diff options
36 files changed, 645 insertions, 465 deletions
diff --git a/Documentation/filesystems/nfs/Exporting b/Documentation/filesystems/nfs/Exporting index e543b1a..c8f036a 100644 --- a/Documentation/filesystems/nfs/Exporting +++ b/Documentation/filesystems/nfs/Exporting @@ -66,23 +66,31 @@ b/ A per-superblock list "s_anon" of dentries which are the roots of c/ Helper routines to allocate anonymous dentries, and to help attach loose directory dentries at lookup time. They are: - d_alloc_anon(inode) will return a dentry for the given inode. + d_obtain_alias(inode) will return a dentry for the given inode. If the inode already has a dentry, one of those is returned. If it doesn't, a new anonymous (IS_ROOT and DCACHE_DISCONNECTED) dentry is allocated and attached. In the case of a directory, care is taken that only one dentry can ever be attached. - d_splice_alias(inode, dentry) will make sure that there is a - dentry with the same name and parent as the given dentry, and - which refers to the given inode. - If the inode is a directory and already has a dentry, then that - dentry is d_moved over the given dentry. - If the passed dentry gets attached, care is taken that this is - mutually exclusive to a d_alloc_anon operation. - If the passed dentry is used, NULL is returned, else the used - dentry is returned. This corresponds to the calling pattern of - ->lookup. - + d_splice_alias(inode, dentry) or d_materialise_unique(dentry, inode) + will introduce a new dentry into the tree; either the passed-in + dentry or a preexisting alias for the given inode (such as an + anonymous one created by d_obtain_alias), if appropriate. The two + functions differ in their handling of directories with preexisting + aliases: + d_splice_alias will use any existing IS_ROOT dentry, but it will + return -EIO rather than try to move a dentry with a different + parent. This is appropriate for local filesystems, which + should never see such an alias unless the filesystem is + corrupted somehow (for example, if two on-disk directory + entries refer to the same directory.) + d_materialise_unique will attempt to move any dentry. This is + appropriate for distributed filesystems, where finding a + directory other than where we last cached it may be a normal + consequence of concurrent operations on other hosts. + Both functions return NULL when the passed-in dentry is used, + following the calling convention of ->lookup. + Filesystem Issues ----------------- @@ -120,12 +128,12 @@ struct which has the following members: fh_to_dentry (mandatory) Given a filehandle fragment, this should find the implied object and - create a dentry for it (possibly with d_alloc_anon). + create a dentry for it (possibly with d_obtain_alias). fh_to_parent (optional but strongly recommended) Given a filehandle fragment, this should find the parent of the - implied object and create a dentry for it (possibly with d_alloc_anon). - May fail if the filehandle fragment is too small. + implied object and create a dentry for it (possibly with + d_obtain_alias). May fail if the filehandle fragment is too small. get_parent (optional but strongly recommended) When given a dentry for a directory, this should return a dentry for diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index a1d0d7a..61d65cc 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -1053,7 +1053,8 @@ struct dentry_operations { If the 'rcu_walk' parameter is true, then the caller is doing a pathwalk in RCU-walk mode. Sleeping is not permitted in this mode, and the caller can be asked to leave it and call again by returning - -ECHILD. + -ECHILD. -EISDIR may also be returned to tell pathwalk to + ignore d_automount or any mounts. This function is only used if DCACHE_MANAGE_TRANSIT is set on the dentry being transited from. diff --git a/fs/Makefile b/fs/Makefile index 4030cbf..90c8852 100644 --- a/fs/Makefile +++ b/fs/Makefile @@ -11,7 +11,7 @@ obj-y := open.o read_write.o file_table.o super.o \ attr.o bad_inode.o file.o filesystems.o namespace.o \ seq_file.o xattr.o libfs.o fs-writeback.o \ pnode.o splice.o sync.o utimes.o \ - stack.o fs_struct.o statfs.o + stack.o fs_struct.o statfs.o fs_pin.o ifeq ($(CONFIG_BLOCK),y) obj-y += buffer.o block_dev.o direct-io.o mpage.o diff --git a/fs/bad_inode.c b/fs/bad_inode.c index 7c93953..afd2b44 100644 --- a/fs/bad_inode.c +++ b/fs/bad_inode.c @@ -218,8 +218,9 @@ static int bad_inode_mknod (struct inode *dir, struct dentry *dentry, return -EIO; } -static int bad_inode_rename (struct inode *old_dir, struct dentry *old_dentry, - struct inode *new_dir, struct dentry *new_dentry) +static int bad_inode_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) { return -EIO; } @@ -279,7 +280,7 @@ static const struct inode_operations bad_inode_ops = .mkdir = bad_inode_mkdir, .rmdir = bad_inode_rmdir, .mknod = bad_inode_mknod, - .rename = bad_inode_rename, + .rename2 = bad_inode_rename2, .readlink = bad_inode_readlink, /* follow_link must be no-op, otherwise unmounting this inode won't work */ diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 3668048..3183742 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -8476,6 +8476,16 @@ out_notrans: return ret; } +static int btrfs_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) +{ + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + + return btrfs_rename(old_dir, old_dentry, new_dir, new_dentry); +} + static void btrfs_run_delalloc_work(struct btrfs_work *work) { struct btrfs_delalloc_work *delalloc_work; @@ -9019,7 +9029,7 @@ static const struct inode_operations btrfs_dir_inode_operations = { .link = btrfs_link, .mkdir = btrfs_mkdir, .rmdir = btrfs_rmdir, - .rename = btrfs_rename, + .rename2 = btrfs_rename2, .symlink = btrfs_symlink, .setattr = btrfs_setattr, .mknod = btrfs_mknod, diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index 8e16bca..67b48b9 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -851,7 +851,6 @@ static struct dentry *get_default_root(struct super_block *sb, struct btrfs_path *path; struct btrfs_key location; struct inode *inode; - struct dentry *dentry; u64 dir_id; int new = 0; @@ -922,13 +921,7 @@ setup_root: return dget(sb->s_root); } - dentry = d_obtain_alias(inode); - if (!IS_ERR(dentry)) { - spin_lock(&dentry->d_lock); - dentry->d_flags &= ~DCACHE_DISCONNECTED; - spin_unlock(&dentry->d_lock); - } - return dentry; + return d_obtain_root(inode); } static int btrfs_fill_super(struct super_block *sb, diff --git a/fs/ceph/super.c b/fs/ceph/super.c index 06150fd..f6e1237 100644 --- a/fs/ceph/super.c +++ b/fs/ceph/super.c @@ -755,7 +755,7 @@ static struct dentry *open_root_dentry(struct ceph_fs_client *fsc, goto out; } } else { - root = d_obtain_alias(inode); + root = d_obtain_root(inode); } ceph_init_dentry(root); dout("open_root_inode success, root dentry is %p\n", root); diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 8883980..ac4f260 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -848,7 +848,7 @@ const struct inode_operations cifs_dir_inode_ops = { .link = cifs_hardlink, .mkdir = cifs_mkdir, .rmdir = cifs_rmdir, - .rename = cifs_rename, + .rename2 = cifs_rename2, .permission = cifs_permission, /* revalidate:cifs_revalidate, */ .setattr = cifs_setattr, diff --git a/fs/cifs/cifsfs.h b/fs/cifs/cifsfs.h index 5604802..b0fafa4 100644 --- a/fs/cifs/cifsfs.h +++ b/fs/cifs/cifsfs.h @@ -68,8 +68,8 @@ extern int cifs_hardlink(struct dentry *, struct inode *, struct dentry *); extern int cifs_mknod(struct inode *, struct dentry *, umode_t, dev_t); extern int cifs_mkdir(struct inode *, struct dentry *, umode_t); extern int cifs_rmdir(struct inode *, struct dentry *); -extern int cifs_rename(struct inode *, struct dentry *, struct inode *, - struct dentry *); +extern int cifs_rename2(struct inode *, struct dentry *, struct inode *, + struct dentry *, unsigned int); extern int cifs_revalidate_file_attr(struct file *filp); extern int cifs_revalidate_dentry_attr(struct dentry *); extern int cifs_revalidate_file(struct file *filp); diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index 41de393..426d6c6 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -1627,8 +1627,9 @@ do_rename_exit: } int -cifs_rename(struct inode *source_dir, struct dentry *source_dentry, - struct inode *target_dir, struct dentry *target_dentry) +cifs_rename2(struct inode *source_dir, struct dentry *source_dentry, + struct inode *target_dir, struct dentry *target_dentry, + unsigned int flags) { char *from_name = NULL; char *to_name = NULL; @@ -1640,6 +1641,9 @@ cifs_rename(struct inode *source_dir, struct dentry *source_dentry, unsigned int xid; int rc, tmprc; + if (flags & ~RENAME_NOREPLACE) + return -EINVAL; + cifs_sb = CIFS_SB(source_dir->i_sb); tlink = cifs_sb_tlink(cifs_sb); if (IS_ERR(tlink)) @@ -1667,6 +1671,12 @@ cifs_rename(struct inode *source_dir, struct dentry *source_dentry, rc = cifs_do_rename(xid, source_dentry, from_name, target_dentry, to_name); + /* + * No-replace is the natural behavior for CIFS, so skip unlink hacks. + */ + if (flags & RENAME_NOREPLACE) + goto cifs_rename_exit; + if (rc == -EEXIST && tcon->unix_ext) { /* * Are src and dst hardlinks of same inode? We can only tell diff --git a/fs/dcache.c b/fs/dcache.c index 06f6585..d30ce69 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -731,8 +731,6 @@ EXPORT_SYMBOL(dget_parent); /** * d_find_alias - grab a hashed alias of inode * @inode: inode in question - * @want_discon: flag, used by d_splice_alias, to request - * that only a DISCONNECTED alias be returned. * * If inode has a hashed alias, or is a directory and has any alias, * acquire the reference to alias and return it. Otherwise return NULL. @@ -741,10 +739,9 @@ EXPORT_SYMBOL(dget_parent); * of a filesystem. * * If the inode has an IS_ROOT, DCACHE_DISCONNECTED alias, then prefer - * any other hashed alias over that one unless @want_discon is set, - * in which case only return an IS_ROOT, DCACHE_DISCONNECTED alias. + * any other hashed alias over that one. */ -static struct dentry *__d_find_alias(struct inode *inode, int want_discon) +static struct dentry *__d_find_alias(struct inode *inode) { struct dentry *alias, *discon_alias; @@ -756,7 +753,7 @@ again: if (IS_ROOT(alias) && (alias->d_flags & DCACHE_DISCONNECTED)) { discon_alias = alias; - } else if (!want_discon) { + } else { __dget_dlock(alias); spin_unlock(&alias->d_lock); return alias; @@ -768,12 +765,9 @@ again: alias = discon_alias; spin_lock(&alias->d_lock); if (S_ISDIR(inode->i_mode) || !d_unhashed(alias)) { - if (IS_ROOT(alias) && - (alias->d_flags & DCACHE_DISCONNECTED)) { - __dget_dlock(alias); - spin_unlock(&alias->d_lock); - return alias; - } + __dget_dlock(alias); + spin_unlock(&alias->d_lock); + return alias; } spin_unlock(&alias->d_lock); goto again; @@ -787,7 +781,7 @@ struct dentry *d_find_alias(struct inode *inode) if (!hlist_empty(&inode->i_dentry)) { spin_lock(&inode->i_lock); - de = __d_find_alias(inode, 0); + de = __d_find_alias(inode); spin_unlock(&inode->i_lock); } return de; @@ -1781,25 +1775,7 @@ struct dentry *d_find_any_alias(struct inode *inode) } EXPORT_SYMBOL(d_find_any_alias); -/** - * d_obtain_alias - find or allocate a dentry for a given inode - * @inode: inode to allocate the dentry for - * - * Obtain a dentry for an inode resulting from NFS filehandle conversion or - * similar open by handle operations. The returned dentry may be anonymous, - * or may have a full name (if the inode was already in the cache). - * - * When called on a directory inode, we must ensure that the inode only ever - * has one dentry. If a dentry is found, that is returned instead of - * allocating a new one. - * - * On successful return, the reference to the inode has been transferred - * to the dentry. In case of an error the reference on the inode is released. - * To make it easier to use in export operations a %NULL or IS_ERR inode may - * be passed in and will be the error will be propagate to the return value, - * with a %NULL @inode replaced by ERR_PTR(-ESTALE). - */ -struct dentry *d_obtain_alias(struct inode *inode) +static struct dentry *__d_obtain_alias(struct inode *inode, int disconnected) { static const struct qstr anonstring = QSTR_INIT("/", 1); struct dentry *tmp; @@ -1830,7 +1806,10 @@ struct dentry *d_obtain_alias(struct inode *inode) } /* attach a disconnected dentry */ - add_flags = d_flags_for_inode(inode) | DCACHE_DISCONNECTED; + add_flags = d_flags_for_inode(inode); + + if (disconnected) + add_flags |= DCACHE_DISCONNECTED; spin_lock(&tmp->d_lock); tmp->d_inode = inode; @@ -1851,59 +1830,51 @@ struct dentry *d_obtain_alias(struct inode *inode) iput(inode); return res; } -EXPORT_SYMBOL(d_obtain_alias); /** - * d_splice_alias - splice a disconnected dentry into the tree if one exists - * @inode: the inode which may have a disconnected dentry - * @dentry: a negative dentry which we want to point to the inode. - * - * If inode is a directory and has a 'disconnected' dentry (i.e. IS_ROOT and - * DCACHE_DISCONNECTED), then d_move that in place of the given dentry - * and return it, else simply d_add the inode to the dentry and return NULL. + * d_obtain_alias - find or allocate a DISCONNECTED dentry for a given inode + * @inode: inode to allocate the dentry for * - * This is needed in the lookup routine of any filesystem that is exportable - * (via knfsd) so that we can build dcache paths to directories effectively. + * Obtain a dentry for an inode resulting from NFS filehandle conversion or + * similar open by handle operations. The returned dentry may be anonymous, + * or may have a full name (if the inode was already in the cache). * - * If a dentry was found and moved, then it is returned. Otherwise NULL - * is returned. This matches the expected return value of ->lookup. + * When called on a directory inode, we must ensure that the inode only ever + * has one dentry. If a dentry is found, that is returned instead of + * allocating a new one. * - * Cluster filesystems may call this function with a negative, hashed dentry. - * In that case, we know that the inode will be a regular file, and also this - * will only occur during atomic_open. So we need to check for the dentry - * being already hashed only in the final case. + * On successful return, the reference to the inode has been transferred + * to the dentry. In case of an error the reference on the inode is released. + * To make it easier to use in export operations a %NULL or IS_ERR inode may + * be passed in and the error will be propagated to the return value, + * with a %NULL @inode replaced by ERR_PTR(-ESTALE). */ -struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) +struct dentry *d_obtain_alias(struct inode *inode) { - struct dentry *new = NULL; - - if (IS_ERR(inode)) - return ERR_CAST(inode); + return __d_obtain_alias(inode, 1); +} +EXPORT_SYMBOL(d_obtain_alias); - if (inode && S_ISDIR(inode->i_mode)) { - spin_lock(&inode->i_lock); - new = __d_find_alias(inode, 1); - if (new) { - BUG_ON(!