From 81def6b9862764924a99ac1b680e73ac8c80ac64 Mon Sep 17 00:00:00 2001 From: Joern Engel Date: Sun, 28 Mar 2010 12:47:09 +0200 Subject: Simplify and fix pad_wbuf A comment in the old code read: /* The math in this function can surely use some love */ And indeed it did. In the case that area->a_used_bytes is exactly 4096 bytes below segment size it fell apart. pad_wbuf is now split into two helpers that are significantly less complicated. Signed-off-by: Joern Engel --- fs/logfs/segment.c | 52 ++++++++++++++++++++++++++++++---------------------- 1 file changed, 30 insertions(+), 22 deletions(-) (limited to 'fs/logfs/segment.c') diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c index 1a14f9910d55..ff9d7f3b4d36 100644 --- a/fs/logfs/segment.c +++ b/fs/logfs/segment.c @@ -93,49 +93,57 @@ void __logfs_buf_write(struct logfs_area *area, u64 ofs, void *buf, size_t len, } while (len); } -/* - * bdev_writeseg will write full pages. Memset the tail to prevent data leaks. - */ -static void pad_wbuf(struct logfs_area *area, int final) +static void pad_partial_page(struct logfs_area *area) { struct super_block *sb = area->a_sb; - struct logfs_super *super = logfs_super(sb); struct page *page; u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes); pgoff_t index = ofs >> PAGE_SHIFT; long offset = ofs & (PAGE_SIZE-1); u32 len = PAGE_SIZE - offset; - if (len == PAGE_SIZE) { - /* The math in this function can surely use some love */ - len = 0; - } - if (len) { - BUG_ON(area->a_used_bytes >= super->s_segsize); - - page = get_mapping_page(area->a_sb, index, 0); + if (len % PAGE_SIZE) { + page = get_mapping_page(sb, index, 0); BUG_ON(!page); /* FIXME: reserve a pool */ memset(page_address(page) + offset, 0xff, len); SetPagePrivate(page); page_cache_release(page); } +} - if (!final) - return; +static void pad_full_pages(struct logfs_area *area) +{ + struct super_block *sb = area->a_sb; + struct logfs_super *super = logfs_super(sb); + u64 ofs = dev_ofs(sb, area->a_segno, area->a_used_bytes); + u32 len = super->s_segsize - area->a_used_bytes; + pgoff_t index = PAGE_CACHE_ALIGN(ofs) >> PAGE_CACHE_SHIFT; + pgoff_t no_indizes = len >> PAGE_CACHE_SHIFT; + struct page *page; - area->a_used_bytes += len; - for ( ; area->a_used_bytes < super->s_segsize; - area->a_used_bytes += PAGE_SIZE) { - /* Memset another page */ - index++; - page = get_mapping_page(area->a_sb, index, 0); + while (no_indizes) { + page = get_mapping_page(sb, index, 0); BUG_ON(!page); /* FIXME: reserve a pool */ - memset(page_address(page), 0xff, PAGE_SIZE); + SetPageUptodate(page); + memset(page_address(page), 0xff, PAGE_CACHE_SIZE); SetPagePrivate(page); page_cache_release(page); + index++; + no_indizes--; } } +/* + * bdev_writeseg will write full pages. Memset the tail to prevent data leaks. + * Also make sure we allocate (and memset) all pages for final writeout. + */ +static void pad_wbuf(struct logfs_area *area, int final) +{ + pad_partial_page(area); + if (final) + pad_full_pages(area); +} + /* * We have to be careful with the alias tree. Since lookup is done by bix, * it needs to be normalized, so 14, 15, 16, etc. all match when dealing with -- cgit v1.2.3 From 723b2ff40876678b49e61df34fb1d8001e34639d Mon Sep 17 00:00:00 2001 From: Joern Engel Date: Sun, 28 Mar 2010 18:10:07 +0200 Subject: [LogFS] Clear PagePrivate when moving journal do_logfs_journal_wl_pass() must call freeseg(), thereby clear PagePrivate on all pages of the current journal segment. Signed-off-by: Joern Engel --- fs/logfs/journal.c | 1 + fs/logfs/logfs.h | 1 + fs/logfs/segment.c | 2 +- 3 files changed, 3 insertions(+), 1 deletion(-) (limited to 'fs/logfs/segment.c') diff --git a/fs/logfs/journal.c b/fs/logfs/journal.c index 6ad30a4c9052..15454ac7bd93 100644 --- a/fs/logfs/journal.c +++ b/fs/logfs/journal.c @@ -821,6 +821,7 @@ void do_logfs_journal_wl_pass(struct super_block *sb) logfs_set_segment_reserved(sb, segno); } /* Manually move journal_area */ + freeseg(sb, area->a_segno); area->a_segno = super->s_journal_seg[0]; area->a_is_open = 0; area->a_used_bytes = 0; diff --git a/fs/logfs/logfs.h b/fs/logfs/logfs.h index 129779431373..b84b0eec6024 100644 --- a/fs/logfs/logfs.h +++ b/fs/logfs/logfs.h @@ -587,6 +587,7 @@ void move_page_to_btree(struct page *page); 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); /* area handling */ int logfs_init_areas(struct super_block *sb); diff --git a/fs/logfs/segment.c b/fs/logfs/segment.c index ff9d7f3b4d36..0ecd8f07c11e 100644 --- a/fs/logfs/segment.c +++ b/fs/logfs/segment.c @@ -691,7 +691,7 @@ int logfs_segment_delete(struct inode *inode, struct logfs_shadow *shadow) return 0; } -static void freeseg(struct super_block *sb, u32 segno) +void freeseg(struct super_block *sb, u32 segno) { struct logfs_super *super = logfs_super(sb); struct address_space *mapping = super->s_mapping_inode->i_mapping; -- cgit v1.2.3