--- /dev/null
+/*
+ * 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/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 "nilfs.h"
+#include "btnode.h"
+#include "page.h"
+#include "segment.h"
+#include "sufile.h"
+#include "cpfile.h"
+#include "ifile.h"
+#include "seglist.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_SKETCH,
+ 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_HISTORY_MASK (NILFS_CF_IFILE_STARTED)
+
+/* 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 nilfs_sb_info *, 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)
+
+/*
+ * Transaction
+ */
+static struct kmem_cache *nilfs_transaction_cachep;
+
+/**
+ * nilfs_init_transaction_cache - create a cache for nilfs_transaction_info
+ *
+ * nilfs_init_transaction_cache() creates a slab cache for the struct
+ * nilfs_transaction_info.
+ *
+ * Return Value: On success, it returns 0. On error, one of the following
+ * negative error code is returned.
+ *
+ * %-ENOMEM - Insufficient memory available.
+ */
+int nilfs_init_transaction_cache(void)
+{
+ nilfs_transaction_cachep =
+ kmem_cache_create("nilfs2_transaction_cache",
+ sizeof(struct nilfs_transaction_info),
+ 0, SLAB_RECLAIM_ACCOUNT, NULL);
+ return (nilfs_transaction_cachep == NULL) ? -ENOMEM : 0;
+}
+
+/**
+ * nilfs_detroy_transaction_cache - destroy the cache for transaction info
+ *
+ * nilfs_destroy_transaction_cache() frees the slab cache for the struct
+ * nilfs_transaction_info.
+ */
+void nilfs_destroy_transaction_cache(void)
+{
+ kmem_cache_destroy(nilfs_transaction_cachep);
+}
+
+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,
+ * we save it and restore on nilfs_transaction_end().
+ * But this should never happen.
+ */
+ 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_end() 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; othewise 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.
+ *
+ * %-ERESTARTSYS - Interrupted
+ *
+ * %-ENOSPC - No space left on device
+ */
+int nilfs_transaction_begin(struct super_block *sb,
+ struct nilfs_transaction_info *ti,
+ int vacancy_check)
+{
+ struct nilfs_sb_info *sbi;
+ struct the_nilfs *nilfs;
+ int ret = nilfs_prepare_segment_lock(ti);
+
+ if (unlikely(ret < 0))
+ return ret;
+ if (ret > 0)
+ return 0;
+
+ sbi = NILFS_SB(sb);
+ nilfs = sbi->s_nilfs;
+ 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);
+ return ret;
+}
+
+/**
+ * nilfs_transaction_end - end indivisible file operations.
+ * @sb: super block
+ * @commit: commit flag (0 for no change)
+ *
+ * nilfs_transaction_end() releases the read semaphore which is
+ * acquired by nilfs_transaction_begin(). Its releasing is only done
+ * in outermost call of this function. If the nilfs_transaction_info
+ * was allocated dynamically, it is given back to a slab cache.
+ */
+int nilfs_transaction_end(struct super_block *sb, int commit)
+{
+ struct nilfs_transaction_info *ti = current->journal_info;
+ struct nilfs_sb_info *sbi;
+ struct nilfs_sc_info *sci;
+ int err = 0;
+
+ BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
+
+ if (commit)
+ ti->ti_flags |= NILFS_TI_COMMIT;
+ if (ti->ti_count > 0) {
+ ti->ti_count--;
+ return 0;
+ }
+ sbi = NILFS_SB(sb);
+ sci = NILFS_SC(sbi);
+ if (sci != NULL) {
+ if (ti->ti_flags & NILFS_TI_COMMIT)
+ nilfs_segctor_start_timer(sci);
+ if (atomic_read(&sbi->s_nilfs->ns_ndirtyblks) >
+ sci->sc_watermark)
+ nilfs_segctor_do_flush(sci, 0);
+ }
+ up_read(&sbi->s_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);
+ return err;
+}
+
+void nilfs_relax_pressure_in_lock(struct super_block *sb)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_sc_info *sci = NILFS_SC(sbi);
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ 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 nilfs_sb_info *sbi,
+ struct nilfs_transaction_info *ti,
+ int gcflag)
+{
+ struct nilfs_transaction_info *cur_ti = current->journal_info;
+
+ BUG_ON(cur_ti);
+ BUG_ON(!ti);
+ ti->ti_flags = NILFS_TI_WRITER;
+ ti->ti_count = 0;
+ ti->ti_save = cur_ti;
+ ti->ti_magic = NILFS_TI_MAGIC;
+ INIT_LIST_HEAD(&ti->ti_garbage);
+ current->journal_info = ti;
+
+ for (;;) {
+ down_write(&sbi->s_nilfs->ns_segctor_sem);
+ if (!test_bit(NILFS_SC_PRIOR_FLUSH, &NILFS_SC(sbi)->sc_flags))
+ break;
+
+ nilfs_segctor_do_immediate_flush(NILFS_SC(sbi));
+
+ up_write(&sbi->s_nilfs->ns_segctor_sem);
+ yield();
+ }
+ if (gcflag)
+ ti->ti_flags |= NILFS_TI_GC;
+}
+
+static void nilfs_transaction_unlock(struct nilfs_sb_info *sbi)
+{
+ struct nilfs_transaction_info *ti = current->journal_info;
+
+ BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
+ BUG_ON(ti->ti_count > 0);
+
+ up_write(&sbi->s_nilfs->ns_segctor_sem);
+ current->journal_info = ti->ti_save;
+ if (!list_empty(&ti->ti_garbage))
+ nilfs_dispose_list(sbi, &ti->ti_garbage, 0);
+}
+
+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);
+ 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, &sci->sc_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));
+ /* 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;
+
+ if (sci->sc_blk_cnt == 0)
+ return;
+
+ ii = NILFS_I(inode);
+ 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(ii->i_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;
+}
+
+static int nilfs_handle_bmap_error(int err, const char *fname,
+ struct inode *inode, struct super_block *sb)
+{
+ if (err == -EINVAL) {
+ nilfs_error(sb, fname, "broken bmap (inode=%lu)\n",
+ inode->i_ino);
+ err = -EIO;
+ }
+ 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;
+
+ /* BUG_ON(!buffer_dirty(bh)); */
+ /* excluded by scan_dirty_data_buffers() */
+ err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
+ if (unlikely(err < 0))
+ return nilfs_handle_bmap_error(err, __func__, inode,
+ sci->sc_super);
+
+ 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)
+{
+ int err;
+
+ /* BUG_ON(!buffer_dirty(bh)); */
+ /* excluded by scan_dirty_node_buffers() */
+ err = nilfs_bmap_propagate(NILFS_I(inode)->i_bmap, bh);
+ if (unlikely(err < 0))
+ return nilfs_handle_bmap_error(err, __func__, inode,
+ sci->sc_super);
+ return 0;
+}
+
+static int nilfs_collect_file_bmap(struct nilfs_sc_info *sci,
+ struct buffer_head *bh,
+ struct inode *inode)
+{
+ BUG_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;
+}
+
+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 (unlikely(err < 0))
+ return nilfs_handle_bmap_error(err, __func__, inode,
+ sci->sc_super);
+
+ 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)
+{
+ BUG_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;
+}
+
+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,
+};
+
+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 int nilfs_lookup_dirty_data_buffers(struct inode *inode,
+ struct list_head *listp,
+ struct nilfs_sc_info *sci)
+{
+ struct nilfs_segment_buffer *segbuf = sci->sc_curseg;
+ struct address_space *mapping = inode->i_mapping;
+ struct pagevec pvec;
