diff options
Diffstat (limited to 'fs/cachefiles/namei.c')
| -rw-r--r-- | fs/cachefiles/namei.c | 1018 |
1 files changed, 0 insertions, 1018 deletions
diff --git a/fs/cachefiles/namei.c b/fs/cachefiles/namei.c deleted file mode 100644 index a9aca5ab5970..000000000000 --- a/fs/cachefiles/namei.c +++ /dev/null @@ -1,1018 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0-or-later -/* CacheFiles path walking and related routines - * - * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. - * Written by David Howells (dhowells@redhat.com) - */ - -#include <linux/module.h> -#include <linux/sched.h> -#include <linux/file.h> -#include <linux/fs.h> -#include <linux/fsnotify.h> -#include <linux/quotaops.h> -#include <linux/xattr.h> -#include <linux/mount.h> -#include <linux/namei.h> -#include <linux/security.h> -#include <linux/slab.h> -#include "internal.h" - -#define CACHEFILES_KEYBUF_SIZE 512 - -/* - * dump debugging info about an object - */ -static noinline -void __cachefiles_printk_object(struct cachefiles_object *object, - const char *prefix) -{ - struct fscache_cookie *cookie; - const u8 *k; - unsigned loop; - - pr_err("%sobject: OBJ%x\n", prefix, object->fscache.debug_id); - pr_err("%sobjstate=%s fl=%lx wbusy=%x ev=%lx[%lx]\n", - prefix, object->fscache.state->name, - object->fscache.flags, work_busy(&object->fscache.work), - object->fscache.events, object->fscache.event_mask); - pr_err("%sops=%u inp=%u exc=%u\n", - prefix, object->fscache.n_ops, object->fscache.n_in_progress, - object->fscache.n_exclusive); - pr_err("%sparent=%x\n", - prefix, object->fscache.parent ? object->fscache.parent->debug_id : 0); - - spin_lock(&object->fscache.lock); - cookie = object->fscache.cookie; - if (cookie) { - pr_err("%scookie=%x [pr=%x nd=%p fl=%lx]\n", - prefix, - cookie->debug_id, - cookie->parent ? cookie->parent->debug_id : 0, - cookie->netfs_data, - cookie->flags); - pr_err("%skey=[%u] '", prefix, cookie->key_len); - k = (cookie->key_len <= sizeof(cookie->inline_key)) ? - cookie->inline_key : cookie->key; - for (loop = 0; loop < cookie->key_len; loop++) - pr_cont("%02x", k[loop]); - pr_cont("'\n"); - } else { - pr_err("%scookie=NULL\n", prefix); - } - spin_unlock(&object->fscache.lock); -} - -/* - * dump debugging info about a pair of objects - */ -static noinline void cachefiles_printk_object(struct cachefiles_object *object, - struct cachefiles_object *xobject) -{ - if (object) - __cachefiles_printk_object(object, ""); - if (xobject) - __cachefiles_printk_object(xobject, "x"); -} - -/* - * mark the owner of a dentry, if there is one, to indicate that that dentry - * has been preemptively deleted - * - the caller must hold the i_mutex on the dentry's parent as required to - * call vfs_unlink(), vfs_rmdir() or vfs_rename() - */ -static void cachefiles_mark_object_buried(struct cachefiles_cache *cache, - struct dentry *dentry, - enum fscache_why_object_killed why) -{ - struct cachefiles_object *object; - struct rb_node *p; - - _enter(",'%pd'", dentry); - - write_lock(&cache->active_lock); - - p = cache->active_nodes.rb_node; - while (p) { - object = rb_entry(p, struct cachefiles_object, active_node); - if (object->dentry > dentry) - p = p->rb_left; - else if (object->dentry < dentry) - p = p->rb_right; - else - goto found_dentry; - } - - write_unlock(&cache->active_lock); - trace_cachefiles_mark_buried(NULL, dentry, why); - _leave(" [no owner]"); - return; - - /* found the dentry for */ -found_dentry: - kdebug("preemptive burial: OBJ%x [%s] %pd", - object->fscache.debug_id, - object->fscache.state->name, - dentry); - - trace_cachefiles_mark_buried(object, dentry, why); - - if (fscache_object_is_live(&object->fscache)) { - pr_err("\n"); - pr_err("Error: Can't preemptively bury live