diff options
| -rw-r--r-- | fs/cachefiles/interface.c | 20 | ||||
| -rw-r--r-- | fs/cachefiles/rdwr.c | 23 | ||||
| -rw-r--r-- | include/linux/fscache-cache.h | 3 |
3 files changed, 39 insertions, 7 deletions
diff --git a/fs/cachefiles/interface.c b/fs/cachefiles/interface.c index dd7f852746cb..8e67abf05985 100644 --- a/fs/cachefiles/interface.c +++ b/fs/cachefiles/interface.c @@ -404,12 +404,26 @@ static int cachefiles_attr_changed(struct fscache_object *_object) if (oi_size == ni_size) return 0; - newattrs.ia_size = ni_size; - newattrs.ia_valid = ATTR_SIZE; - cachefiles_begin_secure(cache, &saved_cred); mutex_lock(&object->backer->d_inode->i_mutex); + + /* if there's an extension to a partial page at the end of the backing + * file, we need to discard the partial page so that we pick up new + * data after it */ + if (oi_size & ~PAGE_MASK && ni_size > oi_size) { + _debug("discard tail %llx", oi_size); + newattrs.ia_valid = ATTR_SIZE; + newattrs.ia_size = oi_size & PAGE_MASK; + ret = notify_change(object->backer, &newattrs); + if (ret < 0) + goto truncate_failed; + } + + newattrs.ia_valid = ATTR_SIZE; + newattrs.ia_size = ni_size; ret = notify_change(object->backer, &newattrs); + +truncate_failed: mutex_unlock(&object->backer->d_inode->i_mutex); cachefiles_end_secure(cache, saved_cred); diff --git a/fs/cachefiles/rdwr.c b/fs/cachefiles/rdwr.c index 3304646dae84..5a84fd7109ad 100644 --- a/fs/cachefiles/rdwr.c +++ b/fs/cachefiles/rdwr.c @@ -803,7 +803,8 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page) struct cachefiles_cache *cache; mm_segment_t old_fs; struct file *file; - loff_t pos; + loff_t pos, eof; + size_t len; void *data; int ret; @@ -837,15 +838,29 @@ int cachefiles_write_page(struct fscache_storage *op, struct page *page) ret = -EIO; if (file->f_op->write) { pos = (loff_t) page->index << PAGE_SHIFT; + + /* we mustn't write more data than we have, so we have + * to beware of a partial page at EOF */ + eof = object->fscache.store_limit_l; + len = PAGE_SIZE; + if (eof & ~PAGE_MASK) { + ASSERTCMP(pos, <, eof); + if (eof - pos < PAGE_SIZE) { + _debug("cut short %llx to %llx", + pos, eof); + len = eof - pos; + ASSERTCMP(pos + len, ==, eof); + } + } + data = kmap(page); old_fs = get_fs(); set_fs(KERNEL_DS); ret = file->f_op->write( - file, (const void __user *) data, PAGE_SIZE, - &pos); + file, (const void __user *) data, len, &pos); set_fs(old_fs); kunmap(page); - if (ret != PAGE_SIZE) + if (ret != len) ret = -EIO; } fput(file); diff --git a/include/linux/fscache-cache.h b/include/linux/fscache-cache.h index 907bb56c5888..5db50002f3b5 100644 --- a/include/linux/fscache-cache.h +++ b/include/linux/fscache-cache.h @@ -395,6 +395,7 @@ struct fscache_object { struct rb_node objlist_link; /* link in global object list */ #endif pgoff_t store_limit; /* current storage limit */ + loff_t store_limit_l; /* current storage limit */ }; extern const char *fscache_object_states[]; @@ -439,6 +440,7 @@ void fscache_object_init(struct fscache_object *object, object->events = object->event_mask = 0; object->flags = 0; object->store_limit = 0; + object->store_limit_l = 0; object->cache = cache; object->cookie = cookie; object->parent = NULL; @@ -491,6 +493,7 @@ static inline void fscache_object_lookup_error(struct fscache_object *object) static inline void fscache_set_store_limit(struct fscache_object *object, loff_t i_size) { + object->store_limit_l = i_size; object->store_limit = i_size >> PAGE_SHIFT; if (i_size & ~PAGE_MASK) object->store_limit++; |