+ unsigned i, ndirties = 0, nlimit;
+ pgoff_t index = 0;
+ int err = 0;
+
+ nlimit = sci->sc_segbuf_nblocks -
+ (sci->sc_nblk_this_inc + segbuf->sb_sum.nblocks);
+ pagevec_init(&pvec, 0);
+ repeat:
+ if (!pagevec_lookup_tag(&pvec, mapping, &index, PAGECACHE_TAG_DIRTY,
+ PAGEVEC_SIZE))
+ return 0;
+
+ for (i = 0; i < pagevec_count(&pvec); i++) {
+ struct buffer_head *bh, *head;
+ struct page *page = pvec.pages[i];
+
+ if (mapping->host) {
+ 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)) {
+ if (ndirties > nlimit) {
+ err = -E2BIG;
+ break;
+ }
+ get_bh(bh);
+ list_add_tail(&bh->b_assoc_buffers, listp);
+ ndirties++;
+ }
+ bh = bh->b_this_page;
+ } while (bh != head);
+ }
+ pagevec_release(&pvec);
+ cond_resched();
+
+ if (!err)
+ goto repeat;
+ return err;
+}
+
+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)) {
+ 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 nilfs_sb_info *sbi,
+ 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(&sbi->s_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,
+ &sbi->s_dirty_files);
+ continue;
+ }
+ ivec[nv++] = ii;
+ if (nv == SC_N_INODEVEC)
+ break;
+ }
+ spin_unlock(&sbi->s_inode_lock);
+
+ for (pii = ivec; nv > 0; pii++, nv--)
+ iput(&(*pii)->vfs_inode);
+ }
+}
+
+static int nilfs_test_metadata_dirty(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int ret = 0;
+
+ if (nilfs_mdt_fetch_dirty(sbi->s_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())
+ if (nilfs_mdt_fetch_dirty(nilfs_dat_inode(nilfs)))
+ 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) &&
+ list_empty(&sci->sc_cleaning_segments) &&
+ (!nilfs_doing_gc() || list_empty(&sci->sc_gc_inodes));
+}
+
+static int nilfs_segctor_confirm(struct nilfs_sc_info *sci)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ int ret = 0;
+
+ if (nilfs_test_metadata_dirty(sbi))
+ set_bit(NILFS_SC_DIRTY, &sci->sc_flags);
+
+ spin_lock(&sbi->s_inode_lock);
+ if (list_empty(&sbi->s_dirty_files) && nilfs_segctor_clean(sci))
+ ret++;
+
+ spin_unlock(&sbi->s_inode_lock);
+ return ret;
+}
+
+static void nilfs_segctor_clear_metadata_dirty(struct nilfs_sc_info *sci)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+
+ nilfs_mdt_clear_dirty(sbi->s_ifile);
+ nilfs_mdt_clear_dirty(nilfs->ns_cpfile);
+ nilfs_mdt_clear_dirty(nilfs->ns_sufile);
+ nilfs_mdt_clear_dirty(nilfs_dat_inode(nilfs));
+}
+
+static int nilfs_segctor_create_checkpoint(struct nilfs_sc_info *sci)
+{
+ struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
+ 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 */
+ nilfs_mdt_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 {
+ BUG_ON(err == -EINVAL || err == -ENOENT);
+ }
+ return err;
+}
+
+static int nilfs_segctor_fill_in_checkpoint(struct nilfs_sc_info *sci)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ 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)) {
+ BUG_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(atomic_read(&sbi->s_inodes_count));
+ raw_cp->cp_blocks_count =
+ cpu_to_le64(atomic_read(&sbi->s_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 (sci->sc_sketch_inode && i_size_read(sci->sc_sketch_inode) > 0)
+ nilfs_checkpoint_set_sketch(raw_cp);
+ nilfs_write_inode_common(sbi->s_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 inode *ifile)
+{
+ struct nilfs_inode_info *ii;
+
+ list_for_each_entry(ii, &sci->sc_dirty_files, i_dirty) {
+ nilfs_fill_in_file_bmap(ifile, ii);
+ set_bit(NILFS_I_COLLECTED, &ii->i_state);
+ }
+ if (sci->sc_sketch_inode) {
+ ii = NILFS_I(sci->sc_sketch_inode);
+ if (test_bit(NILFS_I_DIRTY, &ii->i_state))
+ nilfs_fill_in_file_bmap(ifile, ii);
+ }
+}
+
+/*
+ * CRC calculation routines
+ */
+static void nilfs_fill_in_super_root_crc(struct buffer_head *bh_sr, u32 seed)
+{
+ struct nilfs_super_root *raw_sr =
+ (struct nilfs_super_root *)bh_sr->b_data;
+ u32 crc;
+
+ BUG_ON(NILFS_SR_BYTES > bh_sr->b_size);
+ crc = crc32_le(seed,
+ (unsigned char *)raw_sr + sizeof(raw_sr->sr_sum),
+ NILFS_SR_BYTES - sizeof(raw_sr->sr_sum));
+ raw_sr->sr_sum = cpu_to_le32(crc);
+}
+
+static void nilfs_segctor_fill_in_checksums(struct nilfs_sc_info *sci,
+ u32 seed)
+{
+ struct nilfs_segment_buffer *segbuf;
+
+ if (sci->sc_super_root)
+ nilfs_fill_in_super_root_crc(sci->sc_super_root, seed);
+
+ list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
+ nilfs_segbuf_fill_in_segsum_crc(segbuf, seed);
+ nilfs_segbuf_fill_in_data_crc(segbuf, seed);
+ }
+}
+
+static void nilfs_segctor_fill_in_super_root(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+{
+ struct buffer_head *bh_sr = sci->sc_super_root;
+ struct nilfs_super_root *raw_sr =
+ (struct nilfs_super_root *)bh_sr->b_data;
+ unsigned isz = nilfs->ns_inode_size;
+
+ raw_sr->sr_bytes = cpu_to_le16(NILFS_SR_BYTES);
+ 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_mdt_write_inode_direct(
+ nilfs_dat_inode(nilfs), bh_sr, NILFS_SR_DAT_OFFSET(isz));
+ nilfs_mdt_write_inode_direct(
+ nilfs->ns_cpfile, bh_sr, NILFS_SR_CPFILE_OFFSET(isz));
+ nilfs_mdt_write_inode_direct(
+ nilfs->ns_sufile, bh_sr, NILFS_SR_SUFILE_OFFSET(isz));
+}
+
+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_DIRTY, &ii->i_state);
+ set_bit(NILFS_I_UPDATED, &ii->i_state);
+ }
+}
+
+static void nilfs_segctor_cancel_free_segments(struct nilfs_sc_info *sci,
+ struct inode *sufile)
+
+{
+ struct list_head *head = &sci->sc_cleaning_segments;
+ struct nilfs_segment_entry *ent;
+ int err;
+
+ list_for_each_entry(ent, head, list) {
+ if (!(ent->flags & NILFS_SLH_FREED))
+ break;
+ err = nilfs_sufile_cancel_free(sufile, ent->segnum);
+ BUG_ON(err);
+
+ ent->flags &= ~NILFS_SLH_FREED;
+ }
+}
+
+static int nilfs_segctor_prepare_free_segments(struct nilfs_sc_info *sci,
+ struct inode *sufile)
+{
+ struct list_head *head = &sci->sc_cleaning_segments;
+ struct nilfs_segment_entry *ent;
+ int err;
+
+ list_for_each_entry(ent, head, list) {
+ err = nilfs_sufile_free(sufile, ent->segnum);
+ if (unlikely(err))
+ return err;
+ ent->flags |= NILFS_SLH_FREED;
+ }
+ return 0;
+}
+
+static void nilfs_segctor_commit_free_segments(struct nilfs_sc_info *sci)
+{
+ nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
+}
+
+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_entry(listp->next, struct buffer_head,
+ b_assoc_buffers);
+ list_del_init(&bh->b_assoc_buffers);
+ brelse(bh);
+ }
+ return err;
+}
+
+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, err2;
+
+ if (!(sci->sc_stage.flags & NILFS_CF_NODE)) {
+ err = nilfs_lookup_dirty_data_buffers(inode, &data_buffers,
+ sci);
+ if (err) {
+ err2 = nilfs_segctor_apply_buffers(
+ sci, inode, &data_buffers,
+ err == -E2BIG ? sc_ops->collect_data : NULL);
+ if (err == -E2BIG)
+ err = err2;
+ 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);
+ int err, err2;
+
+ err = nilfs_lookup_dirty_data_buffers(inode, &data_buffers, sci);
+ err2 = nilfs_segctor_apply_buffers(sci, inode, &data_buffers,
+ (!err || err == -E2BIG) ?
