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-rw-r--r--fs/cachefiles/internal.h2
-rw-r--r--fs/cachefiles/volume.c25
-rw-r--r--fs/cachefiles/xattr.c78
3 files changed, 103 insertions, 2 deletions
diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index d5868f5514d3..abdd1b66f6b9 100644
--- a/fs/cachefiles/internal.h
+++ b/fs/cachefiles/internal.h
@@ -270,6 +270,8 @@ extern int cachefiles_remove_object_xattr(struct cachefiles_cache *cache,
struct cachefiles_object *object,
struct dentry *dentry);
extern void cachefiles_prepare_to_write(struct fscache_cookie *cookie);
+extern bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume);
+extern int cachefiles_check_volume_xattr(struct cachefiles_volume *volume);
/*
* Error handling
diff --git a/fs/cachefiles/volume.c b/fs/cachefiles/volume.c
index 4a14f5e72764..89df0ba8ba5e 100644
--- a/fs/cachefiles/volume.c
+++ b/fs/cachefiles/volume.c
@@ -22,7 +22,8 @@ void cachefiles_acquire_volume(struct fscache_volume *vcookie)
struct dentry *vdentry, *fan;
size_t len;
char *name;
- int n_accesses, i;
+ bool is_new = false;
+ int ret, n_accesses, i;
_enter("");
@@ -43,11 +44,29 @@ void cachefiles_acquire_volume(struct fscache_volume *vcookie)
memcpy(name + 1, vcookie->key + 1, len);
name[len + 1] = 0;
- vdentry = cachefiles_get_directory(cache, cache->store, name, NULL);
+retry:
+ vdentry = cachefiles_get_directory(cache, cache->store, name, &is_new);
if (IS_ERR(vdentry))
goto error_name;
volume->dentry = vdentry;
+ if (is_new) {
+ if (!cachefiles_set_volume_xattr(volume))
+ goto error_dir;
+ } else {
+ ret = cachefiles_check_volume_xattr(volume);
+ if (ret < 0) {
+ if (ret != -ESTALE)
+ goto error_dir;
+ inode_lock_nested(d_inode(cache->store), I_MUTEX_PARENT);
+ cachefiles_bury_object(cache, NULL, cache->store, vdentry,
+ FSCACHE_VOLUME_IS_WEIRD);
+ cachefiles_put_directory(volume->dentry);
+ cond_resched();
+ goto retry;
+ }
+ }
+
for (i = 0; i < 256; i++) {
sprintf(name, "@%02x", i);
fan = cachefiles_get_directory(cache, vdentry, name, NULL);
@@ -74,6 +93,7 @@ void cachefiles_acquire_volume(struct fscache_volume *vcookie)
error_fan:
for (i = 0; i < 256; i++)
cachefiles_put_directory(volume->fanout[i]);
+error_dir:
cachefiles_put_directory(volume->dentry);
error_name:
kfree(name);
@@ -114,5 +134,6 @@ void cachefiles_free_volume(struct fscache_volume *vcookie)
void cachefiles_withdraw_volume(struct cachefiles_volume *volume)
{
fscache_withdraw_volume(volume->vcookie);
+ cachefiles_set_volume_xattr(volume);
__cachefiles_free_volume(volume);
}
diff --git a/fs/cachefiles/xattr.c b/fs/cachefiles/xattr.c
index 0601c46a22ef..83f41bd0c3a9 100644
--- a/fs/cachefiles/xattr.c
+++ b/fs/cachefiles/xattr.c
@@ -179,3 +179,81 @@ void cachefiles_prepare_to_write(struct fscache_cookie *cookie)
cachefiles_end_secure(cache, saved_cred);
}
}
+
+/*
+ * Set the state xattr on a volume directory.
+ */
+bool cachefiles_set_volume_xattr(struct cachefiles_volume *volume)
+{
+ unsigned int len = volume->vcookie->coherency_len;
+ const void *p = volume->vcookie->coherency;
+ struct dentry *dentry = volume->dentry;
+ int ret;
+
+ _enter("%x,#%d", volume->vcookie->debug_id, len);
+
+ ret = cachefiles_inject_write_error();
+ if (ret == 0)
+ ret = vfs_setxattr(&init_user_ns, dentry, cachefiles_xattr_cache,
+ p, len, 0);
+ if (ret < 0) {
+ trace_cachefiles_vfs_error(NULL, d_inode(dentry), ret,
+ cachefiles_trace_setxattr_error);
+ trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino,
+ cachefiles_coherency_vol_set_fail);
+ if (ret != -ENOMEM)
+ cachefiles_io_error(
+ volume->cache, "Failed to set xattr with error %d", ret);
+ } else {
+ trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino,
+ cachefiles_coherency_vol_set_ok);
+ }
+
+ _leave(" = %d", ret);
+ return ret == 0;
+}
+
+/*
+ * Check the consistency between the backing cache and the volume cookie.
+ */
+int cachefiles_check_volume_xattr(struct cachefiles_volume *volume)
+{
+ struct cachefiles_xattr *buf;
+ struct dentry *dentry = volume->dentry;
+ unsigned int len = volume->vcookie->coherency_len;
+ const void *p = volume->vcookie->coherency;
+ enum cachefiles_coherency_trace why;
+ ssize_t xlen;
+ int ret = -ESTALE;
+
+ _enter("");
+
+ buf = kmalloc(len, GFP_KERNEL);
+ if (!buf)
+ return -ENOMEM;
+
+ xlen = cachefiles_inject_read_error();
+ if (xlen == 0)
+ xlen = vfs_getxattr(&init_user_ns, dentry, cachefiles_xattr_cache, buf, len);
+ if (xlen != len) {
+ if (xlen < 0) {
+ trace_cachefiles_vfs_error(NULL, d_inode(dentry), xlen,
+ cachefiles_trace_getxattr_error);
+ if (xlen == -EIO)
+ cachefiles_io_error(
+ volume->cache,
+ "Failed to read xattr with error %zd", xlen);
+ }
+ why = cachefiles_coherency_vol_check_xattr;
+ } else if (memcmp(buf->data, p, len) != 0) {
+ why = cachefiles_coherency_vol_check_cmp;
+ } else {
+ why = cachefiles_coherency_vol_check_ok;
+ ret = 0;
+ }
+
+ trace_cachefiles_vol_coherency(volume, d_inode(dentry)->i_ino, why);
+ kfree(buf);
+ _leave(" = %d", ret);
+ return ret;
+}