fs: introduce f_op->mmap_capabilities for nommu mmap support

Since "BDI: Provide backing device capability information [try #3]" the
backing_dev_info structure also provides flags for the kind of mmap
operation available in a nommu environment, which is entirely unrelated
to it's original purpose.

Introduce a new nommu-only file operation to provide this information to
the nommu mmap code instead.  Splitting this from the backing_dev_info
structure allows to remove lots of backing_dev_info instance that aren't
otherwise needed, and entirely gets rid of the concept of providing a
backing_dev_info for a character device.  It also removes the need for
the mtd_inodefs filesystem.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Tejun Heo <tj@kernel.org>
Acked-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2015-01-14 10:42:32 +01:00 committed by Jens Axboe
parent 97b713ba3e
commit b4caecd480
32 changed files with 169 additions and 346 deletions

View file

@ -43,12 +43,12 @@ and it's also much more restricted in the latter case:
even if this was created by another process.
- If possible, the file mapping will be directly on the backing device
if the backing device has the BDI_CAP_MAP_DIRECT capability and
if the backing device has the NOMMU_MAP_DIRECT capability and
appropriate mapping protection capabilities. Ramfs, romfs, cramfs
and mtd might all permit this.
- If the backing device device can't or won't permit direct sharing,
but does have the BDI_CAP_MAP_COPY capability, then a copy of the
but does have the NOMMU_MAP_COPY capability, then a copy of the
appropriate bit of the file will be read into a contiguous bit of
memory and any extraneous space beyond the EOF will be cleared
@ -220,7 +220,7 @@ directly (can't be copied).
The file->f_op->mmap() operation will be called to actually inaugurate the
mapping. It can be rejected at that point. Returning the ENOSYS error will
cause the mapping to be copied instead if BDI_CAP_MAP_COPY is specified.
cause the mapping to be copied instead if NOMMU_MAP_COPY is specified.
The vm_ops->close() routine will be invoked when the last mapping on a chardev
is removed. An existing mapping will be shared, partially or not, if possible
@ -232,7 +232,7 @@ want to handle it, despite the fact it's got an operation. For instance, it
might try directing the call to a secondary driver which turns out not to
implement it. Such is the case for the framebuffer driver which attempts to
direct the call to the device-specific driver. Under such circumstances, the
mapping request will be rejected if BDI_CAP_MAP_COPY is not specified, and a
mapping request will be rejected if NOMMU_MAP_COPY is not specified, and a
copy mapped otherwise.
IMPORTANT NOTE:

View file

@ -607,7 +607,7 @@ struct request_queue *blk_alloc_queue_node(gfp_t gfp_mask, int node_id)
q->backing_dev_info.ra_pages =
(VM_MAX_READAHEAD * 1024) / PAGE_CACHE_SIZE;
q->backing_dev_info.state = 0;
q->backing_dev_info.capabilities = BDI_CAP_MAP_COPY;
q->backing_dev_info.capabilities = 0;
q->backing_dev_info.name = "block";
q->node = node_id;

