Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream

There are few important bug fixes for LogFS

* tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream:
  Logfs: Allow NULL block_isbad() methods
  logfs: Grow inode in delete path
  logfs: Free areas before calling generic_shutdown_super()
  logfs: remove useless BUG_ON
  MAINTAINERS: Add Prasad Joshi in LogFS maintiners
  logfs: Propagate page parameter to __logfs_write_inode
  logfs: set superblock shutdown flag after generic sb shutdown
  logfs: take write mutex lock during fsync and sync
  logfs: Prevent memory corruption
  logfs: update page reference count for pined pages

Fix up conflict in fs/logfs/dev_mtd.c due to semantic change in what
"mtd->block_isbad" means in commit f2933e86ad93: "Logfs: Allow NULL
block_isbad() methods" clashing with the abstraction changes in the
commits 7086c19d0742: "mtd: introduce mtd_block_isbad interface" and
d58b27ed58a3: "logfs: do not use 'mtd->block_isbad' directly".

This resolution takes the semantics from commit f2933e86ad93, and just
makes mtd_block_isbad() return zero (false) if the 'block_isbad'
function is NULL.  But that also means that now "mtd_can_have_bb()"
always returns 0.

Now, "mtd_block_markbad()" will obviously return an error if the
low-level driver doesn't support bad blocks, so this is somewhat
non-symmetric, but it actually makes sense if a NULL "block_isbad"
function is considered to mean "I assume that all my blocks are always
good".

9 files changed, 86 insertions, 35 deletions

diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c
index 501043e8966c..3de7a32cadbe 100644
--- a/fs/logfs/dir.c
+++ b/fs/logfs/dir.c
@@ -71,7 +71,7 @@ static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd,
 
 static int write_inode(struct inode *inode)
 {
-        return __logfs_write_inode(inode, WF_LOCK);
+        return __logfs_write_inode(inode, NULL, WF_LOCK);
 }
 
 static s64 dir_seek_data(struct inode *inode, s64 pos)
diff --git a/fs/logfs/file.c b/fs/logfs/file.c
index b548c87a86f1..3886cded283c 100644
--- a/fs/logfs/file.c
+++ b/fs/logfs/file.c
@@ -230,7 +230,9 @@ int logfs_fsync(struct file *file, loff_t start, loff_t end, int datasync)
                 return ret;
 
         mutex_lock(&inode->i_mutex);
+        logfs_get_wblocks(sb, NULL, WF_LOCK);
         logfs_write_anchor(sb);
+        logfs_put_wblocks(sb, NULL, WF_LOCK);
         mutex_unlock(&inode->i_mutex);
 
         return 0;
diff --git a/fs/logfs/gc.c b/fs/logfs/gc.c
index caa4419285dc..d4efb061bdc5 100644
--- a/fs/logfs/gc.c
+++ b/fs/logfs/gc.c
@@ -367,7 +367,7 @@ static struct gc_candidate *get_candidate(struct super_block *sb)
         int i, max_dist;
         struct gc_candidate *cand = NULL, *this;
 
-        max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS);
+        max_dist = min(no_free_segments(sb), LOGFS_NO_AREAS - 1);
 
         for (i = max_dist; i >= 0; i--) {
                 this = first_in_list(&super->s_low_list[i]);
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index 388df1aa35e5..a422f42238b2 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -286,7 +286,7 @@ static int logfs_write_inode(struct inode *inode, struct writeback_control *wbc)
         if (logfs_inode(inode)->li_flags & LOGFS_IF_STILLBORN)
                 return 0;
 
