nilfs2: segment constructor
Changes
4 files changed · +3577 −3
| File | Status | Add | Del | Content |
|---|---|---|---|---|
| fs/nilfs2/file.c | modified | +59 | −3 | View file |
| fs/nilfs2/seglist.h | added | +85 | −0 | View file |
| fs/nilfs2/segment.c | added | +3187 | −0 | View file |
| fs/nilfs2/segment.h | added | +246 | −0 | View file |
Only the first 600 diff lines are shown. Download the complete patch.
fs/nilfs2/file.c
View filediff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c
index 7ddd42e..8031086 100644
--- a/fs/nilfs2/file.c
+++ b/fs/nilfs2/file.c
@@ -73,10 +73,66 @@ nilfs_file_aio_write(struct kiocb *iocb, const struct iovec *iov,
return ret;
}
-static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct page *page)
+static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf)
{
- if (!(vma->vm_flags & (VM_WRITE | VM_MAYWRITE)))
- return -EPERM;
+ struct page *page = vmf->page;
+ struct inode *inode = vma->vm_file->f_dentry->d_inode;
+ struct nilfs_transaction_info ti;
+ int ret;
+
+ if (unlikely(nilfs_near_disk_full(NILFS_SB(inode->i_sb)->s_nilfs)))
+ return VM_FAULT_SIGBUS; /* -ENOSPC */
+
+ lock_page(page);
+ if (page->mapping != inode->i_mapping ||
+ page_offset(page) >= i_size_read(inode) || !PageUptodate(page)) {
+ unlock_page(page);
+ return VM_FAULT_NOPAGE; /* make the VM retry the fault */
+ }
+
+ /*
+ * check to see if the page is mapped already (no holes)
+ */
+ if (PageMappedToDisk(page)) {
+ unlock_page(page);
+ goto mapped;
+ }
+ if (page_has_buffers(page)) {
+ struct buffer_head *bh, *head;
+ int fully_mapped = 1;
+
+ bh = head = page_buffers(page);
+ do {
+ if (!buffer_mapped(bh)) {
+ fully_mapped = 0;
+ break;
+ }
+ } while (bh = bh->b_this_page, bh != head);
+
+ if (fully_mapped) {
+ SetPageMappedToDisk(page);
+ unlock_page(page);
+ goto mapped;
+ }
+ }
+ unlock_page(page);
+
+ /*
+ * fill hole blocks
+ */
+ ret = nilfs_transaction_begin(inode->i_sb, &ti, 1);
+ /* never returns -ENOMEM, but may return -ENOSPC */
+ if (unlikely(ret))
+ return VM_FAULT_SIGBUS;
+
+ ret = block_page_mkwrite(vma, vmf, nilfs_get_block);
+ if (unlikely(ret)) {
+ nilfs_transaction_abort(inode->i_sb);
+ return ret;
+ }
+ nilfs_transaction_commit(inode->i_sb);
+
+ mapped:
SetPageChecked(page);
wait_on_page_writeback(page);
return 0;
fs/nilfs2/seglist.h
View filediff --git a/fs/nilfs2/seglist.h b/fs/nilfs2/seglist.h
new file mode 100644
index 0000000..d39df91
--- /dev/null
+++ b/fs/nilfs2/seglist.h
@@ -0,0 +1,85 @@
+/*
+ * seglist.h - expediential structure and routines to handle list of segments
+ * (would be removed in a future release)
+ *
+ * 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 <[email protected]>
+ *
+ */
+#ifndef _NILFS_SEGLIST_H
+#define _NILFS_SEGLIST_H
+
+#include <linux/fs.h>
+#include <linux/buffer_head.h>
+#include <linux/nilfs2_fs.h>
+#include "sufile.h"
+
+struct nilfs_segment_entry {
+ __u64 segnum;
+
+#define NILFS_SLH_FREED 0x0001 /* The segment was freed provisonally.
+ It must be cancelled if
+ construction aborted */
+
+ unsigned flags;
+ struct list_head list;
+ struct buffer_head *bh_su;
+ struct nilfs_segment_usage *raw_su;
+};
+
+
+void nilfs_dispose_segment_list(struct list_head *);
+
+static inline struct nilfs_segment_entry *
+nilfs_alloc_segment_entry(__u64 segnum)
+{
+ struct nilfs_segment_entry *ent = kmalloc(sizeof(*ent), GFP_NOFS);
+
+ if (likely(ent)) {
+ ent->segnum = segnum;
+ ent->flags = 0;
+ ent->bh_su = NULL;
+ ent->raw_su = NULL;
+ INIT_LIST_HEAD(&ent->list);
+ }
+ return ent;
+}
+
+static inline int nilfs_open_segment_entry(struct nilfs_segment_entry *ent,
+ struct inode *sufile)
+{
+ return nilfs_sufile_get_segment_usage(sufile, ent->segnum,
+ &ent->raw_su, &ent->bh_su);
+}
+
+static inline void nilfs_close_segment_entry(struct nilfs_segment_entry *ent,
+ struct inode *sufile)
+{
+ if (!ent->bh_su)
+ return;
+ nilfs_sufile_put_segment_usage(sufile, ent->segnum, ent->bh_su);
+ ent->bh_su = NULL;
+ ent->raw_su = NULL;
+}
+
+static inline void nilfs_free_segment_entry(struct nilfs_segment_entry *ent)
+{
+ kfree(ent);
+}
+
+#endif /* _NILFS_SEGLIST_H */
fs/nilfs2/segment.c
View filediff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c
new file mode 100644
index 0000000..2c4c088
--- /dev/null
+++ b/fs/nilfs2/segment.c
@@ -0,0 +1,3187 @@
+/*
+ * 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 <[email protected]>
+ *
+ */
+
+#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;
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fs/nilfs2/segment.h
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