object\n"); - cachefiles_printk_object(object, NULL); - } else { - if (why != FSCACHE_OBJECT_IS_STALE) - fscache_object_mark_killed(&object->fscache, why); - } - - write_unlock(&cache->active_lock); - _leave(" [owner marked]"); -} - -/* - * record the fact that an object is now active - */ -static int cachefiles_mark_object_active(struct cachefiles_cache *cache, - struct cachefiles_object *object) -{ - struct cachefiles_object *xobject; - struct rb_node **_p, *_parent = NULL; - struct dentry *dentry; - - _enter(",%x", object->fscache.debug_id); - -try_again: - write_lock(&cache->active_lock); - - dentry = object->dentry; - trace_cachefiles_mark_active(object, dentry); - - if (test_and_set_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags)) { - pr_err("Error: Object already active\n"); - cachefiles_printk_object(object, NULL); - BUG(); - } - - _p = &cache->active_nodes.rb_node; - while (*_p) { - _parent = *_p; - xobject = rb_entry(_parent, - struct cachefiles_object, active_node); - - ASSERT(xobject != object); - - if (xobject->dentry > dentry) - _p = &(*_p)->rb_left; - else if (xobject->dentry < dentry) - _p = &(*_p)->rb_right; - else - goto wait_for_old_object; - } - - rb_link_node(&object->active_node, _parent, _p); - rb_insert_color(&object->active_node, &cache->active_nodes); - - write_unlock(&cache->active_lock); - _leave(" = 0"); - return 0; - - /* an old object from a previous incarnation is hogging the slot - we - * need to wait for it to be destroyed */ -wait_for_old_object: - trace_cachefiles_wait_active(object, dentry, xobject); - clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); - - if (fscache_object_is_live(&xobject->fscache)) { - pr_err("\n"); - pr_err("Error: Unexpected object collision\n"); - cachefiles_printk_object(object, xobject); - } - atomic_inc(&xobject->usage); - write_unlock(&cache->active_lock); - - if (test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { - wait_queue_head_t *wq; - - signed long timeout = 60 * HZ; - wait_queue_entry_t wait; - bool requeue; - - /* if the object we're waiting for is queued for processing, - * then just put ourselves on the queue behind it */ - if (work_pending(&xobject->fscache.work)) { - _debug("queue OBJ%x behind OBJ%x immediately", - object->fscache.debug_id, - xobject->fscache.debug_id); - goto requeue; - } - - /* otherwise we sleep until either the object we're waiting for - * is done, or the fscache_object is congested */ - wq = bit_waitqueue(&xobject->flags, CACHEFILES_OBJECT_ACTIVE); - init_wait(&wait); - requeue = false; - do { - prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); - if (!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) - break; - - requeue = fscache_object_sleep_till_congested(&timeout); - } while (timeout > 0 && !requeue); - finish_wait(wq, &wait); - - if (requeue && - test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)) { - _debug("queue OBJ%x behind OBJ%x after wait", - object->fscache.debug_id, - xobject->fscache.debug_id); - goto requeue; - } - - if (timeout <= 0) { - pr_err("\n"); - pr_err("Error: Overlong wait for old active object to go away\n"); - cachefiles_printk_object(object, xobject); - goto requeue; - } - } - - ASSERT(!test_bit(CACHEFILES_OBJECT_ACTIVE, &xobject->flags)); - - cache->cache.ops->put_object(&xobject->fscache, - (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_retry); - goto try_again; - -requeue: - cache->cache.ops->put_object(&xobject->fscache, - (enum fscache_obj_ref_trace)cachefiles_obj_put_wait_timeo); - _leave(" = -ETIMEDOUT"); - return -ETIMEDOUT; -} - -/* - * Mark an object as being inactive. - */ -void cachefiles_mark_object_inactive(struct cachefiles_cache *cache, - struct cachefiles_object *object, - blkcnt_t i_blocks) -{ - struct dentry *dentry = object->dentry; - struct inode *inode = d_backing_inode(dentry); - - trace_cachefiles_mark_inactive(object, dentry, inode); - - write_lock(&cache->active_lock); - rb_erase(&object->active_node, &cache->active_nodes); - clear_bit(CACHEFILES_OBJECT_ACTIVE, &object->flags); - write_unlock(&cache->active_lock); - - wake_up_bit(&object->flags, CACHEFILES_OBJECT_ACTIVE); - - /* This object can now be culled, so we need to let the daemon know - * that there is something it can remove if it needs to. - */ - atomic_long_add(i_blocks, &cache->b_released); - if (atomic_inc_return(&cache->f_released)) - cachefiles_state_changed(cache); -} - -/* - * delete an object representation from the cache - * - file backed objects are unlinked - * - directory backed objects are stuffed into the graveyard for userspace to - * delete - * - unlocks the directory mutex - */ -static int cachefiles_bury_object(struct cachefiles_cache *cache, - struct cachefiles_object *object, - struct dentry *dir, - struct dentry *rep, - bool preemptive, - enum fscache_why_object_killed why) -{ - struct dentry *grave, *trap; - struct path path, path_to_graveyard; - char nbuffer[8 + 8 + 1]; - int ret; - - _enter(",'%pd','%pd'", dir, rep); - - /* non-directories can just be unlinked */ - if (!d_is_dir(rep)) { - _debug("unlink stale object"); - - path.mnt = cache->mnt; - path.dentry = dir; - ret = security_path_unlink(&path, rep); - if (ret < 0) { - cachefiles_io_error(cache, "Unlink security error"); - } else { - trace_cachefiles_unlink(object, rep, why); - ret = vfs_unlink(&init_user_ns, d_inode(dir), rep, - NULL); - - if (preemptive) - cachefiles_mark_object_buried(cache, rep, why); - } - - inode_unlock(d_inode(dir)); - - if (ret == -EIO) - cachefiles_io_error(cache, "Unlink failed"); - - _leave(" = %d", ret); - return ret; - } - - /* directories have to be moved to the graveyard */ - _debug("move stale object to graveyard"); - inode_unlock(d_inode(dir)); - -try_again: - /* first step is to make up a grave dentry in the graveyard */ - sprintf(nbuffer, "%08x%08x", - (uint32_t) ktime_get_real_seconds(), - (uint32_t) atomic_inc_return(&cache->gravecounter)); - - /* do the multiway lock magic */ - trap = lock_rename(cache->graveyard, dir); - - /* do some checks before getting the grave dentry */ - if (rep->d_parent != dir || IS_DEADDIR(d_inode(rep))) { - /* the entry was probably culled when we dropped the parent dir - * lock */ - unlock_rename(cache->graveyard, dir); - _leave(" = 0 [culled?]"); - return 0; - } - - if (!d_can_lookup(cache->graveyard)) { - unlock_rename(cache->graveyard, dir); - cachefiles_io_error(cache, "Graveyard no longer a directory"); - return -EIO; - } - - if (trap == rep) { - unlock_rename(cache->graveyard, dir); - cachefiles_io_error(cache, "May not make directory loop"); - return -EIO; - } - - if (d_mountpoint(rep)) { - unlock_rename(cache->graveyard, dir); - cachefiles_io_error(cache, "Mountpoint in cache"); - return -EIO; - } - - grave = lookup_one_len(nbuffer, cache->graveyard, strlen(nbuffer)); - if (IS_ERR(grave)) { - unlock_rename(cache->graveyard, dir); - - if (PTR_ERR(grave) == -ENOMEM) { - _leave(" = -ENOMEM"); - return -ENOMEM; - } - - cachefiles_io_error(cache, "Lookup error %ld", - PTR_ERR(grave)); - return -EIO; - } - - if (d_is_positive(grave)) { - unlock_rename(cache->graveyard, dir); - dput(grave); - grave = NULL; - cond_resched(); - goto try_again; - } - - if (d_mountpoint(grave)) { - unlock_rename(cache->graveyard, dir); - dput(grave); - cachefiles_io_error(cache, "Mountpoint in graveyard"); - return -EIO; - } - - /* target should not be an ancestor of source */ - if (trap == grave) { - unlock_rename(cache->graveyard, dir); - dput(grave); - cachefiles_io_error(cache, "May