| From | Greg Kroah-Hartman <> | Subject | [PATCH 3.12 094/118] exportfs: fix 32-bit nfsd handling of 64-bit inode numbers | Date | Wed, 18 Dec 2013 13:12:11 -0800 |
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3.12-stable review patch. If anyone has any objections, please let me know.
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From: "J. Bruce Fields" <bfields@redhat.com>
commit 950ee9566a5b6cc45d15f5fe044bab4f1e8b62cb upstream.
Symptoms were spurious -ENOENTs on stat of an NFS filesystem from a 32-bit NFS server exporting a very large XFS filesystem, when the server's cache is cold (so the inodes in question are not in cache).
Reviewed-by: Christoph Hellwig <hch@lst.de> Reported-by: Trevor Cordes <trevor@tecnopolis.ca> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
--- fs/exportfs/expfs.c | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-)
--- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -215,7 +215,7 @@ struct getdents_callback { struct dir_context ctx; char *name; /* name that was found. It already points to a buffer NAME_MAX+1 is size */ - unsigned long ino; /* the inum we are looking for */ + u64 ino; /* the inum we are looking for */ int found; /* inode matched? */ int sequence; /* sequence counter */ }; @@ -255,10 +255,14 @@ static int get_name(const struct path *p struct inode *dir = path->dentry->d_inode; int error; struct file *file; + struct kstat stat; + struct path child_path = { + .mnt = path->mnt, + .dentry = child, + }; struct getdents_callback buffer = { .ctx.actor = filldir_one, .name = name, - .ino = child->d_inode->i_ino }; error = -ENOTDIR; @@ -268,6 +272,16 @@ static int get_name(const struct path *p if (!dir->i_fop) goto out; /* + * inode->i_ino is unsigned long, kstat->ino is u64, so the + * former would be insufficient on 32-bit hosts when the + * filesystem supports 64-bit inode numbers. So we need to + * actually call ->getattr, not just read i_ino: + */ + error = vfs_getattr_nosec(&child_path, &stat); + if (error) + return error; + buffer.ino = stat.ino; + /* * Open the directory ... */ file = dentry_open(path, O_RDONLY, cred);
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