-        ret = __logfs_write_inode(inode, flags);
+        ret = __logfs_write_inode(inode, NULL, flags);
         LOGFS_BUG_ON(ret, inode->i_sb);
         return ret;
 }
@@ -363,7 +363,9 @@ static void logfs_init_once(void *_li)
 
 static int logfs_sync_fs(struct super_block *sb, int wait)
 {
+        logfs_get_wblocks(sb, NULL, WF_LOCK);
         logfs_write_anchor(sb);
+        logfs_put_wblocks(sb, NULL, WF_LOCK);
         return 0;
 }
 
diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c
index 9da29706f91c..1e1c369df22b 100644
--- a/fs/logfs/journal.c
+++ b/fs/logfs/journal.c
@@ -612,7 +612,6 @@ 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) {
                 memcpy(data, buf, len);
diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h
index 926373866a55..5f0937609465 100644
--- a/fs/logfs/logfs.h
+++ b/fs/logfs/logfs.h
@@ -528,7 +528,7 @@ void logfs_destroy_inode_cache(void);
 void logfs_set_blocks(struct inode *inode, u64 no);
 /* these logically belong into inode.c but actually reside in readwrite.c */
 int logfs_read_inode(struct inode *inode);
-int __logfs_write_inode(struct inode *inode, long flags);
+int __logfs_write_inode(struct inode *inode, struct page *, long flags);
 void logfs_evict_inode(struct inode *inode);
 
 /* journal.c */
@@ -577,6 +577,8 @@ void initialize_block_counters(struct page *page, struct logfs_block *block,
                 __be64 *array, int page_is_empty);
 int logfs_exist_block(struct inode *inode, u64 bix);
 int get_page_reserve(struct inode *inode, struct page *page);
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock);
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock);
 extern struct logfs_block_ops indirect_block_ops;
 
 /* segment.c */
@@ -594,6 +596,7 @@ int logfs_init_mapping(struct super_block *sb);
 void logfs_sync_area(struct logfs_area *area);
 void logfs_sync_segments(struct super_block *sb);
 void freeseg(struct super_block *sb, u32 segno);
+void free_areas(struct super_block *sb);
 
 /* area handling */
 int logfs_init_areas(struct super_block *sb);
diff --git a/fs/logfs/readwrite.c b/fs/logfs/readwrite.c
index 2ac4217b7901..4153e65b0148 100644
--- a/fs/logfs/readwrite.c
+++ b/fs/logfs/readwrite.c
@@ -244,8 +244,7 @@ static void preunlock_page(struct super_block *sb, struct page *page, int lock)
  * is waiting for s_write_mutex.  We annotate this fact by setting PG_pre_locked
  * in addition to PG_locked.
  */
-static void logfs_get_wblocks(struct super_block *sb, struct page *page,
-                int lock)
+void logfs_get_wblocks(struct super_block *sb, struct page *page, int lock)
 {
         struct logfs_super *super = logfs_super(sb);
 
@@ -260,8 +259,7 @@ static void logfs_get_wblocks(struct super_block *sb, struct page *page,
         }
 }
 
-static void logfs_put_wblocks(struct super_block *sb, struct page *page,
-                int lock)
+void logfs_put_wblocks(struct super_block *sb, struct page *page, int lock)
 {
         struct logfs_super *super = logfs_super(sb);
 
@@ -424,7 +422,7 @@ static void inode_write_block(struct logfs_block *block)
         if (inode->i_ino == LOGFS_INO_MASTER)
                 logfs_write_anchor(inode->i_sb);
         else {
-                ret = __logfs_write_inode(inode, 0);
+                ret = __logfs_write_inode(inode, NULL, 0);
                 /* see indirect_write_block comment */
                 BUG_ON(ret);
         }
@@ -560,8 +558,13 @@ static void inode_free_block(struct super_block *sb, struct logfs_block *block)
 static void indirect_free_block(struct super_block *sb,
                 struct logfs_block *block)
 {
-        ClearPagePrivate(block->page);
-        block->page->private = 0;
+        struct page *page = block->page;
+
+        if (PagePrivate(page)) {
+                ClearPagePrivate(page);
+                page_cache_release(page);
+                set_page_private(page, 0);
+        }
         __free_block(sb, block);
 }
 
@@ -650,8 +653,11 @@ static void alloc_data_block(struct inode *inode, struct page *page)
         logfs_unpack_index(page->index, &bix, &level);
         block = __alloc_block(inode->i_sb, inode->i_ino, bix, level);
         block->page = page;
+
         SetPagePrivate(page);
-        page->private = (unsigned long)block;
+        page_cache_get(page);
+        set_page_private(page, (unsigned long) block);
+
         block->ops = &indirect_block_ops;
 }
 
