6 files changed, 91 insertions, 55 deletions

diff --git a/fs/logfs/gc.c b/fs/logfs/gc.c
index 84e36f52fe95..76c242fbe1b0 100644
--- a/fs/logfs/gc.c
+++ b/fs/logfs/gc.c
@@ -459,6 +459,14 @@ static void __logfs_gc_pass(struct super_block *sb, int target)
         struct logfs_block *block;
         int round, progress, last_progress = 0;
 
+        /*
+         * Doing too many changes to the segfile at once would result
+         * in a large number of aliases.  Write the journal before
+         * things get out of hand.
+         */
+        if (super->s_shadow_tree.no_shadowed_segments >= MAX_OBJ_ALIASES)
+                logfs_write_anchor(sb);
+
         if (no_free_segments(sb) >= target &&
                         super->s_no_object_aliases < MAX_OBJ_ALIASES)
                 return;
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c
index 33bd260b8309..fb0a613f885b 100644
--- a/fs/logfs/journal.c
+++ b/fs/logfs/journal.c
@@ -389,7 +389,10 @@ static void journal_get_erase_count(struct logfs_area *area)
 static int journal_erase_segment(struct logfs_area *area)
 {
         struct super_block *sb = area->a_sb;
-        struct logfs_segment_header sh;
+        union {
+                struct logfs_segment_header sh;
+                unsigned char c[ALIGN(sizeof(struct logfs_segment_header), 16)];
+        } u;
         u64 ofs;
         int err;
 
@@ -397,20 +400,21 @@ static int journal_erase_segment(struct logfs_area *area)
         if (err)
                 return err;
 
-        sh.pad = 0;
-        sh.type = SEG_JOURNAL;
-        sh.level = 0;
-        sh.segno = cpu_to_be32(area->a_segno);
-        sh.ec = cpu_to_be32(area->a_erase_count);
-        sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
-        sh.crc = logfs_crc32(&sh, sizeof(sh), 4);
+        memset(&u, 0, sizeof(u));
+        u.sh.pad = 0;
+        u.sh.type = SEG_JOURNAL;
+        u.sh.level = 0;
+        u.sh.segno = cpu_to_be32(area->a_segno);
+        u.sh.ec = cpu_to_be32(area->a_erase_count);
+        u.sh.gec = cpu_to_be64(logfs_super(sb)->s_gec);
+        u.sh.crc = logfs_crc32(&u.sh, sizeof(u.sh), 4);
 
         /* This causes a bug in segment.c.  Not yet. */
         //logfs_set_segment_erased(sb, area->a_segno, area->a_erase_count, 0);
 
         ofs = dev_ofs(sb, area->a_segno, 0);
-        area->a_used_bytes = ALIGN(sizeof(sh), 16);
-        logfs_buf_write(area, ofs, &sh, sizeof(sh));
+        area->a_used_bytes = sizeof(u);
+        logfs_buf_write(area, ofs, &u, sizeof(u));
         return 0;
 }
 
@@ -494,6 +498,8 @@ static void account_shadows(struct super_block *sb)
 
         btree_grim_visitor64(&tree->new, (unsigned long)sb, account_shadow);
         btree_grim_visitor64(&tree->old, (unsigned long)sb, account_shadow);
+        btree_grim_visitor32(&tree->segment_map, 0, NULL);
+        tree->no_shadowed_segments = 0;
 
         if (li->li_block) {
                 /*
@@ -607,9 +613,9 @@ static size_t __logfs_write_je(struct super_block *sb, void *buf, u16 type,
         if (len == 0)
                 return logfs_write_header(super, header, 0, type);
 
+        BUG_ON(len > sb->s_blocksize);
         compr_len = logfs_compress(buf, data, len, sb->s_blocksize);
         if (compr_len < 0 || type == JE_ANCHOR) {
-                BUG_ON(len > sb->s_blocksize);
                 memcpy(data, buf, len);
                 compr_len = len;
                 compr = COMPR_NONE;
@@ -661,6 +667,7 @@ static int logfs_write_je_buf(struct super_block *sb, void *buf, u16 type,
         if (ofs < 0)
                 return ofs;
         logfs_buf_write(area, ofs, super->s_compressed_je, len);
+        BUG_ON(super->s_no_je >= MAX_JOURNAL_ENTRIES);
         super->s_je_array[super->s_no_je++] = cpu_to_be64(ofs);
         return 0;
 }
diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
index b84b0eec6024..0a3df1a0c936 100644
--- a/fs/logfs/logfs.h
+++ b/fs/logfs/logfs.h
@@ -257,10 +257,14 @@ struct logfs_shadow {
  * struct shadow_tree
  * @new:                        shadows where old_ofs==0, indexed by new_ofs
  * @old:                        shadows where old_ofs!=0, indexed by old_ofs
+ * @segment_map:                bitfield of segments containing shadows
+ * @no_shadowed_segment:        number of segments containing shadows
  */
 struct shadow_tree {
         struct btree_head64 new;
         struct btree_head64 old;
+        struct btree_head32 segment_map;
+        int no_shadowed_segments;
 };
 
