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author | NeilBrown <neilb@suse.com> | 2017-08-25 17:34:41 +1000 |
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committer | Anna Schumaker <Anna.Schumaker@Netapp.com> | 2017-10-16 13:51:27 -0400 |
commit | b688741cb06695312f18b730653d6611e1bad28d (patch) | |
tree | fe9d267f6433e78db556eaeea66b468569411624 /mm/memory.c | |
parent | 1750d929b08764dd293d5bdddaa9bc4d3f94d228 (diff) | |
download | linux-b688741cb06695312f18b730653d6611e1bad28d.tar.bz2 |
NFS: revalidate "." etc correctly on "open".
For correct close-to-open semantics, NFS must validate
the change attribute of a directory (or file) on open.
Since commit ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a
d_weak_revalidate dentry op"), open() of "." or a path ending ".." is
not revalidated reliably (except when that direct is a mount point).
Prior to that commit, "." was revalidated using nfs_lookup_revalidate()
which checks the LOOKUP_OPEN flag and forces revalidation if the flag is
set.
Since that commit, nfs_weak_revalidate() is used for NFSv3 (which
ignores the flags) and nothing is used for NFSv4.
This is fixed by using nfs_lookup_verify_inode() in
nfs_weak_revalidate(). This does the revalidation exactly when needed.
Also, add a definition of .d_weak_revalidate for NFSv4.
The incorrect behavior is easily demonstrated by running "echo *" in
some non-mountpoint NFS directory while watching network traffic.
Without this patch, "echo *" sometimes doesn't produce any traffic.
With the patch it always does.
Fixes: ecf3d1f1aa74 ("vfs: kill FS_REVAL_DOT by adding a d_weak_revalidate dentry op")
cc: stable@vger.kernel.org (3.9+)
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'mm/memory.c')
0 files changed, 0 insertions, 0 deletions