not make directory loop"); - return -EIO; - } - - /* attempt the rename */ - path.mnt = cache->mnt; - path.dentry = dir; - path_to_graveyard.mnt = cache->mnt; - path_to_graveyard.dentry = cache->graveyard; - ret = security_path_rename(&path, rep, &path_to_graveyard, grave, 0); - if (ret < 0) { - cachefiles_io_error(cache, "Rename security error %d", ret); - } else { - struct renamedata rd = { - .old_mnt_userns = &init_user_ns, - .old_dir = d_inode(dir), - .old_dentry = rep, - .new_mnt_userns = &init_user_ns, - .new_dir = d_inode(cache->graveyard), - .new_dentry = grave, - }; - trace_cachefiles_rename(object, rep, grave, why); - ret = vfs_rename(&rd); - if (ret != 0 && ret != -ENOMEM) - cachefiles_io_error(cache, - "Rename failed with error %d", ret); - - if (preemptive) - cachefiles_mark_object_buried(cache, rep, why); - } - - unlock_rename(cache->graveyard, dir); - dput(grave); - _leave(" = 0"); - return 0; -} - -/* - * delete an object representation from the cache - */ -int cachefiles_delete_object(struct cachefiles_cache *cache, - struct cachefiles_object *object) -{ - struct dentry *dir; - int ret; - - _enter(",OBJ%x{%pd}", object->fscache.debug_id, object->dentry); - - ASSERT(object->dentry); - ASSERT(d_backing_inode(object->dentry)); - ASSERT(object->dentry->d_parent); - - dir = dget_parent(object->dentry); - - inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); - - if (test_bit(FSCACHE_OBJECT_KILLED_BY_CACHE, &object->fscache.flags)) { - /* object allocation for the same key preemptively deleted this - * object's file so that it could create its own file */ - _debug("object preemptively buried"); - inode_unlock(d_inode(dir)); - ret = 0; - } else { - /* we need to check that our parent is _still_ our parent - it - * may have been renamed */ - if (dir == object->dentry->d_parent) { - ret = cachefiles_bury_object(cache, object, dir, - object->dentry, false, - FSCACHE_OBJECT_WAS_RETIRED); - } else { - /* it got moved, presumably by cachefilesd culling it, - * so it's no longer in the key path and we can ignore - * it */ - inode_unlock(d_inode(dir)); - ret = 0; - } - } - - dput(dir); - _leave(" = %d", ret); - return ret; -} - -/* - * walk from the parent object to the child object through the backing - * filesystem, creating directories as we go - */ -int cachefiles_walk_to_object(struct cachefiles_object *parent, - struct cachefiles_object *object, - const char *key, - struct cachefiles_xattr *auxdata) -{ - struct cachefiles_cache *cache; - struct dentry *dir, *next = NULL; - struct inode *inode; - struct path path; - const char *name; - int ret, nlen; - - _enter("OBJ%x{%pd},OBJ%x,%s,", - parent->fscache.debug_id, parent->dentry, - object->fscache.debug_id, key); - - cache = container_of(parent->fscache.cache, - struct cachefiles_cache, cache); - path.mnt = cache->mnt; - - ASSERT(parent->dentry); - ASSERT(d_backing_inode(parent->dentry)); - - if (!(d_is_dir(parent->dentry))) { - // TODO: convert file to dir - _leave("looking up in none directory"); - return -ENOBUFS; - } - - dir = dget(parent->dentry); - -advance: - /* attempt to transit the first directory component */ - name = key; - nlen = strlen(key); - - /* key ends in a double NUL */ - key = key + nlen + 1; - if (!