diff options
| -rw-r--r-- | fs/kernfs/dir.c | 2 | ||||
| -rw-r--r-- | fs/kernfs/file.c | 51 | ||||
| -rw-r--r-- | fs/kernfs/kernfs-internal.h | 2 | ||||
| -rw-r--r-- | include/linux/kernfs.h | 10 |
4 files changed, 57 insertions, 8 deletions
diff --git a/fs/kernfs/dir.c b/fs/kernfs/dir.c index cf4c636ff4da..0b9d23bcceb5 100644 --- a/fs/kernfs/dir.c +++ b/fs/kernfs/dir.c @@ -468,7 +468,7 @@ static void kernfs_drain(struct kernfs_node *kn) rwsem_release(&kn->dep_map, 1, _RET_IP_); } - kernfs_unmap_bin_file(kn); + kernfs_drain_open_files(kn); mutex_lock(&kernfs_mutex); } diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index d0b6fb13ead0..20c396291ac1 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -708,7 +708,8 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) if (error) goto err_free; - ((struct seq_file *)file->private_data)->private = of; + of->seq_file = file->private_data; + of->seq_file->private = of; /* seq_file clears PWRITE unconditionally, restore it if WRITE */ if (file->f_mode & FMODE_WRITE) @@ -717,13 +718,22 @@ static int kernfs_fop_open(struct inode *inode, struct file *file) /* make sure we have open node struct */ error = kernfs_get_open_node(kn, of); if (error) - goto err_close; + goto err_seq_release; + + if (ops->open) { + /* nobody has access to @of yet, skip @of->mutex */ + error = ops->open(of); + if (error) + goto err_put_node; + } /* open succeeded, put active references */ kernfs_put_active(kn); return 0; -err_close: +err_put_node: + kernfs_put_open_node(kn, of); +err_seq_release: seq_release(inode, file); err_free: kfree(of->prealloc_buf); @@ -733,11 +743,32 @@ err_out: return error; } +/* used from release/drain to ensure that ->release() is called exactly once */ +static void kernfs_release_file(struct kernfs_node *kn, + struct kernfs_open_file *of) +{ + if (!(kn->flags & KERNFS_HAS_RELEASE)) + return; + + mutex_lock(&of->mutex); + if (!of->released) { + /* + * A file is never detached without being released and we + * need to be able to release files which are deactivated + * and being drained. Don't use kernfs_ops(). + */ + kn->attr.ops->release(of); + of->released = true; + } + mutex_unlock(&of->mutex); +} + static int kernfs_fop_release(struct inode *inode, struct file *filp) { struct kernfs_node *kn = filp->f_path.dentry->d_fsdata; struct kernfs_open_file *of = kernfs_of(filp); + kernfs_release_file(kn, of); kernfs_put_open_node(kn, of); seq_release(inode, filp); kfree(of->prealloc_buf); @@ -746,12 +777,12 @@ static int kernfs_fop_release(struct inode *inode, struct file *filp) return 0; } -void kernfs_unmap_bin_file(struct kernfs_node *kn) +void kernfs_drain_open_files(struct kernfs_node *kn) { struct kernfs_open_node *on; struct kernfs_open_file *of; - if (!(kn->flags & KERNFS_HAS_MMAP)) + if (!(kn->flags & (KERNFS_HAS_MMAP | KERNFS_HAS_RELEASE))) return; spin_lock_irq(&kernfs_open_node_lock); @@ -763,10 +794,16 @@ void kernfs_unmap_bin_file(struct kernfs_node *kn) return; mutex_lock(&kernfs_open_file_mutex); + list_for_each_entry(of, &on->files, list) { struct inode *inode = file_inode(of->file); - unmap_mapping_range(inode->i_mapping, 0, 0, 1); + + if (kn->flags & KERNFS_HAS_MMAP) + unmap_mapping_range(inode->i_mapping, 0, 0, 1); + + kernfs_release_file(kn, of); } + mutex_unlock(&kernfs_open_file_mutex); kernfs_put_open_node(kn, NULL); @@ -965,6 +1002,8 @@ struct kernfs_node *__kernfs_create_file(struct kernfs_node *parent, kn->flags |= KERNFS_HAS_SEQ_SHOW; if (ops->mmap) kn->flags |= KERNFS_HAS_MMAP; + if (ops->release) + kn->flags |= KERNFS_HAS_RELEASE; rc = kernfs_add_one(kn); if (rc) { diff --git a/fs/kernfs/kernfs-internal.h b/fs/kernfs/kernfs-internal.h index bfd551bbf231..3100987cf8ba 100644 --- a/fs/kernfs/kernfs-internal.h +++ b/fs/kernfs/kernfs-internal.h @@ -104,7 +104,7 @@ struct kernfs_node *kernfs_new_node(struct kernfs_node *parent, */ extern const struct file_operations kernfs_file_fops; -void kernfs_unmap_bin_file(struct kernfs_node *kn); +void kernfs_drain_open_files(struct kernfs_node *kn); /* * symlink.c diff --git a/include/linux/kernfs.h b/include/linux/kernfs.h index afd4e5abc4fb..a9b11b8d06f2 100644 --- a/include/linux/kernfs.h +++ b/include/linux/kernfs.h @@ -46,6 +46,7 @@ enum kernfs_node_flag { KERNFS_SUICIDAL = 0x0400, KERNFS_SUICIDED = 0x0800, KERNFS_EMPTY_DIR = 0x1000, + KERNFS_HAS_RELEASE = 0x2000, }; /* @flags for kernfs_create_root() */ @@ -175,6 +176,7 @@ struct kernfs_open_file { /* published fields */ struct kernfs_node *kn; struct file *file; + struct seq_file *seq_file; void *priv; /* private fields, do not use outside kernfs proper */ @@ -186,11 +188,19 @@ struct kernfs_open_file { size_t atomic_write_len; bool mmapped:1; + bool released:1; const struct vm_operations_struct *vm_ops; }; struct kernfs_ops { /* + * Optional open/release methods. Both are called with + * @of->seq_file populated. + */ + int (*open)(struct kernfs_open_file *of); + void (*release)(struct kernfs_open_file *of); + + /* * Read is handled by either seq_file or raw_read(). * * If seq_show() is present, seq_file path is active. Other seq |