diff --git a/fs/cachefiles/internal.h b/fs/cachefiles/internal.h
index d5868f5514d3a6dc310c490d460649cf40f7bf93..abdd1b66f6b98feda096e65c509a822eb447565f 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 4a14f5e72764ea91fdf965dfa3635675a272b085..89df0ba8ba5e7ba74acc538a5951cf91a833a606 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 0601c46a22ef3fa8bd15736b63574f9bc45526cb..83f41bd0c3a9749d3aa66fb7fadb2337985095d7 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;
+}
diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c
index e1a8e92a6adb5acaf01e8f97e47b1b4623330832..a57c6cbee858a2bfeeb87738e6268631a724c738 100644
--- a/fs/fscache/volume.c
+++ b/fs/fscache/volume.c
@@ -205,15 +205,22 @@ static struct fscache_volume *fscache_alloc_volume(const char *volume_key,
size_t klen, hlen;
char *key;
+ if (!coherency_data)
+ coherency_len = 0;
+
cache = fscache_lookup_cache(cache_name, false);
if (IS_ERR(cache))
return NULL;
- volume = kzalloc(sizeof(*volume), GFP_KERNEL);
+ volume = kzalloc(struct_size(volume, coherency, coherency_len),
+ GFP_KERNEL);
if (!volume)
goto err_cache;
volume->cache = cache;
+ volume->coherency_len = coherency_len;
+ if (coherency_data)
+ memcpy(volume->coherency, coherency_data, coherency_len);
INIT_LIST_HEAD(&volume->proc_link);
INIT_WORK(&volume->work, fscache_create_volume_work);
refcount_set(&volume->ref, 1);
@@ -421,8 +428,11 @@ void __fscache_relinquish_volume(struct fscache_volume *volume,
if (WARN_ON(test_and_set_bit(FSCACHE_VOLUME_RELINQUISHED, &volume->flags)))
return;
- if (invalidate)
+ if (invalidate) {
set_bit(FSCACHE_VOLUME_INVALIDATE, &volume->flags);
+ } else if (coherency_data) {
+ memcpy(volume->coherency, coherency_data, volume->coherency_len);
+ }
fscache_put_volume(volume, fscache_volume_put_relinquish);
}
diff --git a/include/linux/fscache.h b/include/linux/fscache.h
index 86b1c0db1de5704b6e88cf512c64f95348640157..7bd35f60d19a80b7f7d5f30ee406c02ada565104 100644
--- a/include/linux/fscache.h
+++ b/include/linux/fscache.h
@@ -87,6 +87,8 @@ struct fscache_volume {
#define FSCACHE_VOLUME_COLLIDED_WITH 2 /* Volume was collided with */
#define FSCACHE_VOLUME_ACQUIRE_PENDING 3 /* Volume is waiting to complete acquisition */
#define FSCACHE_VOLUME_CREATING 4 /* Volume is being created on disk */
+ u8 coherency_len; /* Length of the coherency data */
+ u8 coherency[]; /* Coherency data */
};
/*
diff --git a/include/trace/events/cachefiles.h b/include/trace/events/cachefiles.h
index ab1376ebc3ab9d359b9a0874d2f85865e3ef75a7..1172529b5b4945367c9487f8e2c7932bf404caea 100644
--- a/include/trace/events/cachefiles.h
+++ b/include/trace/events/cachefiles.h
@@ -40,6 +40,7 @@ enum fscache_why_object_killed {
FSCACHE_OBJECT_NO_SPACE,
FSCACHE_OBJECT_WAS_RETIRED,
FSCACHE_OBJECT_WAS_CULLED,
+ FSCACHE_VOLUME_IS_WEIRD,
};
enum cachefiles_coherency_trace {
@@ -53,6 +54,11 @@ enum cachefiles_coherency_trace {
cachefiles_coherency_check_xattr,
cachefiles_coherency_set_fail,
cachefiles_coherency_set_ok,
+ cachefiles_coherency_vol_check_cmp,
+ cachefiles_coherency_vol_check_ok,
+ cachefiles_coherency_vol_check_xattr,
+ cachefiles_coherency_vol_set_fail,
+ cachefiles_coherency_vol_set_ok,
};
enum cachefiles_trunc_trace {
@@ -103,7 +109,8 @@ enum cachefiles_error_trace {
EM(FSCACHE_OBJECT_INVALIDATED, "inval") \
EM(FSCACHE_OBJECT_NO_SPACE, "no_space") \
EM(FSCACHE_OBJECT_WAS_RETIRED, "was_retired") \
- E_(FSCACHE_OBJECT_WAS_CULLED, "was_culled")
+ EM(FSCACHE_OBJECT_WAS_CULLED, "was_culled") \
+ E_(FSCACHE_VOLUME_IS_WEIRD, "volume_weird")
#define cachefiles_obj_ref_traces \
EM(cachefiles_obj_get_ioreq, "GET ioreq") \
@@ -129,7 +136,12 @@ enum cachefiles_error_trace {
EM(cachefiles_coherency_check_type, "BAD type") \
EM(cachefiles_coherency_check_xattr, "BAD xatt") \
EM(cachefiles_coherency_set_fail, "SET fail") \
- E_(cachefiles_coherency_set_ok, "SET ok ")
+ EM(cachefiles_coherency_set_ok, "SET ok ") \
+ EM(cachefiles_coherency_vol_check_cmp, "VOL BAD cmp ") \
+ EM(cachefiles_coherency_vol_check_ok, "VOL OK ") \
+ EM(cachefiles_coherency_vol_check_xattr,"VOL BAD xatt") \
+ EM(cachefiles_coherency_vol_set_fail, "VOL SET fail") \
+ E_(cachefiles_coherency_vol_set_ok, "VOL SET ok ")
#define cachefiles_trunc_traces \
EM(cachefiles_trunc_dio_adjust, "DIOADJ") \
@@ -365,6 +377,32 @@ TRACE_EVENT(cachefiles_coherency,
__entry->content)
);
+TRACE_EVENT(cachefiles_vol_coherency,
+ TP_PROTO(struct cachefiles_volume *volume,
+ ino_t ino,
+ enum cachefiles_coherency_trace why),
+
+ TP_ARGS(volume, ino, why),
+
+ /* Note that obj may be NULL */
+ TP_STRUCT__entry(
+ __field(unsigned int, vol )
+ __field(enum cachefiles_coherency_trace, why )
+ __field(u64, ino )
+ ),
+
+ TP_fast_assign(
+ __entry->vol = volume->vcookie->debug_id;
+ __entry->why = why;
+ __entry->ino = ino;
+ ),
+
+ TP_printk("V=%08x %s i=%llx",
+ __entry->vol,
+ __print_symbolic(__entry->why, cachefiles_coherency_traces),
+ __entry->ino)
+ );
+
TRACE_EVENT(cachefiles_prep_read,
TP_PROTO(struct netfs_read_subrequest *sreq,
enum netfs_read_source source,