mark, and collect dirty blocks + */ +static int nilfs_collect_file_data(struct nilfs_sc_info *sci, + struct buffer_head *bh, struct inode *inode) +{ + int err; + + err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); + if (err < 0) + return err; + + err = nilfs_segctor_add_file_block(sci, bh, inode, + sizeof(struct nilfs_binfo_v)); + if (!err) + sci->sc_datablk_cnt++; + return err; +} + +static int nilfs_collect_file_node(struct nilfs_sc_info *sci, + struct buffer_head *bh, + struct inode *inode) +{ + return nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); +} + +static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci, + struct buffer_head *bh, + struct inode *inode) +{ + WARN_ON(!buffer_dirty(bh)); + return nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); +} + +static void nilfs_write_file_data_binfo(struct nilfs_sc_info *sci, + struct nilfs_segsum_pointer *ssp, + union nilfs_binfo *binfo) +{ + struct nilfs_binfo_v *binfo_v = nilfs_segctor_map_segsum_entry( + sci, ssp, sizeof(*binfo_v)); + *binfo_v = binfo->bi_v; +} + +static void nilfs_write_file_node_binfo(struct nilfs_sc_info *sci, + struct nilfs_segsum_pointer *ssp, + union nilfs_binfo *binfo) +{ + __le64 *vblocknr = nilfs_segctor_map_segsum_entry( + sci, ssp, sizeof(*vblocknr)); + *vblocknr = binfo->bi_v.bi_vblocknr; +} + +static struct nilfs_sc_operations nilfs_sc_file_ops = { + .collect_data = nilfs_collect_file_data, + .collect_node = nilfs_collect_file_node, + .collect_bmap = nilfs_collect_file_bmap, + .write_data_binfo = nilfs_write_file_data_binfo, + .write_node_binfo = nilfs_write_file_node_binfo, +}; + +static int nilfs_collect_dat_data(struct nilfs_sc_info *sci, + struct buffer_head *bh, struct inode *inode) +{ + int err; + + err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh); + if (err < 0) + return err; + + err = nilfs_segctor_add_file_block(sci, bh, inode, sizeof(__le64)); + if (!err) + sci->sc_datablk_cnt++; + return err; +} + +static int nilfs_collect_dat_bmap(struct nilfs_sc_info *sci, + struct buffer_head *bh, struct inode *inode) +{ + WARN_ON(!buffer_dirty(bh)); + return nilfs_segctor_add_file_block(sci, bh, inode, + sizeof(struct nilfs_binfo_dat)); +} + +static void nilfs_write_dat_data_binfo(struct nilfs_sc_info *sci, + struct nilfs_segsum_pointer *ssp, + union nilfs_binfo *binfo) +{ + __le64 *blkoff = nilfs_segctor_map_segsum_entry(sci, ssp, + sizeof(*blkoff)); + *blkoff = binfo->bi_dat.bi_blkoff; +} + +static void nilfs_write_dat_node_binfo(struct nilfs_sc_info *sci, + struct nilfs_segsum_pointer *ssp, + union nilfs_binfo *binfo) +{ + struct nilfs_binfo_dat *binfo_dat = + nilfs_segctor_map_segsum_entry(sci, ssp, sizeof(*binfo_dat)); + *binfo_dat = binfo->bi_dat; +} + +static struct nilfs_sc_operations nilfs_sc_dat_ops = { + .collect_data = nilfs_collect_dat_data, + .collect_node = nilfs_collect_file_node, + .collect_bmap = nilfs_collect_dat_bmap, + .write_data_binfo = nilfs_write_dat_data_binfo, + .write_node_binfo = nilfs_write_dat_node_binfo, +}; + +static struct nilfs_sc_operations nilfs_sc_dsync_ops = { + .collect_data = nilfs_collect_file_data, + .collect_node = NULL, + .collect_bmap = NULL, + .write_data_binfo = nilfs_write_file_data_binfo, + .write_node_binfo = NULL, +}; + +static size_t nilfs_lookup_dirty_data_buffers(struct inode *inode, + struct list_head *listp, + size_t nlimit, + loff_t start, loff_t end) +{ + struct address_space *mapping = inode->i_mapping; + struct pagevec pvec; + pgoff_t index = 0, last = ULONG_MAX; + size_t ndirties = 0; + int i; + + if (unlikely(start != 0 || end != LLONG_MAX)) { + /* + * A valid range is given for sync-ing data pages. The + * range is rounded to per-page; extra dirty buffers + * may be included if blocksize < pagesize. + */ + index = start >> PAGE_SHIFT; + last = end >> PAGE_SHIFT; + } + pagevec_init(&pvec, 0); + repeat: + if (unlikely(index > last) || + !pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, + min_t(pgoff_t, last - index, + PAGEVEC_SIZE - 1) + 1)) + return ndirties; + + for (i = 0; i < pagevec_count(&pvec); i++) { + struct buffer_head *bh, *head; + struct page *page = pvec.pages[i]; + + if (unlikely(page->index > last)) + break; + + lock_page(page); + if (!page_has_buffers(page)) + create_empty_buffers(page, 1 << inode->i_blkbits, 0); + unlock_page(page); + + bh = head = page_buffers(page); + do { + if (!buffer_dirty(bh) || buffer_async_write(bh)) + continue; + get_bh(bh); + list_add_tail(&bh->b_assoc_buffers, listp); + ndirties++; + if (unlikely(ndirties >= nlimit)) { + pagevec_release(&pvec); + cond_resched(); + return ndirties; + } + } while (bh = bh->b_this_page, bh != head); + } + pagevec_release(&pvec); + cond_resched(); + goto repeat; +} + +static void nilfs_lookup_dirty_node_buffers(struct inode *inode, + struct list_head *listp) +{ + struct nilfs_inode_info *ii = NILFS_I(inode); + struct address_space *mapping = &ii->i_btnode_cache; + struct pagevec pvec; + struct buffer_head *bh, *head; + unsigned int i; + pgoff_t index = 0; + + pagevec_init(&pvec, 0); + + while (pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY, + PAGEVEC_SIZE)) { + for (i = 0; i < pagevec_count(&pvec); i++) { + bh = head = page_buffers(pvec.pages[i]); + do { + if (buffer_dirty(bh) && + !buffer_async_write(bh)) { + get_bh(bh); + list_add_tail(&bh->b_assoc_buffers, + listp); + } + bh = bh->b_this_page; + } while (bh != head); + } + pagevec_release(&pvec); + cond_resched(); + } +} + +static void nilfs_dispose_list(struct the_nilfs *nilfs, + struct list_head *head, int force) +{ + struct nilfs_inode_info *ii, *n; + struct nilfs_inode_info *ivec[SC_N_INODEVEC], **pii; + unsigned nv = 0; + + while (!list_empty(head)) { + spin_lock(&nilfs->ns_inode_lock); + list_for_each_entry_safe(ii, n, head, i_dirty) { + list_del_init(&ii->i_dirty); + if (force) { + if (unlikely(ii->i_bh)) { + brelse(ii->i_bh); + ii->i_bh = NULL; + } + } else if (test_bit(NILFS_I_DIRTY, &ii->i_state)) { + set_bit(NILFS_I_QUEUED, &ii->i_state); + list_add_tail(&ii->i_dirty, + &nilfs->ns_dirty_files); + continue; + } + ivec[nv++] = ii; + if (nv == SC_N_INODEVEC) + break; + } + spin_unlock(&nilfs->ns_inode_lock); + + for (pii = ivec; nv > 0; pii++, nv--) + iput(&(*pii)->vfs_inode); + } +} + +static void nilfs_iput_work_func(struct work_struct *work) +{ + struct nilfs_sc_info *sci = container_of(work, struct nilfs_sc_info, + sc_iput_work); + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + + nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 0); +} + +static int nilfs_test_metadata_dirty(struct the_nilfs *nilfs, + struct nilfs_root *root) +{ + int ret = 0; + + if (nilfs_mdt_fetch_dirty(root->ifile)) + ret++; + if (nilfs_mdt_fetch_dirty(nilfs->ns_cpfile)) + ret++; + if (nilfs_mdt_fetch_dirty(nilfs->ns_sufile)) + ret++; + if ((ret || nilfs_doing_gc()) && nilfs_mdt_fetch_dirty(nilfs->ns_dat)) + ret++; + return ret; +} + +static int nilfs_segctor_clean(struct nilfs_sc_info *sci) +{ + return list_empty(&sci->sc_dirty_files) && + !test_bit(NILFS_SC_DIRTY, &sci->sc_flags) && + sci->sc_nfreesegs == 0 && + (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes)); +} + +static int nilfs_segctor_confirm(struct nilfs_sc_info *sci) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + int ret = 0; + + if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) + set_bit(NILFS_SC_DIRTY, &sci->sc_flags); + + spin_lock(&nilfs->ns_inode_lock); + if (list_empty(&nilfs->ns_dirty_files) && nilfs_segctor_clean(sci)) + ret++; + + spin_unlock(&nilfs->ns_inode_lock); + return ret; +} + +static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + + nilfs_mdt_clear_dirty(sci->sc_root->ifile); + nilfs_mdt_clear_dirty(nilfs->ns_cpfile); + nilfs_mdt_clear_dirty(nilfs->ns_sufile); + nilfs_mdt_clear_dirty(nilfs->ns_dat); +} + +static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + struct buffer_head *bh_cp; + struct nilfs_checkpoint *raw_cp; + int err; + + /* XXX: this interface will be changed */ + err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 1, + &raw_cp, &bh_cp); + if (likely(!err)) { + /* The following code is duplicated with cpfile. But, it is + needed to collect the checkpoint even if it was not newly + created */ + mark_buffer_dirty(bh_cp); + nilfs_mdt_mark_dirty(nilfs->ns_cpfile); + nilfs_cpfile_put_checkpoint( + nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); + } else + WARN_ON(err == -EINVAL || err == -ENOENT); + + return err; +} + +static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + struct buffer_head *bh_cp; + struct nilfs_checkpoint *raw_cp; + int err; + + err = nilfs_cpfile_get_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, 0, + &raw_cp, &bh_cp); + if (unlikely(err)) { + WARN_ON(err == -EINVAL || err == -ENOENT); + goto failed_ibh; + } + raw_cp->cp_snapshot_list.ssl_next = 0; + raw_cp->cp_snapshot_list.ssl_prev = 0; + raw_cp->cp_inodes_count = + cpu_to_le64(atomic64_read(&sci->sc_root->inodes_count)); + raw_cp->cp_blocks_count = + cpu_to_le64(atomic64_read(&sci->sc_root->blocks_count)); + raw_cp->cp_nblk_inc = + cpu_to_le64(sci->sc_nblk_inc + sci->sc_nblk_this_inc); + raw_cp->cp_create = cpu_to_le64(sci->sc_seg_ctime); + raw_cp->cp_cno = cpu_to_le64(nilfs->ns_cno); + + if (test_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags)) + nilfs_checkpoint_clear_minor(raw_cp); + else + nilfs_checkpoint_set_minor(raw_cp); + + nilfs_write_inode_common(sci->sc_root->ifile, + &raw_cp->cp_ifile_inode, 1); + nilfs_cpfile_put_checkpoint(nilfs->ns_cpfile, nilfs->ns_cno, bh_cp); + return 0; + + failed_ibh: + return err; +} + +static void nilfs_fill_in_file_bmap(struct inode *ifile, + struct nilfs_inode_info *ii) + +{ + struct buffer_head *ibh; + struct nilfs_inode *raw_inode; + + if (test_bit(NILFS_I_BMAP, &ii->i_state)) { + ibh = ii->i_bh; + BUG_ON(!ibh); + raw_inode = nilfs_ifile_map_inode(ifile, ii->vfs_inode.i_ino, + ibh); + nilfs_bmap_write(ii->i_bmap, raw_inode); + nilfs_ifile_unmap_inode(ifile, ii->vfs_inode.i_ino, ibh); + } +} + +static void nilfs_segctor_fill_in_file_bmap(struct nilfs_sc_info *sci) +{ + struct nilfs_inode_info *ii; + + list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) { + nilfs_fill_in_file_bmap(sci->sc_root->ifile, ii); + set_bit(NILFS_I_COLLECTED, &ii->i_state); + } +} + +static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs) +{ + struct buffer_head *bh_sr; + struct nilfs_super_root *raw_sr; + unsigned isz, srsz; + + bh_sr = NILFS_LAST_SEGBUF(&sci->sc_segbufs)->sb_super_root; + raw_sr = (struct nilfs_super_root *)bh_sr->b_data; + isz = nilfs->ns_inode_size; + srsz = NILFS_SR_BYTES(isz); + + raw_sr->sr_bytes = cpu_to_le16(srsz); + raw_sr->sr_nongc_ctime + = cpu_to_le64(nilfs_doing_gc() ? + nilfs->ns_nongc_ctime : sci->sc_seg_ctime); + raw_sr->sr_flags = 0; + + nilfs_write_inode_common(nilfs->ns_dat, (void *)raw_sr + + NILFS_SR_DAT_OFFSET(isz), 1); + nilfs_write_inode_common(nilfs->ns_cpfile, (void *)raw_sr + + NILFS_SR_CPFILE_OFFSET(isz), 1); + nilfs_write_inode_common(nilfs->ns_sufile, (void *)raw_sr + + NILFS_SR_SUFILE_OFFSET(isz), 1); + memset((void *)raw_sr + srsz, 0, nilfs->ns_blocksize - srsz); +} + +static void nilfs_redirty_inodes(struct list_head *head) +{ + struct nilfs_inode_info *ii; + + list_for_each_entry(ii, head, i_dirty) { + if (test_bit(NILFS_I_COLLECTED, &ii->i_state)) + clear_bit(NILFS_I_COLLECTED, &ii->i_state); + } +} + +static void nilfs_drop_collected_inodes(struct list_head *head) +{ + struct nilfs_inode_info *ii; + + list_for_each_entry(ii, head, i_dirty) { + if (!test_and_clear_bit(NILFS_I_COLLECTED, &ii->i_state)) + continue; + + clear_bit(NILFS_I_INODE_SYNC, &ii->i_state); + set_bit(NILFS_I_UPDATED, &ii->i_state); + } +} + +static int nilfs_segctor_apply_buffers(struct nilfs_sc_info *sci, + struct inode *inode, + struct list_head *listp, + int (*collect)(struct nilfs_sc_info *, + struct buffer_head *, + struct inode *)) +{ + struct buffer_head *bh, *n; + int err = 0; + + if (collect) { + list_for_each_entry_safe(bh, n, listp, b_assoc_buffers) { + list_del_init(&bh->b_assoc_buffers); + err = collect(sci, bh, inode); + brelse(bh); + if (unlikely(err)) + goto dispose_buffers; + } + return 0; + } + + dispose_buffers: + while (!list_empty(listp)) { + bh = list_first_entry(listp, struct buffer_head, + b_assoc_buffers); + list_del_init(&bh->b_assoc_buffers); + brelse(bh); + } + return err; +} + +static size_t nilfs_segctor_buffer_rest(struct nilfs_sc_info *sci) +{ + /* Remaining number of blocks within segment buffer */ + return sci->sc_segbuf_nblocks - + (sci->sc_nblk_this_inc + sci->sc_curseg->sb_sum.nblocks); +} + +static int nilfs_segctor_scan_file(struct nilfs_sc_info *sci, + struct inode *inode, + struct nilfs_sc_operations *sc_ops) +{ + LIST_HEAD(data_buffers); + LIST_HEAD(node_buffers); + int err; + + if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { + size_t n, rest = nilfs_segctor_buffer_rest(sci); + + n = nilfs_lookup_dirty_data_buffers( + inode, &data_buffers, rest + 1, 0, LLONG_MAX); + if (n > rest) { + err = nilfs_segctor_apply_buffers( + sci, inode, &data_buffers, + sc_ops->collect_data); + BUG_ON(!err); /* always receive -E2BIG or true error */ + goto break_or_fail; + } + } + nilfs_lookup_dirty_node_buffers(inode, &node_buffers); + + if (!(sci->sc_stage.flags & NILFS_CF_NODE)) { + err = nilfs_segctor_apply_buffers( + sci, inode, &data_buffers, sc_ops->collect_data); + if (unlikely(err)) { + /* dispose node list */ + nilfs_segctor_apply_buffers( + sci, inode, &node_buffers, NULL); + goto break_or_fail; + } + sci->sc_stage.flags |= NILFS_CF_NODE; + } + /* Collect node */ + err = nilfs_segctor_apply_buffers( + sci, inode, &node_buffers, sc_ops->collect_node); + if (unlikely(err)) + goto break_or_fail; + + nilfs_bmap_lookup_dirty_buffers(NILFS_I(inode)->i_bmap, &node_buffers); + err = nilfs_segctor_apply_buffers( + sci, inode, &node_buffers, sc_ops->collect_bmap); + if (unlikely(err)) + goto break_or_fail; + + nilfs_segctor_end_finfo(sci, inode); + sci->sc_stage.flags &= ~NILFS_CF_NODE; + + break_or_fail: + return err; +} + +static int nilfs_segctor_scan_file_dsync(struct nilfs_sc_info *sci, + struct inode *inode) +{ + LIST_HEAD(data_buffers); + size_t n, rest = nilfs_segctor_buffer_rest(sci); + int err; + + n = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, rest + 1, + sci->sc_dsync_start, + sci->sc_dsync_end); + + err = nilfs_segctor_apply_buffers(sci, inode, &data_buffers, + nilfs_collect_file_data); + if (!err) { + nilfs_segctor_end_finfo(sci, inode); + BUG_ON(n > rest); + /* always receive -E2BIG or true error if n > rest */ + } + return err; +} + +static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + struct list_head *head; + struct nilfs_inode_info *ii; + size_t ndone; + int err = 0; + + switch (sci->sc_stage.scnt) { + case