@@ -1570,11 +1576,15 @@ int logfs_write_buf(struct inode *inode, struct page *page, long flags)
 static int __logfs_delete(struct inode *inode, struct page *page)
 {
         long flags = WF_DELETE;
+        int err;
 
         inode->i_ctime = inode->i_mtime = CURRENT_TIME;
 
         if (page->index < I0_BLOCKS)
                 return logfs_write_direct(inode, page, flags);
+        err = grow_inode(inode, page->index, 0);
+        if (err)
+                return err;
         return logfs_write_rec(inode, page, page->index, 0, flags);
 }
 
@@ -1623,7 +1633,7 @@ int logfs_rewrite_block(struct inode *inode, u64 bix, u64 ofs,
                         if (inode->i_ino == LOGFS_INO_MASTER)
                                 logfs_write_anchor(inode->i_sb);
                         else {
-                                err = __logfs_write_inode(inode, flags);
+                                err = __logfs_write_inode(inode, page, flags);
                         }
                 }
         }
@@ -1873,7 +1883,7 @@ int logfs_truncate(struct inode *inode, u64 target)
                 logfs_get_wblocks(sb, NULL, 1);
                 err = __logfs_truncate(inode, size);
                 if (!err)
-                        err = __logfs_write_inode(inode, 0);
+                        err = __logfs_write_inode(inode, NULL, 0);
                 logfs_put_wblocks(sb, NULL, 1);
         }
 
@@ -1901,8 +1911,11 @@ static void move_page_to_inode(struct inode *inode, struct page *page)
         li->li_block = block;
 
         block->page = NULL;
-        page->private = 0;
-        ClearPagePrivate(page);
+        if (PagePrivate(page)) {
+                ClearPagePrivate(page);
+                page_cache_release(page);
+                set_page_private(page, 0);
+        }
 }
 
 static void move_inode_to_page(struct page *page, struct inode *inode)
@@ -1918,8 +1931,12 @@ static void move_inode_to_page(struct page *page, struct inode *inode)
         BUG_ON(PagePrivate(page));
         block->ops = &indirect_block_ops;
         block->page = page;
-        page->private = (unsigned long)block;
-        SetPagePrivate(page);
+
+        if (!PagePrivate(page)) {
+                SetPagePrivate(page);
+                page_cache_get(page);
+                set_page_private(page, (unsigned long) block);
+        }
 
         block->inode = NULL;
         li->li_block = NULL;
@@ -2106,14 +2123,14 @@ void logfs_set_segment_unreserved(struct super_block *sb, u32 segno, u32 ec)
                         ec_level);
 }
 
-int __logfs_write_inode(struct inode *inode, long flags)
+int __logfs_write_inode(struct inode *inode, struct page *page, long flags)
 {
         struct super_block *sb = inode->i_sb;
         int ret;
 
-        logfs_get_wblocks(sb, NULL, flags & WF_LOCK);
+        logfs_get_wblocks(sb, page, flags & WF_LOCK);
         ret = do_write_inode(inode);
-        logfs_put_wblocks(sb, NULL, flags & WF_LOCK);
+        logfs_put_wblocks(sb, page, flags & WF_LOCK);
         return ret;
 }
 
diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c
index 9d5187353255..ab798ed1cc88 100644
--- a/fs/logfs/segment.c
+++ b/fs/logfs/segment.c
@@ -86,7 +86,11 @@ int __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len,
                 BUG_ON(!page); /* FIXME: reserve a pool */
                 SetPageUptodate(page);
                 memcpy(page_address(page) + offset, buf, copylen);
-                SetPagePrivate(page);
+
+                if (!PagePrivate(page)) {
+                        SetPagePrivate(page);
+                        page_cache_get(page);
+                }
                 page_cache_release(page);
 
