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Date: Fri, 4 May 2012 20:27:07 +0300
From: Artem Bityutskiy <dedekind1@...il.com>
To: David Woodhouse <dwmw2@...radead.org>,
MTD Maling List <linux-mtd@...ts.infradead.org>
Cc: Linux Kernel Maling List <linux-kernel@...r.kernel.org>,
Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
Subject: [PATCH 1/2] jffs2: introduce fake wbuf inode
From: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
This patch is just a preparation for further changes. It introduces a special
inode ('wbuf_inode') in JFFS2 file-system which we'll later use for delayed
write-out of the write-buffer.
We do not allocate JFFS2 data structures like 'struct jffs2_inode_info' for
this inode because we won't need them. We allocate the next available inode
number for 'wbuf_inode' after the JFFS2 media is scanned. Of course, wbuf_inode
won't ever be written to the flash media.
Signed-off-by: Artem Bityutskiy <artem.bityutskiy@...ux.intel.com>
---
fs/jffs2/fs.c | 13 ++++++++++---
fs/jffs2/jffs2_fs_sb.h | 1 +
fs/jffs2/os-linux.h | 4 ++++
fs/jffs2/super.c | 1 +
fs/jffs2/wbuf.c | 24 ++++++++++++++++++++++++
5 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index bb6f993..94016a9 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -241,7 +241,8 @@ void jffs2_evict_inode (struct inode *inode)
__func__, inode->i_ino, inode->i_mode);
truncate_inode_pages(&inode->i_data, 0);
end_writeback(inode);
- jffs2_do_clear_inode(c, f);
+ if (inode != c->wbuf_inode)
+ jffs2_do_clear_inode(c, f);
}
struct inode *jffs2_iget(struct super_block *sb, unsigned long ino)
@@ -562,12 +563,16 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
if ((ret = jffs2_do_mount_fs(c)))
goto out_inohash;
+ ret = jffs2_setup_wbuf_inode(c);
+ if (ret)
+ goto out_root;
+
jffs2_dbg(1, "%s(): Getting root inode\n", __func__);
root_i = jffs2_iget(sb, 1);
if (IS_ERR(root_i)) {
jffs2_dbg(1, "get root inode failed\n");
ret = PTR_ERR(root_i);
- goto out_root;
+ goto out_wbuf_inode;
}
ret = -ENOMEM;
@@ -575,7 +580,7 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
jffs2_dbg(1, "%s(): d_make_root()\n", __func__);
sb->s_root = d_make_root(root_i);
if (!sb->s_root)
- goto out_root;
+ goto out_wbuf_inode;
sb->s_maxbytes = 0xFFFFFFFF;
sb->s_blocksize = PAGE_CACHE_SIZE;
@@ -585,6 +590,8 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
jffs2_start_garbage_collect_thread(c);
return 0;
+out_wbuf_inode:
+ jffs2_free_wbuf_inode(c);
out_root:
jffs2_free_ino_caches(c);
jffs2_free_raw_node_refs(c);
diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h
index 55a0c1d..11d43f2 100644
--- a/fs/jffs2/jffs2_fs_sb.h
+++ b/fs/jffs2/jffs2_fs_sb.h
@@ -125,6 +125,7 @@ struct jffs2_sb_info {
uint32_t wbuf_len;
struct jffs2_inodirty *wbuf_inodes;
struct rw_semaphore wbuf_sem; /* Protects the write buffer */
+ struct inode *wbuf_inode; /* Fake inode for delayed wbuf write-out */
unsigned char *oobbuf;
int oobavail; /* How many bytes are available for JFFS2 in OOB */
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index 1cd3aec..6f28cc5 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -82,6 +82,8 @@ static inline void jffs2_init_inode_info(struct jffs2_inode_info *f)
#define jffs2_write_nand_badblock(c,jeb,bad_offset) (1)
#define jffs2_nand_flash_setup(c) (0)
#define jffs2_nand_flash_cleanup(c) do {} while(0)
+#define jffs2_setup_wbuf_inode(c) 0
+#define jffs2_free_wbuf_inode(c) do {} while(0)
#define jffs2_wbuf_dirty(c) (0)
#define jffs2_flash_writev(a,b,c,d,e,f) jffs2_flash_direct_writev(a,b,c,d,e)
#define jffs2_wbuf_timeout NULL
@@ -124,6 +126,8 @@ int jffs2_flush_wbuf_gc(struct jffs2_sb_info *c, uint32_t ino);
int jffs2_flush_wbuf_pad(struct jffs2_sb_info *c);
int jffs2_nand_flash_setup(struct jffs2_sb_info *c);
void jffs2_nand_flash_cleanup(struct jffs2_sb_info *c);
+int jffs2_setup_wbuf_inode(struct jffs2_sb_info *c);
+void jffs2_free_wbuf_inode(struct jffs2_sb_info *c);
#define jffs2_dataflash(c) (c->mtd->type == MTD_DATAFLASH)
int jffs2_dataflash_setup(struct jffs2_sb_info *c);
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index f9916f3..a180409 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -326,6 +326,7 @@ static void jffs2_put_super (struct super_block *sb)
jffs2_flush_wbuf_pad(c);
mutex_unlock(&c->alloc_sem);
+ jffs2_free_wbuf_inode(c);
jffs2_sum_exit(c);
jffs2_free_ino_caches(c);
diff --git a/fs/jffs2/wbuf.c b/fs/jffs2/wbuf.c
index 74d9be1..65373cf 100644
--- a/fs/jffs2/wbuf.c
+++ b/fs/jffs2/wbuf.c
@@ -1315,3 +1315,27 @@ int jffs2_ubivol_setup(struct jffs2_sb_info *c) {
void jffs2_ubivol_cleanup(struct jffs2_sb_info *c) {
kfree(c->wbuf);
}
+
+/*
+ * Allocate a fake inode and which is used for delayed write-out of the
+ * write-buffer: we mark it as dirty when the write-buffer is not empty we will
+ * synchronize the write-buffer in 'jffs2_write_inode'.
+ */
+int jffs2_setup_wbuf_inode(struct jffs2_sb_info *c)
+{
+ struct super_block *sb = OFNI_BS_2SFFJ(c);
+
+ c->wbuf_inode = new_inode(sb);
+ if (!c->wbuf_inode)
+ return -ENOMEM;
+
+ c->wbuf_inode->i_ino = ++c->highest_ino;
+ insert_inode_hash(c->wbuf_inode);
+
+ return 0;
+}
+
+void jffs2_free_wbuf_inode(struct jffs2_sb_info *c)
+{
+ iput(c->wbuf_inode);
+}
--
1.7.7.6
--
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