NILFS_ST_INIT: + /* Pre-processes */ + sci->sc_stage.flags = 0; + + if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) { + sci->sc_nblk_inc = 0; + sci->sc_curseg->sb_sum.flags = NILFS_SS_LOGBGN; + if (mode == SC_LSEG_DSYNC) { + sci->sc_stage.scnt = NILFS_ST_DSYNC; + goto dsync_mode; + } + } + + sci->sc_stage.dirty_file_ptr = NULL; + sci->sc_stage.gc_inode_ptr = NULL; + if (mode == SC_FLUSH_DAT) { + sci->sc_stage.scnt = NILFS_ST_DAT; + goto dat_stage; + } + sci->sc_stage.scnt++; /* Fall through */ + case NILFS_ST_GC: + if (nilfs_doing_gc()) { + head = &sci->sc_gc_inodes; + ii = list_prepare_entry(sci->sc_stage.gc_inode_ptr, + head, i_dirty); + list_for_each_entry_continue(ii, head, i_dirty) { + err = nilfs_segctor_scan_file( + sci, &ii->vfs_inode, + &nilfs_sc_file_ops); + if (unlikely(err)) { + sci->sc_stage.gc_inode_ptr = list_entry( + ii->i_dirty.prev, + struct nilfs_inode_info, + i_dirty); + goto break_or_fail; + } + set_bit(NILFS_I_COLLECTED, &ii->i_state); + } + sci->sc_stage.gc_inode_ptr = NULL; + } + sci->sc_stage.scnt++; /* Fall through */ + case NILFS_ST_FILE: + head = &sci->sc_dirty_files; + ii = list_prepare_entry(sci->sc_stage.dirty_file_ptr, head, + i_dirty); + list_for_each_entry_continue(ii, head, i_dirty) { + clear_bit(NILFS_I_DIRTY, &ii->i_state); + + err = nilfs_segctor_scan_file(sci, &ii->vfs_inode, + &nilfs_sc_file_ops); + if (unlikely(err)) { + sci->sc_stage.dirty_file_ptr = + list_entry(ii->i_dirty.prev, + struct nilfs_inode_info, + i_dirty); + goto break_or_fail; + } + /* sci->sc_stage.dirty_file_ptr = NILFS_I(inode); */ + /* XXX: required ? */ + } + sci->sc_stage.dirty_file_ptr = NULL; + if (mode == SC_FLUSH_FILE) { + sci->sc_stage.scnt = NILFS_ST_DONE; + return 0; + } + sci->sc_stage.scnt++; + sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED; + /* Fall through */ + case NILFS_ST_IFILE: + err = nilfs_segctor_scan_file(sci, sci->sc_root->ifile, + &nilfs_sc_file_ops); + if (unlikely(err)) + break; + sci->sc_stage.scnt++; + /* Creating a checkpoint */ + err = nilfs_segctor_create_checkpoint(sci); + if (unlikely(err)) + break; + /* Fall through */ + case NILFS_ST_CPFILE: + err = nilfs_segctor_scan_file(sci, nilfs->ns_cpfile, + &nilfs_sc_file_ops); + if (unlikely(err)) + break; + sci->sc_stage.scnt++; /* Fall through */ + case NILFS_ST_SUFILE: + err = nilfs_sufile_freev(nilfs->ns_sufile, sci->sc_freesegs, + sci->sc_nfreesegs, &ndone); + if (unlikely(err)) { + nilfs_sufile_cancel_freev(nilfs->ns_sufile, + sci->sc_freesegs, ndone, + NULL); + break; + } + sci->sc_stage.flags |= NILFS_CF_SUFREED; + + err = nilfs_segctor_scan_file(sci, nilfs->ns_sufile, + &nilfs_sc_file_ops); + if (unlikely(err)) + break; + sci->sc_stage.scnt++; /* Fall through */ + case NILFS_ST_DAT: + dat_stage: + err = nilfs_segctor_scan_file(sci, nilfs->ns_dat, + &nilfs_sc_dat_ops); + if (unlikely(err)) + break; + if (mode == SC_FLUSH_DAT) { + sci->sc_stage.scnt = NILFS_ST_DONE; + return 0; + } + sci->sc_stage.scnt++; /* Fall through */ + case NILFS_ST_SR: + if (mode == SC_LSEG_SR) { + /* Appending a super root */ + err = nilfs_segctor_add_super_root(sci); + if (unlikely(err)) + break; + } + /* End of a logical segment */ + sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; + sci->sc_stage.scnt = NILFS_ST_DONE; + return 0; + case NILFS_ST_DSYNC: + dsync_mode: + sci->sc_curseg->sb_sum.flags |= NILFS_SS_SYNDT; + ii = sci->sc_dsync_inode; + if (!test_bit(NILFS_I_BUSY, &ii->i_state)) + break; + + err = nilfs_segctor_scan_file_dsync(sci, &ii->vfs_inode); + if (unlikely(err)) + break; + sci->sc_curseg->sb_sum.flags |= NILFS_SS_LOGEND; + sci->sc_stage.scnt = NILFS_ST_DONE; + return 0; + case NILFS_ST_DONE: + return 0; + default: + BUG(); + } + + break_or_fail: + return err; +} + +/** + * nilfs_segctor_begin_construction - setup segment buffer to make a new log + * @sci: nilfs_sc_info + * @nilfs: nilfs object + */ +static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs) +{ + struct nilfs_segment_buffer *segbuf, *prev; + __u64 nextnum; + int err, alloc = 0; + + segbuf = nilfs_segbuf_new(sci->sc_super); + if (unlikely(!segbuf)) + return -ENOMEM; + + if (list_empty(&sci->sc_write_logs)) { + nilfs_segbuf_map(segbuf, nilfs->ns_segnum, + nilfs->ns_pseg_offset, nilfs); + if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { + nilfs_shift_to_next_segment(nilfs); + nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs); + } + + segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq; + nextnum = nilfs->ns_nextnum; + + if (nilfs->ns_segnum == nilfs->ns_nextnum) + /* Start from the head of a new full segment */ + alloc++; + } else { + /* Continue logs */ + prev = NILFS_LAST_SEGBUF(&sci->sc_write_logs); + nilfs_segbuf_map_cont(segbuf, prev); + segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq; + nextnum = prev->sb_nextnum; + + if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) { + nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); + segbuf->sb_sum.seg_seq++; + alloc++; + } + } + + err = nilfs_sufile_mark_dirty(nilfs->ns_sufile, segbuf->sb_segnum); + if (err) + goto failed; + + if (alloc) { + err = nilfs_sufile_alloc(nilfs->ns_sufile, &nextnum); + if (err) + goto failed; + } + nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs); + + BUG_ON(!list_empty(&sci->sc_segbufs)); + list_add_tail(&segbuf->sb_list, &sci->sc_segbufs); + sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks; + return 0; + + failed: + nilfs_segbuf_free(segbuf); + return err; +} + +static int nilfs_segctor_extend_segments(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs, int nadd) +{ + struct nilfs_segment_buffer *segbuf, *prev; + struct inode *sufile = nilfs->ns_sufile; + __u64 nextnextnum; + LIST_HEAD(list); + int err, ret, i; + + prev = NILFS_LAST_SEGBUF(&sci->sc_segbufs); + /* + * Since the segment specified with nextnum might be allocated during + * the previous construction, the buffer including its segusage may + * not be dirty. The following call ensures that the buffer is dirty + * and will pin the buffer on memory until the sufile is written. + */ + err = nilfs_sufile_mark_dirty(sufile, prev->sb_nextnum); + if (unlikely(err)) + return err; + + for (i = 0; i < nadd; i++) { + /* extend segment info */ + err = -ENOMEM; + segbuf = nilfs_segbuf_new(sci->sc_super); + if (unlikely(!segbuf)) + goto failed; + + /* map this buffer to region of segment on-disk */ + nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs); + sci->sc_segbuf_nblocks += segbuf->sb_rest_blocks; + + /* allocate the next next full segment */ + err = nilfs_sufile_alloc(sufile, &nextnextnum); + if (unlikely(err)) + goto failed_segbuf; + + segbuf->sb_sum.seg_seq = prev->sb_sum.seg_seq + 1; + nilfs_segbuf_set_next_segnum(segbuf, nextnextnum, nilfs); + + list_add_tail(&segbuf->sb_list, &list); + prev = segbuf; + } + list_splice_tail(&list, &sci->sc_segbufs); + return 0; + + failed_segbuf: + nilfs_segbuf_free(segbuf); + failed: + list_for_each_entry(segbuf, &list, sb_list) { + ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); + WARN_ON(ret); /* never fails */ + } + nilfs_destroy_logs(&list); + return err; +} + +static void nilfs_free_incomplete_logs(struct list_head *logs, + struct the_nilfs *nilfs) +{ + struct nilfs_segment_buffer *segbuf, *prev; + struct inode *sufile = nilfs->ns_sufile; + int ret; + + segbuf = NILFS_FIRST_SEGBUF(logs); + if (nilfs->ns_nextnum != segbuf->sb_nextnum) { + ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); + WARN_ON(ret); /* never fails */ + } + if (atomic_read(&segbuf->sb_err)) { + /* Case 1: The first segment failed */ + if (segbuf->sb_pseg_start != segbuf->sb_fseg_start) + /* Case 1a: Partial segment appended into an existing + segment */ + nilfs_terminate_segment(nilfs, segbuf->sb_fseg_start, + segbuf->sb_fseg_end); + else /* Case 1b: New full segment */ + set_nilfs_discontinued(nilfs); + } + + prev = segbuf; + list_for_each_entry_continue(segbuf, logs, sb_list) { + if (prev->sb_nextnum != segbuf->sb_nextnum) { + ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); + WARN_ON(ret); /* never fails */ + } + if (atomic_read(&segbuf->sb_err) && + segbuf->sb_segnum != nilfs->ns_nextnum) + /* Case 2: extended segment (!