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; +} diff --git a/fs/fscache/volume.c b/fs/fscache/volume.c index e1a8e92a6adb..a57c6cbee858 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 86b1c0db1de5..7bd35f60d19a 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 ab1376ebc3ab..1172529b5b49 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,