在 2023/5/6 12:56, Christian Marangi 写道:

From: Fabian Frederick fabf@skynet.be

Use kcalloc() for allocation/flush of 128 pointers table to reduce stack usage.

Function now returns -ENOMEM or 0 on success.

stackusage Before: ./fs/jffs2/xattr.c:775 jffs2_build_xattr_subsystem 1208 dynamic,bounded

After: ./fs/jffs2/xattr.c:775 jffs2_build_xattr_subsystem 192 dynamic,bounded

Also update definition when CONFIG_JFFS2_FS_XATTR is not enabled

Tested with an MTD mount point and some user set/getfattr.

Many current target on OpenWRT also suffer from a compilation warning (that become an error with CONFIG_WERROR) with the following output:

fs/jffs2/xattr.c: In function 'jffs2_build_xattr_subsystem': fs/jffs2/xattr.c:887:1: error: the frame size of 1088 bytes is larger than 1024 bytes [-Werror=frame-larger-than=] 887 | } | ^

Using dynamic allocation fix this compilation warning.

Fixes: c9f700f840bd ("[JFFS2][XATTR] using 'delete marker' for xdatum/xref deletion") Reported-by: Tim Gardner tim.gardner@canonical.com Reported-by: kernel test robot lkp@intel.com Reported-by: Ron Economos re@w6rz.net Reported-by: Nathan Chancellor nathan@kernel.org Reviewed-by: Nick Desaulniers ndesaulniers@google.com Signed-off-by: Fabian Frederick fabf@skynet.be Signed-off-by: Christian Marangi ansuelsmth@gmail.com Cc: stable@vger.kernel.org

---

fs/jffs2/build.c | 5 ++++- fs/jffs2/xattr.c | 13 +++++++++---- fs/jffs2/xattr.h | 4 ++-- 3 files changed, 15 insertions(+), 7 deletions(-)

diff --git a/fs/jffs2/build.c b/fs/jffs2/build.c index 837cd55fd4c5..6ae9d6fefb86 100644 --- a/fs/jffs2/build.c +++ b/fs/jffs2/build.c @@ -211,7 +211,10 @@ static int jffs2_build_filesystem(struct jffs2_sb_info *c) ic->scan_dents = NULL; cond_resched(); }

• jffs2_build_xattr_subsystem(c);

• ret = jffs2_build_xattr_subsystem(c);
• if (ret)

• goto exit;
  

• c->flags &= ~JFFS2_SB_FLAG_BUILDING;

dbg_fsbuild("FS build complete\n"); diff --git a/fs/jffs2/xattr.c b/fs/jffs2/xattr.c index aa4048a27f31..3b6bdc9a49e1 100644 --- a/fs/jffs2/xattr.c +++ b/fs/jffs2/xattr.c @@ -772,10 +772,10 @@ void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c) } #define XREF_TMPHASH_SIZE (128) -void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) +int jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) { struct jffs2_xattr_ref *ref, *_ref;

• struct jffs2_xattr_ref *xref_tmphash[XREF_TMPHASH_SIZE];

• struct jffs2_xattr_ref **xref_tmphash; struct jffs2_xattr_datum *xd, *_xd; struct jffs2_inode_cache *ic; struct jffs2_raw_node_ref *raw;

@@ -784,9 +784,12 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) BUG_ON(!(c->flags & JFFS2_SB_FLAG_BUILDING));

• xref_tmphash = kcalloc(XREF_TMPHASH_SIZE,

• 	       sizeof(struct jffs2_xattr_ref *), GFP_KERNEL);
  

• if (!xref_tmphash)

• return -ENOMEM;
  

I have made some fault injection tests, jffs2 works fine, this patch imports no memleak problems. It seems okay.

/* Phase.1 : Merge same xref */

• for (i=0; i < XREF_TMPHASH_SIZE; i++)

• xref_tmphash[i] = NULL;
  

  for (ref=c->xref_temp; ref; ref=_ref) { struct jffs2_xattr_ref *tmp;

@@ -884,6 +887,8 @@ void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c) "%u of xref (%u dead, %u orphan) found.\n", xdatum_count, xdatum_unchecked_count, xdatum_orphan_count, xref_count, xref_dead_count, xref_orphan_count);

• kfree(xref_tmphash);
• return 0; }

struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c, diff --git a/fs/jffs2/xattr.h b/fs/jffs2/xattr.h index 720007b2fd65..1b5030a3349d 100644 --- a/fs/jffs2/xattr.h +++ b/fs/jffs2/xattr.h @@ -71,7 +71,7 @@ static inline int is_xattr_ref_dead(struct jffs2_xattr_ref *ref) #ifdef CONFIG_JFFS2_FS_XATTR extern void jffs2_init_xattr_subsystem(struct jffs2_sb_info *c); -extern void jffs2_build_xattr_subsystem(struct jffs2_sb_info *c); +extern int jffs2_build_xattr_subsystem(struct jffs2_sb_info *c); extern void jffs2_clear_xattr_subsystem(struct jffs2_sb_info *c); extern struct jffs2_xattr_datum *jffs2_setup_xattr_datum(struct jffs2_sb_info *c, @@ -103,7 +103,7 @@ extern ssize_t jffs2_listxattr(struct dentry *, char *, size_t); #else #define jffs2_init_xattr_subsystem(c) -#define jffs2_build_xattr_subsystem(c) +#define jffs2_build_xattr_subsystem(c) (0) #define jffs2_clear_xattr_subsystem(c) #define jffs2_xattr_do_crccheck_inode(c, ic)