View file

@ -287,13 +287,24 @@ static unsigned long get_unmapped_area_mem(struct file *file,
return pgoff << PAGE_SHIFT;
}
/* permit direct mmap, for read, write or exec */
static unsigned memory_mmap_capabilities(struct file *file)
{
return NOMMU_MAP_DIRECT |
NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC;
}
static unsigned zero_mmap_capabilities(struct file *file)
{
return NOMMU_MAP_COPY;
}
/* can't do an in-place private mapping if there's no MMU */
static inline int private_mapping_ok(struct vm_area_struct *vma)
{
return vma->vm_flags & VM_MAYSHARE;
}
#else
#define get_unmapped_area_mem NULL
static inline int private_mapping_ok(struct vm_area_struct *vma)
{
@ -721,7 +732,10 @@ static const struct file_operations mem_fops = {
.write = write_mem,
.mmap = mmap_mem,
.open = open_mem,
#ifndef CONFIG_MMU
.get_unmapped_area = get_unmapped_area_mem,
.mmap_capabilities = memory_mmap_capabilities,
#endif
};
#ifdef CONFIG_DEVKMEM
@ -731,7 +745,10 @@ static const struct file_operations kmem_fops = {
.write = write_kmem,
.mmap = mmap_kmem,
.open = open_kmem,
#ifndef CONFIG_MMU
.get_unmapped_area = get_unmapped_area_mem,
.mmap_capabilities = memory_mmap_capabilities,
#endif
};
#endif
@ -760,16 +777,9 @@ static const struct file_operations zero_fops = {
.read_iter = read_iter_zero,
.aio_write = aio_write_zero,
.mmap = mmap_zero,
};
/*
* capabilities for /dev/zero
* - permits private mappings, "copies" are taken of the source of zeros
* - no writeback happens
*/
static struct backing_dev_info zero_bdi = {
.name = "char/mem",
.capabilities = BDI_CAP_MAP_COPY | BDI_CAP_NO_ACCT_AND_WRITEBACK,
#ifndef CONFIG_MMU
.mmap_capabilities = zero_mmap_capabilities,
#endif
};
static const struct file_operations full_fops = {
@ -783,22 +793,22 @@ static const struct memdev {
const char *name;
umode_t mode;
const struct file_operations *fops;
struct backing_dev_info *dev_info;
fmode_t fmode;
} devlist[] = {
[1] = { "mem", 0, &mem_fops, &directly_mappable_cdev_bdi },
[1] = { "mem", 0, &mem_fops, FMODE_UNSIGNED_OFFSET },
#ifdef CONFIG_DEVKMEM
[2] = { "kmem", 0, &kmem_fops, &directly_mappable_cdev_bdi },
[2] = { "kmem", 0, &kmem_fops, FMODE_UNSIGNED_OFFSET },
#endif
[3] = { "null", 0666, &null_fops, NULL },
[3] = { "null", 0666, &null_fops, 0 },
#ifdef CONFIG_DEVPORT
[4] = { "port", 0, &port_fops, NULL },
[4] = { "port", 0, &port_fops, 0 },
#endif
[5] = { "zero", 0666, &zero_fops, &zero_bdi },
[7] = { "full", 0666, &full_fops, NULL },
[8] = { "random", 0666, &random_fops, NULL },
[9] = { "urandom", 0666, &urandom_fops, NULL },
[5] = { "zero", 0666, &zero_fops, 0 },
[7] = { "full", 0666, &full_fops, 0 },
[8] = { "random", 0666, &random_fops, 0 },
[9] = { "urandom", 0666, &urandom_fops, 0 },
#ifdef CONFIG_PRINTK
[11] = { "kmsg", 0644, &kmsg_fops, NULL },
[11] = { "kmsg", 0644, &kmsg_fops, 0 },
#endif
};
@ -816,12 +826,7 @@ static int memory_open(struct inode *inode, struct file *filp)
return -ENXIO;
filp->f_op = dev->fops;
if (dev->dev_info)
filp->f_mapping->backing_dev_info = dev->dev_info;
/* Is /dev/mem or /dev/kmem ? */
if (dev->dev_info == &directly_mappable_cdev_bdi)
filp->f_mode |= FMODE_UNSIGNED_OFFSET;
filp->f_mode |= dev->fmode;
if (dev->fops->open)
return dev->fops->open(inode, filp);
@ -846,11 +851,6 @@ static struct class *mem_class;
static int __init chr_dev_init(void)
{
int minor;
int err;
err = bdi_init(&zero_bdi);
if (err)
return err;
if (register_chrdev(MEM_MAJOR, "mem", &memory_fops))
printk("unable to get major %d for memory devs\n", MEM_MAJOR);

View file

@ -49,7 +49,6 @@ static DEFINE_MUTEX(mtd_mutex);
*/
struct mtd_file_info {
struct mtd_info *mtd;
struct inode *ino;
enum mtd_file_modes mode;
};
@ -59,10 +58,6 @@ static loff_t mtdchar_lseek(struct file *file, loff_t offset, int orig)
return fixed_size_llseek(file, offset, orig, mfi->mtd->size);
}
static int count;
static struct vfsmount *mnt;
static struct file_system_type mtd_inodefs_type;
static int mtdchar_open(struct inode *inode, struct file *file)
{
int minor = iminor(inode);
@ -70,7 +65,6 @@ static int mtdchar_open(struct inode *inode, struct file *file)
int ret = 0;
struct mtd_info *mtd;
struct mtd_file_info *mfi;
struct inode *mtd_ino;
pr_debug("MTD_open\n");
@ -78,10 +72,6 @@ static int mtdchar_open(struct inode *inode, struct file *file)
if ((file->f_mode & FMODE_WRITE) && (minor & 1))
return -EACCES;
ret = simple_pin_fs(&mtd_inodefs_type, &mnt, &count);
if (ret)
return ret;
mutex_lock(&mtd_mutex);
mtd = get_mtd_device(NULL, devnum);
@ -95,43 +85,26 @@ static int mtdchar_open(struct inode *inode, struct file *file)
goto out1;
}
mtd_ino = iget_locked(mnt->mnt_sb, devnum);
if (!mtd_ino) {
ret = -ENOMEM;
goto out1;
}
if (mtd_ino->i_state & I_NEW) {
mtd_ino->i_private = mtd;
mtd_ino->i_mode = S_IFCHR;
mtd_ino->i_data.backing_dev_info = mtd->backing_dev_info;
unlock_new_inode(mtd_ino);
}
file->f_mapping = mtd_ino->i_mapping;
/* You can't open it RW if it's not a writeable device */
if ((file->f_mode & FMODE_WRITE) && !(mtd->flags & MTD_WRITEABLE)) {
ret = -EACCES;
goto out2;
goto out1;
}
mfi = kzalloc(sizeof(*mfi), GFP_KERNEL);
if (!mfi) {
ret = -ENOMEM;
goto out2;
goto out1;
}
mfi->ino = mtd_ino;
mfi->mtd = mtd;
file->private_data = mfi;
mutex_unlock(&mtd_mutex);
return 0;
out2:
iput(mtd_ino);
out1:
put_mtd_device(mtd);
out:
mutex_unlock(&mtd_mutex);
simple_release_fs(&mnt, &count);
return ret;
} /* mtdchar_open */
@ -148,12 +121,9 @@ static int mtdchar_close(struct inode *inode, struct file *file)
if ((file->f_mode & FMODE_WRITE))
mtd_sync(mtd);
iput(mfi->ino);
put_mtd_device(mtd);
file->private_data = NULL;
kfree(mfi);
simple_release_fs(&mnt, &count);
return 0;
} /* mtdchar_close */
@ -1117,6 +1087,13 @@ static unsigned long mtdchar_get_unmapped_area(struct file *file,
ret = mtd_get_unmapped_area(mtd, len, offset, flags);
return ret == -EOPNOTSUPP ? -ENODEV : ret;
}
static unsigned mtdchar_mmap_capabilities(struct file *file)
{
struct mtd_file_info *mfi = file->private_data;
return mtd_mmap_capabilities(mfi->mtd);
}
#endif
/*
@ -1160,27 +1137,10 @@ static const struct file_operations mtd_fops = {
.mmap = mtdchar_mmap,
#ifndef CONFIG_MMU
.get_unmapped_area = mtdchar_get_unmapped_area,
.mmap_capabilities = mtdchar_mmap_capabilities,
#endif
};
static const struct super_operations mtd_ops = {
.drop_inode = generic_delete_inode,
.statfs = simple_statfs,
};
static struct dentry *mtd_inodefs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
return mount_pseudo(fs_type, "mtd_inode:", &mtd_ops, NULL, MTD_INODE_FS_MAGIC);
}
static struct file_system_type mtd_inodefs_type = {
.name = "mtd_inodefs",
.mount = mtd_inodefs_mount,
.kill_sb = kill_anon_super,
};
MODULE_ALIAS_FS("mtd_inodefs");
int __init init_mtdchar(void)
{
int ret;
@ -1193,23 +1153,11 @@ int __init init_mtdchar(void)
return ret;
}
ret = register_filesystem(&mtd_inodefs_type);
if (ret) {
pr_err("Can't register mtd_inodefs filesystem, error %d\n",
ret);
goto err_unregister_chdev;
}
return ret;
err_unregister_chdev:
__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
return ret;
}
void __exit cleanup_mtdchar(void)
{
unregister_filesystem(&mtd_inodefs_type);
__unregister_chrdev(MTD_CHAR_MAJOR, 0, 1 << MINORBITS, "mtd");
}