+ nilfs_collect_file_data : NULL);
+ if (err == -E2BIG)
+ err = err2;
+ if (!err)
+ nilfs_segctor_end_finfo(sci, inode);
+ return err;
+}
+
+static int nilfs_segctor_collect_blocks(struct nilfs_sc_info *sci, int mode)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct list_head *head;
+ struct nilfs_inode_info *ii;
+ 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++; /* Fall through */
+ case NILFS_ST_SKETCH:
+ if (mode == SC_LSEG_SR && sci->sc_sketch_inode) {
+ ii = NILFS_I(sci->sc_sketch_inode);
+ if (test_bit(NILFS_I_DIRTY, &ii->i_state)) {
+ sci->sc_sketch_inode->i_ctime.tv_sec
+ = sci->sc_seg_ctime;
+ sci->sc_sketch_inode->i_mtime.tv_sec
+ = sci->sc_seg_ctime;
+ err = nilfs_mark_inode_dirty(
+ sci->sc_sketch_inode);
+ if (unlikely(err))
+ goto break_or_fail;
+ }
+ err = nilfs_segctor_scan_file(sci,
+ sci->sc_sketch_inode,
+ &nilfs_sc_file_ops);
+ if (unlikely(err))
+ goto break_or_fail;
+ }
+ sci->sc_stage.scnt++;
+ sci->sc_stage.flags |= NILFS_CF_IFILE_STARTED;
+ /* Fall through */
+ case NILFS_ST_IFILE:
+ err = nilfs_segctor_scan_file(sci, sbi->s_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_segctor_prepare_free_segments(sci,
+ nilfs->ns_sufile);
+ if (unlikely(err))
+ break;
+ 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_dat_inode(nilfs),
+ &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_stage.dirty_file_ptr;
+ 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_stage.dirty_file_ptr = NULL;
+ 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;
+}
+
+static int nilfs_segctor_terminate_segment(struct nilfs_sc_info *sci,
+ struct nilfs_segment_buffer *segbuf,
+ struct inode *sufile)
+{
+ struct nilfs_segment_entry *ent = segbuf->sb_segent;
+ int err;
+
+ err = nilfs_open_segment_entry(ent, sufile);
+ if (unlikely(err))
+ return err;
+ nilfs_mdt_mark_buffer_dirty(ent->bh_su);
+ nilfs_mdt_mark_dirty(sufile);
+ nilfs_close_segment_entry(ent, sufile);
+
+ list_add_tail(&ent->list, &sci->sc_active_segments);
+ segbuf->sb_segent = NULL;
+ return 0;
+}
+
+static int nilfs_touch_segusage(struct inode *sufile, __u64 segnum)
+{
+ struct buffer_head *bh_su;
+ struct nilfs_segment_usage *raw_su;
+ int err;
+
+ err = nilfs_sufile_get_segment_usage(sufile, segnum, &raw_su, &bh_su);
+ if (unlikely(err))
+ return err;
+ nilfs_mdt_mark_buffer_dirty(bh_su);
+ nilfs_mdt_mark_dirty(sufile);
+ nilfs_sufile_put_segment_usage(sufile, segnum, bh_su);
+ return 0;
+}
+
+static int nilfs_segctor_begin_construction(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+{
+ struct nilfs_segment_buffer *segbuf, *n;
+ struct inode *sufile = nilfs->ns_sufile;
+ __u64 nextnum;
+ int err;
+
+ if (list_empty(&sci->sc_segbufs)) {
+ segbuf = nilfs_segbuf_new(sci->sc_super);
+ if (unlikely(!segbuf))
+ return -ENOMEM;
+ list_add(&segbuf->sb_list, &sci->sc_segbufs);
+ } else
+ segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+
+ err = nilfs_segbuf_map(segbuf, nilfs->ns_segnum,
+ nilfs->ns_pseg_offset, nilfs);
+ if (unlikely(err))
+ return err;
+
+ if (segbuf->sb_rest_blocks < NILFS_PSEG_MIN_BLOCKS) {
+ err = nilfs_segctor_terminate_segment(sci, segbuf, sufile);
+ if (unlikely(err))
+ return err;
+
+ nilfs_shift_to_next_segment(nilfs);
+ err = nilfs_segbuf_map(segbuf, nilfs->ns_segnum, 0, nilfs);
+ }
+ sci->sc_segbuf_nblocks = segbuf->sb_rest_blocks;
+
+ err = nilfs_touch_segusage(sufile, segbuf->sb_segnum);
+ if (unlikely(err))
+ return err;
+
+ if (nilfs->ns_segnum == nilfs->ns_nextnum) {
+ /* Start from the head of a new full segment */
+ err = nilfs_sufile_alloc(sufile, &nextnum);
+ if (unlikely(err))
+ return err;
+ } else
+ nextnum = nilfs->ns_nextnum;
+
+ segbuf->sb_sum.seg_seq = nilfs->ns_seg_seq;
+ nilfs_segbuf_set_next_segnum(segbuf, nextnum, nilfs);
+
+ /* truncating segment buffers */
+ list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
+ sb_list) {
+ list_del_init(&segbuf->sb_list);
+ 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, *n;
+ 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_touch_segusage(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 */
+ err = nilfs_segbuf_map(segbuf, prev->sb_nextnum, 0, nilfs);
+ if (unlikely(err))
+ goto failed_segbuf;
+
+ 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(&list, sci->sc_segbufs.prev);
+ return 0;
+
+ failed_segbuf:
+ nilfs_segbuf_free(segbuf);
+ failed:
+ list_for_each_entry_safe(segbuf, n, &list, sb_list) {
+ ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
+ BUG_ON(ret);
+ list_del_init(&segbuf->sb_list);
+ nilfs_segbuf_free(segbuf);
+ }
+ return err;
+}
+
+static void nilfs_segctor_free_incomplete_segments(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+{
+ struct nilfs_segment_buffer *segbuf;
+ int ret, done = 0;
+
+ segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+ if (nilfs->ns_nextnum != segbuf->sb_nextnum) {
+ ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
+ BUG_ON(ret);
+ }
+ if (segbuf->sb_io_error) {
+ /* 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);
+ done++;
+ }
+
+ list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
+ ret = nilfs_sufile_free(nilfs->ns_sufile, segbuf->sb_nextnum);
+ BUG_ON(ret);
+ if (!done && segbuf->sb_io_error) {
+ if (segbuf->sb_segnum != nilfs->ns_nextnum)
+ /* Case 2: extended segment (!= next) failed */
+ nilfs_sufile_set_error(nilfs->ns_sufile,
+ segbuf->sb_segnum);
+ done++;
+ }
+ }
+}
+
+static void nilfs_segctor_clear_segment_buffers(struct nilfs_sc_info *sci)
+{
+ struct nilfs_segment_buffer *segbuf;
+
+ list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list)
+ nilfs_segbuf_clear(segbuf);
+ sci->sc_super_root = NULL;
+}
+
+static void nilfs_segctor_destroy_segment_buffers(struct nilfs_sc_info *sci)
+{
+ struct nilfs_segment_buffer *segbuf;
+
+ while (!list_empty(&sci->sc_segbufs)) {
+ segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+ list_del_init(&segbuf->sb_list);
+ nilfs_segbuf_free(segbuf);
+ }
+ /* sci->sc_curseg = NULL; */
+}
+
+static void nilfs_segctor_end_construction(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs, int err)
+{
+ if (unlikely(err)) {
+ nilfs_segctor_free_incomplete_segments(sci, nilfs);
+ nilfs_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
+ }
+ nilfs_segctor_clear_segment_buffers(sci);
+}
+
+static void nilfs_segctor_update_segusage(struct nilfs_sc_info *sci,
+ struct inode *sufile)
+{