 struct object_alias_item {
@@ -305,13 +309,14 @@ typedef int write_alias_t(struct super_block *sb, u64 ino, u64 bix,
                 level_t level, int child_no, __be64 val);
 struct logfs_block_ops {
         void    (*write_block)(struct logfs_block *block);
-        gc_level_t      (*block_level)(struct logfs_block *block);
         void    (*free_block)(struct super_block *sb, struct logfs_block*block);
         int     (*write_alias)(struct super_block *sb,
                         struct logfs_block *block,
                         write_alias_t *write_one_alias);
 };
 
+#define MAX_JOURNAL_ENTRIES 256
+
 struct logfs_super {
         struct mtd_info *s_mtd;                 /* underlying device */
         struct block_device *s_bdev;            /* underlying device */
@@ -378,7 +383,7 @@ struct logfs_super {
         u32      s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */
         u64      s_last_version;
         struct logfs_area *s_journal_area;      /* open journal segment */
-        __be64  s_je_array[64];
+        __be64  s_je_array[MAX_JOURNAL_ENTRIES];
         int     s_no_je;
 
         int      s_sum_index;                   /* for the 12 summaries */
@@ -722,4 +727,10 @@ static inline struct logfs_area *get_area(struct super_block *sb,
         return logfs_super(sb)->s_area[(__force u8)gc_level];
 }
 
+static inline void logfs_mempool_destroy(mempool_t *pool)
+{
+        if (pool)
+                mempool_destroy(pool);
+}
+
 #endif
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index bff40253dfb2..3159db6958e5 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -430,25 +430,6 @@ static void inode_write_block(struct logfs_block *block)
         }
 }
 
-static gc_level_t inode_block_level(struct logfs_block *block)
-{
-        BUG_ON(block->inode->i_ino == LOGFS_INO_MASTER);
-        return GC_LEVEL(LOGFS_MAX_LEVELS);
-}
-
-static gc_level_t indirect_block_level(struct logfs_block *block)
-{
-        struct page *page;
-        struct inode *inode;
-        u64 bix;
-        level_t level;
-
-        page = block->page;
-        inode = page->mapping->host;
-        logfs_unpack_index(page->index, &bix, &level);
-        return expand_level(inode->i_ino, level);
-}
-
 /*
  * This silences a false, yet annoying gcc warning.  I hate it when my editor
  * jumps into bitops.h each time I recompile this file.
@@ -587,14 +568,12 @@ static void indirect_free_block(struct super_block *sb,
 
 static struct logfs_block_ops inode_block_ops = {
         .write_block = inode_write_block,
-        .block_level = inode_block_level,
         .free_block = inode_free_block,
         .write_alias = inode_write_alias,
 };
 
 struct logfs_block_ops indirect_block_ops = {
         .write_block = indirect_write_block,
-        .block_level = indirect_block_level,
         .free_block = indirect_free_block,
         .write_alias = indirect_write_alias,
 };
@@ -1241,6 +1220,18 @@ static void free_shadow(struct inode *inode, struct logfs_shadow *shadow)
         mempool_free(shadow, super->s_shadow_pool);
 }
 
+static void mark_segment(struct shadow_tree *tree, u32 segno)
+{
+        int err;
+
+        if (!btree_lookup32(&tree->segment_map, segno)) {
+                err = btree_insert32(&tree->segment_map, segno, (void *)1,
+                                GFP_NOFS);
+                BUG_ON(err);
+                tree->no_shadowed_segments++;
+        }
+}
+
 /**
  * fill_shadow_tree - Propagate shadow tree changes due to a write
  * @inode:      Inode owning the page
@@ -1288,6 +1279,8 @@ static void fill_shadow_tree(struct inode *inode, struct page *page,
 
                 super->s_dirty_used_bytes += shadow->new_len;
                 super->s_dirty_free_bytes += shadow->old_len;
+                mark_segment(tree, shadow->old_ofs >> super->s_segshift);
+                mark_segment(tree, shadow->new_ofs >> super->s_segshift);
         }
 }
 
@@ -1845,19 +1838,37 @@ static int __logfs_truncate(struct inode *inode, u64 size)
         return logfs_truncate_direct(inode, size);
 }
 
