From 0d08d7b7e13b5060181b11ecdde82d8fda322123 Mon Sep 17 00:00:00 2001 From: Andrew Morton Date: Thu, 5 Apr 2012 14:25:07 -0700 Subject: [PATCH] fs/xattr.c:listxattr(): fall back to vmalloc() if kmalloc() failed This allocation can be as large as 64k. As David points out, "falling back to vmalloc here is much better solution than failing to retreive the attribute - it will work no matter how fragmented memory gets. That means we don't get incomplete backups occurring after days or months of uptime and successful backups". Cc: Dave Chinner Cc: Dave Jones Cc: David Rientjes Cc: Al Viro Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/xattr.c | 17 +++++++++++++---- 1 file changed, 13 insertions(+), 4 deletions(-) diff --git a/fs/xattr.c b/fs/xattr.c index a14d842ccb21..d14afbae3c13 100644 --- a/fs/xattr.c +++ b/fs/xattr.c @@ -19,8 +19,9 @@ #include #include #include -#include +#include +#include /* * Check permissions for extended attribute access. This is a bit complicated @@ -492,13 +493,18 @@ listxattr(struct dentry *d, char __user *list, size_t size) { ssize_t error; char *klist = NULL; + char *vlist = NULL; /* If non-NULL, we used vmalloc() */ if (size) { if (size > XATTR_LIST_MAX) size = XATTR_LIST_MAX; klist = kmalloc(size, __GFP_NOWARN | GFP_KERNEL); - if (!klist) - return -ENOMEM; + if (!klist) { + vlist = vmalloc(size); + if (!vlist) + return -ENOMEM; + klist = vlist; + } } error = vfs_listxattr(d, klist, size); @@ -510,7 +516,10 @@ listxattr(struct dentry *d, char __user *list, size_t size) than XATTR_LIST_MAX bytes. Not possible. */ error = -E2BIG; } - kfree(klist); + if (vlist) + vfree(vlist); + else + kfree(klist); return error; } -- 2.30.2