View file

@ -732,8 +732,6 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c
concat->mtd.ecc_stats.badblocks = subdev[0]->ecc_stats.badblocks;
concat->mtd.backing_dev_info = subdev[0]->backing_dev_info;
concat->subdev[0] = subdev[0];
for (i = 1; i < num_devs; i++) {
@ -761,14 +759,6 @@ struct mtd_info *mtd_concat_create(struct mtd_info *subdev[], /* subdevices to c
subdev[i]->flags & MTD_WRITEABLE;
}
/* only permit direct mapping if the BDIs are all the same
* - copy-mapping is still permitted
*/
if (concat->mtd.backing_dev_info !=
subdev[i]->backing_dev_info)
concat->mtd.backing_dev_info =
&default_backing_dev_info;
concat->mtd.size += subdev[i]->size;
concat->mtd.ecc_stats.badblocks +=
subdev[i]->ecc_stats.badblocks;

View file

@ -43,33 +43,7 @@
#include "mtdcore.h"
/*
* backing device capabilities for non-mappable devices (such as NAND flash)
* - permits private mappings, copies are taken of the data
*/
static struct backing_dev_info mtd_bdi_unmappable = {
.capabilities = BDI_CAP_MAP_COPY,
};
/*
* backing device capabilities for R/O mappable devices (such as ROM)
* - permits private mappings, copies are taken of the data
* - permits non-writable shared mappings
*/
static struct backing_dev_info mtd_bdi_ro_mappable = {
.capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP),
};
/*
* backing device capabilities for writable mappable devices (such as RAM)
* - permits private mappings, copies are taken of the data
* - permits non-writable shared mappings
*/
static struct backing_dev_info mtd_bdi_rw_mappable = {
.capabilities = (BDI_CAP_MAP_COPY | BDI_CAP_MAP_DIRECT |
BDI_CAP_EXEC_MAP | BDI_CAP_READ_MAP |
BDI_CAP_WRITE_MAP),
static struct backing_dev_info mtd_bdi = {
};
static int mtd_cls_suspend(struct device *dev, pm_message_t state);
@ -365,6 +339,22 @@ static struct device_type mtd_devtype = {
.release = mtd_release,
};
#ifndef CONFIG_MMU
unsigned mtd_mmap_capabilities(struct mtd_info *mtd)
{
switch (mtd->type) {
case MTD_RAM:
return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
NOMMU_MAP_READ | NOMMU_MAP_WRITE;
case MTD_ROM:
return NOMMU_MAP_COPY | NOMMU_MAP_DIRECT | NOMMU_MAP_EXEC |
NOMMU_MAP_READ;
default:
return NOMMU_MAP_COPY;
}
}
#endif
/**
* add_mtd_device - register an MTD device
* @mtd: pointer to new MTD device info structure
@ -380,19 +370,7 @@ int add_mtd_device(struct mtd_info *mtd)
struct mtd_notifier *not;
int i, error;
if (!mtd->backing_dev_info) {
switch (mtd->type) {
case MTD_RAM:
mtd->backing_dev_info = &mtd_bdi_rw_mappable;
break;
case MTD_ROM:
mtd->backing_dev_info = &mtd_bdi_ro_mappable;
break;
default:
mtd->backing_dev_info = &mtd_bdi_unmappable;
break;
}
}
mtd->backing_dev_info = &mtd_bdi;
BUG_ON(mtd->writesize == 0);
mutex_lock(&mtd_table_mutex);
@ -1237,17 +1215,9 @@ static int __init init_mtd(void)
if (ret)
goto err_reg;
ret = mtd_bdi_init(&mtd_bdi_unmappable, "mtd-unmap");
ret = mtd_bdi_init(&mtd_bdi, "mtd");
if (ret)
goto err_bdi1;
ret = mtd_bdi_init(&mtd_bdi_ro_mappable, "mtd-romap");
if (ret)
goto err_bdi2;
ret = mtd_bdi_init(&mtd_bdi_rw_mappable, "mtd-rwmap");
if (ret)
goto err_bdi3;
goto err_bdi;
proc_mtd = proc_create("mtd", 0, NULL, &mtd_proc_ops);
@ -1260,11 +1230,7 @@ static int __init init_mtd(void)
out_procfs:
if (proc_mtd)
remove_proc_entry("mtd", NULL);
err_bdi3:
bdi_destroy(&mtd_bdi_ro_mappable);
err_bdi2:
bdi_destroy(&mtd_bdi_unmappable);
err_bdi1:
err_bdi:
class_unregister(&mtd_class);
err_reg:
pr_err("Error registering mtd class or bdi: %d\n", ret);
@ -1277,9 +1243,7 @@ static void __exit cleanup_mtd(void)
if (proc_mtd)
remove_proc_entry("mtd", NULL);
class_unregister(&mtd_class);
bdi_destroy(&mtd_bdi_unmappable);
bdi_destroy(&mtd_bdi_ro_mappable);
bdi_destroy(&mtd_bdi_rw_mappable);
bdi_destroy(&mtd_bdi);
}
module_init(init_mtd);