+ struct nilfs_segment_buffer *segbuf;
+ struct buffer_head *bh_su;
+ struct nilfs_segment_usage *raw_su;
+ unsigned long live_blocks;
+ int ret;
+
+ list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
+ ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
+ &raw_su, &bh_su);
+ BUG_ON(ret); /* always succeed because bh_su is dirty */
+ live_blocks = segbuf->sb_sum.nblocks +
+ (segbuf->sb_pseg_start - segbuf->sb_fseg_start);
+ raw_su->su_lastmod = cpu_to_le64(sci->sc_seg_ctime);
+ raw_su->su_nblocks = cpu_to_le32(live_blocks);
+ nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
+ bh_su);
+ }
+}
+
+static void nilfs_segctor_cancel_segusage(struct nilfs_sc_info *sci,
+ struct inode *sufile)
+{
+ struct nilfs_segment_buffer *segbuf;
+ struct buffer_head *bh_su;
+ struct nilfs_segment_usage *raw_su;
+ int ret;
+
+ segbuf = NILFS_FIRST_SEGBUF(&sci->sc_segbufs);
+ ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
+ &raw_su, &bh_su);
+ BUG_ON(ret); /* always succeed because bh_su is dirty */
+ raw_su->su_nblocks = cpu_to_le32(segbuf->sb_pseg_start -
+ segbuf->sb_fseg_start);
+ nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum, bh_su);
+
+ list_for_each_entry_continue(segbuf, &sci->sc_segbufs, sb_list) {
+ ret = nilfs_sufile_get_segment_usage(sufile, segbuf->sb_segnum,
+ &raw_su, &bh_su);
+ BUG_ON(ret); /* always succeed */
+ raw_su->su_nblocks = 0;
+ nilfs_sufile_put_segment_usage(sufile, segbuf->sb_segnum,
+ bh_su);
+ }
+}
+
+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, *n;
+ int ret;
+
+ list_for_each_entry_safe_continue(segbuf, n, &sci->sc_segbufs,
+ sb_list) {
+ list_del_init(&segbuf->sb_list);
+ sci->sc_segbuf_nblocks -= segbuf->sb_rest_blocks;
+ ret = nilfs_sufile_free(sufile, segbuf->sb_nextnum);
+ BUG_ON(ret);
+ nilfs_segbuf_free(segbuf);
+ }
+}
+
+
+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_super_root = NULL;
+ 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_segctor_cancel_free_segments(sci, nilfs->ns_sufile);
+ nilfs_segctor_clear_segment_buffers(sci);
+
+ 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 == sci->sc_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);
+
+ if (buffer_nilfs_node(bh))
+ inode = NILFS_BTNC_I(bh->b_page->mapping);
+ else
+ inode = NILFS_AS_I(bh->b_page->mapping);
+
+ 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:
+ err = nilfs_handle_bmap_error(err, __func__, inode, sci->sc_super);
+ 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 int
+nilfs_copy_replace_page_buffers(struct page *page, struct list_head *out)
+{
+ struct page *clone_page;
+ struct buffer_head *bh, *head, *bh2;
+ void *kaddr;
+
+ bh = head = page_buffers(page);
+
+ clone_page = nilfs_alloc_private_page(bh->b_bdev, bh->b_size, 0);
+ if (unlikely(!clone_page))
+ return -ENOMEM;
+
+ bh2 = page_buffers(clone_page);
+ kaddr = kmap_atomic(page, KM_USER0);
+ do {
+ if (list_empty(&bh->b_assoc_buffers))
+ continue;
+ get_bh(bh2);
+ page_cache_get(clone_page); /* for each bh */
+ memcpy(bh2->b_data, kaddr + bh_offset(bh), bh2->b_size);
+ bh2->b_blocknr = bh->b_blocknr;
+ list_replace(&bh->b_assoc_buffers, &bh2->b_assoc_buffers);
+ list_add_tail(&bh->b_assoc_buffers, out);
+ } while (bh = bh->b_this_page, bh2 = bh2->b_this_page, bh != head);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ if (!TestSetPageWriteback(clone_page))
+ inc_zone_page_state(clone_page, NR_WRITEBACK);
+ unlock_page(clone_page);
+
+ return 0;
+}
+
+static int nilfs_test_page_to_be_frozen(struct page *page)
+{
+ struct address_space *mapping = page->mapping;
+
+ if (!mapping || !mapping->host || S_ISDIR(mapping->host->i_mode))
+ return 0;
+
+ if (page_mapped(page)) {
+ ClearPageChecked(page);
+ return 1;
+ }
+ return PageChecked(page);
+}
+
+static int nilfs_begin_page_io(struct page *page, struct list_head *out)
+{
+ 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 0;
+
+ lock_page(page);
+ clear_page_dirty_for_io(page);
+ set_page_writeback(page);
+ unlock_page(page);
+
+ if (nilfs_test_page_to_be_frozen(page)) {
+ int err = nilfs_copy_replace_page_buffers(page, out);
+ if (unlikely(err))
+ return err;
+ }
+ return 0;
+}
+
+static int nilfs_segctor_prepare_write(struct nilfs_sc_info *sci,
+ struct page **failed_page)
+{
+ struct nilfs_segment_buffer *segbuf;
+ struct page *bd_page = NULL, *fs_page = NULL;
+ struct list_head *list = &sci->sc_copied_buffers;
+ int err;
+
+ *failed_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) {
+ if (bh == sci->sc_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) {
+ err = nilfs_begin_page_io(fs_page, list);
+ if (unlikely(err)) {
+ *failed_page = fs_page;
+ goto out;
+ }
+ 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);
+ }
+ err = nilfs_begin_page_io(fs_page, list);
+ if (unlikely(err))
+ *failed_page = fs_page;
+ out:
+ return err;
+}
+
+static int nilfs_segctor_write(struct nilfs_sc_info *sci,
+ struct backing_dev_info *bdi)
+{
+ struct nilfs_segment_buffer *segbuf;
+ struct nilfs_write_info wi;
+ int err, res;
+
+ wi.sb = sci->sc_super;
+ wi.bh_sr = sci->sc_super_root;
+ wi.bdi = bdi;
+
+ list_for_each_entry(segbuf, &sci->sc_segbufs, sb_list) {
+ nilfs_segbuf_prepare_write(segbuf, &wi);
+ err = nilfs_segbuf_write(segbuf, &wi);
+
+ res = nilfs_segbuf_wait(segbuf, &wi);
+ err = unlikely(err) ? : res;
+ if (unlikely(err))
+ return err;
+ }
+ return 0;
+}
+
+static int nilfs_page_has_uncleared_buffer(struct page *page)
+{
+ struct buffer_head *head, *bh;
+
+ head = bh = page_buffers(page);
+ do {
+ if (buffer_dirty(bh) && !list_empty(&bh->b_assoc_buffers))
+ return 1;
+ bh = bh->b_this_page;
+ } while (bh != head);
+ return 0;
+}
+
+static void __nilfs_end_page_io(struct page *page, int err)
+{
+ /* BUG_ON(err > 0); */
+ if (!err) {
+ if (!nilfs_page_buffers_clean(page))
+ __set_page_dirty_nobuffers(page);
+ ClearPageError(page);
+ } else {
+ __set_page_dirty_nobuffers(page);
+ SetPageError(page);
+ }
+
+ if (buffer_nilfs_allocated(page_buffers(page))) {
+ if (TestClearPageWriteback(page))
+ dec_zone_page_state(page, NR_WRITEBACK);
+ } else
+ end_page_writeback(page);
+}
+
+static void nilfs_end_page_io(struct page *page, int err)
+{
+ if (!page)
+ return;
+
+ if (buffer_nilfs_node(page_buffers(page)) &&
+ nilfs_page_has_uncleared_buffer(page))
+ /* For b-tree node pages, this function may be called twice
+ or more because they might be split in a segment.