= next) failed */ + nilfs_sufile_set_error(sufile, segbuf->sb_segnum); + prev = segbuf; + } +} + +static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci, + struct inode *sufile) +{ + struct nilfs_segment_buffer *segbuf; + unsigned long live_blocks; + int ret; + + list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { + live_blocks = segbuf->sb_sum.nblocks + + (segbuf->sb_pseg_start - segbuf->sb_fseg_start); + ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, + live_blocks, + sci->sc_seg_ctime); + WARN_ON(ret); /* always succeed because the segusage is dirty */ + } +} + +static void nilfs_cancel_segusage(struct list_head *logs, struct inode *sufile) +{ + struct nilfs_segment_buffer *segbuf; + int ret; + + segbuf = NILFS_FIRST_SEGBUF(logs); + ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, + segbuf->sb_pseg_start - + segbuf->sb_fseg_start, 0); + WARN_ON(ret); /* always succeed because the segusage is dirty */ + + list_for_each_entry_continue(segbuf, logs, sb_list) { + ret = nilfs_sufile_set_segment_usage(sufile, segbuf->sb_segnum, + 0, 0); + WARN_ON(ret); /* always succeed */ + } +} + +static void nilfs_segctor_truncate_segments(struct nilfs_sc_info *sci, + struct nilfs_segment_buffer *last, + struct inode *sufile) +{ + struct nilfs_segment_buffer *segbuf = last; + int ret; + + list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) { + sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks; + ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum); + WARN_ON(ret); + } + nilfs_truncate_logs(&sci->sc_segbufs, last); +} + + +static int nilfs_segctor_collect(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs, int mode) +{ + struct nilfs_cstage prev_stage = sci->sc_stage; + int err, nadd = 1; + + /* Collection retry loop */ + for (;;) { + sci->sc_nblk_this_inc = 0; + sci->sc_curseg = NILFS_FIRST_SEGBUF(&sci->sc_segbufs); + + err = nilfs_segctor_reset_segment_buffer(sci); + if (unlikely(err)) + goto failed; + + err = nilfs_segctor_collect_blocks(sci, mode); + sci->sc_nblk_this_inc += sci->sc_curseg->sb_sum.nblocks; + if (!err) + break; + + if (unlikely(err != -E2BIG)) + goto failed; + + /* The current segment is filled up */ + if (mode != SC_LSEG_SR || sci->sc_stage.scnt < NILFS_ST_CPFILE) + break; + + nilfs_clear_logs(&sci->sc_segbufs); + + if (sci->sc_stage.flags & NILFS_CF_SUFREED) { + err = nilfs_sufile_cancel_freev(nilfs->ns_sufile, + sci->sc_freesegs, + sci->sc_nfreesegs, + NULL); + WARN_ON(err); /* do not happen */ + sci->sc_stage.flags &= ~NILFS_CF_SUFREED; + } + + err = nilfs_segctor_extend_segments(sci, nilfs, nadd); + if (unlikely(err)) + return err; + + nadd = min_t(int, nadd << 1, SC_MAX_SEGDELTA); + sci->sc_stage = prev_stage; + } + nilfs_segctor_truncate_segments(sci, sci->sc_curseg, nilfs->ns_sufile); + return 0; + + failed: + return err; +} + +static void nilfs_list_replace_buffer(struct buffer_head *old_bh, + struct buffer_head *new_bh) +{ + BUG_ON(!list_empty(&new_bh->b_assoc_buffers)); + + list_replace_init(&old_bh->b_assoc_buffers, &new_bh->b_assoc_buffers); + /* The caller must release old_bh */ +} + +static int +nilfs_segctor_update_payload_blocknr(struct nilfs_sc_info *sci, + struct nilfs_segment_buffer *segbuf, + int mode) +{ + struct inode *inode = NULL; + sector_t blocknr; + unsigned long nfinfo = segbuf->sb_sum.nfinfo; + unsigned long nblocks = 0, ndatablk = 0; + struct nilfs_sc_operations *sc_op = NULL; + struct nilfs_segsum_pointer ssp; + struct nilfs_finfo *finfo = NULL; + union nilfs_binfo binfo; + struct buffer_head *bh, *bh_org; + ino_t ino = 0; + int err = 0; + + if (!nfinfo) + goto out; + + blocknr = segbuf->sb_pseg_start + segbuf->sb_sum.nsumblk; + ssp.bh = NILFS_SEGBUF_FIRST_BH(&segbuf->sb_segsum_buffers); + ssp.offset = sizeof(struct nilfs_segment_summary); + + list_for_each_entry(bh, &segbuf->sb_payload_buffers, b_assoc_buffers) { + if (bh == segbuf->sb_super_root) + break; + if (!finfo) { + finfo = nilfs_segctor_map_segsum_entry( + sci, &ssp, sizeof(*finfo)); + ino = le64_to_cpu(finfo->fi_ino); + nblocks = le32_to_cpu(finfo->fi_nblocks); + ndatablk = le32_to_cpu(finfo->fi_ndatablk); + + inode = bh->b_page->mapping->host; + + if (mode == SC_LSEG_DSYNC) + sc_op = &nilfs_sc_dsync_ops; + else if (ino == NILFS_DAT_INO) + sc_op = &nilfs_sc_dat_ops; + else /* file blocks */ + sc_op = &nilfs_sc_file_ops; + } + bh_org = bh; + get_bh(bh_org); + err = nilfs_bmap_assign(NILFS_I(inode)->i_bmap, &bh, blocknr, + &binfo); + if (bh != bh_org) + nilfs_list_replace_buffer(bh_org, bh); + brelse(bh_org); + if (unlikely(err)) + goto failed_bmap; + + if (ndatablk > 0) + sc_op->write_data_binfo(sci, &ssp, &binfo); + else + sc_op->write_node_binfo(sci, &ssp, &binfo); + + blocknr++; + if (--nblocks == 0) { + finfo = NULL; + if (--nfinfo == 0) + break; + } else if (ndatablk > 0) + ndatablk--; + } + out: + return 0; + + failed_bmap: + return err; +} + +static int nilfs_segctor_assign(struct nilfs_sc_info *sci, int mode) +{ + struct nilfs_segment_buffer *segbuf; + int err; + + list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { + err = nilfs_segctor_update_payload_blocknr(sci, segbuf, mode); + if (unlikely(err)) + return err; + nilfs_segbuf_fill_in_segsum(segbuf); + } + return 0; +} + +static void nilfs_begin_page_io(struct page *page) +{ + if (!page || PageWriteback(page)) + /* For split b-tree node pages, this function may be called + twice. We ignore the 2nd or later calls by this check. */ + return; + + lock_page(page); + clear_page_dirty_for_io(page); + set_page_writeback(page); + unlock_page(page); +} + +static void nilfs_segctor_prepare_write(struct nilfs_sc_info *sci) +{ + struct nilfs_segment_buffer *segbuf; + struct page *bd_page = NULL, *fs_page = NULL; + + list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) { + struct buffer_head *bh; + + list_for_each_entry(bh, &segbuf->sb_segsum_buffers, + b_assoc_buffers) { + if (bh->b_page != bd_page) { + if (bd_page) { + lock_page(bd_page); + clear_page_dirty_for_io(bd_page); + set_page_writeback(bd_page); + unlock_page(bd_page); + } + bd_page = bh->b_page; + } + } + + list_for_each_entry(bh, &segbuf->sb_payload_buffers, + b_assoc_buffers) { + set_buffer_async_write(bh); + if (bh == segbuf->sb_super_root) { + if (bh->b_page != bd_page) { + lock_page(bd_page); + clear_page_dirty_for_io(bd_page); + set_page_writeback(bd_page); + unlock_page(bd_page); + bd_page = bh->b_page; + } + break; + } + if (bh->b_page != fs_page) { + nilfs_begin_page_io(fs_page); + fs_page = bh->b_page; + } + } + } + if (bd_page) { + lock_page(bd_page); + clear_page_dirty_for_io(bd_page); + set_page_writeback(bd_page); + unlock_page(bd_page); + } + nilfs_begin_page_io(fs_page); +} + +static int nilfs_segctor_write(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs) +{ + int ret; + + ret = nilfs_write_logs(&sci->sc_segbufs, nilfs); + list_splice_tail_init(&sci->sc_segbufs, &sci->sc_write_logs); + return ret; +} + +static void nilfs_end_page_io(struct page *page, int err) +{ + if (!page) + return; + + if (buffer_nilfs_node(page_buffers(page)) && !PageWriteback(page)) { + /* + * For b-tree node pages, this function may be called twice + * or more because they might be split in a segment. + */ + if (PageDirty(page)) { + /* + * For pages holding split b-tree node buffers, dirty + * flag on the buffers may be cleared discretely. + * In that case, the page is once redirtied for + * remaining buffers, and it must be cancelled if + * all the buffers get cleaned later. + */ + lock_page(page); + if (nilfs_page_buffers_clean(page)) + __nilfs_clear_page_dirty(page); + unlock_page(page); + } + return; + } + + if (!err) { + if (!nilfs_page_buffers_clean(page)) + __set_page_dirty_nobuffers(page); + ClearPageError(page); + } else { + __set_page_dirty_nobuffers(page); + SetPageError(page); + } + + end_page_writeback(page); +} + +static void nilfs_abort_logs(struct list_head *logs, int err) +{ + struct nilfs_segment_buffer *segbuf; + struct page *bd_page = NULL, *fs_page = NULL; + struct buffer_head *bh; + + if (list_empty(logs)) + return; + + list_for_each_entry(segbuf, logs, sb_list) { + list_for_each_entry(bh, &segbuf->sb_segsum_buffers, + b_assoc_buffers) { + if (bh->b_page != bd_page) { + if (bd_page) + end_page_writeback(bd_page); + bd_page = bh->b_page; + } + } + + list_for_each_entry(bh, &segbuf->sb_payload_buffers, + b_assoc_buffers) { + clear_buffer_async_write(bh); + if (bh == segbuf->sb_super_root) { + if (bh->b_page != bd_page) { + end_page_writeback(bd_page); + bd_page = bh->b_page; + } + break; + } + if (bh->b_page != fs_page) { + nilfs_end_page_io(fs_page, err); + fs_page = bh->b_page; + } + } + } + if (bd_page) + end_page_writeback(bd_page); + + nilfs_end_page_io(fs_page, err); +} + +static void nilfs_segctor_abort_construction(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs, int err) +{ + LIST_HEAD(logs); + int ret; + + list_splice_tail_init(&sci->sc_write_logs, &logs); + ret = nilfs_wait_on_logs(&logs); + nilfs_abort_logs(&logs, ret ? : err); + + list_splice_tail_init(&sci->sc_segbufs, &logs); + nilfs_cancel_segusage(&logs, nilfs->ns_sufile); + nilfs_free_incomplete_logs(&logs, nilfs); + + if (sci->sc_stage.flags & NILFS_CF_SUFREED) { + ret = nilfs_sufile_cancel_freev(nilfs->ns_sufile, + sci->sc_freesegs, + sci->sc_nfreesegs, + NULL); + WARN_ON(ret); /* do not happen */ + } + + nilfs_destroy_logs(&logs); +} + +static void nilfs_set_next_segment(struct the_nilfs *nilfs, + struct nilfs_segment_buffer *segbuf) +{ + nilfs->ns_segnum = segbuf->sb_segnum; + nilfs->ns_nextnum = segbuf->sb_nextnum; + nilfs->ns_pseg_offset = segbuf->sb_pseg_start - segbuf->sb_fseg_start + + segbuf->sb_sum.nblocks; + nilfs->ns_seg_seq = segbuf->sb_sum.seg_seq; + nilfs->ns_ctime = segbuf->sb_sum.ctime; +} + +static void nilfs_segctor_complete_write(struct nilfs_sc_info *sci) +{ + struct nilfs_segment_buffer *segbuf; + struct page *bd_page = NULL, *fs_page = NULL; + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + int update_sr = false; + + list_for_each_entry(segbuf, &sci->sc_write_logs, sb_list) { + struct buffer_head *bh; + + list_for_each_entry(bh, &segbuf->sb_segsum_buffers, + b_assoc_buffers) { + set_buffer_uptodate(bh); + clear_buffer_dirty(bh); + if (bh->b_page != bd_page) { + if (bd_page) + end_page_writeback(bd_page); + bd_page = bh->b_page; + } + } + /* + * We assume that the buffers which belong to the same page + * continue over the buffer list. + * Under this assumption, the last BHs of pages is + * identifiable by the discontinuity of bh->b_page + * (page != fs_page). + * + * For B-tree node blocks, however, this assumption is not + * guaranteed. The cleanup code of B-tree node pages needs + * special care. + */ + list_for_each_entry(bh, &segbuf->sb_payload_buffers, + b_assoc_buffers) { + const unsigned long set_bits = (1 << BH_Uptodate); + const unsigned long clear_bits = + (1 << BH_Dirty | 1 << BH_Async_Write | + 1 << BH_Delay | 1 << BH_NILFS_Volatile | + 1 << BH_NILFS_Redirected); + + set_mask_bits(&bh->b_state, clear_bits, set_bits); + if (bh == segbuf->sb_super_root) { + if (bh->b_page != bd_page) { + end_page_writeback(bd_page); + bd_page = bh->b_page; + } + update_sr = true; + break; + } + if (bh->b_page != fs_page) { + nilfs_end_page_io(fs_page, 0); + fs_page = bh->b_page; + } + } + + if (!nilfs_segbuf_simplex(segbuf)) { + if (segbuf->sb_sum.flags & NILFS_SS_LOGBGN) { + set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); + sci->sc_lseg_stime = jiffies; + } + if (segbuf->sb_sum.flags & NILFS_SS_LOGEND) + clear_bit(NILFS_SC_UNCLOSED, &sci->sc_flags); + } + } + /* + * Since pages may continue over multiple segment buffers, + * end of the last page must be checked outside of the loop. + */ + if (bd_page) + end_page_writeback(bd_page); + + nilfs_end_page_io(fs_page, 0); + + nilfs_drop_collected_inodes(&sci->sc_dirty_files); + + if (nilfs_doing_gc()) + nilfs_drop_collected_inodes(&sci->sc_gc_inodes); + else + nilfs->ns_nongc_ctime = sci->sc_seg_ctime; + + sci->sc_nblk_inc += sci->sc_nblk_this_inc; + + segbuf = NILFS_LAST_SEGBUF(&sci->sc_write_logs); + nilfs_set_next_segment(nilfs, segbuf); + + if (update_sr) { + nilfs->ns_flushed_device = 0; + nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start, + segbuf->sb_sum.seg_seq, nilfs->ns_cno++); + + clear_bit(NILFS_SC_HAVE_DELTA, &sci->sc_flags); + clear_bit(NILFS_SC_DIRTY, &sci->sc_flags); + set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); + nilfs_segctor_clear_metadata_dirty(sci); + } else + clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags); +} + +static int nilfs_segctor_wait(struct nilfs_sc_info *sci) +{ + int ret; + + ret = nilfs_wait_on_logs(&sci->sc_write_logs); + if (!ret) { + nilfs_segctor_complete_write(sci); + nilfs_destroy_logs(&sci->sc_write_logs); + } + return ret; +} + +static int nilfs_segctor_collect_dirty_files(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs) +{ + struct nilfs_inode_info *ii, *n; + struct inode *ifile = sci->sc_root->ifile; + + spin_lock(&nilfs->ns_inode_lock); + retry: + list_for_each_entry_safe(ii, n, &nilfs->ns_dirty_files, i_dirty) { + if (!ii->i_bh) { + struct buffer_head *ibh; + int err; + + spin_unlock(&nilfs->ns_inode_lock); + err = nilfs_ifile_get_inode_block( + ifile, ii->vfs_inode.i_ino, &ibh); + if (unlikely(err)) { + nilfs_warning(sci->sc_super, __func__, + "failed to get inode block.\n"); + return err; + } + mark_buffer_dirty(ibh); + nilfs_mdt_mark_dirty(ifile); + spin_lock(&nilfs->ns_inode_lock); + if (likely(!ii->i_bh)) + ii->i_bh = ibh; + else + brelse(ibh); + goto retry; + } + + clear_bit(NILFS_I_QUEUED, &ii->i_state); + set_bit(NILFS_I_BUSY, &ii->i_state); + list_move_tail(&ii->i_dirty, &sci->sc_dirty_files); + } + spin_unlock(&nilfs->ns_inode_lock); + + return 0; +} + +static void nilfs_segctor_drop_written_files(struct nilfs_sc_info *sci, + struct the_nilfs *nilfs) +{ + struct nilfs_inode_info *ii, *n; + int during_mount = !