View file

@ -378,7 +378,6 @@ static struct mtd_part *allocate_partition(struct mtd_info *master,
slave->mtd.name = name;
slave->mtd.owner = master->owner;
slave->mtd.backing_dev_info = master->backing_dev_info;
/* NOTE: we don't arrange MTDs as a tree; it'd be error-prone
* to have the same data be in two different partitions.

View file

@ -987,7 +987,7 @@ int ll_fill_super(struct super_block *sb, struct vfsmount *mnt)
if (err)
goto out_free;
lsi->lsi_flags |= LSI_BDI_INITIALIZED;
lsi->lsi_bdi.capabilities = BDI_CAP_MAP_COPY;
lsi->lsi_bdi.capabilities = 0;
err = ll_bdi_register(&lsi->lsi_bdi);
if (err)
goto out_free;

View file

@ -335,7 +335,7 @@ struct p9_fid *v9fs_session_init(struct v9fs_session_info *v9ses,
}
init_rwsem(&v9ses->rename_sem);
rc = bdi_setup_and_register(&v9ses->bdi, "9p", BDI_CAP_MAP_COPY);
rc = bdi_setup_and_register(&v9ses->bdi, "9p");
if (rc) {
kfree(v9ses->aname);
kfree(v9ses->uname);

View file

@ -106,7 +106,7 @@ struct afs_volume *afs_volume_lookup(struct afs_mount_params *params)
volume->cell = params->cell;
volume->vid = vlocation->vldb.vid[params->type];
ret = bdi_setup_and_register(&volume->bdi, "afs", BDI_CAP_MAP_COPY);
ret = bdi_setup_and_register(&volume->bdi, "afs");
if (ret)
goto error_bdi;

View file

@ -165,15 +165,6 @@ static struct vfsmount *aio_mnt;
static const struct file_operations aio_ring_fops;
static const struct address_space_operations aio_ctx_aops;
/* Backing dev info for aio fs.
* -no dirty page accounting or writeback happens
*/
static struct backing_dev_info aio_fs_backing_dev_info = {
.name = "aiofs",
.state = 0,
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK | BDI_CAP_MAP_COPY,
};
static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
{
struct qstr this = QSTR_INIT("[aio]", 5);
@ -185,7 +176,7 @@ static struct file *aio_private_file(struct kioctx *ctx, loff_t nr_pages)
inode->i_mapping->a_ops = &aio_ctx_aops;
inode->i_mapping->private_data = ctx;
inode->i_mapping->backing_dev_info = &aio_fs_backing_dev_info;
inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
inode->i_size = PAGE_SIZE * nr_pages;
path.dentry = d_alloc_pseudo(aio_mnt->mnt_sb, &this);
@ -230,9 +221,6 @@ static int __init aio_setup(void)
if (IS_ERR(aio_mnt))
panic("Failed to create aio fs mount.");
if (bdi_init(&aio_fs_backing_dev_info))
panic("Failed to init aio fs backing dev info.");
kiocb_cachep = KMEM_CACHE(kiocb, SLAB_HWCACHE_ALIGN|SLAB_PANIC);
kioctx_cachep = KMEM_CACHE(kioctx,SLAB_HWCACHE_ALIGN|SLAB_PANIC);

View file

@ -1715,8 +1715,7 @@ static int setup_bdi(struct btrfs_fs_info *info, struct backing_dev_info *bdi)
{
int err;
bdi->capabilities = BDI_CAP_MAP_COPY;
err = bdi_setup_and_register(bdi, "btrfs", BDI_CAP_MAP_COPY);
err = bdi_setup_and_register(bdi, "btrfs");
if (err)
return err;