+ This check assures that cleanup has been done for all
+ buffers in a split btnode page. */
+ return;
+
+ __nilfs_end_page_io(page, err);
+}
+
+static void nilfs_clear_copied_buffers(struct list_head *list, int err)
+{
+ struct buffer_head *bh, *head;
+ struct page *page;
+
+ while (!list_empty(list)) {
+ bh = list_entry(list->next, struct buffer_head,
+ b_assoc_buffers);
+ page = bh->b_page;
+ page_cache_get(page);
+ head = bh = page_buffers(page);
+ do {
+ if (!list_empty(&bh->b_assoc_buffers)) {
+ list_del_init(&bh->b_assoc_buffers);
+ if (!err) {
+ set_buffer_uptodate(bh);
+ clear_buffer_dirty(bh);
+ clear_buffer_nilfs_volatile(bh);
+ }
+ brelse(bh); /* for b_assoc_buffers */
+ }
+ } while ((bh = bh->b_this_page) != head);
+
+ __nilfs_end_page_io(page, err);
+ page_cache_release(page);
+ }
+}
+
+static void nilfs_segctor_abort_write(struct nilfs_sc_info *sci,
+ struct page *failed_page, int err)
+{
+ 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)
+ end_page_writeback(bd_page);
+ bd_page = bh->b_page;
+ }
+ }
+
+ list_for_each_entry(bh, &segbuf->sb_payload_buffers,
+ b_assoc_buffers) {
+ if (bh == sci->sc_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);
+ if (unlikely(fs_page == failed_page))
+ goto done;
+ fs_page = bh->b_page;
+ }
+ }
+ }
+ if (bd_page)
+ end_page_writeback(bd_page);
+
+ nilfs_end_page_io(fs_page, err);
+ done:
+ nilfs_clear_copied_buffers(&sci->sc_copied_buffers, err);
+}
+
+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 nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int update_sr = (sci->sc_super_root != 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) {
+ 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) {
+ set_buffer_uptodate(bh);
+ clear_buffer_dirty(bh);
+ clear_buffer_nilfs_volatile(bh);
+ if (bh == sci->sc_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, 0);
+ fs_page = bh->b_page;
+ }
+ }
+
+ if (!NILFS_SEG_SIMPLEX(&segbuf->sb_sum)) {
+ if (NILFS_SEG_LOGBGN(&segbuf->sb_sum)) {
+ set_bit(NILFS_SC_UNCLOSED, &sci->sc_flags);
+ sci->sc_lseg_stime = jiffies;
+ }
+ if (NILFS_SEG_LOGEND(&segbuf->sb_sum))
+ 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_clear_copied_buffers(&sci->sc_copied_buffers, 0);
+
+ nilfs_drop_collected_inodes(&sci->sc_dirty_files);
+
+ if (nilfs_doing_gc()) {
+ nilfs_drop_collected_inodes(&sci->sc_gc_inodes);
+ if (update_sr)
+ nilfs_commit_gcdat_inode(nilfs);
+ } else {
+ nilfs->ns_nongc_ctime = sci->sc_seg_ctime;
+ set_nilfs_cond_nongc_write(nilfs);
+ wake_up(&nilfs->ns_cleanerd_wq);
+ }
+
+ sci->sc_nblk_inc += sci->sc_nblk_this_inc;
+
+ segbuf = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
+ nilfs_set_next_segment(nilfs, segbuf);
+
+ if (update_sr) {
+ nilfs_set_last_segment(nilfs, segbuf->sb_pseg_start,
+ segbuf->sb_sum.seg_seq, nilfs->ns_cno);
+
+ clear_bit(NILFS_SC_DIRTY, &sci->sc_flags);
+ set_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
+ } else
+ clear_bit(NILFS_SC_SUPER_ROOT, &sci->sc_flags);
+}
+
+static int nilfs_segctor_check_in_files(struct nilfs_sc_info *sci,
+ struct nilfs_sb_info *sbi)
+{
+ struct nilfs_inode_info *ii, *n;
+ __u64 cno = sbi->s_nilfs->ns_cno;
+
+ spin_lock(&sbi->s_inode_lock);
+ retry:
+ list_for_each_entry_safe(ii, n, &sbi->s_dirty_files, i_dirty) {
+ if (!ii->i_bh) {
+ struct buffer_head *ibh;
+ int err;
+
+ spin_unlock(&sbi->s_inode_lock);
+ err = nilfs_ifile_get_inode_block(
+ sbi->s_ifile, ii->vfs_inode.i_ino, &ibh);
+ if (unlikely(err)) {
+ nilfs_warning(sbi->s_super, __func__,
+ "failed to get inode block.\n");
+ return err;
+ }
+ nilfs_mdt_mark_buffer_dirty(ibh);
+ nilfs_mdt_mark_dirty(sbi->s_ifile);
+ spin_lock(&sbi->s_inode_lock);
+ if (likely(!ii->i_bh))
+ ii->i_bh = ibh;
+ else
+ brelse(ibh);
+ goto retry;
+ }
+ ii->i_cno = cno;
+
+ clear_bit(NILFS_I_QUEUED, &ii->i_state);
+ set_bit(NILFS_I_BUSY, &ii->i_state);
+ list_del(&ii->i_dirty);
+ list_add_tail(&ii->i_dirty, &sci->sc_dirty_files);
+ }
+ spin_unlock(&sbi->s_inode_lock);
+
+ NILFS_I(sbi->s_ifile)->i_cno = cno;
+
+ return 0;
+}
+
+static void nilfs_segctor_check_out_files(struct nilfs_sc_info *sci,
+ struct nilfs_sb_info *sbi)
+{
+ struct nilfs_transaction_info *ti = current->journal_info;
+ struct nilfs_inode_info *ii, *n;
+ __u64 cno = sbi->s_nilfs->ns_cno;
+
+ spin_lock(&sbi->s_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)) {
+ /* The current checkpoint number (=nilfs->ns_cno) is
+ changed between check-in and check-out only if the
+ super root is written out. So, we can update i_cno
+ for the inodes that remain in the dirty list. */
+ ii->i_cno = cno;
+ continue;
+ }
+ clear_bit(NILFS_I_BUSY, &ii->i_state);
+ brelse(ii->i_bh);
+ ii->i_bh = NULL;
+ list_del(&ii->i_dirty);
+ list_add_tail(&ii->i_dirty, &ti->ti_garbage);
+ }
+ spin_unlock(&sbi->s_inode_lock);
+}
+
+/*
+ * Nasty routines to manipulate active flags on sufile.
+ * These would be removed in a future release.