*key) - key = NULL; - -lookup_again: - /* search the current directory for the element name */ - _debug("lookup '%s'", name); - - inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); - - next = lookup_one_len(name, dir, nlen); - if (IS_ERR(next)) { - trace_cachefiles_lookup(object, next, NULL); - goto lookup_error; - } - - inode = d_backing_inode(next); - trace_cachefiles_lookup(object, next, inode); - _debug("next -> %pd %s", next, inode ? "positive" : "negative"); - - if (!key) - object->new = !inode; - - /* if this element of the path doesn't exist, then the lookup phase - * failed, and we can release any readers in the certain knowledge that - * there's nothing for them to actually read */ - if (d_is_negative(next)) - fscache_object_lookup_negative(&object->fscache); - - /* we need to create the object if it's negative */ - if (key || object->type == FSCACHE_COOKIE_TYPE_INDEX) { - /* index objects and intervening tree levels must be subdirs */ - if (d_is_negative(next)) { - ret = cachefiles_has_space(cache, 1, 0); - if (ret < 0) - goto no_space_error; - - path.dentry = dir; - ret = security_path_mkdir(&path, next, 0); - if (ret < 0) - goto create_error; - ret = vfs_mkdir(&init_user_ns, d_inode(dir), next, 0); - if (!key) - trace_cachefiles_mkdir(object, next, ret); - if (ret < 0) - goto create_error; - - if (unlikely(d_unhashed(next))) { - dput(next); - inode_unlock(d_inode(dir)); - goto lookup_again; - } - ASSERT(d_backing_inode(next)); - - _debug("mkdir -> %pd{ino=%lu}", - next, d_backing_inode(next)->i_ino); - - } else if (!d_can_lookup(next)) { - pr_err("inode %lu is not a directory\n", - d_backing_inode(next)->i_ino); - ret = -ENOBUFS; - goto error; - } - - } else { - /* non-index objects start out life as files */ - if (d_is_negative(next)) { - ret = cachefiles_has_space(cache, 1, 0); - if (ret < 0) - goto no_space_error; - - path.dentry = dir; - ret = security_path_mknod(&path, next, S_IFREG, 0); - if (ret < 0) - goto create_error; - ret = vfs_create(&init_user_ns, d_inode(dir), next, - S_IFREG, true); - trace_cachefiles_create(object, next, ret); - if (ret < 0) - goto create_error; - - ASSERT(d_backing_inode(next)); - - _debug("create -> %pd{ino=%lu}", - next, d_backing_inode(next)->i_ino); - - } else if (!d_can_lookup(next) && - !d_is_reg(next) - ) { - pr_err("inode %lu is not a file or directory\n", - d_backing_inode(next)->i_ino); - ret = -ENOBUFS; - goto error; - } - } - - /* process the next component */ - if (key) { - _debug("advance"); - inode_unlock(d_inode(dir)); - dput(dir); - dir = next; - next = NULL; - goto advance; - } - - /* we've found the object we were looking for */ - object->dentry = next; - - /* if we've found that the terminal object exists, then we need to - * check its attributes and delete it if it's out of date */ - if (!object->new) { - _debug("validate '%pd'", next); - - ret = cachefiles_check_object_xattr(object, auxdata); - if (ret == -ESTALE) { - /* delete the object (the deleter drops the directory - * mutex) */ - object->dentry = NULL; - - ret = cachefiles_bury_object(cache, object, dir, next, - true, - FSCACHE_OBJECT_IS_STALE); - dput(next); - next = NULL; - - if (ret < 0) - goto delete_error; - - _debug("redo lookup"); - fscache_object_retrying_stale(&object->fscache); - goto lookup_again; - } - } - - /* note that we're now using this object */ - ret = cachefiles_mark_object_active(cache, object); - - inode_unlock(d_inode(dir)); - dput(dir); - dir = NULL; - - if (ret == -ETIMEDOUT) - goto mark_active_timed_out; - - _debug("=== OBTAINED_OBJECT ==="); - - if (object->new) { - /* attach data to a newly constructed terminal object */ - ret = cachefiles_set_object_xattr(object, auxdata); - if (ret < 0) - goto check_error; - } else { - /* always update the atime on an object we've just looked up - * (this is used to keep track of culling, and atimes are only - * updated by read, write and readdir but not lookup or - * open) */ - path.dentry = next; - touch_atime(&path); - } - - /* open a file interface onto a data file */ - if (object->type != FSCACHE_COOKIE_TYPE_INDEX) { - if (d_is_reg(object->dentry)) { - const struct address_space_operations *aops; - - ret = -EPERM; - aops = d_backing_inode(object->dentry)->i_mapping->a_ops; - if (!aops->bmap) - goto check_error; - if (object->dentry->d_sb->s_blocksize > PAGE_SIZE) - goto check_error; - - object->backer = object->dentry; - } else { - BUG(); // TODO: open file in data-class subdir - } - } - - object->new = 0; - fscache_obtained_object(&object->fscache); - - _leave(" = 0 [%lu]", d_backing_inode(object->dentry)->i_ino); - return 0; - -no_space_error: - fscache_object_mark_killed(&object->fscache, FSCACHE_OBJECT_NO_SPACE); -create_error: - _debug("create error %d", ret); - if (ret == -EIO) - cachefiles_io_error(cache, "Create/mkdir failed"); - goto error; - -mark_active_timed_out: - _debug("mark active timed out"); - goto release_dentry; - -check_error: - _debug("check error %d", ret); - cachefiles_mark_object_inactive( - cache, object, d_backing_inode(object->dentry)->i_blocks); -release_dentry: - dput(object->dentry); - object->dentry = NULL; - goto error_out; - -delete_error: - _debug("delete error %d", ret); - goto error_out2; - -lookup_error: - _debug("lookup error %ld", PTR_ERR(next)); - ret = PTR_ERR(next); - if (ret == -EIO) - cachefiles_io_error(cache, "Lookup failed"); - next = NULL; -error: - inode_unlock(d_inode(dir)); - dput(next); -error_out2: - dput(dir); -error_out: - _leave(" = error %d", -ret); - return ret; -} - -/* - * get a subdirectory - */ -struct dentry *cachefiles_get_directory(struct cachefiles_cache *cache, - struct dentry *dir, - const char *dirname) -{ - struct dentry *subdir; - struct path path; - int ret; - - _enter(",,%s", dirname); - - /* search the current directory for the element name */ - inode_lock(d_inode(dir)); - -retry: - subdir = lookup_one_len(dirname, dir, strlen(dirname)); - if (IS_ERR(subdir)) { - if (PTR_ERR(subdir) == -ENOMEM) - goto nomem_d_alloc; - goto lookup_error; - } - - _debug("subdir -> %pd %s", - subdir, d_backing_inode(subdir) ? "positive" : "negative"); - - /* we need to create the subdir if it doesn't exist yet */ - if (d_is_negative(subdir)) { - ret = cachefiles_has_space(cache, 1, 0); - if (ret < 0) - goto mkdir_error; - - _debug("attempt mkdir"); - - path.mnt = cache->mnt; - path.dentry = dir; - ret = security_path_mkdir(&path, subdir, 0700); - if (ret < 0) - goto mkdir_error; - ret = vfs_mkdir(&init_user_ns, d_inode(dir), subdir, 0700); - if (ret < 0) - goto mkdir_error; - - if (unlikely(d_unhashed(subdir))) { - dput(subdir); - goto retry; - } - ASSERT(d_backing_inode(subdir)); - - _debug("mkdir -> %pd{ino=%lu}", - subdir, d_backing_inode(subdir)->i_ino); - } - - inode_unlock(d_inode(dir)); - - /* we need to make sure the subdir is a directory */ - ASSERT(d_backing_inode(subdir)); - - if (!d_can_lookup(subdir)) { - pr_err("%s is not a directory\n", dirname); - ret = -EIO; - goto check_error; - } - - ret = -EPERM; - if (!(d_backing_inode(subdir)->i_opflags & IOP_XATTR) || - !d_backing_inode(subdir)->i_op->lookup || - !d_backing_inode(subdir)->i_op->mkdir || - !d_backing_inode(subdir)->i_op->create || - !d_backing_inode(subdir)->i_op->rename || - !d_backing_inode(subdir)->i_op->rmdir || - !d_backing_inode(subdir)->i_op->unlink) - goto check_error; - - _leave(" = [%lu]", d_backing_inode(subdir)->i_ino); - return subdir; - -check_error: - dput(subdir); - _leave(" = %d [check]", ret); - return ERR_PTR(ret); - -mkdir_error: - inode_unlock(d_inode(dir)); - dput(subdir); - pr_err("mkdir %s failed with error %d\n", dirname, ret); - return ERR_PTR(ret); - -lookup_error: - inode_unlock(d_inode(dir)); - ret = PTR_ERR(subdir); - pr_err("Lookup %s failed with error %d\n", dirname, ret); - return ERR_PTR(ret); - -nomem_d_alloc: - inode_unlock(d_inode(dir)); - _leave(" = -ENOMEM"); - return ERR_PTR(-ENOMEM); -} - -/* - * find out if an object is in use or not - * - if finds object and it's not in use: - * - returns