View file

@ -24,27 +24,6 @@
#include "internal.h"
/*
* capabilities for /dev/mem, /dev/kmem and similar directly mappable character
* devices
* - permits shared-mmap for read, write and/or exec
* - does not permit private mmap in NOMMU mode (can't do COW)
* - no readahead or I/O queue unplugging required
*/
struct backing_dev_info directly_mappable_cdev_bdi = {
.name = "char",
.capabilities = (
#ifdef CONFIG_MMU
/* permit private copies of the data to be taken */
BDI_CAP_MAP_COPY |
#endif
/* permit direct mmap, for read, write or exec */
BDI_CAP_MAP_DIRECT |
BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP |
/* no writeback happens */
BDI_CAP_NO_ACCT_AND_WRITEBACK),
};
static struct kobj_map *cdev_map;
static DEFINE_MUTEX(chrdevs_lock);
@ -575,8 +554,6 @@ static struct kobject *base_probe(dev_t dev, int *part, void *data)
void __init chrdev_init(void)
{
cdev_map = kobj_map_init(base_probe, &chrdevs_lock);
if (bdi_init(&directly_mappable_cdev_bdi))
panic("Failed to init directly mappable cdev bdi");
}
@ -590,4 +567,3 @@ EXPORT_SYMBOL(cdev_del);
EXPORT_SYMBOL(cdev_add);
EXPORT_SYMBOL(__register_chrdev);
EXPORT_SYMBOL(__unregister_chrdev);
EXPORT_SYMBOL(directly_mappable_cdev_bdi);

View file

@ -3446,7 +3446,7 @@ cifs_mount(struct cifs_sb_info *cifs_sb, struct smb_vol *volume_info)
int referral_walks_count = 0;
#endif
rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs", BDI_CAP_MAP_COPY);
rc = bdi_setup_and_register(&cifs_sb->bdi, "cifs");
if (rc)
return rc;

View file

@ -183,7 +183,7 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
goto unlock_out;
}
error = bdi_setup_and_register(&vc->bdi, "coda", BDI_CAP_MAP_COPY);
error = bdi_setup_and_register(&vc->bdi, "coda");
if (error)
goto unlock_out;

View file

@ -70,8 +70,6 @@ extern int configfs_is_root(struct config_item *item);
extern struct inode * configfs_new_inode(umode_t mode, struct configfs_dirent *, struct super_block *);
extern int configfs_create(struct dentry *, umode_t mode, int (*init)(struct inode *));
extern int configfs_inode_init(void);
extern void configfs_inode_exit(void);
extern int configfs_create_file(struct config_item *, const struct configfs_attribute *);
extern int configfs_make_dirent(struct configfs_dirent *,

View file

@ -50,12 +50,6 @@ static const struct address_space_operations configfs_aops = {
.write_end = simple_write_end,
};
static struct backing_dev_info configfs_backing_dev_info = {
.name = "configfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK,
};
static const struct inode_operations configfs_inode_operations ={
.setattr = configfs_setattr,
};
@ -137,7 +131,7 @@ struct inode *configfs_new_inode(umode_t mode, struct configfs_dirent *sd,
if (inode) {
inode->i_ino = get_next_ino();
inode->i_mapping->a_ops = &configfs_aops;
inode->i_mapping->backing_dev_info = &configfs_backing_dev_info;
inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
inode->i_op = &configfs_inode_operations;
if (sd->s_iattr) {
@ -283,13 +277,3 @@ void configfs_hash_and_remove(struct dentry * dir, const char * name)
}
mutex_unlock(&dir->d_inode->i_mutex);
}
int __init configfs_inode_init(void)
{
return bdi_init(&configfs_backing_dev_info);
}
void configfs_inode_exit(void)
{
bdi_destroy(&configfs_backing_dev_info);
}

View file

@ -145,19 +145,13 @@ static int __init configfs_init(void)
if (!config_kobj)
goto out2;
err = configfs_inode_init();
err = register_filesystem(&configfs_fs_type);
if (err)
goto out3;
err = register_filesystem(&configfs_fs_type);
if (err)
goto out4;
return 0;
out4:
pr_err("Unable to register filesystem!\n");
configfs_inode_exit();
out3:
pr_err("Unable to register filesystem!\n");
kobject_put(config_kobj);
out2:
kmem_cache_destroy(configfs_dir_cachep);
@ -172,7 +166,6 @@ static void __exit configfs_exit(void)
kobject_put(config_kobj);
kmem_cache_destroy(configfs_dir_cachep);
configfs_dir_cachep = NULL;
configfs_inode_exit();
}
MODULE_AUTHOR("Oracle");

View file

@ -520,7 +520,7 @@ static struct dentry *ecryptfs_mount(struct file_system_type *fs_type, int flags
goto out;
}
rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs", BDI_CAP_MAP_COPY);
rc = bdi_setup_and_register(&sbi->bdi, "ecryptfs");
if (rc)
goto out1;

View file

@ -836,7 +836,7 @@ static int exofs_fill_super(struct super_block *sb, void *data, int silent)
goto free_sbi;
}
ret = bdi_setup_and_register(&sbi->bdi, "exofs", BDI_CAP_MAP_COPY);
ret = bdi_setup_and_register(&sbi->bdi, "exofs");
if (ret) {
EXOFS_DBGMSG("Failed to bdi_setup_and_register\n");
dput(sb->s_root);