(sci->sc_super->s_flags & MS_ACTIVE); + int defer_iput = false; + + spin_lock(&nilfs->ns_inode_lock); + list_for_each_entry_safe(ii, n, &sci->sc_dirty_files, i_dirty) { + if (!test_and_clear_bit(NILFS_I_UPDATED, &ii->i_state) || + test_bit(NILFS_I_DIRTY, &ii->i_state)) + continue; + + clear_bit(NILFS_I_BUSY, &ii->i_state); + brelse(ii->i_bh); + ii->i_bh = NULL; + list_del_init(&ii->i_dirty); + if (!ii->vfs_inode.i_nlink || during_mount) { + /* + * Defer calling iput() to avoid deadlocks if + * i_nlink == 0 or mount is not yet finished. + */ + list_add_tail(&ii->i_dirty, &sci->sc_iput_queue); + defer_iput = true; + } else { + spin_unlock(&nilfs->ns_inode_lock); + iput(&ii->vfs_inode); + spin_lock(&nilfs->ns_inode_lock); + } + } + spin_unlock(&nilfs->ns_inode_lock); + + if (defer_iput) + schedule_work(&sci->sc_iput_work); +} + +/* + * Main procedure of segment constructor + */ +static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + int err; + + sci->sc_stage.scnt = NILFS_ST_INIT; + sci->sc_cno = nilfs->ns_cno; + + err = nilfs_segctor_collect_dirty_files(sci, nilfs); + if (unlikely(err)) + goto out; + + if (nilfs_test_metadata_dirty(nilfs, sci->sc_root)) + set_bit(NILFS_SC_DIRTY, &sci->sc_flags); + + if (nilfs_segctor_clean(sci)) + goto out; + + do { + sci->sc_stage.flags &= ~NILFS_CF_HISTORY_MASK; + + err = nilfs_segctor_begin_construction(sci, nilfs); + if (unlikely(err)) + goto out; + + /* Update time stamp */ + sci->sc_seg_ctime = get_seconds(); + + err = nilfs_segctor_collect(sci, nilfs, mode); + if (unlikely(err)) + goto failed; + + /* Avoid empty segment */ + if (sci->sc_stage.scnt == NILFS_ST_DONE && + nilfs_segbuf_empty(sci->sc_curseg)) { + nilfs_segctor_abort_construction(sci, nilfs, 1); + goto out; + } + + err = nilfs_segctor_assign(sci, mode); + if (unlikely(err)) + goto failed; + + if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) + nilfs_segctor_fill_in_file_bmap(sci); + + if (mode == SC_LSEG_SR && + sci->sc_stage.scnt >= NILFS_ST_CPFILE) { + err = nilfs_segctor_fill_in_checkpoint(sci); + if (unlikely(err)) + goto failed_to_write; + + nilfs_segctor_fill_in_super_root(sci, nilfs); + } + nilfs_segctor_update_segusage(sci, nilfs->ns_sufile); + + /* Write partial segments */ + nilfs_segctor_prepare_write(sci); + + nilfs_add_checksums_on_logs(&sci->sc_segbufs, + nilfs->ns_crc_seed); + + err = nilfs_segctor_write(sci, nilfs); + if (unlikely(err)) + goto failed_to_write; + + if (sci->sc_stage.scnt == NILFS_ST_DONE || + nilfs->ns_blocksize_bits != PAGE_CACHE_SHIFT) { + /* + * At this point, we avoid double buffering + * for blocksize < pagesize because page dirty + * flag is turned off during write and dirty + * buffers are not properly collected for + * pages crossing over segments. + */ + err = nilfs_segctor_wait(sci); + if (err) + goto failed_to_write; + } + } while (sci->sc_stage.scnt != NILFS_ST_DONE); + + out: + nilfs_segctor_drop_written_files(sci, nilfs); + return err; + + failed_to_write: + if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED) + nilfs_redirty_inodes(&sci->sc_dirty_files); + + failed: + if (nilfs_doing_gc()) + nilfs_redirty_inodes(&sci->sc_gc_inodes); + nilfs_segctor_abort_construction(sci, nilfs, err); + goto out; +} + +/** + * nilfs_segctor_start_timer - set timer of background write + * @sci: nilfs_sc_info + * + * If the timer has already been set, it ignores the new request. + * This function MUST be called within a section locking the segment + * semaphore. + */ +static void nilfs_segctor_start_timer(struct nilfs_sc_info *sci) +{ + spin_lock(&sci->sc_state_lock); + if (!(sci->sc_state & NILFS_SEGCTOR_COMMIT)) { + sci->sc_timer.expires = jiffies + sci->sc_interval; + add_timer(&sci->sc_timer); + sci->sc_state |= NILFS_SEGCTOR_COMMIT; + } + spin_unlock(&sci->sc_state_lock); +} + +static void nilfs_segctor_do_flush(struct nilfs_sc_info *sci, int bn) +{ + spin_lock(&sci->sc_state_lock); + if (!(sci->sc_flush_request & (1 << bn))) { + unsigned long prev_req = sci->sc_flush_request; + + sci->sc_flush_request |= (1 << bn); + if (!prev_req) + wake_up(&sci->sc_wait_daemon); + } + spin_unlock(&sci->sc_state_lock); +} + +/** + * nilfs_flush_segment - trigger a segment construction for resource control + * @sb: super block + * @ino: inode number of the file to be flushed out. + */ +void nilfs_flush_segment(struct super_block *sb, ino_t ino) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + + if (!sci || nilfs_doing_construction()) + return; + nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0); + /* assign bit 0 to data files */ +} + +struct nilfs_segctor_wait_request { + wait_queue_t wq; + __u32 seq; + int err; + atomic_t done; +}; + +static int nilfs_segctor_sync(struct nilfs_sc_info *sci) +{ + struct nilfs_segctor_wait_request wait_req; + int err = 0; + + spin_lock(&sci->sc_state_lock); + init_wait(&wait_req.wq); + wait_req.err = 0; + atomic_set(&wait_req.done, 0); + wait_req.seq = ++sci->sc_seq_request; + spin_unlock(&sci->sc_state_lock); + + init_waitqueue_entry(&wait_req.wq, current); + add_wait_queue(&sci->sc_wait_request, &wait_req.wq); + set_current_state(TASK_INTERRUPTIBLE); + wake_up(&sci->sc_wait_daemon); + + for (;;) { + if (atomic_read(&wait_req.done)) { + err = wait_req.err; + break; + } + if (!signal_pending(current)) { + schedule(); + continue; + } + err = -ERESTARTSYS; + break; + } + finish_wait(&sci->sc_wait_request, &wait_req.wq); + return err; +} + +static void nilfs_segctor_wakeup(struct nilfs_sc_info *sci, int err) +{ + struct nilfs_segctor_wait_request *wrq, *n; + unsigned long flags; + + spin_lock_irqsave(&sci->sc_wait_request.lock, flags); + list_for_each_entry_safe(wrq, n, &sci->sc_wait_request.task_list, + wq.task_list) { + if (!atomic_read(&wrq->done) && + nilfs_cnt32_ge(sci->sc_seq_done, wrq->seq)) { + wrq->err = err; + atomic_set(&wrq->done, 1); + } + if (atomic_read(&wrq->done)) { + wrq->wq.func(&wrq->wq, + TASK_UNINTERRUPTIBLE | TASK_INTERRUPTIBLE, + 0, NULL); + } + } + spin_unlock_irqrestore(&sci->sc_wait_request.lock, flags); +} + +/** + * nilfs_construct_segment - construct a logical segment + * @sb: super block + * + * Return Value: On success, 0 is retured. On errors, one of the following + * negative error code is returned. + * + * %-EROFS - Read only filesystem. + * + * %-EIO - I/O error + * + * %-ENOSPC - No space left on device (only in a panic state). + * + * %-ERESTARTSYS - Interrupted. + * + * %-ENOMEM - Insufficient memory available. + */ +int nilfs_construct_segment(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + struct nilfs_transaction_info *ti; + int err; + + if (!sci) + return -EROFS; + + /* A call inside transactions causes a deadlock. */ + BUG_ON((ti = current->journal_info) && ti->ti_magic == NILFS_TI_MAGIC); + + err = nilfs_segctor_sync(sci); + return err; +} + +/** + * nilfs_construct_dsync_segment - construct a data-only logical segment + * @sb: super block + * @inode: inode whose data blocks should be written out + * @start: start byte offset + * @end: end byte offset (inclusive) + * + * Return Value: On success, 0 is retured. On errors, one of the following + * negative error code is returned. + * + * %-EROFS - Read only filesystem. + * + * %-EIO - I/O error + * + * %-ENOSPC - No space left on device (only in a panic state). + * + * %-ERESTARTSYS - Interrupted. + * + * %-ENOMEM - Insufficient memory available. + */ +int nilfs_construct_dsync_segment(struct super_block *sb, struct inode *inode, + loff_t