+ */
+static void nilfs_segctor_reactivate_segments(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+{
+ struct nilfs_segment_buffer *segbuf, *last;
+ struct nilfs_segment_entry *ent, *n;
+ struct inode *sufile = nilfs->ns_sufile;
+ struct list_head *head;
+
+ last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
+ nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
+ ent = segbuf->sb_segent;
+ if (!ent)
+ break; /* ignore unmapped segments (should check it?)*/
+ nilfs_segment_usage_set_active(ent->raw_su);
+ nilfs_close_segment_entry(ent, sufile);
+ }
+
+ head = &sci->sc_active_segments;
+ list_for_each_entry_safe(ent, n, head, list) {
+ nilfs_segment_usage_set_active(ent->raw_su);
+ nilfs_close_segment_entry(ent, sufile);
+ }
+
+ down_write(&nilfs->ns_sem);
+ head = &nilfs->ns_used_segments;
+ list_for_each_entry(ent, head, list) {
+ nilfs_segment_usage_set_volatile_active(ent->raw_su);
+ }
+ up_write(&nilfs->ns_sem);
+}
+
+static int nilfs_segctor_deactivate_segments(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+{
+ struct nilfs_segment_buffer *segbuf, *last;
+ struct nilfs_segment_entry *ent;
+ struct inode *sufile = nilfs->ns_sufile;
+ struct list_head *head;
+ int err;
+
+ last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
+ nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
+ /*
+ * Deactivate ongoing full segments. The last segment is kept
+ * active because it is a start point of recovery, and is not
+ * relocatable until the super block points to a newer
+ * checkpoint.
+ */
+ ent = segbuf->sb_segent;
+ if (!ent)
+ break; /* ignore unmapped segments (should check it?)*/
+ err = nilfs_open_segment_entry(ent, sufile);
+ if (unlikely(err))
+ goto failed;
+ nilfs_segment_usage_clear_active(ent->raw_su);
+ BUG_ON(!buffer_dirty(ent->bh_su));
+ }
+
+ head = &sci->sc_active_segments;
+ list_for_each_entry(ent, head, list) {
+ err = nilfs_open_segment_entry(ent, sufile);
+ if (unlikely(err))
+ goto failed;
+ nilfs_segment_usage_clear_active(ent->raw_su);
+ BUG_ON(!buffer_dirty(ent->bh_su));
+ }
+
+ down_write(&nilfs->ns_sem);
+ head = &nilfs->ns_used_segments;
+ list_for_each_entry(ent, head, list) {
+ /* clear volatile active for segments of older generations */
+ nilfs_segment_usage_clear_volatile_active(ent->raw_su);
+ }
+ up_write(&nilfs->ns_sem);
+ return 0;
+
+ failed:
+ nilfs_segctor_reactivate_segments(sci, nilfs);
+ return err;
+}
+
+static void nilfs_segctor_bead_completed_segments(struct nilfs_sc_info *sci)
+{
+ struct nilfs_segment_buffer *segbuf, *last;
+ struct nilfs_segment_entry *ent;
+
+ /* move each segbuf->sb_segent to the list of used active segments */
+ last = NILFS_LAST_SEGBUF(&sci->sc_segbufs);
+ nilfs_for_each_segbuf_before(segbuf, last, &sci->sc_segbufs) {
+ ent = segbuf->sb_segent;
+ if (!ent)
+ break; /* ignore unmapped segments (should check it?)*/
+ list_add_tail(&ent->list, &sci->sc_active_segments);
+ segbuf->sb_segent = NULL;
+ }
+}
+
+static void
+__nilfs_segctor_commit_deactivate_segments(struct nilfs_sc_info *sci,
+ struct the_nilfs *nilfs)
+
+{
+ struct nilfs_segment_entry *ent;
+
+ list_splice_init(&sci->sc_active_segments,
+ nilfs->ns_used_segments.prev);
+
+ list_for_each_entry(ent, &nilfs->ns_used_segments, list) {
+ nilfs_segment_usage_set_volatile_active(ent->raw_su);
+ /* These segments are kept open */
+ }
+}
+
+/*
+ * Main procedure of segment constructor
+ */
+static int nilfs_segctor_do_construct(struct nilfs_sc_info *sci, int mode)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct page *failed_page;
+ int err, has_sr = 0;
+
+ sci->sc_stage.scnt = NILFS_ST_INIT;
+
+ err = nilfs_segctor_check_in_files(sci, sbi);
+ if (unlikely(err))
+ goto out;
+
+ if (nilfs_test_metadata_dirty(sbi))
+ 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;
+
+ has_sr = (sci->sc_super_root != NULL);
+
+ /* Avoid empty segment */
+ if (sci->sc_stage.scnt == NILFS_ST_DONE &&
+ NILFS_SEG_EMPTY(&sci->sc_curseg->sb_sum)) {
+ BUG_ON(mode == SC_LSEG_SR);
+ nilfs_segctor_end_construction(sci, nilfs, 1);
+ goto out;
+ }
+
+ err = nilfs_segctor_assign(sci, mode);
+ if (unlikely(err))
+ goto failed;
+
+ if (has_sr) {
+ err = nilfs_segctor_deactivate_segments(sci, nilfs);
+ if (unlikely(err))
+ goto failed;
+ }
+ if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
+ nilfs_segctor_fill_in_file_bmap(sci, sbi->s_ifile);
+
+ if (has_sr) {
+ err = nilfs_segctor_fill_in_checkpoint(sci);
+ if (unlikely(err))
+ goto failed_to_make_up;
+
+ nilfs_segctor_fill_in_super_root(sci, nilfs);
+ }
+ nilfs_segctor_update_segusage(sci, nilfs->ns_sufile);
+
+ /* Write partial segments */
+ err = nilfs_segctor_prepare_write(sci, &failed_page);
+ if (unlikely(err))
+ goto failed_to_write;
+
+ nilfs_segctor_fill_in_checksums(sci, nilfs->ns_crc_seed);
+
+ err = nilfs_segctor_write(sci, nilfs->ns_bdi);
+ if (unlikely(err))
+ goto failed_to_write;
+
+ nilfs_segctor_complete_write(sci);
+
+ /* Commit segments */
+ nilfs_segctor_bead_completed_segments(sci);
+ if (has_sr) {
+ down_write(&nilfs->ns_sem);
+ nilfs_update_last_segment(sbi, 1);
+ __nilfs_segctor_commit_deactivate_segments(sci, nilfs);
+ up_write(&nilfs->ns_sem);
+ nilfs_segctor_commit_free_segments(sci);
+ nilfs_segctor_clear_metadata_dirty(sci);
+ }
+
+ nilfs_segctor_end_construction(sci, nilfs, 0);
+
+ } while (sci->sc_stage.scnt != NILFS_ST_DONE);
+
+ /* Clearing sketch data */
+ if (has_sr && sci->sc_sketch_inode) {
+ if (i_size_read(sci->sc_sketch_inode) == 0)
+ clear_bit(NILFS_I_DIRTY,
+ &NILFS_I(sci->sc_sketch_inode)->i_state);
+ i_size_write(sci->sc_sketch_inode, 0);
+ }
+ out:
+ nilfs_segctor_destroy_segment_buffers(sci);
+ nilfs_segctor_check_out_files(sci, sbi);
+ return err;
+
+ failed_to_write:
+ nilfs_segctor_abort_write(sci, failed_page, err);
+ nilfs_segctor_cancel_segusage(sci, nilfs->ns_sufile);
+
+ failed_to_make_up:
+ if (sci->sc_stage.flags & NILFS_CF_IFILE_STARTED)
+ nilfs_redirty_inodes(&sci->sc_dirty_files);
+ if (has_sr)