View file

@ -560,7 +560,7 @@ static int ncp_fill_super(struct super_block *sb, void *raw_data, int silent)
server = NCP_SBP(sb);
memset(server, 0, sizeof(*server));
error = bdi_setup_and_register(&server->bdi, "ncpfs", BDI_CAP_MAP_COPY);
error = bdi_setup_and_register(&server->bdi, "ncpfs");
if (error)
goto out_fput;

View file

@ -34,7 +34,14 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
unsigned long flags);
static int ramfs_nommu_mmap(struct file *file, struct vm_area_struct *vma);
static unsigned ramfs_mmap_capabilities(struct file *file)
{
return NOMMU_MAP_DIRECT | NOMMU_MAP_COPY | NOMMU_MAP_READ |
NOMMU_MAP_WRITE | NOMMU_MAP_EXEC;
}
const struct file_operations ramfs_file_operations = {
.mmap_capabilities = ramfs_mmap_capabilities,
.mmap = ramfs_nommu_mmap,
.get_unmapped_area = ramfs_nommu_get_unmapped_area,
.read = new_sync_read,

View file

@ -50,14 +50,6 @@ static const struct address_space_operations ramfs_aops = {
.set_page_dirty = __set_page_dirty_no_writeback,
};
static struct backing_dev_info ramfs_backing_dev_info = {
.name = "ramfs",
.ra_pages = 0, /* No readahead */
.capabilities = BDI_CAP_NO_ACCT_AND_WRITEBACK |
BDI_CAP_MAP_DIRECT | BDI_CAP_MAP_COPY |
BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP,
};
struct inode *ramfs_get_inode(struct super_block *sb,
const struct inode *dir, umode_t mode, dev_t dev)
{
@ -67,7 +59,7 @@ struct inode *ramfs_get_inode(struct super_block *sb,
inode->i_ino = get_next_ino();
inode_init_owner(inode, dir, mode);
inode->i_mapping->a_ops = &ramfs_aops;
inode->i_mapping->backing_dev_info = &ramfs_backing_dev_info;
inode->i_mapping->backing_dev_info = &noop_backing_dev_info;
mapping_set_gfp_mask(inode->i_mapping, GFP_HIGHUSER);
mapping_set_unevictable(inode->i_mapping);
inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
@ -267,19 +259,9 @@ static struct file_system_type ramfs_fs_type = {
int __init init_ramfs_fs(void)
{
static unsigned long once;
int err;
if (test_and_set_bit(0, &once))
return 0;
err = bdi_init(&ramfs_backing_dev_info);
if (err)
return err;
err = register_filesystem(&ramfs_fs_type);
if (err)
bdi_destroy(&ramfs_backing_dev_info);
return err;
return register_filesystem(&ramfs_fs_type);
}
fs_initcall(init_ramfs_fs);

View file

@ -70,6 +70,15 @@ static int romfs_mmap(struct file *file, struct vm_area_struct *vma)
return vma->vm_flags & (VM_SHARED | VM_MAYSHARE) ? 0 : -ENOSYS;
}
static unsigned romfs_mmap_capabilities(struct file *file)
{
struct mtd_info *mtd = file_inode(file)->i_sb->s_mtd;
if (!mtd)
return NOMMU_MAP_COPY;
return mtd_mmap_capabilities(mtd);
}
const struct file_operations romfs_ro_fops = {
.llseek = generic_file_llseek,
.read = new_sync_read,
@ -77,4 +86,5 @@ const struct file_operations romfs_ro_fops = {
.splice_read = generic_file_splice_read,
.mmap = romfs_mmap,
.get_unmapped_area = romfs_get_unmapped_area,
.mmap_capabilities = romfs_mmap_capabilities,
};

View file

@ -2017,7 +2017,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
* Read-ahead will be disabled because @c->bdi.ra_pages is 0.
*/
c->bdi.name = "ubifs",
c->bdi.capabilities = BDI_CAP_MAP_COPY;
c->bdi.capabilities = 0;
err = bdi_init(&c->bdi);
if (err)
goto out_close;