(new->d_flags & DCACHE_DISCONNECTED)); - spin_unlock(&inode->i_lock); - security_d_instantiate(new, inode); - d_move(new, dentry); - iput(inode); - } else { - /* already taking inode->i_lock, so d_add() by hand */ - __d_instantiate(dentry, inode); - spin_unlock(&inode->i_lock); - security_d_instantiate(dentry, inode); - d_rehash(dentry); - } - } else { - d_instantiate(dentry, inode); - if (d_unhashed(dentry)) - d_rehash(dentry); - } - return new; +/** + * d_obtain_root - find or allocate a dentry for a given inode + * @inode: inode to allocate the dentry for + * + * Obtain an IS_ROOT dentry for the root of a filesystem. + * + * We must ensure that directory inodes only ever have one dentry. If a + * dentry is found, that is returned instead of allocating a new one. + * + * On successful return, the reference to the inode has been transferred + * to the dentry. In case of an error the reference on the inode is + * released. A %NULL or IS_ERR inode may be passed in and will be the + * error will be propagate to the return value, with a %NULL @inode + * replaced by ERR_PTR(-ESTALE). + */ +struct dentry *d_obtain_root(struct inode *inode) +{ + return __d_obtain_alias(inode, 0); } -EXPORT_SYMBOL(d_splice_alias); +EXPORT_SYMBOL(d_obtain_root); /** * d_add_ci - lookup or allocate new dentry with case-exact name @@ -2697,6 +2668,75 @@ static void __d_materialise_dentry(struct dentry *dentry, struct dentry *anon) } /** + * d_splice_alias - splice a disconnected dentry into the tree if one exists + * @inode: the inode which may have a disconnected dentry + * @dentry: a negative dentry which we want to point to the inode. + * + * If inode is a directory and has an IS_ROOT alias, then d_move that in + * place of the given dentry and return it, else simply d_add the inode + * to the dentry and return NULL. + * + * If a non-IS_ROOT directory is found, the filesystem is corrupt, and + * we should error out: directories can't have multiple aliases. + * + * This is needed in the lookup routine of any filesystem that is exportable + * (via knfsd) so that we can build dcache paths to directories effectively. + * + * If a dentry was found and moved, then it is returned. Otherwise NULL + * is returned. This matches the expected return value of ->lookup. + * + * Cluster filesystems may call this function with a negative, hashed dentry. + * In that case, we know that the inode will be a regular file, and also this + * will only occur during atomic_open. So we need to check for the dentry + * being already hashed only in the final case. + */ +struct dentry *d_splice_alias(struct inode *inode, struct dentry *dentry) +{ + struct dentry *new = NULL; + + if (IS_ERR(inode)) + return ERR_CAST(inode); + + if (inode && S_ISDIR(inode->i_mode)) { + spin_lock(&inode->i_lock); + new = __d_find_any_alias(inode); + if (new) { + if (!IS_ROOT(new)) { + spin_unlock(&inode->i_lock); + dput(new); + return ERR_PTR(-EIO); + } + if (d_ancestor(new, dentry)) { + spin_unlock(&inode->i_lock); + dput(new); + return ERR_PTR(-EIO); + } + write_seqlock(&rename_lock); + __d_materialise_dentry(dentry, new); + write_sequnlock(&rename_lock); + __d_drop(new); + _d_rehash(new); + spin_unlock(&new->d_lock); + spin_unlock(&inode->i_lock); + security_d_instantiate(new, inode); + iput(inode); + } else { + /* already taking inode->i_lock, so d_add() by hand */ + __d_instantiate(dentry, inode); + spin_unlock(&inode->i_lock); + security_d_instantiate(dentry, inode); + d_rehash(dentry); + } + } else { + d_instantiate(dentry, inode); + if (d_unhashed(dentry)) + d_rehash(dentry); + } + return new; +} +EXPORT_SYMBOL(d_splice_alias); + +/** * d_materialise_unique - introduce an inode into the tree * @dentry: candidate dentry * @inode: inode to bind to the dentry, to which aliases may be attached @@ -2724,7 +2764,7 @@ struct dentry *d_materialise_unique(struct dentry *dentry, struct inode *inode) struct dentry *alias; /* Does an aliased dentry already exist? */ - alias = __d_find_alias(inode, 0); + alias = __d_find_alias(inode); if (alias) { actual = alias; write_seqlock(&rename_lock); diff --git a/fs/direct-io.c b/fs/direct-io.c index 17e39b0..c311640 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -158,7 +158,7 @@ static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio) { ssize_t ret; - ret = iov_iter_get_pages(sdio->iter, dio->pages, DIO_PAGES * PAGE_SIZE, + ret = iov_iter_get_pages(sdio->iter, dio->pages, DIO_PAGES, &sdio->from); if (ret < 0 && sdio->blocks_available && (dio->rw & WRITE)) { diff --git a/fs/ext4/namei.c b/fs/ext4/namei.c index 3520ab8..b147a67 100644 --- a/fs/ext4/namei.c +++ b/fs/ext4/namei.c @@ -3455,7 +3455,6 @@ const struct inode_operations ext4_dir_inode_operations = { .rmdir = ext4_rmdir, .mknod = ext4_mknod, .tmpfile = ext4_tmpfile, - .rename = ext4_rename, .rename2 = ext4_rename2, .setattr = ext4_setattr, .setxattr = generic_setxattr, diff --git a/fs/fs_pin.c b/fs/fs_pin.c new file mode 100644 index 0000000..9368236 --- /dev/null +++ b/fs/fs_pin.c @@ -0,0 +1,78 @@ +#include <linux/fs.h> +#include <linux/slab.h> +#include <linux/fs_pin.h> +#include "internal.h" +#include "mount.h" + +static void pin_free_rcu(struct rcu_head *head) +{ + kfree(container_of(head, struct fs_pin, rcu)); +} + +static DEFINE_SPINLOCK(pin_lock); + +void pin_put(struct fs_pin *p) +{ + if (atomic_long_dec_and_test(&p->count)) + call_rcu(&p->rcu, pin_free_rcu); +} + +void pin_remove(struct fs_pin *pin) +{ + spin_lock(&pin_lock); + hlist_del(&pin->m_list); + hlist_del(&pin->s_list); + spin_unlock(&pin_lock); +} + +void pin_insert(struct fs_pin *pin, struct vfsmount *m) +{ + spin_lock(&pin_lock); + hlist_add_head(&pin->s_list, &m->mnt_sb->s_pins); + hlist_add_head(&pin->m_list, &real_mount(m)->mnt_pins); + spin_unlock(&pin_lock); +} + +void mnt_pin_kill(struct mount *m) +{ + while (1) { + struct hlist_node *p; + struct fs_pin *pin; + rcu_read_lock(); + p = ACCESS_ONCE(m->mnt_pins.first); + if (!p) { + rcu_read_unlock(); + break; + } + pin = hlist_entry(p, struct fs_pin, m_list); + if (!atomic_long_inc_not_zero(&pin->count)) { + rcu_read_unlock(); + cpu_relax(); + continue; + } + rcu_read_unlock(); + pin->kill(pin); + } +} + +void sb_pin_kill(struct super_block *sb) +{ + while (1) { + struct hlist_node *p; + struct fs_pin *pin; + rcu_read_lock(); + p = ACCESS_ONCE(sb->s_pins.first); + if (!p) { + rcu_read_unlock(); + break; + } + pin = hlist_entry(p, struct fs_pin, s_list); + if (!atomic_long_inc_not_zero(&pin->count)) { + rcu_read_unlock(); + cpu_relax(); + continue; + } + rcu_read_unlock(); + pin->kill(pin); + } +} diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 0c60482..de1d84a 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -845,12 +845,6 @@ static int fuse_rename2(struct inode *olddir, struct dentry *oldent, return err; } -static int fuse_rename(struct inode *olddir, struct dentry *oldent, - struct inode *newdir, struct dentry *newent) -{ - return fuse_rename2(olddir, oldent, newdir, newent, 0); -} - static int fuse_link(struct dentry *entry, struct inode *newdir, struct dentry *newent) { @@ -2024,7 +2018,6 @@ static