                 buf += copylen;
@@ -110,7 +114,10 @@ static void pad_partial_page(struct logfs_area *area)
                 page = get_mapping_page(sb, index, 0);
                 BUG_ON(!page); /* FIXME: reserve a pool */
                 memset(page_address(page) + offset, 0xff, len);
-                SetPagePrivate(page);
+                if (!PagePrivate(page)) {
+                        SetPagePrivate(page);
+                        page_cache_get(page);
+                }
                 page_cache_release(page);
         }
 }
@@ -130,7 +137,10 @@ static void pad_full_pages(struct logfs_area *area)
                 BUG_ON(!page); /* FIXME: reserve a pool */
                 SetPageUptodate(page);
                 memset(page_address(page), 0xff, PAGE_CACHE_SIZE);
-                SetPagePrivate(page);
+                if (!PagePrivate(page)) {
+                        SetPagePrivate(page);
+                        page_cache_get(page);
+                }
                 page_cache_release(page);
                 index++;
                 no_indizes--;
@@ -485,8 +495,12 @@ static void move_btree_to_page(struct inode *inode, struct page *page,
                 mempool_free(item, super->s_alias_pool);
         }
         block->page = page;
-        SetPagePrivate(page);
-        page->private = (unsigned long)block;
+
+        if (!PagePrivate(page)) {
+                SetPagePrivate(page);
+                page_cache_get(page);
+                set_page_private(page, (unsigned long) block);
+        }
         block->ops = &indirect_block_ops;
         initialize_block_counters(page, block, data, 0);
 }
@@ -536,8 +550,12 @@ void move_page_to_btree(struct page *page)
                 list_add(&item->list, &block->item_list);
         }
         block->page = NULL;
-        ClearPagePrivate(page);
-        page->private = 0;
+
+        if (PagePrivate(page)) {
+                ClearPagePrivate(page);
+                page_cache_release(page);
+                set_page_private(page, 0);
+        }
         block->ops = &btree_block_ops;
         err = alias_tree_insert(block->sb, block->ino, block->bix, block->level,
                         block);
@@ -702,7 +720,10 @@ void freeseg(struct super_block *sb, u32 segno)
                 page = find_get_page(mapping, ofs >> PAGE_SHIFT);
                 if (!page)
                         continue;
-                ClearPagePrivate(page);
+                if (PagePrivate(page)) {
+                        ClearPagePrivate(page);
+                        page_cache_release(page);
+                }
                 page_cache_release(page);
         }
 }
@@ -841,6 +862,16 @@ static void free_area(struct logfs_area *area)
         kfree(area);
 }
 
+void free_areas(struct super_block *sb)
+{
+        struct logfs_super *super = logfs_super(sb);
+        int i;
+
+        for_each_area(i)
+                free_area(super->s_area[i]);
+        free_area(super->s_journal_area);
+}
+
 static struct logfs_area *alloc_area(struct super_block *sb)
 {
         struct logfs_area *area;
@@ -923,10 +954,6 @@ err:
 void logfs_cleanup_areas(struct super_block *sb)
 {
         struct logfs_super *super = logfs_super(sb);
-        int i;
 
         btree_grim_visitor128(&super->s_object_alias_tree, 0, kill_alias);
-        for_each_area(i)
-                free_area(super->s_area[i]);
-        free_area(super->s_journal_area);
 }
diff --git a/fs/logfs/super.c b/fs/logfs/super.c
index e795c234ea33..c9ee7f5d1caf 100644
--- a/fs/logfs/super.c
+++ b/fs/logfs/super.c
@@ -486,14 +486,15 @@ static void logfs_kill_sb(struct super_block *sb)
         /* Alias entries slow down mount, so evict as many as possible */
         sync_filesystem(sb);
         logfs_write_anchor(sb);
+        free_areas(sb);
 
         /*
          * From this point on alias entries are simply dropped - and any
          * writes to the object store are considered bugs.
          */
-        super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN;
         log_super("LogFS: Now in shutdown\n");
         generic_shutdown_super(sb);
+        super->s_flags |= LOGFS_SB_FLAG_SHUTDOWN;
 
         BUG_ON(super->s_dirty_used_bytes || super->s_dirty_free_bytes);