[PATCH] ceph: request xattrs if xattr_version is zero

[Yan, Zheng]

Following sequence of events can happen.
- Client releases an inode, queues cap release message.
- A 'lookup' reply brings the same inode back, but the reply
doesn't contain xattrs because MDS didn't receive the cap release
message and thought client already has up-to-data xattrs.

The fix is force sending a getattr request to MDS if xattrs_version is 0.
The getattr mask is set to CEPH_STAT_CAP_XATTR, so MDS knows client does
not have xattr.

Signed-off-by: Yan, Zheng <***@redhat.com>
---
fs/ceph/file.c | 5 ++---
fs/ceph/inode.c | 8 ++++----
fs/ceph/ioctl.c | 4 ++--
fs/ceph/super.h | 2 +-
fs/ceph/xattr.c | 29 ++++++++++-------------------
5 files changed, 19 insertions(+), 29 deletions(-)

diff --git a/fs/ceph/file.c b/fs/ceph/file.c
index 46a0525f..bf926fb 100644
--- a/fs/ceph/file.c
+++ b/fs/ceph/file.c
@@ -841,8 +841,7 @@ again:
ceph_put_cap_refs(ci, got);

if (checkeof && ret >= 0) {
- int statret = ceph_do_getattr(inode,
- CEPH_STAT_CAP_SIZE);
+ int statret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);

/* hit EOF or hole? */
if (statret == 0 && iocb->ki_pos < inode->i_size &&
@@ -1010,7 +1009,7 @@ static loff_t ceph_llseek(struct file *file, loff_t offset, int whence)
mutex_lock(&inode->i_mutex);

if (whence == SEEK_END || whence == SEEK_DATA || whence == SEEK_HOLE) {
- ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE);
+ ret = ceph_do_getattr(inode, CEPH_STAT_CAP_SIZE, false);
if (ret < 0) {
offset = ret;
goto out;
diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
index 04c89c2..40e6289 100644
--- a/fs/ceph/inode.c
+++ b/fs/ceph/inode.c
@@ -1907,7 +1907,7 @@ out_put:
* Verify that we have a lease on the given mask. If not,
* do a getattr against an mds.
*/
-int ceph_do_getattr(struct inode *inode, int mask)
+int ceph_do_getattr(struct inode *inode, int mask, bool force)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(inode->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
@@ -1920,7 +1920,7 @@ int ceph_do_getattr(struct inode *inode, int mask)
}

dout("do_getattr inode %p mask %s mode 0%o\n", inode, ceph_cap_string(mask), inode->i_mode);
- if (ceph_caps_issued_mask(ceph_inode(inode), mask, 1))
+ if (!force && ceph_caps_issued_mask(ceph_inode(inode), mask, 1))
return 0;

req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_GETATTR, USE_ANY_MDS);
@@ -1948,7 +1948,7 @@ int ceph_permission(struct inode *inode, int mask)
if (mask & MAY_NOT_BLOCK)
return -ECHILD;

- err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED);
+ err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED, false);

if (!err)
err = generic_permission(inode, mask);
@@ -1966,7 +1966,7 @@ int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct ceph_inode_info *ci = ceph_inode(inode);
int err;

- err = ceph_do_getattr(inode, CEPH_STAT_CAP_INODE_ALL);
+ err = ceph_do_getattr(inode, CEPH_STAT_CAP_INODE_ALL, false);
if (!err) {
generic_fillattr(inode, stat);
stat->ino = ceph_translate_ino(inode->i_sb, inode->i_ino);
diff --git a/fs/ceph/ioctl.c b/fs/ceph/ioctl.c
index a822a6e..d7dc812 100644
--- a/fs/ceph/ioctl.c
+++ b/fs/ceph/ioctl.c
@@ -19,7 +19,7 @@ static long ceph_ioctl_get_layout(struct file *file, void __user *arg)
struct ceph_ioctl_layout l;
int err;

