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authorTejun Heo <tj@kernel.org>2013-10-01 17:42:07 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2013-10-05 17:27:40 -0700
commit73d9714627adced2942e8d53ce0e73d9699a996c (patch)
treebd144cf3a7871240386c70fae6c4492f3331c093 /fs/sysfs
parent2f0c6b7593a590eef7fa35344da57380fcee7581 (diff)
sysfs: copy bin mmap support from fs/sysfs/bin.c to fs/sysfs/file.c
sysfs bin file handling will be merged into the regular file support. This patch copies mmap support from bin so that fs/sysfs/file.c can handle mmapping bin files. The code is copied mostly verbatim with the following updates. * ->mmapped and ->vm_ops are added to sysfs_open_file and bin_buffer references are replaced with sysfs_open_file ones. * Symbols are prefixed with sysfs_. * sysfs_unmap_bin_file() grabs sysfs_open_dirent and traverses ->files. Invocation of this function is added to sysfs_addrm_finish(). * sysfs_bin_mmap() is added to sysfs_bin_operations. This is a preparation and the new mmap path isn't used yet. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/sysfs')
-rw-r--r--fs/sysfs/dir.c1
-rw-r--r--fs/sysfs/file.c247
-rw-r--r--fs/sysfs/sysfs.h2
3 files changed, 249 insertions, 1 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index b518afd0d11..c4040ddb830 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -595,6 +595,7 @@ void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
acxt->removed = sd->u.removed_list;
sysfs_deactivate(sd);
+ sysfs_unmap_bin_file(sd);
unmap_bin_file(sd);
sysfs_put(sd);
}
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 9ba492a3d93..02797a134cf 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -22,6 +22,7 @@
#include <linux/limits.h>
#include <linux/uaccess.h>
#include <linux/seq_file.h>
+#include <linux/mm.h>
#include "sysfs.h"
@@ -52,6 +53,9 @@ struct sysfs_open_file {
struct mutex mutex;
int event;
struct list_head list;
+
+ bool mmapped;
+ const struct vm_operations_struct *vm_ops;
};
static bool sysfs_is_bin(struct sysfs_dirent *sd)
@@ -301,6 +305,218 @@ out_free:
return len;
}
+static void sysfs_bin_vma_open(struct vm_area_struct *vma)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+
+ if (!of->vm_ops)
+ return;
+
+ if (!sysfs_get_active(of->sd))
+ return;
+
+ if (of->vm_ops->open)
+ of->vm_ops->open(vma);
+
+ sysfs_put_active(of->sd);
+}
+
+static int sysfs_bin_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ int ret;
+
+ if (!of->vm_ops)
+ return VM_FAULT_SIGBUS;
+
+ if (!sysfs_get_active(of->sd))
+ return VM_FAULT_SIGBUS;
+
+ ret = VM_FAULT_SIGBUS;
+ if (of->vm_ops->fault)
+ ret = of->vm_ops->fault(vma, vmf);
+
+ sysfs_put_active(of->sd);
+ return ret;
+}
+
+static int sysfs_bin_page_mkwrite(struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ int ret;
+
+ if (!of->vm_ops)
+ return VM_FAULT_SIGBUS;
+
+ if (!sysfs_get_active(of->sd))
+ return VM_FAULT_SIGBUS;
+
+ ret = 0;
+ if (of->vm_ops->page_mkwrite)
+ ret = of->vm_ops->page_mkwrite(vma, vmf);
+ else
+ file_update_time(file);
+
+ sysfs_put_active(of->sd);
+ return ret;
+}
+
+static int sysfs_bin_access(struct vm_area_struct *vma, unsigned long addr,
+ void *buf, int len, int write)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ int ret;
+
+ if (!of->vm_ops)
+ return -EINVAL;
+
+ if (!sysfs_get_active(of->sd))
+ return -EINVAL;
+
+ ret = -EINVAL;
+ if (of->vm_ops->access)
+ ret = of->vm_ops->access(vma, addr, buf, len, write);
+
+ sysfs_put_active(of->sd);
+ return ret;
+}
+
+#ifdef CONFIG_NUMA
+static int sysfs_bin_set_policy(struct vm_area_struct *vma,
+ struct mempolicy *new)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ int ret;
+
+ if (!of->vm_ops)
+ return 0;
+
+ if (!sysfs_get_active(of->sd))
+ return -EINVAL;
+
+ ret = 0;
+ if (of->vm_ops->set_policy)
+ ret = of->vm_ops->set_policy(vma, new);
+
+ sysfs_put_active(of->sd);
+ return ret;
+}
+
+static struct mempolicy *sysfs_bin_get_policy(struct vm_area_struct *vma,
+ unsigned long addr)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ struct mempolicy *pol;
+
+ if (!of->vm_ops)
+ return vma->vm_policy;