const struct inode_operations fuse_dir_inode_operations = { .symlink = fuse_symlink, .unlink = fuse_unlink, .rmdir = fuse_rmdir, - .rename = fuse_rename, .rename2 = fuse_rename2, .link = fuse_link, .setattr = fuse_setattr, diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 40ac262..912061a 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1303,10 +1303,10 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, while (nbytes < *nbytesp && req->num_pages < req->max_pages) { unsigned npages; size_t start; - unsigned n = req->max_pages - req->num_pages; ssize_t ret = iov_iter_get_pages(ii, &req->pages[req->num_pages], - n * PAGE_SIZE, &start); + req->max_pages - req->num_pages, + &start); if (ret < 0) return ret; diff --git a/fs/hostfs/hostfs.h b/fs/hostfs/hostfs.h index 9c88da0..4fcd40d 100644 --- a/fs/hostfs/hostfs.h +++ b/fs/hostfs/hostfs.h @@ -89,6 +89,7 @@ extern int do_mknod(const char *file, int mode, unsigned int major, extern int link_file(const char *from, const char *to); extern int hostfs_do_readlink(char *file, char *buf, int size); extern int rename_file(char *from, char *to); +extern int rename2_file(char *from, char *to, unsigned int flags); extern int do_statfs(char *root, long *bsize_out, long long *blocks_out, long long *bfree_out, long long *bavail_out, long long *files_out, long long *ffree_out, diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index bb529f3..fd62cae 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -741,21 +741,31 @@ static int hostfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, return err; } -static int hostfs_rename(struct inode *from_ino, struct dentry *from, - struct inode *to_ino, struct dentry *to) +static int hostfs_rename2(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry, + unsigned int flags) { - char *from_name, *to_name; + char *old_name, *new_name; int err; - if ((from_name = dentry_name(from)) == NULL) + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) + return -EINVAL; + + old_name = dentry_name(old_dentry); + if (old_name == NULL) return -ENOMEM; - if ((to_name = dentry_name(to)) == NULL) { - __putname(from_name); + new_name = dentry_name(new_dentry); + if (new_name == NULL) { + __putname(old_name); return -ENOMEM; } - err = rename_file(from_name, to_name); - __putname(from_name); - __putname(to_name); + if (!flags) + err = rename_file(old_name, new_name); + else + err = rename2_file(old_name, new_name, flags); + + __putname(old_name); + __putname(new_name); return err; } @@ -867,7 +877,7 @@ static const struct inode_operations hostfs_dir_iops = { .mkdir = hostfs_mkdir, .rmdir = hostfs_rmdir, .mknod = hostfs_mknod, - .rename = hostfs_rename, + .rename2 = hostfs_rename2, .permission = hostfs_permission, .setattr = hostfs_setattr, }; diff --git a/fs/hostfs/hostfs_user.c b/fs/hostfs/hostfs_user.c index 67838f3..9765dab 100644 --- a/fs/hostfs/hostfs_user.c +++ b/fs/hostfs/hostfs_user.c @@ -14,6 +14,7 @@ #include <sys/time.h> #include <sys/types.h> #include <sys/vfs.h> +#include <sys/syscall.h> #include "hostfs.h" #include <utime.h> @@ -360,6 +361,33 @@ int rename_file(char *from, char *to) return 0; } +int rename2_file(char *from, char *to, unsigned int flags) +{ + int err; + +#ifndef SYS_renameat2 +# ifdef __x86_64__ +# define SYS_renameat2 316 +# endif +# ifdef __i386__ +# define SYS_renameat2 353 +# endif +#endif + +#ifdef SYS_renameat2 + err = syscall(SYS_renameat2, AT_FDCWD, from, AT_FDCWD, to, flags); + if (err < 0) { + if (errno != ENOSYS) + return -errno; + else + return -EINVAL; + } + return 0; +#else + return -EINVAL; +#endif +} + int do_statfs(char *root, long *bsize_out, long long *blocks_out, long long *bfree_out, long long *bavail_out, long long *files_out, long long *ffree_out, diff --git a/fs/internal.h b/fs/internal.h index 4657424..e325b4f 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -131,7 +131,6 @@ extern long prune_dcache_sb(struct super_block *sb, unsigned long nr_to_scan, /* * read_write.c */ -extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern int rw_verify_area(int, struct file *, const loff_t *, size_t); /* @@ -144,3 +143,9 @@ extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, * pipe.c */ extern const struct file_operations pipefifo_fops; + +/* + * fs_pin.c + */ +extern void sb_pin_kill(struct super_block *sb); +extern void mnt_pin_kill(struct mount *m); @@ -55,7 +55,7 @@ struct mount { int mnt_id; /* mount identifier */ int mnt_group_id; /* peer group identifier */ int mnt_expiry_mark; /* true if marked for expiry */ - int mnt_pinned; + struct hlist_head mnt_pins; struct path mnt_ex_mountpoint; }; @@ -1091,10 +1091,10 @@ int follow_down_one(struct path *path) } EXPORT_SYMBOL(follow_down_one); -static inline bool managed_dentry_might_block(struct dentry *dentry) +static inline int managed_dentry_rcu(struct dentry *dentry) { - return (dentry->d_flags & DCACHE_MANAGE_TRANSIT && - dentry->d_op->d_manage(dentry, true) < 0); + return (dentry->d_flags & DCACHE_MANAGE_TRANSIT) ? + dentry->d_op->d_manage(dentry, true) : 0; } /* @@ -1110,11 +1110,18 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, * Don't forget we might have a non-mountpoint managed dentry * that wants to block transit. */ - if (unlikely(managed_dentry_might_block(path->dentry))) + switch (managed_dentry_rcu(path->dentry)) { + case -ECHILD: + default: return false; + case -EISDIR: + return true; + case 0: + break; + } if (!d_mountpoint(path->dentry)) - return true; + return !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT); mounted = __lookup_mnt(path->mnt, path->dentry); if (!mounted) @@ -1130,7 +1137,8 @@ static bool __follow_mount_rcu(struct nameidata *nd, struct path *path, */ *inode = path->dentry->d_inode; } - return read_seqretry(&mount_lock, nd->m_seq); + return read_seqretry(&mount_lock, nd->m_seq) && + !(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT); } static int follow_dotdot_rcu(struct nameidata *nd) @@ -1402,11 +1410,8 @@ static int lookup_fast(struct nameidata *nd, } path->mnt = mnt; path->dentry = dentry; - if (unlikely(!__follow_mount_rcu(nd, path, inode))) - goto unlazy; - if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT)) - goto unlazy; - return 0; + if (likely(__follow_mount_rcu(nd, path, inode))) + return 0; unlazy: if (unlazy_walk(nd, dentry)) return -ECHILD; @@ -4019,7 +4024,7 @@ SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname * The worst of all namespace operations - renaming directory. "Perverted" * doesn't even start to describe it. Somebody in UCB had a heck of a trip... * Problems: - * a) we can get into loop creation. Check is done in is_subdir(). + * a) we can get into loop creation. * b) race potential - two innocent renames can create a loop together. * That's where 4.4 screws up. Current fix: serialization on * sb->s_vfs_rename_mutex. We might be more accurate, but that's another @@ -4075,7 +4080,7 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (error) return error; - if (!old_dir->i_op->rename) + if (!old_dir->i_op->rename && !old_dir->i_op->rename2) return -EPERM; if (flags && !old_dir->i_op->rename2) @@ -4134,10 +4139,11 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, if (error) goto out; } - if (!flags) { + if (!old_dir->i_op->rename2) { error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); } else { + WARN_ON(old_dir->i_op->rename != NULL); error = old_dir->i_op->rename2(old_dir, old_dentry, new_dir, new_dentry, flags); } diff --git a/fs/namespace.c b/fs/namespace.c index 0acabea..a01c773 100644 --- a/fs/namespace.c +++ b/fs/namespace.c @@ -16,7 +16,6 @@ #include <linux/namei.h> #include <linux/security.h> #include <linux/idr.h> -#include <linux/acct.h> /* acct_auto_close_mnt */ #include <linux/init.h> /* init_rootfs */ #include <linux/fs_struct.h> /* get_fs_root et.al. */ #include <linux/fsnotify.h> /* fsnotify_vfsmount_delete */ @@ -779,6 +778,20 @@ static void attach_mnt(struct mount *mnt, list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); } +static void attach_shadowed(struct mount *mnt, + struct mount *parent, + struct mount *shadows) +{ + if (shadows) { + hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash); + list_add(&mnt->mnt_child, &shadows->mnt_child); + } else { + hlist_add_head_rcu(&mnt->mnt_hash, + m_hash(&parent->mnt, mnt->mnt_mountpoint)); + list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); + } +} + /* * vfsmount lock must be held for write */ @@ -797,12 +810,7 @@ static void commit_tree(struct mount *mnt, struct mount *shadows) list_splice(&head, n->list.prev); - if (shadows) - hlist_add_behind_rcu(&mnt->mnt_hash, &shadows->mnt_hash); - else - hlist_add_head_rcu(&mnt->mnt_hash, - m_hash(&parent->mnt, mnt->mnt_mountpoint)); - list_add_tail(&mnt->mnt_child, &parent->mnt_mounts); + attach_shadowed(mnt, parent, shadows); touch_mnt_namespace(n); } @@ -951,7 +959,6 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root, static void mntput_no_expire(struct mount *mnt) { -put_again: rcu_read_lock(); mnt_add_count(mnt, -1); if (likely(mnt->mnt_ns)) { /* shouldn't be the last one */ @@ -964,14 +971,6 @@ put_again: unlock_mount_hash(); return; } - if (unlikely(mnt->mnt_pinned)) { - mnt_add_count(mnt, mnt->mnt_pinned + 1); - mnt->mnt_pinned = 0; - rcu_read_unlock(); - unlock_mount_hash(); - acct_auto_close_mnt(&mnt->mnt); - goto put_again; - } if (unlikely(mnt->mnt.mnt_flags & MNT_DOOMED)) { rcu_read_unlock(); unlock_mount_hash(); @@ -994,6 +993,8 @@ put_again: * so mnt_get_writers() below is safe. */ WARN_ON(mnt_get_writers(mnt)); + if (unlikely(mnt->mnt_pins.first)) + mnt_pin_kill(mnt); fsnotify_vfsmount_delete(&mnt->mnt); dput(mnt->mnt.mnt_root); deactivate_super(mnt->mnt.mnt_sb); @@ -1021,25 +1022,15 @@ struct vfsmount *mntget(struct vfsmount *mnt) } EXPORT_SYMBOL(mntget); -void mnt_pin(struct vfsmount *mnt) -{ - lock_mount_hash(); - real_mount(mnt)->mnt_pinned++; - unlock_mount_hash(); -} -EXPORT_SYMBOL(mnt_pin); - -void mnt_unpin(struct vfsmount *m) +struct vfsmount *mnt_clone_internal(struct path *path) { - struct mount *mnt = real_mount(m); - lock_mount_hash(); - if (mnt->mnt_pinned) { - mnt_add_count(mnt, 1); - mnt->mnt_pinned--; - } - unlock_mount_hash(); + struct mount *p; + p = clone_mnt(real_mount(path->mnt), path->dentry, CL_PRIVATE); + if (IS_ERR(p)) + return ERR_CAST(p); + p->mnt.mnt_flags |= MNT_INTERNAL; + return &p->mnt; } -EXPORT_SYMBOL(mnt_unpin); static inline void mangle(struct seq_file *m, const char *s) { @@ -1505,6 +1496,7 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, continue; for (s = r; s; s = next_mnt(s, r)) { + struct mount *t = NULL; if (!(flag & CL_COPY_UNBINDABLE) && IS_MNT_UNBINDABLE(s)) { s = skip_mnt_tree(s); @@ -1526,7 +1518,14 @@ struct mount *copy_tree(struct mount *mnt, struct dentry *dentry, goto out; lock_mount_hash(); list_add_tail(&q->mnt_list, &res->mnt_list); - attach_mnt(q, parent, p->mnt_mp); + mnt_set_mountpoint(parent, p->mnt_mp, q); + if (!list_empty(&parent->mnt_mounts)) { + t = list_last_entry(&parent->mnt_mounts, + struct mount, mnt_child); + if (t->mnt_mp != p->mnt_mp) + t = NULL; + } + attach_shadowed(q, parent, t); unlock_mount_hash(); } } diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c index b94f804..880618a 100644 --- a/fs/nfs/getroot.c +++ b/fs/nfs/getroot.c @@ -112,7 +112,7 @@ struct dentry *nfs_get_root(struct super_block *sb, struct nfs_fh *mntfh, * if the dentry tree reaches them; however if the dentry already * exists, we'll pick it up at this point and use it as the root */ - ret = d_obtain_alias(inode); + ret = d_obtain_root(inode); if (IS_ERR(ret)) { dprintk("nfs_get_root: get root dentry failed\n"); goto out; diff --git a/fs/nilfs2/super.c b/fs/nilfs2/super.c index c519927..228f5bd 100644 --- a/fs/nilfs2/super.c +++ b/fs/nilfs2/super.c @@ -942,7 +942,7 @@ static int nilfs_get_root_dentry(struct super_block *sb, iput(inode); } } else { - dentry = d_obtain_alias(inode); + dentry = d_obtain_root(inode); if (IS_ERR(dentry)) { ret = PTR_ERR(dentry); goto failed_dentry; @@ -22,7 +22,6 @@ #include <linux/export.h> #include <linux/slab.h> -#include <linux/acct.h> #include <linux/blkdev.h> #include <linux/mount.h> #include <linux/security.h> @@ -702,12 +701,22 @@ int do_remount_sb(struct super_block *sb, int flags, void *data, int force) return -EACCES; #endif - if (flags & MS_RDONLY) - acct_auto_close(sb); - shrink_dcache_sb(sb); - remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); + if (remount_ro) { + if (sb->s_pins.first) { + up_write(&sb->s_umount); + sb_pin_kill(sb); + down_write(&sb->s_umount); + if (!sb->s_root) + return 0; + if (sb->s_writers.frozen != SB_UNFROZEN) + return -EBUSY; + remount_ro = (flags & MS_RDONLY) && !(sb->s_flags & MS_RDONLY); + } + } + shrink_dcache_sb(sb); + /* If we are remounting RDONLY and current sb is read/write, make sure there are no rw files opened */ if (remount_ro) { diff --git a/include/linux/acct.h b/include/linux/acct.h index 4a5b7cb..dccc2d4 100644 --- a/include/linux/acct.h +++ b/include/linux/acct.h @@ -24,14 +24,10 @@ struct super_block; struct pacct_struct; struct pid_namespace; extern int acct_parm[]; /* for sysctl */ -extern void acct_auto_close_mnt(struct vfsmount *m); -extern void acct_auto_close(struct super_block *sb); extern void acct_collect(long exitcode, int group_dead); extern void acct_process(void); extern void acct_exit_ns(struct pid_namespace *); #else -#define acct_auto_close_mnt(x) do { } while (0) -#define acct_auto_close(x) do { } while (0) #define acct_collect(x,y) do { } while (0) #define acct_process() do { } while (0) #define acct_exit_ns(ns) do { } while (0) diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 3c7ec32..e4ae2ad 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -249,6 +249,7 @@ extern struct dentry * d_splice_alias(struct inode *, struct dentry *); extern struct dentry * d_add_ci(struct dentry *, struct inode *, struct qstr *); extern struct dentry *d_find_any_alias(struct inode *inode); extern struct dentry * d_obtain_alias(struct inode *); +extern struct dentry * d_obtain_root(struct inode *); extern void shrink_dcache_sb(struct super_block *); extern void shrink_dcache_parent(struct dentry *); extern void shrink_dcache_for_umount(struct super_block *); diff --git a/include/linux/fs.h b/include/linux/fs.h index f0890e4..94187721 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1275,6 +1275,7 @@ struct super_block { /* AIO completions deferred from interrupt context */ struct workqueue_struct *s_dio_done_wq; + struct hlist_head s_pins; /* * Keep the lru lists last in the structure so they always sit on their @@ -2360,6 +2361,7 @@ extern int do_pipe_flags(int *, int); extern int kernel_read(struct file *, loff_t, char *, unsigned