+ nilfs_segctor_reactivate_segments(sci, nilfs);
+
+ failed:
+ if (nilfs_doing_gc())
+ nilfs_redirty_inodes(&sci->sc_gc_inodes);
+ nilfs_segctor_end_construction(sci, nilfs, err);
+ goto out;
+}
+
+/**
+ * nilfs_secgtor_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_timer && !(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 nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_sc_info *sci = NILFS_SC(sbi);
+
+ if (!sci || nilfs_doing_construction())
+ return;
+ nilfs_segctor_do_flush(sci, NILFS_MDT_INODE(sb, ino) ? ino : 0);
+ /* assign bit 0 to data files */
+}
+
+int nilfs_segctor_add_segments_to_be_freed(struct nilfs_sc_info *sci,
+ __u64 *segnum, size_t nsegs)
+{
+ struct nilfs_segment_entry *ent;
+ struct the_nilfs *nilfs = sci->sc_sbi->s_nilfs;
+ struct inode *sufile = nilfs->ns_sufile;
+ LIST_HEAD(list);
+ __u64 *pnum;
+ const char *flag_name;
+ size_t i;
+ int err, err2 = 0;
+
+ for (pnum = segnum, i = 0; i < nsegs; pnum++, i++) {
+ ent = nilfs_alloc_segment_entry(*pnum);
+ if (unlikely(!ent)) {
+ err = -ENOMEM;
+ goto failed;
+ }
+ list_add_tail(&ent->list, &list);
+
+ err = nilfs_open_segment_entry(ent, sufile);
+ if (unlikely(err))
+ goto failed;
+
+ if (unlikely(le32_to_cpu(ent->raw_su->su_flags) !=
+ (1UL << NILFS_SEGMENT_USAGE_DIRTY))) {
+ if (nilfs_segment_usage_clean(ent->raw_su))
+ flag_name = "clean";
+ else if (nilfs_segment_usage_active(ent->raw_su))
+ flag_name = "active";
+ else if (nilfs_segment_usage_volatile_active(
+ ent->raw_su))
+ flag_name = "volatile active";
+ else if (!nilfs_segment_usage_dirty(ent->raw_su))
+ flag_name = "non-dirty";
+ else
+ flag_name = "erroneous";
+
+ printk(KERN_ERR
+ "NILFS: %s segment is requested to be cleaned "
+ "(segnum=%llu)\n",
+ flag_name, (unsigned long long)ent->segnum);
+ err2 = -EINVAL;
+ }
+ nilfs_close_segment_entry(ent, sufile);
+ }
+ if (unlikely(err2)) {
+ err = err2;
+ goto failed;
+ }
+ list_splice(&list, sci->sc_cleaning_segments.prev);
+ return 0;
+
+ failed:
+ nilfs_dispose_segment_list(&list);
+ return err;
+}
+
+void nilfs_segctor_clear_segments_to_be_freed(struct nilfs_sc_info *sci)
+{
+ nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
+}
+
+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 nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_sc_info *sci = NILFS_SC(sbi);
+ 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: the inode whose data blocks should be written out
+ *
+ * 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)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_sc_info *sci = NILFS_SC(sbi);
+ struct nilfs_inode_info *ii;
+ struct nilfs_transaction_info ti;
+ int err = 0;
+
+ if (!sci)
+ return -EROFS;
+
+ nilfs_transaction_lock(sbi, &ti, 0);
+
+ ii = NILFS_I(inode);
+ if (test_bit(NILFS_I_INODE_DIRTY, &ii->i_state) ||
+ nilfs_test_opt(sbi, STRICT_ORDER) ||
+ test_bit(NILFS_SC_UNCLOSED, &sci->sc_flags) ||
+ nilfs_discontinued(sbi->s_nilfs)) {
+ nilfs_transaction_unlock(sbi);
+ err = nilfs_segctor_sync(sci);
+ return err;
+ }
+
+ spin_lock(&sbi->s_inode_lock);
+ if (!test_bit(NILFS_I_QUEUED, &ii->i_state) &&
+ !test_bit(NILFS_I_BUSY, &ii->i_state)) {
+ spin_unlock(&sbi->s_inode_lock);
+ nilfs_transaction_unlock(sbi);
+ return 0;
+ }
+ spin_unlock(&sbi->s_inode_lock);
+ sci->sc_stage.dirty_file_ptr = ii;
+
+ err = nilfs_segctor_do_construct(sci, SC_LSEG_DSYNC);
+
+ nilfs_transaction_unlock(sbi);
+ return err;
+}
+
+struct nilfs_segctor_req {
+ int mode;
+ __u32 seq_accepted;
+ int sc_err; /* construction failure */
+ int sb_err; /* super block writeback failure */
+};
+
+#define FLUSH_FILE_BIT (0x1) /* data file only */
+#define FLUSH_DAT_BIT (1 << NILFS_DAT_INO) /* DAT only */
+
+static void nilfs_segctor_accept(struct nilfs_sc_info *sci,
+ struct nilfs_segctor_req *req)
+{
+ BUG_ON(!sci);
+
+ req->sc_err = req->sb_err = 0;
+ spin_lock(&sci->sc_state_lock);
+ req->seq_accepted = sci->sc_seq_request;
+ spin_unlock(&sci->sc_state_lock);
+
+ if (sci->sc_timer)
+ del_timer_sync(sci->sc_timer);
+}
+
+static void nilfs_segctor_notify(struct nilfs_sc_info *sci,
+ struct nilfs_segctor_req *req)
+{
+ /* Clear requests (even when the construction failed) */
+ spin_lock(&sci->sc_state_lock);
+
+ sci->sc_state &= ~NILFS_SEGCTOR_COMMIT;
+
+ if (req->mode == SC_LSEG_SR) {
+ sci->sc_seq_done = req->seq_accepted;
+ nilfs_segctor_wakeup(sci, req->sc_err ? : req->sb_err);
+ sci->sc_flush_request = 0;
+ } else if (req->mode == SC_FLUSH_FILE)
+ sci->sc_flush_request &= ~FLUSH_FILE_BIT;
+ else if (req->mode == SC_FLUSH_DAT)
+ sci->sc_flush_request &= ~FLUSH_DAT_BIT;
+
+ spin_unlock(&sci->sc_state_lock);
+}
+
+static int nilfs_segctor_construct(struct nilfs_sc_info *sci,
+ struct nilfs_segctor_req *req)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int err = 0;
+
+ if (nilfs_discontinued(nilfs))
+ req->mode = SC_LSEG_SR;
+ if (!nilfs_segctor_confirm(sci)) {
+ err = nilfs_segctor_do_construct(sci, req->mode);
+ req->sc_err = err;
+ }
+ if (likely(!err)) {
+ if (req->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);
+ req->sb_err = nilfs_commit_super(sbi);
+ up_write(&nilfs->ns_sem);
+ }
+ }
+ 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;
+ hlist_del_init(&ii->vfs_inode.i_hash);
+ list_del_init(&ii->i_dirty);
+ nilfs_clear_gcinode(&ii->vfs_inode);
+ }
+}
+
+int nilfs_clean_segments(struct super_block *sb, void __user *argp)
+{
+ struct nilfs_sb_info *sbi = NILFS_SB(sb);
+ struct nilfs_sc_info *sci = NILFS_SC(sbi);
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ struct nilfs_transaction_info ti;
+ struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
+ int err;
+
+ if (unlikely(!sci))
+ return -EROFS;
+
+ nilfs_transaction_lock(sbi, &ti, 1);
+
+ err = nilfs_init_gcdat_inode(nilfs);
+ if (unlikely(err))
+ goto out_unlock;
+ err = nilfs_ioctl_prepare_clean_segments(nilfs, argp);
+ if (unlikely(err))
+ goto out_unlock;
+
+ list_splice_init(&nilfs->ns_gc_inodes, sci->sc_gc_inodes.prev);
+
+ for (;;) {
+ nilfs_segctor_accept(sci, &req);