-int logfs_truncate(struct inode *inode, u64 size)
+/*
+ * Truncate, by changing the segment file, can consume a fair amount
+ * of resources.  So back off from time to time and do some GC.
+ * 8 or 2048 blocks should be well within safety limits even if
+ * every single block resided in a different segment.
+ */
+#define TRUNCATE_STEP   (8 * 1024 * 1024)
+int logfs_truncate(struct inode *inode, u64 target)
 {
         struct super_block *sb = inode->i_sb;
-        int err;
+        u64 size = i_size_read(inode);
+        int err = 0;
 
-        logfs_get_wblocks(sb, NULL, 1);
-        err = __logfs_truncate(inode, size);
-        if (!err)
-                err = __logfs_write_inode(inode, 0);
-        logfs_put_wblocks(sb, NULL, 1);
+        size = ALIGN(size, TRUNCATE_STEP);
+        while (size > target) {
+                if (size > TRUNCATE_STEP)
+                        size -= TRUNCATE_STEP;
+                else
+                        size = 0;
+                if (size < target)
+                        size = target;
+
+                logfs_get_wblocks(sb, NULL, 1);
+                err = __logfs_truncate(inode, target);
+                if (!err)
+                        err = __logfs_write_inode(inode, 0);
+                logfs_put_wblocks(sb, NULL, 1);
+        }
 
         if (!err)
-                err = vmtruncate(inode, size);
+                err = vmtruncate(inode, target);
 
         /* I don't trust error recovery yet. */
         WARN_ON(err);
@@ -2251,8 +2262,6 @@ void logfs_cleanup_rw(struct super_block *sb)
         struct logfs_super *super = logfs_super(sb);
 
         destroy_meta_inode(super->s_segfile_inode);
-        if (super->s_block_pool)
-                mempool_destroy(super->s_block_pool);
-        if (super->s_shadow_pool)
-                mempool_destroy(super->s_shadow_pool);
+        logfs_mempool_destroy(super->s_block_pool);
+        logfs_mempool_destroy(super->s_shadow_pool);
 }
diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
index 801a3a141625..f77ce2b470ba 100644
--- a/fs/logfs/segment.c
+++ b/fs/logfs/segment.c
@@ -183,14 +183,8 @@ static int btree_write_alias(struct super_block *sb, struct logfs_block *block,
         return 0;
 }
 
-static gc_level_t btree_block_level(struct logfs_block *block)
-{
-        return expand_level(block->ino, block->level);
-}
-
 static struct logfs_block_ops btree_block_ops = {
         .write_block    = btree_write_block,
-        .block_level    = btree_block_level,
         .free_block     = __free_block,
         .write_alias    = btree_write_alias,
 };
@@ -919,7 +913,7 @@ err:
         for (i--; i >= 0; i--)
                 free_area(super->s_area[i]);
         free_area(super->s_journal_area);
-        mempool_destroy(super->s_alias_pool);
+        logfs_mempool_destroy(super->s_alias_pool);
         return -ENOMEM;
 }
 
diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index b60bfac3263c..5866ee6e1327 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -12,6 +12,7 @@
 #include "logfs.h"
 #include <linux/bio.h>
 #include <linux/slab.h>
+#include <linux/blkdev.h>
 #include <linux/mtd/mtd.h>
 #include <linux/statfs.h>
 #include <linux/buffer_head.h>
@@ -137,6 +138,10 @@ static int logfs_sb_set(struct super_block *sb, void *_super)
         sb->s_fs_info = super;
         sb->s_mtd = super->s_mtd;
         sb->s_bdev = super->s_bdev;
+        if (sb->s_bdev)
+                sb->s_bdi = &bdev_get_queue(sb->s_bdev)->backing_dev_info;
+        if (sb->s_mtd)
+                sb->s_bdi = sb->s_mtd->backing_dev_info;
         return 0;
 }
 
@@ -452,6 +457,8 @@ static int logfs_read_sb(struct super_block *sb, int read_only)
 
         btree_init_mempool64(&super->s_shadow_tree.new, super->s_btree_pool);
         btree_init_mempool64(&super->s_shadow_tree.old, super->s_btree_pool);
+        btree_init_mempool32(&super->s_shadow_tree.segment_map,
+                        super->s_btree_pool);
 
         ret = logfs_init_mapping(sb);
         if (ret)
@@ -516,8 +523,8 @@ static void logfs_kill_sb(struct super_block *sb)
         if (super->s_erase_page)
                 __free_page(super->s_erase_page);
         super->s_devops->put_device(sb);
-        mempool_destroy(super->s_btree_pool);
-        mempool_destroy(super->s_alias_pool);
+        logfs_mempool_destroy(super->s_btree_pool);
+        logfs_mempool_destroy(super->s_alias_pool);
         kfree(super);
         log_super("LogFS: Finished unmounting\n");
 }