long); extern ssize_t kernel_write(struct file *, const char *, size_t, loff_t); +extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); extern struct file * open_exec(const char *); /* fs/dcache.c -- generic fs support functions */ diff --git a/include/linux/fs_pin.h b/include/linux/fs_pin.h new file mode 100644 index 0000000..f66525e --- /dev/null +++ b/include/linux/fs_pin.h @@ -0,0 +1,17 @@ +#include <linux/fs.h> + +struct fs_pin { + atomic_long_t count; + union { + struct { + struct hlist_node s_list; + struct hlist_node m_list; + }; + struct rcu_head rcu; + }; + void (*kill)(struct fs_pin *); +}; + +void pin_put(struct fs_pin *); +void pin_remove(struct fs_pin *); +void pin_insert(struct fs_pin *, struct vfsmount *); diff --git a/include/linux/mount.h b/include/linux/mount.h index b0c1e65..9262e4b 100644 --- a/include/linux/mount.h +++ b/include/linux/mount.h @@ -69,6 +69,7 @@ struct vfsmount { }; struct file; /* forward dec */ +struct path; extern int mnt_want_write(struct vfsmount *mnt); extern int mnt_want_write_file(struct file *file); @@ -77,8 +78,7 @@ extern void mnt_drop_write(struct vfsmount *mnt); extern void mnt_drop_write_file(struct file *file); extern void mntput(struct vfsmount *mnt); extern struct vfsmount *mntget(struct vfsmount *mnt); -extern void mnt_pin(struct vfsmount *mnt); -extern void mnt_unpin(struct vfsmount *mnt); +extern struct vfsmount *mnt_clone_internal(struct path *path); extern int __mnt_is_readonly(struct vfsmount *mnt); struct file_system_type; diff --git a/include/linux/uio.h b/include/linux/uio.h index 09a7cffc..48d64e6 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -84,7 +84,7 @@ unsigned long iov_iter_alignment(const struct iov_iter *i); void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, unsigned long nr_segs, size_t count); ssize_t iov_iter_get_pages(struct iov_iter *i, struct page **pages, - size_t maxsize, size_t *start); + unsigned maxpages, size_t *start); ssize_t iov_iter_get_pages_alloc(struct iov_iter *i, struct page ***pages, size_t maxsize, size_t *start); int iov_iter_npages(const struct iov_iter *i, int maxpages); diff --git a/kernel/acct.c b/kernel/acct.c index 5179352..b4c667d 100644 --- a/kernel/acct.c +++ b/kernel/acct.c @@ -59,6 +59,7 @@ #include <asm/div64.h> #include <linux/blkdev.h> /* sector_div */ #include <linux/pid_namespace.h> +#include <linux/fs_pin.h> /* * These constants control the amount of freespace that suspend and @@ -75,172 +76,190 @@ int acct_parm[3] = {4, 2, 30}; /* * External references and all of the globals. */ -static void do_acct_process(struct bsd_acct_struct *acct, - struct pid_namespace *ns, struct file *); +static void do_acct_process(struct bsd_acct_struct *acct); -/* - * This structure is used so that all the data protected by lock - * can be placed in the same cache line as the lock. This primes - * the cache line to have the data after getting the lock. - */ struct bsd_acct_struct { + struct fs_pin pin; + struct mutex lock; int active; unsigned long needcheck; struct file *file; struct pid_namespace *ns; - struct list_head list; + struct work_struct work; + struct completion done; }; -static DEFINE_SPINLOCK(acct_lock); -static LIST_HEAD(acct_list); - /* * Check the amount of free space and suspend/resume accordingly. */ -static int check_free_space(struct bsd_acct_struct *acct, struct file *file) +static int check_free_space(struct bsd_acct_struct *acct) { struct kstatfs sbuf; - int res; - int act; - u64 resume; - u64 suspend; - - spin_lock(&acct_lock); - res = acct->active; - if (!file || time_is_before_jiffies(acct->needcheck)) + + if (time_is_before_jiffies(acct->needcheck)) goto out; - spin_unlock(&acct_lock); /* May block */ - if (vfs_statfs(&file->f_path, &sbuf)) - return res; - suspend = sbuf.f_blocks * SUSPEND; - resume = sbuf.f_blocks * RESUME; - - do_div(suspend, 100); - do_div(resume, 100); - - if (sbuf.f_bavail <= suspend) - act = -1; - else if (sbuf.f_bavail >= resume) - act = 1; - else - act = 0; - - /* - * If some joker switched acct->file under us we'ld better be - * silent and _not_ touch anything. - */ - spin_lock(&acct_lock); - if (file != acct->file) { - if (act) - res = act > 0; + if (vfs_statfs(&acct->file->f_path, &sbuf)) goto out; - } if (acct->active) { - if (act < 0) { + u64 suspend = sbuf.f_blocks * SUSPEND; + do_div(suspend, 100); + if (sbuf.f_bavail <= suspend) { acct->active = 0; pr_info("Process accounting paused\n"); } } else { - if (act > 0) { + u64 resume = sbuf.f_blocks * RESUME; + do_div(resume, 100); + if (sbuf.f_bavail >= resume) { acct->active = 1; pr_info("Process accounting resumed\n"); } } acct->needcheck = jiffies + ACCT_TIMEOUT*HZ; - res = acct->active; out: - spin_unlock(&acct_lock); + return acct->active; +} + +static struct bsd_acct_struct *acct_get(struct pid_namespace *ns) +{ + struct bsd_acct_struct *res; +again: + smp_rmb(); + rcu_read_lock(); + res = ACCESS_ONCE(ns->bacct); + if (!res) { + rcu_read_unlock(); + return NULL; + } + if (!atomic_long_inc_not_zero(&res->pin.count)) { + rcu_read_unlock(); + cpu_relax(); + goto again; + } + rcu_read_unlock(); + mutex_lock(&res->lock); + if (!res->ns) { + mutex_unlock(&res->lock); + pin_put(&res->pin); + goto again; + } return res; } -/* - * Close the old accounting file (if currently open) and then replace - * it with file (if non-NULL). - * - * NOTE: acct_lock MUST be held on entry and exit. - */ -static void acct_file_reopen(struct bsd_acct_struct *acct, struct file *file, - struct pid_namespace *ns) +static void close_work(struct work_struct *work) { - struct file *old_acct = NULL; - struct pid_namespace *old_ns = NULL; - - if (acct->file) { - old_acct = acct->file; - old_ns = acct->ns; - acct->active = 0; - acct->file = NULL; + struct bsd_acct_struct *acct = container_of(work, struct bsd_acct_struct, work); + struct file *file = acct->file; + if (file->f_op->flush) + file->f_op->flush(file, NULL); + __fput_sync(file); + complete(&acct->done); +} + +static void acct_kill(struct bsd_acct_struct *acct, + struct bsd_acct_struct *new) +{ + if (acct) { + struct pid_namespace *ns = acct->ns; + do_acct_process(acct); + INIT_WORK(&acct->work, close_work); + init_completion(&acct->done); + schedule_work(&acct->work); + wait_for_completion(&acct->done); + pin_remove(&acct->pin); + ns->bacct = new; acct->ns = NULL; - list_del(&acct->list); - } - if (file) { - acct->file = file; - acct->ns = ns; - acct->needcheck = jiffies + ACCT_TIMEOUT*HZ; - acct->active = 1; - list_add(&acct->list, &acct_list); + atomic_long_dec(&acct->pin.count); + mutex_unlock(&acct->lock); + pin_put(&acct->pin); } - if (old_acct) { - mnt_unpin(old_acct->f_path.mnt); - spin_unlock(&acct_lock); - do_acct_process(acct, old_ns, old_acct); - filp_close(old_acct, NULL); - spin_lock(&acct_lock); +} + +static void acct_pin_kill(struct fs_pin *pin) +{ + struct bsd_acct_struct *acct; + acct = container_of(pin, struct bsd_acct_struct, pin); + mutex_lock(&acct->lock); + if (!acct->ns) { + mutex_unlock(&acct->lock); + pin_put(pin); + acct = NULL; } + acct_kill(acct, NULL); } static int acct_on(struct filename *pathname) { struct file *file; - struct vfsmount *mnt; - struct pid_namespace *ns; - struct bsd_acct_struct *acct = NULL; + struct vfsmount *mnt, *internal; + struct pid_namespace *ns = task_active_pid_ns(current); + struct bsd_acct_struct *acct, *old; + int err; + + acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL); + if (!acct) + return -ENOMEM; /* Difference from BSD - they don't do O_APPEND */ file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0); - if (IS_ERR(file)) + if (IS_ERR(file)) { + kfree(acct); return PTR_ERR(file); + } if (!S_ISREG(file_inode(file)->i_mode)) { + kfree(acct); filp_close(file, NULL); return -EACCES; } if (!file->f_op->write) { + kfree(acct); filp_close(file, NULL); return -EIO; } - - ns = task_active_pid_ns(current); - if (ns->bacct == NULL) { - acct = kzalloc(sizeof(struct bsd_acct_struct), GFP_KERNEL); - if (acct == NULL) { - filp_close(file, NULL); - return -ENOMEM; - } + internal = mnt_clone_internal(&file->f_path); + if (IS_ERR(internal)) { + kfree(acct); + filp_close(file, NULL); + return PTR_ERR(internal); } - - spin_lock(&acct_lock); - if (ns->bacct == NULL) { - ns->bacct = acct; - acct = NULL; + err = mnt_want_write(internal); + if (err) { + mntput(internal); + kfree(acct); + filp_close(file, NULL); + return err; } - mnt = file->f_path.mnt; - mnt_pin(mnt); - acct_file_reopen(ns->bacct, file, ns); - spin_unlock(&acct_lock); - - mntput(mnt); /* it's pinned, now give up active reference */ - kfree(acct); - + file->f_path.mnt = internal; + + atomic_long_set(&acct->pin.count, 1); + acct->pin.kill = acct_pin_kill; + acct->file = file; + acct->needcheck = jiffies; + acct->ns = ns; + mutex_init(&acct->lock); + mutex_lock_nested(&acct->lock, 1); /* nobody has seen it yet */ + pin_insert(&acct->pin, mnt); + + old = acct_get(ns); + if (old) + acct_kill(old, acct); + else + ns->bacct = acct; + mutex_unlock(&acct->lock); + mnt_drop_write(mnt); + mntput(mnt); return 0; } +static DEFINE_MUTEX(acct_on_mutex); + /** * sys_acct - enable/disable process accounting * @name: file name for accounting records or NULL to shutdown accounting @@ -264,78 +283,20 @@ SYSCALL_DEFINE1(acct, const char __user *, name) if (IS_ERR(tmp)) return PTR_ERR(tmp); + mutex_lock(&acct_on_mutex); error = acct_on(tmp); + mutex_unlock(&acct_on_mutex); putname(tmp); } else { - struct bsd_acct_struct *acct; - - acct = task_active_pid_ns(current)->bacct; - if (acct == NULL) - return 0; - - spin_lock(&acct_lock); - acct_file_reopen(acct, NULL, NULL); - spin_unlock(&acct_lock); + acct_kill(acct_get(task_active_pid_ns(current)), NULL); } return error; } -/** - * acct_auto_close - turn off a filesystem's accounting if it is on - * @m: vfsmount being shut down - * - * If the accounting is turned on for a file in the subtree pointed to - * to by m, turn accounting off. Done when m is about to die. - */ -void acct_auto_close_mnt(struct vfsmount *m) -{ - struct bsd_acct_struct *acct; - - spin_lock(&acct_lock); -restart: - list_for_each_entry(acct, &acct_list, list) - if (acct->file && acct->file->f_path.mnt == m) { - acct_file_reopen(acct, NULL, NULL); - goto restart; - } - spin_unlock(&acct_lock); -} - -/** - * acct_auto_close - turn off a filesystem's accounting if it is on - * @sb: super block for the filesystem - * - * If the accounting is turned on for a file in the filesystem pointed - * to by sb, turn accounting off. - */ -void acct_auto_close(struct super_block *sb) -{ - struct bsd_acct_struct *acct; - - spin_lock(&acct_lock); -restart: - list_for_each_entry(acct, &acct_list, list) - if (acct->file && acct->file->f_path.dentry->d_sb == sb) { - acct_file_reopen(acct, NULL, NULL); - goto restart; - } - spin_unlock(&acct_lock); -} - void acct_exit_ns(struct pid_namespace *ns) { - struct bsd_acct_struct *acct = ns->bacct; - - if (acct == NULL) - return; - - spin_lock(&acct_lock); - if (acct->file != NULL) - acct_file_reopen(acct, NULL, NULL); - spin_unlock(&acct_lock); - - kfree(acct); + acct_kill(acct_get(ns), NULL); } /* @@ -450,38 +411,20 @@ static u32 encode_float(u64 value) * do_exit() or when switching to a different output file. */ -/* - * do_acct_process does all actual work. Caller holds the reference to file. - */ -static void do_acct_process(struct bsd_acct_struct *acct, - struct pid_namespace *ns, struct file *file) +static void fill_ac(acct_t *ac) { struct pacct_struct *pacct = ¤t->signal->pacct; - acct_t ac; - mm_segment_t fs; - unsigned long flim; u64 elapsed, run_time; struct tty_struct *tty; - const struct cred *orig_cred; - - /* Perform file operations on behalf of whoever enabled accounting */ - orig_cred = override_creds(file->f_cred); - - /* - * First check to see if there is enough free_space to continue - * the process accounting system. - */ - if (!check_free_space(acct, file)) - goto out; /* * Fill the accounting struct with the needed info as recorded * by the different kernel functions. */ - memset(&ac, 0, sizeof(acct_t)); + memset(ac, 0, sizeof(acct_t)); - ac.ac_version = ACCT_VERSION | ACCT_BYTEORDER; - strlcpy(ac.ac_comm, current->comm, sizeof(ac.ac_comm)); + ac->ac_version = ACCT_VERSION | ACCT_BYTEORDER; + strlcpy(ac->ac_comm, current->comm, sizeof(ac->ac_comm)); /* calculate run_time in nsec*/ run_time = ktime_get_ns(); @@ -489,9 +432,9 @@ static void do_acct_process(struct bsd_acct_struct *acct, /* convert nsec -> AHZ */ elapsed = nsec_to_AHZ(run_time); #if ACCT_VERSION == 3 - ac.ac_etime = encode_float(elapsed); + ac->ac_etime = encode_float(elapsed); #else - ac.ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ? + ac->ac_etime = encode_comp_t(elapsed < (unsigned long) -1l ? (unsigned long) elapsed : (unsigned long) -1l); #endif #if ACCT_VERSION == 1 || ACCT_VERSION == 2 @@ -499,18 +442,58 @@ static void do_acct_process(struct bsd_acct_struct *acct, /* new enlarged etime field */ comp2_t etime = encode_comp2_t(elapsed); - ac.ac_etime_hi = etime >> 16; - ac.ac_etime_lo = (u16) etime; + ac->ac_etime_hi = etime >> 16; + ac->ac_etime_lo = (u16) etime; } #endif do_div(elapsed, AHZ); - ac.ac_btime = get_seconds() - elapsed; + ac->ac_btime = get_seconds() - elapsed; +#if ACCT_VERSION==2 + ac->ac_ahz = AHZ; +#endif + + spin_lock_irq(¤t->sighand->siglock); + tty = current->signal->tty; /* Safe as we hold the siglock */ + ac->ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; + ac->ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); + ac->ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); + ac->ac_flag = pacct->ac_flag; + ac->ac_mem = encode_comp_t(pacct->ac_mem); + ac->ac_minflt = encode_comp_t(pacct->ac_minflt); + ac->ac_majflt = encode_comp_t(pacct->ac_majflt); + ac->ac_exitcode = pacct->ac_exitcode; + spin_unlock_irq(¤t->sighand->siglock); +} +/* + * do_acct_process does all actual work. Caller holds the reference to file. + */ +static void do_acct_process(struct bsd_acct_struct *acct) +{ + acct_t ac; + unsigned long flim; + const struct cred *orig_cred; + struct pid_namespace *ns = acct->ns; + struct file *file = acct->file; + + /* + * Accounting records are not subject to resource limits. + */ + flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; + current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; + /* Perform file operations on behalf of whoever enabled accounting */ + orig_cred = override_creds(file->f_cred); + + /* + * First check to see if there is enough free_space to continue + * the process accounting system. + */ + if (!check_free_space(acct)) + goto out; + + fill_ac(&ac); /* we really need to bite the bullet and change layout */ ac.ac_uid = from_kuid_munged(file->f_cred->user_ns, orig_cred->uid); ac.ac_gid = from_kgid_munged(file->f_cred->user_ns, orig_cred->gid); -#if ACCT_VERSION == 2 - ac.ac_ahz = AHZ; -#endif #if ACCT_VERSION == 1 || ACCT_VERSION == 2 /* backward-compatible 16 bit fields */ ac.ac_uid16 = ac.ac_uid; @@ -522,45 +505,18 @@ static void do_acct_process(struct bsd_acct_struct *acct, ac.ac_ppid = task_tgid_nr_ns(rcu_dereference(current->real_parent), ns); rcu_read_unlock(); #endif - - spin_lock_irq(¤t->sighand->siglock); - tty = current->signal->tty; /* Safe as we hold the siglock */ - ac.ac_tty = tty ? old_encode_dev(tty_devnum(tty)) : 0; - ac.ac_utime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_utime))); - ac.ac_stime = encode_comp_t(jiffies_to_AHZ(cputime_to_jiffies(pacct->ac_stime))); - ac.ac_flag = pacct->ac_flag; - ac.ac_mem = encode_comp_t(pacct->ac_mem); - ac.ac_minflt = encode_comp_t(pacct->ac_minflt); - ac.ac_majflt = encode_comp_t(pacct->ac_majflt); - ac.ac_exitcode = pacct->ac_exitcode; - spin_unlock_irq(¤t->sighand->siglock); - ac.ac_io = encode_comp_t(0 /* current->io_usage */); /* %% */ - ac.ac_rw = encode_comp_t(ac.ac_io / 1024); - ac.ac_swaps = encode_comp_t(0); - /* * Get freeze protection. If the fs is frozen, just skip the write * as we could deadlock the system otherwise. */ - if (!file_start_write_trylock(file)) - goto out; - /* - * Kernel segment override to datasegment and write it - * to the accounting file. - */ - fs = get_fs(); - set_fs(KERNEL_DS); - /* - * Accounting records are not subject to resource limits. - */ - flim = current->signal->rlim[RLIMIT_FSIZE].rlim_cur; - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = RLIM_INFINITY; - file->f_op->write(file, (char *)&ac, - sizeof(acct_t), &file->f_pos); - current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; - set_fs(fs); - file_end_write(file); + if (file_start_write_trylock(file)) { + /* it's been opened O_APPEND, so position is irrelevant */ + loff_t pos = 0; + __kernel_write(file, (char *)&ac, sizeof(acct_t), &pos); + file_end_write(file); + } out: + current->signal->rlim[RLIMIT_FSIZE].rlim_cur = flim; revert_creds(orig_cred); } @@ -609,34 +565,20 @@ void acct_collect(long exitcode, int group_dead) spin_unlock_irq(¤t->sighand->siglock); } -static void acct_process_in_ns(struct pid_namespace *ns) +static void slow_acct_process(struct pid_namespace *ns) { - struct file *file = NULL; - struct bsd_acct_struct *acct; - - acct = ns->bacct; - /* - * accelerate the common fastpath: - */ - if (!acct || !acct->file) - return; - - spin_lock(&acct_lock); - file = acct->file; - if (unlikely(!file)) { - spin_unlock(&acct_lock); - return; + for ( ; ns; ns = ns->parent) { + struct bsd_acct_struct *acct = acct_get(ns); + if (acct) { + do_acct_process(acct); + mutex_unlock(&acct->lock); + pin_put(&acct->pin); + } } - get_file(file); - spin_unlock(&acct_lock); - - do_acct_process(acct, ns, file); - fput(file); } /** - * acct_process - now just a wrapper around acct_process_in_ns, - * which in turn is a wrapper around do_acct_process. + * acct_process * * handles process accounting for an exiting task */ @@ -649,6 +591,10 @@ void acct_process(void) * alive and holds its namespace, which in turn holds * its parent. */ - for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) - acct_process_in_ns(ns); + for (ns = task_active_pid_ns(current); ns != NULL; ns = ns->parent) { + if (ns->bacct) + break; + } + if (unlikely(ns)) + slow_acct_process(ns); } diff --git a/mm/filemap.c b/mm/filemap.c index f501b56..90effcd 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2602,7 +2602,7 @@ ssize_t __generic_file_write_iter(struct kiocb *iocb, struct iov_iter *from) * that this differs from normal direct-io semantics, which * will return -EFOO even if some bytes were written. */ - if (unlikely(status < 0) && !written) { + if (unlikely(status < 0)) { err = status; goto out; } diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 7b5dbd1..ab88dc0 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -310,7 +310,7 @@ void iov_iter_init(struct iov_iter *i, int direction, EXPORT_SYMBOL(iov_iter_init); static ssize_t get_pages_iovec(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, unsigned maxpages, size_t *start) { size_t offset = i->iov_offset; @@ -323,10 +323,10 @@ static ssize_t get_pages_iovec(struct iov_iter *i, len = iov->iov_len - offset; if (len > i->count) len = i->count; - if (len > maxsize) - len = maxsize; addr = (unsigned long)iov->iov_base + offset; len += *start = addr & (PAGE_SIZE - 1); + if (len > maxpages * PAGE_SIZE) + len = maxpages * PAGE_SIZE; addr &= ~(PAGE_SIZE - 1); n = (len + PAGE_SIZE - 1) / PAGE_SIZE; res = get_user_pages_fast(addr, n, (i->type & WRITE) != WRITE, pages); @@ -588,15 +588,14 @@ static unsigned long alignment_bvec(const struct iov_iter *i) } static ssize_t get_pages_bvec(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, unsigned maxpages, size_t *start) { const struct bio_vec *bvec = i->bvec; size_t len = bvec->bv_len - i->iov_offset; if (len > i->count) len = i->count; - if (len > maxsize) - len = maxsize; + /* can't be more than PAGE_SIZE */ *start = bvec->bv_offset + i->iov_offset; get_page(*pages = bvec->bv_page); @@ -712,13 +711,13 @@ unsigned long iov_iter_alignment(const struct iov_iter *i) EXPORT_SYMBOL(iov_iter_alignment); ssize_t iov_iter_get_pages(struct iov_iter *i, - struct page **pages, size_t maxsize, + struct page **pages, unsigned maxpages, size_t *start) { if (i->type & ITER_BVEC) - return get_pages_bvec(i, pages, maxsize, start); + return get_pages_bvec(i, pages, maxpages, start); else - return get_pages_iovec(i, pages, maxsize, start); + return get_pages_iovec(i, pages, maxpages, start); } EXPORT_SYMBOL(iov_iter_get_pages); @@ -2323,17 +2323,45 @@ static int shmem_rmdir(struct inode *dir, struct dentry *dentry) return shmem_unlink(dir, dentry); } +static int shmem_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) +{ + bool old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode); + bool new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode); + + if (old_dir != new_dir && old_is_dir != new_is_dir) { + if (old_is_dir) { + drop_nlink(old_dir); + inc_nlink(new_dir); + } else { + drop_nlink(new_dir); + inc_nlink(old_dir); + } + } + old_dir->i_ctime = old_dir->i_mtime = + new_dir->i_ctime = new_dir->i_mtime = + old_dentry->d_inode->i_ctime = + new_dentry->d_inode->i_ctime = CURRENT_TIME; + + return 0; +} + /* * The VFS layer already does all the dentry stuff for rename, * we just have to decrement the usage count for the target if * it exists so that the VFS layer correctly free's it when it * gets overwritten. */ -static int shmem_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) +static int shmem_rename2(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry, unsigned int flags) { struct inode *inode = old_dentry->d_inode; int they_are_dirs = S_ISDIR(inode->i_mode); + if (flags & ~(RENAME_NOREPLACE | RENAME_EXCHANGE)) + return -EINVAL; + + if (flags & RENAME_EXCHANGE) + return shmem_exchange(old_dir, old_dentry, new_dir, new_dentry); + if (!simple_empty(new_dentry)) return -ENOTEMPTY; @@ -3087,7 +3115,7 @@ static const struct inode_operations shmem_dir_inode_operations = { .mkdir = shmem_mkdir, .rmdir = shmem_rmdir, .mknod = shmem_mknod, - .rename = shmem_rename, + .rename2 = shmem_rename2, .tmpfile = shmem_tmpfile, #endif #ifdef CONFIG_TMPFS_XATTR |