View file

@ -114,7 +114,7 @@ int bdi_register(struct backing_dev_info *bdi, struct device *parent,
const char *fmt, ...);
int bdi_register_dev(struct backing_dev_info *bdi, dev_t dev);
void bdi_unregister(struct backing_dev_info *bdi);
int __must_check bdi_setup_and_register(struct backing_dev_info *, char *, unsigned int);
int __must_check bdi_setup_and_register(struct backing_dev_info *, char *);
void bdi_start_writeback(struct backing_dev_info *bdi, long nr_pages,
enum wb_reason reason);
void bdi_start_background_writeback(struct backing_dev_info *bdi);
@ -228,42 +228,17 @@ int bdi_set_max_ratio(struct backing_dev_info *bdi, unsigned int max_ratio);
* BDI_CAP_NO_ACCT_DIRTY: Dirty pages shouldn't contribute to accounting
* BDI_CAP_NO_WRITEBACK: Don't write pages back
* BDI_CAP_NO_ACCT_WB: Don't automatically account writeback pages
*
* These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems.
*
* BDI_CAP_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
* BDI_CAP_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
* BDI_CAP_READ_MAP: Can be mapped for reading
* BDI_CAP_WRITE_MAP: Can be mapped for writing
* BDI_CAP_EXEC_MAP: Can be mapped for execution
*
* BDI_CAP_STRICTLIMIT: Keep number of dirty pages below bdi threshold.
*/
#define BDI_CAP_NO_ACCT_DIRTY 0x00000001
#define BDI_CAP_NO_WRITEBACK 0x00000002
#define BDI_CAP_MAP_COPY 0x00000004
#define BDI_CAP_MAP_DIRECT 0x00000008
#define BDI_CAP_READ_MAP 0x00000010
#define BDI_CAP_WRITE_MAP 0x00000020
#define BDI_CAP_EXEC_MAP 0x00000040
#define BDI_CAP_NO_ACCT_WB 0x00000080
#define BDI_CAP_STABLE_WRITES 0x00000200
#define BDI_CAP_STRICTLIMIT 0x00000400
#define BDI_CAP_VMFLAGS \
(BDI_CAP_READ_MAP | BDI_CAP_WRITE_MAP | BDI_CAP_EXEC_MAP)
#define BDI_CAP_NO_ACCT_WB 0x00000004
#define BDI_CAP_STABLE_WRITES 0x00000008
#define BDI_CAP_STRICTLIMIT 0x00000010
#define BDI_CAP_NO_ACCT_AND_WRITEBACK \
(BDI_CAP_NO_WRITEBACK | BDI_CAP_NO_ACCT_DIRTY | BDI_CAP_NO_ACCT_WB)
#if defined(VM_MAYREAD) && \
(BDI_CAP_READ_MAP != VM_MAYREAD || \
BDI_CAP_WRITE_MAP != VM_MAYWRITE || \
BDI_CAP_EXEC_MAP != VM_MAYEXEC)
#error please change backing_dev_info::capabilities flags
#endif
extern struct backing_dev_info default_backing_dev_info;
extern struct backing_dev_info noop_backing_dev_info;

View file

@ -30,6 +30,4 @@ void cdev_del(struct cdev *);
void cd_forget(struct inode *);
extern struct backing_dev_info directly_mappable_cdev_bdi;
#endif

View file

@ -1502,6 +1502,26 @@ struct block_device_operations;
#define HAVE_COMPAT_IOCTL 1
#define HAVE_UNLOCKED_IOCTL 1
/*
* These flags let !MMU mmap() govern direct device mapping vs immediate
* copying more easily for MAP_PRIVATE, especially for ROM filesystems.
*
* NOMMU_MAP_COPY: Copy can be mapped (MAP_PRIVATE)
* NOMMU_MAP_DIRECT: Can be mapped directly (MAP_SHARED)
* NOMMU_MAP_READ: Can be mapped for reading
* NOMMU_MAP_WRITE: Can be mapped for writing
* NOMMU_MAP_EXEC: Can be mapped for execution
*/
#define NOMMU_MAP_COPY 0x00000001
#define NOMMU_MAP_DIRECT 0x00000008
#define NOMMU_MAP_READ VM_MAYREAD
#define NOMMU_MAP_WRITE VM_MAYWRITE
#define NOMMU_MAP_EXEC VM_MAYEXEC
#define NOMMU_VMFLAGS \
(NOMMU_MAP_READ | NOMMU_MAP_WRITE | NOMMU_MAP_EXEC)
struct iov_iter;
struct file_operations {
@ -1536,6 +1556,9 @@ struct file_operations {
long (*fallocate)(struct file *file, int mode, loff_t offset,
loff_t len);
void (*show_fdinfo)(struct seq_file *m, struct file *f);
#ifndef CONFIG_MMU
unsigned (*mmap_capabilities)(struct file *);
#endif
};
struct inode_operations {

View file

@ -408,4 +408,6 @@ static inline int mtd_is_bitflip_or_eccerr(int err) {
return mtd_is_bitflip(err) || mtd_is_eccerr(err);
}
unsigned mtd_mmap_capabilities(struct mtd_info *mtd);
#endif /* __MTD_MTD_H__ */

View file

@ -17,8 +17,6 @@ static atomic_long_t bdi_seq = ATOMIC_LONG_INIT(0);
struct backing_dev_info default_backing_dev_info = {
.name = "default",
.ra_pages = VM_MAX_READAHEAD * 1024 / PAGE_CACHE_SIZE,
.state = 0,
.capabilities = BDI_CAP_MAP_COPY,
};
EXPORT_SYMBOL_GPL(default_backing_dev_info);
@ -513,13 +511,12 @@ EXPORT_SYMBOL(bdi_destroy);
* For use from filesystems to quickly init and register a bdi associated
* with dirty writeback
*/
int bdi_setup_and_register(struct backing_dev_info *bdi, char *name,
unsigned int cap)
int bdi_setup_and_register(struct backing_dev_info *bdi, char *name)
{
int err;
bdi->name = name;
bdi->capabilities = cap;
bdi->capabilities = 0;
err = bdi_init(bdi);
if (err)
return err;