- err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT);
+ err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT, false);
if (!err) {
l.stripe_unit = ceph_file_layout_su(ci->i_layout);
l.stripe_count = ceph_file_layout_stripe_count(ci->i_layout);
@@ -74,7 +74,7 @@ static long ceph_ioctl_set_layout(struct file *file, void __user *arg)
return -EFAULT;

/* validate changed params against current layout */
- err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT);
+ err = ceph_do_getattr(file_inode(file), CEPH_STAT_CAP_LAYOUT, false);
if (err)
return err;

diff --git a/fs/ceph/super.h b/fs/ceph/super.h
index 0cfb1ec..8405a79 100644
--- a/fs/ceph/super.h
+++ b/fs/ceph/super.h
@@ -714,7 +714,7 @@ extern void ceph_queue_vmtruncate(struct inode *inode);
extern void ceph_queue_invalidate(struct inode *inode);
extern void ceph_queue_writeback(struct inode *inode);

-extern int ceph_do_getattr(struct inode *inode, int mask);
+extern int ceph_do_getattr(struct inode *inode, int mask, bool force);
extern int ceph_permission(struct inode *inode, int mask);
extern int ceph_setattr(struct dentry *dentry, struct iattr *attr);
extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry,
diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
index 12f58d2..eab3e2f 100644
--- a/fs/ceph/xattr.c
+++ b/fs/ceph/xattr.c
@@ -736,24 +736,20 @@ ssize_t __ceph_getxattr(struct inode *inode, const char *name, void *value,
dout("getxattr %p ver=%lld index_ver=%lld\n", inode,
ci->i_xattrs.version, ci->i_xattrs.index_version);

- if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
- (ci->i_xattrs.index_version >= ci->i_xattrs.version)) {
- goto get_xattr;
- } else {
+ if (ci->i_xattrs.version == 0 ||
+ !__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1)) {
spin_unlock(&ci->i_ceph_lock);
/* get xattrs from mds (if we don't already have them) */
- err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR);
+ err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
if (err)
return err;
+ spin_lock(&ci->i_ceph_lock);
}

- spin_lock(&ci->i_ceph_lock);
-
err = __build_xattrs(inode);
if (err < 0)
goto out;

-get_xattr:
err = -ENODATA; /* == ENOATTR */
xattr = __get_xattr(ci, name);
if (!xattr)
@@ -798,23 +794,18 @@ ssize_t ceph_listxattr(struct dentry *dentry, char *names, size_t size)
dout("listxattr %p ver=%lld index_ver=%lld\n", inode,
ci->i_xattrs.version, ci->i_xattrs.index_version);

- if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1) &&
- (ci->i_xattrs.index_version >= ci->i_xattrs.version)) {
- goto list_xattr;
- } else {
+ if (ci->i_xattrs.version == 0 ||
+ !__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1)) {
spin_unlock(&ci->i_ceph_lock);
- err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR);
+ err = ceph_do_getattr(inode, CEPH_STAT_CAP_XATTR, true);
if (err)
return err;
+ spin_lock(&ci->i_ceph_lock);
}

- spin_lock(&ci->i_ceph_lock);
-
err = __build_xattrs(inode);
if (err < 0)
goto out;
-
-list_xattr:
/*
* Start with virtual dir xattr names (if any) (including
* terminating '\0' characters for each).
@@ -968,7 +959,7 @@ int __ceph_setxattr(struct dentry *dentry, const char *name,
retry:
issued = __ceph_caps_issued(ci, NULL);
dout("setxattr %p issued %s\n", inode, ceph_cap_string(issued));
- if (!(issued & CEPH_CAP_XATTR_EXCL))
+ if (ci->i_xattrs.version == 0 || !(issued & CEPH_CAP_XATTR_EXCL))
goto do_sync;
__build_xattrs(inode);

@@ -1077,7 +1068,7 @@ retry:
issued = __ceph_caps_issued(ci, NULL);
dout("removexattr %p issued %s\n", inode, ceph_cap_string(issued));

- if (!(issued & CEPH_CAP_XATTR_EXCL))
+ if (ci->i_xattrs.version == 0 && !(issued & CEPH_CAP_XATTR_EXCL))
goto do_sync;
__build_xattrs(inode);