+ err = nilfs_segctor_construct(sci, &req);
+ nilfs_remove_written_gcinodes(nilfs, &sci->sc_gc_inodes);
+ nilfs_segctor_notify(sci, &req);
+
+ if (likely(!err))
+ break;
+
+ nilfs_warning(sb, __func__,
+ "segment construction failed. (err=%d)", err);
+ set_current_state(TASK_INTERRUPTIBLE);
+ schedule_timeout(sci->sc_interval);
+ }
+
+ out_unlock:
+ nilfs_clear_gcdat_inode(nilfs);
+ nilfs_transaction_unlock(sbi);
+ return err;
+}
+
+static void nilfs_segctor_thread_construct(struct nilfs_sc_info *sci, int mode)
+{
+ struct nilfs_sb_info *sbi = sci->sc_sbi;
+ struct nilfs_transaction_info ti;
+ struct nilfs_segctor_req req = { .mode = mode };
+
+ nilfs_transaction_lock(sbi, &ti, 0);
+
+ nilfs_segctor_accept(sci, &req);
+ nilfs_segctor_construct(sci, &req);
+ nilfs_segctor_notify(sci, &req);
+
+ /*
+ * 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(sbi);
+}
+
+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 timer_list timer;
+ int timeout = 0;
+
+ init_timer(&timer);
+ timer.data = (unsigned long)current;
+ timer.function = nilfs_construction_timeout;
+ sci->sc_timer = &timer;
+
+ /* 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);
+ refrigerator();
+ 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));
+ }
+ goto loop;
+
+ end_thread:
+ spin_unlock(&sci->sc_state_lock);
+ del_timer_sync(sci->sc_timer);
+ sci->sc_timer = NULL;
+
+ /* 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)
+{
+ 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);
+ }
+}
+
+static int nilfs_segctor_init(struct nilfs_sc_info *sci,
+ struct nilfs_recovery_info *ri)
+{
+ int err;
+ struct inode *inode = nilfs_iget(sci->sc_super, NILFS_SKETCH_INO);
+
+ sci->sc_sketch_inode = IS_ERR(inode) ? NULL : inode;
+ if (sci->sc_sketch_inode)
+ i_size_write(sci->sc_sketch_inode, 0);
+
+ sci->sc_seq_done = sci->sc_seq_request;
+ if (ri)
+ list_splice_init(&ri->ri_used_segments,
+ sci->sc_active_segments.prev);
+
+ err = nilfs_segctor_start_thread(sci);
+ if (err) {
+ if (ri)
+ list_splice_init(&sci->sc_active_segments,
+ ri->ri_used_segments.prev);
+ if (sci->sc_sketch_inode) {
+ iput(sci->sc_sketch_inode);
+ sci->sc_sketch_inode = NULL;
+ }
+ }
+ return err;
+}
+
+/*
+ * Setup & clean-up functions
+ */
+static struct nilfs_sc_info *nilfs_segctor_new(struct nilfs_sb_info *sbi)
+{
+ struct nilfs_sc_info *sci;
+
+ sci = kzalloc(sizeof(*sci), GFP_KERNEL);
+ if (!sci)
+ return NULL;
+
+ sci->sc_sbi = sbi;
+ sci->sc_super = sbi->s_super;
+
+ 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_gc_inodes);
+ INIT_LIST_HEAD(&sci->sc_active_segments);
+ INIT_LIST_HEAD(&sci->sc_cleaning_segments);
+ INIT_LIST_HEAD(&sci->sc_copied_buffers);
+
+ 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 (sbi->s_interval)
+ sci->sc_interval = sbi->s_interval;
+ if (sbi->s_watermark)
+ sci->sc_watermark = sbi->s_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_sb_info *sbi = sci->sc_sbi;
+ struct nilfs_transaction_info ti;
+ struct nilfs_segctor_req req = { .mode = SC_LSEG_SR };
+
+ nilfs_transaction_lock(sbi, &ti, 0);
+ nilfs_segctor_accept(sci, &req);
+ ret = nilfs_segctor_construct(sci, &req);
+ nilfs_segctor_notify(sci, &req);
+ nilfs_transaction_unlock(sbi);
+
+ } 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 nilfs_sb_info *sbi = sci->sc_sbi;
+ int flag;
+
+ up_write(&sbi->s_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 (flag || nilfs_segctor_confirm(sci))
+ nilfs_segctor_write_out(sci);
+
+ BUG_ON(!list_empty(&sci->sc_copied_buffers));
+
+ if (!list_empty(&sci->sc_dirty_files)) {
+ nilfs_warning(sbi->s_super, __func__,
+ "dirty file(s) after the final construction\n");
+ nilfs_dispose_list(sbi, &sci->sc_dirty_files, 1);
+ }
+ if (!list_empty(&sci->sc_active_segments))
+ nilfs_dispose_segment_list(&sci->sc_active_segments);
+
+ if (!list_empty(&sci->sc_cleaning_segments))
+ nilfs_dispose_segment_list(&sci->sc_cleaning_segments);
+
+ BUG_ON(!list_empty(&sci->sc_segbufs));
+
+ if (sci->sc_sketch_inode) {
+ iput(sci->sc_sketch_inode);
+ sci->sc_sketch_inode = NULL;
+ }
+ down_write(&sbi->s_nilfs->ns_segctor_sem);
+
+ kfree(sci);
+}
+
+/**
+ * nilfs_attach_segment_constructor - attach a segment constructor
+ * @sbi: nilfs_sb_info
+ * @ri: nilfs_recovery_info
+ *
+ * nilfs_attach_segment_constructor() allocates a struct nilfs_sc_info,
+ * initilizes it, and starts the segment constructor.
+ *
+ * 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_segment_constructor(struct nilfs_sb_info *sbi,
+ struct nilfs_recovery_info *ri)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ int err;
+
+ /* Each field of nilfs_segctor is cleared through the initialization
+ of super-block info */
+ sbi->s_sc_info = nilfs_segctor_new(sbi);
+ if (!sbi->s_sc_info)
+ return -ENOMEM;
+
+ nilfs_attach_writer(nilfs, sbi);
+ err = nilfs_segctor_init(NILFS_SC(sbi), ri);
+ if (err) {
+ nilfs_detach_writer(nilfs, sbi);
+ kfree(sbi->s_sc_info);
+ sbi->s_sc_info = NULL;
+ }
+ return err;
+}
+
+/**
+ * nilfs_detach_segment_constructor - destroy the segment constructor
+ * @sbi: nilfs_sb_info
+ *
+ * nilfs_detach_segment_constructor() kills the segment constructor daemon,
+ * frees the struct nilfs_sc_info, and destroy the dirty file list.
+ */
+void nilfs_detach_segment_constructor(struct nilfs_sb_info *sbi)
+{
+ struct the_nilfs *nilfs = sbi->s_nilfs;
+ LIST_HEAD(garbage_list);
+
+ down_write(&nilfs->ns_segctor_sem);
+ if (NILFS_SC(sbi)) {
+ nilfs_segctor_destroy(NILFS_SC(sbi));
+ sbi->s_sc_info = NULL;
+ }
+
+ /* Force to free the list of dirty files */
+ spin_lock(&sbi->s_inode_lock);
+ if (!list_empty(&sbi->s_dirty_files)) {
+ list_splice_init(&sbi->s_dirty_files, &garbage_list);
+ nilfs_warning(sbi->s_super, __func__,
+ "Non empty dirty list after the last "
+ "segment construction\n");
+ }
+ spin_unlock(&sbi->s_inode_lock);
+ up_write(&nilfs->ns_segctor_sem);
+
+ nilfs_dispose_list(sbi, &garbage_list, 1);
+ nilfs_detach_writer(nilfs, sbi);
+}
git.openpandora.org / pandora-kernel.git / commitdiff