start, loff_t end) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + struct nilfs_inode_info *ii; + struct nilfs_transaction_info ti; + int err = 0; + + if (!sci) + return -EROFS; + + nilfs_transaction_lock(sb, &ti, 0); + + ii = NILFS_I(inode); + if (test_bit(NILFS_I_INODE_SYNC, &ii->i_state) || + nilfs_test_opt(nilfs, STRICT_ORDER) || + test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || + nilfs_discontinued(nilfs)) { + nilfs_transaction_unlock(sb); + err = nilfs_segctor_sync(sci); + return err; + } + + spin_lock(&nilfs->ns_inode_lock); + if (!test_bit(NILFS_I_QUEUED, &ii->i_state) && + !test_bit(NILFS_I_BUSY, &ii->i_state)) { + spin_unlock(&nilfs->ns_inode_lock); + nilfs_transaction_unlock(sb); + return 0; + } + spin_unlock(&nilfs->ns_inode_lock); + sci->sc_dsync_inode = ii; + sci->sc_dsync_start = start; + sci->sc_dsync_end = end; + + err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC); + if (!err) + nilfs->ns_flushed_device = 0; + + nilfs_transaction_unlock(sb); + return err; +} + +#define FLUSH_FILE_BIT (0x1) /* data file only */ +#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */ + +/** + * nilfs_segctor_accept - record accepted sequence count of log-write requests + * @sci: segment constructor object + */ +static void nilfs_segctor_accept(struct nilfs_sc_info *sci) +{ + spin_lock(&sci->sc_state_lock); + sci->sc_seq_accepted = sci->sc_seq_request; + spin_unlock(&sci->sc_state_lock); + del_timer_sync(&sci->sc_timer); +} + +/** + * nilfs_segctor_notify - notify the result of request to caller threads + * @sci: segment constructor object + * @mode: mode of log forming + * @err: error code to be notified + */ +static void nilfs_segctor_notify(struct nilfs_sc_info *sci, int mode, int err) +{ + /* Clear requests (even when the construction failed) */ + spin_lock(&sci->sc_state_lock); + + if (mode == SC_LSEG_SR) { + sci->sc_state &= ~NILFS_SEGCTOR_COMMIT; + sci->sc_seq_done = sci->sc_seq_accepted; + nilfs_segctor_wakeup(sci, err); + sci->sc_flush_request = 0; + } else { + if (mode == SC_FLUSH_FILE) + sci->sc_flush_request &= ~FLUSH_FILE_BIT; + else if (mode == SC_FLUSH_DAT) + sci->sc_flush_request &= ~FLUSH_DAT_BIT; + + /* re-enable timer if checkpoint creation was not done */ + if ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && + time_before(jiffies, sci->sc_timer.expires)) + add_timer(&sci->sc_timer); + } + spin_unlock(&sci->sc_state_lock); +} + +/** + * nilfs_segctor_construct - form logs and write them to disk + * @sci: segment constructor object + * @mode: mode of log forming + */ +static int nilfs_segctor_construct(struct nilfs_sc_info *sci, int mode) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + struct nilfs_super_block **sbp; + int err = 0; + + nilfs_segctor_accept(sci); + + if (nilfs_discontinued(nilfs)) + mode = SC_LSEG_SR; + if (!nilfs_segctor_confirm(sci)) + err = nilfs_segctor_do_construct(sci, mode); + + if (likely(!err)) { + if (mode != SC_FLUSH_DAT) + atomic_set(&nilfs->ns_ndirtyblks, 0); + if (test_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags) && + nilfs_discontinued(nilfs)) { + down_write(&nilfs->ns_sem); + err = -EIO; + sbp = nilfs_prepare_super(sci->sc_super, + nilfs_sb_will_flip(nilfs)); + if (likely(sbp)) { + nilfs_set_log_cursor(sbp[0], nilfs); + err = nilfs_commit_super(sci->sc_super, + NILFS_SB_COMMIT); + } + up_write(&nilfs->ns_sem); + } + } + + nilfs_segctor_notify(sci, mode, err); + return err; +} + +static void nilfs_construction_timeout(unsigned long data) +{ + struct task_struct *p = (struct task_struct *)data; + wake_up_process(p); +} + +static void +nilfs_remove_written_gcinodes(struct the_nilfs *nilfs, struct list_head *head) +{ + struct nilfs_inode_info *ii, *n; + + list_for_each_entry_safe(ii, n, head, i_dirty) { + if (!test_bit(NILFS_I_UPDATED, &ii->i_state)) + continue; + list_del_init(&ii->i_dirty); + truncate_inode_pages(&ii->vfs_inode.i_data, 0); + nilfs_btnode_cache_clear(&ii->i_btnode_cache); + iput(&ii->vfs_inode); + } +} + +int nilfs_clean_segments(struct super_block *sb, struct nilfs_argv *argv, + void **kbufs) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci = nilfs->ns_writer; + struct nilfs_transaction_info ti; + int err; + + if (unlikely(!sci)) + return -EROFS; + + nilfs_transaction_lock(sb, &ti, 1); + + err = nilfs_mdt_save_to_shadow_map(nilfs->ns_dat); + if (unlikely(err)) + goto out_unlock; + + err = nilfs_ioctl_prepare_clean_segments(nilfs, argv, kbufs); + if (unlikely(err)) { + nilfs_mdt_restore_from_shadow_map(nilfs->ns_dat); + goto out_unlock; + } + + sci->sc_freesegs = kbufs[4]; + sci->sc_nfreesegs = argv[4].v_nmembs; + list_splice_tail_init(&nilfs->ns_gc_inodes, &sci->sc_gc_inodes); + + for (;;) { + err = nilfs_segctor_construct(sci, SC_LSEG_SR); + nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes); + + if (likely(!err)) + break; + + nilfs_warning(sb, __func__, + "segment construction failed. (err=%d)", err); + set_current_state(TASK_INTERRUPTIBLE); + schedule_timeout(sci->sc_interval); + } + if (nilfs_test_opt(nilfs, DISCARD)) { + int ret = nilfs_discard_segments(nilfs, sci->sc_freesegs, + sci->sc_nfreesegs); + if (ret) { + printk(KERN_WARNING + "NILFS warning: error %d on discard request, " + "turning discards off for the device\n", ret); + nilfs_clear_opt(nilfs, DISCARD); + } + } + + out_unlock: + sci->sc_freesegs = NULL; + sci->sc_nfreesegs = 0; + nilfs_mdt_clear_shadow_map(nilfs->ns_dat); + nilfs_transaction_unlock(sb); + return err; +} + +static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode) +{ + struct nilfs_transaction_info ti; + + nilfs_transaction_lock(sci->sc_super, &ti, 0); + nilfs_segctor_construct(sci, mode); + + /* + * Unclosed segment should be retried. We do this using sc_timer. + * Timeout of sc_timer will invoke complete construction which leads + * to close the current logical segment. + */ + if (test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags)) + nilfs_segctor_start_timer(sci); + + nilfs_transaction_unlock(sci->sc_super); +} + +static void nilfs_segctor_do_immediate_flush(struct nilfs_sc_info *sci) +{ + int mode = 0; + int err; + + spin_lock(&sci->sc_state_lock); + mode = (sci->sc_flush_request & FLUSH_DAT_BIT) ? + SC_FLUSH_DAT : SC_FLUSH_FILE; + spin_unlock(&sci->sc_state_lock); + + if (mode) { + err = nilfs_segctor_do_construct(sci, mode); + + spin_lock(&sci->sc_state_lock); + sci->sc_flush_request &= (mode == SC_FLUSH_FILE) ? + ~FLUSH_FILE_BIT : ~FLUSH_DAT_BIT; + spin_unlock(&sci->sc_state_lock); + } + clear_bit(NILFS_SC_PRIOR_FLUSH, &sci->sc_flags); +} + +static int nilfs_segctor_flush_mode(struct nilfs_sc_info *sci) +{ + if (!test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) || + time_before(jiffies, sci->sc_lseg_stime + sci->sc_mjcp_freq)) { + if (!(sci->sc_flush_request & ~FLUSH_FILE_BIT)) + return SC_FLUSH_FILE; + else if (!