+
+ if (!sysfs_get_active(of->sd))
+ return vma->vm_policy;
+
+ pol = vma->vm_policy;
+ if (of->vm_ops->get_policy)
+ pol = of->vm_ops->get_policy(vma, addr);
+
+ sysfs_put_active(of->sd);
+ return pol;
+}
+
+static int sysfs_bin_migrate(struct vm_area_struct *vma, const nodemask_t *from,
+ const nodemask_t *to, unsigned long flags)
+{
+ struct file *file = vma->vm_file;
+ struct sysfs_open_file *of = sysfs_of(file);
+ int ret;
+
+ if (!of->vm_ops)
+ return 0;
+
+ if (!sysfs_get_active(of->sd))
+ return 0;
+
+ ret = 0;
+ if (of->vm_ops->migrate)
+ ret = of->vm_ops->migrate(vma, from, to, flags);
+
+ sysfs_put_active(of->sd);
+ return ret;
+}
+#endif
+
+static const struct vm_operations_struct sysfs_bin_vm_ops = {
+ .open = sysfs_bin_vma_open,
+ .fault = sysfs_bin_fault,
+ .page_mkwrite = sysfs_bin_page_mkwrite,
+ .access = sysfs_bin_access,
+#ifdef CONFIG_NUMA
+ .set_policy = sysfs_bin_set_policy,
+ .get_policy = sysfs_bin_get_policy,
+ .migrate = sysfs_bin_migrate,
+#endif
+};
+
+static int sysfs_bin_mmap(struct file *file, struct vm_area_struct *vma)
+{
+ struct sysfs_open_file *of = sysfs_of(file);
+ struct bin_attribute *battr = of->sd->s_bin_attr.bin_attr;
+ struct kobject *kobj = of->sd->s_parent->s_dir.kobj;
+ int rc;
+
+ mutex_lock(&of->mutex);
+
+ /* need of->sd for battr, its parent for kobj */
+ rc = -ENODEV;
+ if (!sysfs_get_active(of->sd))
+ goto out_unlock;
+
+ rc = -EINVAL;
+ if (!battr->mmap)
+ goto out_put;
+
+ rc = battr->mmap(file, kobj, battr, vma);
+ if (rc)
+ goto out_put;
+
+ /*
+ * PowerPC's pci_mmap of legacy_mem uses shmem_zero_setup()
+ * to satisfy versions of X which crash if the mmap fails: that
+ * substitutes a new vm_file, and we don't then want bin_vm_ops.
+ */
+ if (vma->vm_file != file)
+ goto out_put;
+
+ rc = -EINVAL;
+ if (of->mmapped && of->vm_ops != vma->vm_ops)
+ goto out_put;
+
+ /*
+ * It is not possible to successfully wrap close.
+ * So error if someone is trying to use close.
+ */
+ rc = -EINVAL;
+ if (vma->vm_ops && vma->vm_ops->close)
+ goto out_put;
+
+ rc = 0;
+ of->mmapped = 1;
+ of->vm_ops = vma->vm_ops;
+ vma->vm_ops = &sysfs_bin_vm_ops;
+out_put:
+ sysfs_put_active(of->sd);
+out_unlock:
+ mutex_unlock(&of->mutex);
+
+ return rc;
+}
+
/**
* sysfs_get_open_dirent - get or create sysfs_open_dirent
* @sd: target sysfs_dirent
@@ -375,7 +591,9 @@ static void sysfs_put_open_dirent(struct sysfs_dirent *sd,
mutex_lock(&sysfs_open_file_mutex);
spin_lock_irqsave(&sysfs_open_dirent_lock, flags);
- list_del(&of->list);
+ if (of)
+ list_del(&of->list);
+
if (atomic_dec_and_test(&od->refcnt))
sd->s_attr.open = NULL;
else
@@ -477,6 +695,32 @@ static int sysfs_release(struct inode *inode, struct file *filp)
return 0;
}
+void sysfs_unmap_bin_file(struct sysfs_dirent *sd)
+{
+ struct sysfs_open_dirent *od;
+ struct sysfs_open_file *of;
+
+ if (!sysfs_is_bin(sd))
+ return;
+
+ spin_lock_irq(&sysfs_open_dirent_lock);
+ od = sd->s_attr.open;
+ if (od)
+ atomic_inc(&od->refcnt);
+ spin_unlock_irq(&sysfs_open_dirent_lock);
+ if (!od)
+ return;
+
+ mutex_lock(&sysfs_open_file_mutex);
+ list_for_each_entry(of, &od->files, list) {
+ struct inode *inode = file_inode(of->file);
+ unmap_mapping_range(inode->i_mapping, 0, 0, 1);
+ }
+ mutex_unlock(&sysfs_open_file_mutex);
+
+ sysfs_put_open_dirent(sd, NULL);
+}
+
/* Sysfs attribute files are pollable. The idea is that you read
* the content and then you use 'poll' or 'select' to wait for
* the content to change. When the content changes (assuming the
@@ -562,6 +806,7 @@ const struct file_operations sysfs_bin_operations = {
.read = sysfs_bin_read,
.write = sysfs_write_file,
.llseek = generic_file_llseek,
+ .mmap = sysfs_bin_mmap,
};
int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h
index f103bac53df..c960d6272cf 100644
--- a/fs/sysfs/sysfs.h
+++ b/fs/sysfs/sysfs.h
@@ -220,6 +220,8 @@ int sysfs_add_file(struct sysfs_dirent *dir_sd,
int sysfs_add_file_mode_ns(struct sysfs_dirent *dir_sd,
const struct attribute *attr, int type,
umode_t amode, const void *ns);
+void sysfs_unmap_bin_file(struct sysfs_dirent *sd);
+
/*
* bin.c
*/