a pointer to the object and a reference on it - * - returns with the directory locked - */ -static struct dentry *cachefiles_check_active(struct cachefiles_cache *cache, - struct dentry *dir, - char *filename) -{ - struct cachefiles_object *object; - struct rb_node *_n; - struct dentry *victim; - int ret; - - //_enter(",%pd/,%s", - // dir, filename); - - /* look up the victim */ - inode_lock_nested(d_inode(dir), I_MUTEX_PARENT); - - victim = lookup_one_len(filename, dir, strlen(filename)); - if (IS_ERR(victim)) - goto lookup_error; - - //_debug("victim -> %pd %s", - // victim, d_backing_inode(victim) ? "positive" : "negative"); - - /* if the object is no longer there then we probably retired the object - * at the netfs's request whilst the cull was in progress - */ - if (d_is_negative(victim)) { - inode_unlock(d_inode(dir)); - dput(victim); - _leave(" = -ENOENT [absent]"); - return ERR_PTR(-ENOENT); - } - - /* check to see if we're using this object */ - read_lock(&cache->active_lock); - - _n = cache->active_nodes.rb_node; - - while (_n) { - object = rb_entry(_n, struct cachefiles_object, active_node); - - if (object->dentry > victim) - _n = _n->rb_left; - else if (object->dentry < victim) - _n = _n->rb_right; - else - goto object_in_use; - } - - read_unlock(&cache->active_lock); - - //_leave(" = %pd", victim); - return victim; - -object_in_use: - read_unlock(&cache->active_lock); - inode_unlock(d_inode(dir)); - dput(victim); - //_leave(" = -EBUSY [in use]"); - return ERR_PTR(-EBUSY); - -lookup_error: - inode_unlock(d_inode(dir)); - ret = PTR_ERR(victim); - if (ret == -ENOENT) { - /* file or dir now absent - probably retired by netfs */ - _leave(" = -ESTALE [absent]"); - return ERR_PTR(-ESTALE); - } - - if (ret == -EIO) { - cachefiles_io_error(cache, "Lookup failed"); - } else if (ret != -ENOMEM) { - pr_err("Internal error: %d\n", ret); - ret = -EIO; - } - - _leave(" = %d", ret); - return ERR_PTR(ret); -} - -/* - * cull an object if it's not in use - * - called only by cache manager daemon - */ -int cachefiles_cull(struct cachefiles_cache *cache, struct dentry *dir, - char *filename) -{ - struct dentry *victim; - int ret; - - _enter(",%pd/,%s", dir, filename); - - victim = cachefiles_check_active(cache, dir, filename); - if (IS_ERR(victim)) - return PTR_ERR(victim); - - _debug("victim -> %pd %s", - victim, d_backing_inode(victim) ? "positive" : "negative"); - - /* okay... the victim is not being used so we can cull it - * - start by marking it as stale - */ - _debug("victim is cullable"); - - ret = cachefiles_remove_object_xattr(cache, victim); - if (ret < 0) - goto error_unlock; - - /* actually remove the victim (drops the dir mutex) */ - _debug("bury"); - - ret = cachefiles_bury_object(cache, NULL, dir, victim, false, - FSCACHE_OBJECT_WAS_CULLED); - if (ret < 0) - goto error; - - dput(victim); - _leave(" = 0"); - return 0; - -error_unlock: - inode_unlock(d_inode(dir)); -error: - dput(victim); - if (ret == -ENOENT) { - /* file or dir now absent - probably retired by netfs */ - _leave(" = -ESTALE [absent]"); - return -ESTALE; - } - - if (ret != -ENOMEM) { - pr_err("Internal error: %d\n", ret); - ret = -EIO; - } - - _leave(" = %d", ret); - return ret; -} - -/* - * find out if an object is in use or not - * - called only by cache manager daemon - * - returns -EBUSY or 0 to indicate whether an object is in use or not - */ -int cachefiles_check_in_use(struct cachefiles_cache *cache, struct dentry *dir, - char *filename) -{ - struct dentry *victim; - - //_enter(",%pd/,%s", - // dir, filename); - - victim = cachefiles_check_active(cache, dir, filename); - if (IS_ERR(victim)) - return PTR_ERR(victim); - - inode_unlock(d_inode(dir)); - dput(victim); - //_leave(" = 0"); - return 0; -} |