(sci->sc_flush_request & ~FLUSH_DAT_BIT)) + return SC_FLUSH_DAT; + } + return SC_LSEG_SR; +} + +/** + * nilfs_segctor_thread - main loop of the segment constructor thread. + * @arg: pointer to a struct nilfs_sc_info. + * + * nilfs_segctor_thread() initializes a timer and serves as a daemon + * to execute segment constructions. + */ +static int nilfs_segctor_thread(void *arg) +{ + struct nilfs_sc_info *sci = (struct nilfs_sc_info *)arg; + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + int timeout = 0; + + sci->sc_timer.data = (unsigned long)current; + sci->sc_timer.function = nilfs_construction_timeout; + + /* start sync. */ + sci->sc_task = current; + wake_up(&sci->sc_wait_task); /* for nilfs_segctor_start_thread() */ + printk(KERN_INFO + "segctord starting. Construction interval = %lu seconds, " + "CP frequency < %lu seconds\n", + sci->sc_interval / HZ, sci->sc_mjcp_freq / HZ); + + spin_lock(&sci->sc_state_lock); + loop: + for (;;) { + int mode; + + if (sci->sc_state & NILFS_SEGCTOR_QUIT) + goto end_thread; + + if (timeout || sci->sc_seq_request != sci->sc_seq_done) + mode = SC_LSEG_SR; + else if (!sci->sc_flush_request) + break; + else + mode = nilfs_segctor_flush_mode(sci); + + spin_unlock(&sci->sc_state_lock); + nilfs_segctor_thread_construct(sci, mode); + spin_lock(&sci->sc_state_lock); + timeout = 0; + } + + + if (freezing(current)) { + spin_unlock(&sci->sc_state_lock); + try_to_freeze(); + spin_lock(&sci->sc_state_lock); + } else { + DEFINE_WAIT(wait); + int should_sleep = 1; + + prepare_to_wait(&sci->sc_wait_daemon, &wait, + TASK_INTERRUPTIBLE); + + if (sci->sc_seq_request != sci->sc_seq_done) + should_sleep = 0; + else if (sci->sc_flush_request) + should_sleep = 0; + else if (sci->sc_state & NILFS_SEGCTOR_COMMIT) + should_sleep = time_before(jiffies, + sci->sc_timer.expires); + + if (should_sleep) { + spin_unlock(&sci->sc_state_lock); + schedule(); + spin_lock(&sci->sc_state_lock); + } + finish_wait(&sci->sc_wait_daemon, &wait); + timeout = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) && + time_after_eq(jiffies, sci->sc_timer.expires)); + + if (nilfs_sb_dirty(nilfs) && nilfs_sb_need_update(nilfs)) + set_nilfs_discontinued(nilfs); + } + goto loop; + + end_thread: + spin_unlock(&sci->sc_state_lock); + + /* end sync. */ + sci->sc_task = NULL; + wake_up(&sci->sc_wait_task); /* for nilfs_segctor_kill_thread() */ + return 0; +} + +static int nilfs_segctor_start_thread(struct nilfs_sc_info *sci) +{ + struct task_struct *t; + + t = kthread_run(nilfs_segctor_thread, sci, "segctord"); + if (IS_ERR(t)) { + int err = PTR_ERR(t); + + printk(KERN_ERR "NILFS: error %d creating segctord thread\n", + err); + return err; + } + wait_event(sci->sc_wait_task, sci->sc_task != NULL); + return 0; +} + +static void nilfs_segctor_kill_thread(struct nilfs_sc_info *sci) + __acquires(&sci->sc_state_lock) + __releases(&sci->sc_state_lock) +{ + sci->sc_state |= NILFS_SEGCTOR_QUIT; + + while (sci->sc_task) { + wake_up(&sci->sc_wait_daemon); + spin_unlock(&sci->sc_state_lock); + wait_event(sci->sc_wait_task, sci->sc_task == NULL); + spin_lock(&sci->sc_state_lock); + } +} + +/* + * Setup & clean-up functions + */ +static struct nilfs_sc_info *nilfs_segctor_new(struct super_block *sb, + struct nilfs_root *root) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + struct nilfs_sc_info *sci; + + sci = kzalloc(sizeof(*sci), GFP_KERNEL); + if (!sci) + return NULL; + + sci->sc_super = sb; + + nilfs_get_root(root); + sci->sc_root = root; + + init_waitqueue_head(&sci->sc_wait_request); + init_waitqueue_head(&sci->sc_wait_daemon); + init_waitqueue_head(&sci->sc_wait_task); + spin_lock_init(&sci->sc_state_lock); + INIT_LIST_HEAD(&sci->sc_dirty_files); + INIT_LIST_HEAD(&sci->sc_segbufs); + INIT_LIST_HEAD(&sci->sc_write_logs); + INIT_LIST_HEAD(&sci->sc_gc_inodes); + INIT_LIST_HEAD(&sci->sc_iput_queue); + INIT_WORK(&sci->sc_iput_work, nilfs_iput_work_func); + init_timer(&sci->sc_timer); + + sci->sc_interval = HZ * NILFS_SC_DEFAULT_TIMEOUT; + sci->sc_mjcp_freq = HZ * NILFS_SC_DEFAULT_SR_FREQ; + sci->sc_watermark = NILFS_SC_DEFAULT_WATERMARK; + + if (nilfs->ns_interval) + sci->sc_interval = HZ * nilfs->ns_interval; + if (nilfs->ns_watermark) + sci->sc_watermark = nilfs->ns_watermark; + return sci; +} + +static void nilfs_segctor_write_out(struct nilfs_sc_info *sci) +{ + int ret, retrycount = NILFS_SC_CLEANUP_RETRY; + + /* The segctord thread was stopped and its timer was removed. + But some tasks remain. */ + do { + struct nilfs_transaction_info ti; + + nilfs_transaction_lock(sci->sc_super, &ti, 0); + ret = nilfs_segctor_construct(sci, SC_LSEG_SR); + nilfs_transaction_unlock(sci->sc_super); + + flush_work(&sci->sc_iput_work); + + } while (ret && retrycount-- > 0); +} + +/** + * nilfs_segctor_destroy - destroy the segment constructor. + * @sci: nilfs_sc_info + * + * nilfs_segctor_destroy() kills the segctord thread and frees + * the nilfs_sc_info struct. + * Caller must hold the segment semaphore. + */ +static void nilfs_segctor_destroy(struct nilfs_sc_info *sci) +{ + struct the_nilfs *nilfs = sci->sc_super->s_fs_info; + int flag; + + up_write(&nilfs->ns_segctor_sem); + + spin_lock(&sci->sc_state_lock); + nilfs_segctor_kill_thread(sci); + flag = ((sci->sc_state & NILFS_SEGCTOR_COMMIT) || sci->sc_flush_request + || sci->sc_seq_request != sci->sc_seq_done); + spin_unlock(&sci->sc_state_lock); + + if (flush_work(&sci->sc_iput_work)) + flag = true; + + if (flag || !nilfs_segctor_confirm(sci)) + nilfs_segctor_write_out(sci); + + if (!list_empty(&sci->sc_dirty_files)) { + nilfs_warning(sci->sc_super, __func__, + "dirty file(s) after the final construction\n"); + nilfs_dispose_list(nilfs, &sci->sc_dirty_files, 1); + } + + if (!list_empty(&sci->sc_iput_queue)) { + nilfs_warning(sci->sc_super, __func__, + "iput queue is not empty\n"); + nilfs_dispose_list(nilfs, &sci->sc_iput_queue, 1); + } + + WARN_ON(!list_empty(&sci->sc_segbufs)); + WARN_ON(!list_empty(&sci->sc_write_logs)); + + nilfs_put_root(sci->sc_root); + + down_write(&nilfs->ns_segctor_sem); + + del_timer_sync(&sci->sc_timer); + kfree(sci); +} + +/** + * nilfs_attach_log_writer - attach log writer + * @sb: super block instance + * @root: root object of the current filesystem tree + * + * This allocates a log writer object, initializes it, and starts the + * log writer. + * + * Return Value: On success, 0 is returned. On error, one of the following + * negative error code is returned. + * + * %-ENOMEM - Insufficient memory available. + */ +int nilfs_attach_log_writer(struct super_block *sb, struct nilfs_root *root) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + int err; + + if (nilfs->ns_writer) { + /* + * This happens if the filesystem was remounted + * read/write after nilfs_error degenerated it into a + * read-only mount. + */ + nilfs_detach_log_writer(sb); + } + + nilfs->ns_writer = nilfs_segctor_new(sb, root); + if (!nilfs->ns_writer) + return -ENOMEM; + + err = nilfs_segctor_start_thread(nilfs->ns_writer); + if (err) { + kfree(nilfs->ns_writer); + nilfs->ns_writer = NULL; + } + return err; +} + +/** + * nilfs_detach_log_writer - destroy log writer + * @sb: super block instance + * + * This kills log writer daemon, frees the log writer object, and + * destroys list of dirty files. + */ +void nilfs_detach_log_writer(struct super_block *sb) +{ + struct the_nilfs *nilfs = sb->s_fs_info; + LIST_HEAD(garbage_list); + + down_write(&nilfs->ns_segctor_sem); + if (nilfs->ns_writer) { + nilfs_segctor_destroy(nilfs->ns_writer); + nilfs->ns_writer = NULL; + } + + /* Force to free the list of dirty files */ + spin_lock(&nilfs->ns_inode_lock); + if (!list_empty(&nilfs->ns_dirty_files)) { + list_splice_init(&nilfs->ns_dirty_files, &garbage_list); + nilfs_warning(sb, __func__, + "Hit dirty file after stopped log writer\n"); + } + spin_unlock(&nilfs->ns_inode_lock); + up_write(&nilfs->ns_segctor_sem); + + nilfs_dispose_list(nilfs, &garbage_list, 1); +} |