View file

@ -946,9 +946,6 @@ static int validate_mmap_request(struct file *file,
return -EOVERFLOW;
if (file) {
/* validate file mapping requests */
struct address_space *mapping;
/* files must support mmap */
if (!file->f_op->mmap)
return -ENODEV;
@ -957,28 +954,22 @@ static int validate_mmap_request(struct file *file,
* - we support chardevs that provide their own "memory"
* - we support files/blockdevs that are memory backed
*/
mapping = file->f_mapping;
if (!mapping)
mapping = file_inode(file)->i_mapping;
capabilities = 0;
if (mapping && mapping->backing_dev_info)
capabilities = mapping->backing_dev_info->capabilities;
if (!capabilities) {
if (file->f_op->mmap_capabilities) {
capabilities = file->f_op->mmap_capabilities(file);
} else {
/* no explicit capabilities set, so assume some
* defaults */
switch (file_inode(file)->i_mode & S_IFMT) {
case S_IFREG:
case S_IFBLK:
capabilities = BDI_CAP_MAP_COPY;
capabilities = NOMMU_MAP_COPY;
break;
case S_IFCHR:
capabilities =
BDI_CAP_MAP_DIRECT |
BDI_CAP_READ_MAP |
BDI_CAP_WRITE_MAP;
NOMMU_MAP_DIRECT |
NOMMU_MAP_READ |
NOMMU_MAP_WRITE;
break;
default:
@ -989,9 +980,9 @@ static int validate_mmap_request(struct file *file,
/* eliminate any capabilities that we can't support on this
* device */
if (!file->f_op->get_unmapped_area)
capabilities &= ~BDI_CAP_MAP_DIRECT;
capabilities &= ~NOMMU_MAP_DIRECT;
if (!file->f_op->read)
capabilities &= ~BDI_CAP_MAP_COPY;
capabilities &= ~NOMMU_MAP_COPY;
/* The file shall have been opened with read permission. */
if (!(file->f_mode & FMODE_READ))
@ -1010,29 +1001,29 @@ static int validate_mmap_request(struct file *file,
if (locks_verify_locked(file))
return -EAGAIN;
if (!(capabilities & BDI_CAP_MAP_DIRECT))
if (!(capabilities & NOMMU_MAP_DIRECT))
return -ENODEV;
/* we mustn't privatise shared mappings */
capabilities &= ~BDI_CAP_MAP_COPY;
capabilities &= ~NOMMU_MAP_COPY;
} else {
/* we're going to read the file into private memory we
* allocate */
if (!(capabilities & BDI_CAP_MAP_COPY))
if (!(capabilities & NOMMU_MAP_COPY))
return -ENODEV;
/* we don't permit a private writable mapping to be
* shared with the backing device */
if (prot & PROT_WRITE)
capabilities &= ~BDI_CAP_MAP_DIRECT;
capabilities &= ~NOMMU_MAP_DIRECT;
}
if (capabilities & BDI_CAP_MAP_DIRECT) {
if (((prot & PROT_READ) && !(capabilities & BDI_CAP_READ_MAP)) ||
((prot & PROT_WRITE) && !(capabilities & BDI_CAP_WRITE_MAP)) ||
((prot & PROT_EXEC) && !(capabilities & BDI_CAP_EXEC_MAP))
if (capabilities & NOMMU_MAP_DIRECT) {
if (((prot & PROT_READ) && !(capabilities & NOMMU_MAP_READ)) ||
((prot & PROT_WRITE) && !(capabilities & NOMMU_MAP_WRITE)) ||
((prot & PROT_EXEC) && !(capabilities & NOMMU_MAP_EXEC))
) {
capabilities &= ~BDI_CAP_MAP_DIRECT;
capabilities &= ~NOMMU_MAP_DIRECT;
if (flags & MAP_SHARED) {
printk(KERN_WARNING
"MAP_SHARED not completely supported on !MMU\n");
@ -1049,21 +1040,21 @@ static int validate_mmap_request(struct file *file,
} else if ((prot & PROT_READ) && !(prot & PROT_EXEC)) {
/* handle implication of PROT_EXEC by PROT_READ */
if (current->personality & READ_IMPLIES_EXEC) {
if (capabilities & BDI_CAP_EXEC_MAP)
if (capabilities & NOMMU_MAP_EXEC)
prot |= PROT_EXEC;
}
} else if ((prot & PROT_READ) &&
(prot & PROT_EXEC) &&
!(capabilities & BDI_CAP_EXEC_MAP)
!(capabilities & NOMMU_MAP_EXEC)
) {
/* backing file is not executable, try to copy */
capabilities &= ~BDI_CAP_MAP_DIRECT;
capabilities &= ~NOMMU_MAP_DIRECT;
}
} else {
/* anonymous mappings are always memory backed and can be
* privately mapped
*/
capabilities = BDI_CAP_MAP_COPY;
capabilities = NOMMU_MAP_COPY;
/* handle PROT_EXEC implication by PROT_READ */
if ((prot & PROT_READ) &&
@ -1095,7 +1086,7 @@ static unsigned long determine_vm_flags(struct file *file,
vm_flags = calc_vm_prot_bits(prot) | calc_vm_flag_bits(flags);
/* vm_flags |= mm->def_flags; */
if (!(capabilities & BDI_CAP_MAP_DIRECT)) {
if (!(capabilities & NOMMU_MAP_DIRECT)) {
/* attempt to share read-only copies of mapped file chunks */
vm_flags |= VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC;
if (file && !(prot & PROT_WRITE))
@ -1104,7 +1095,7 @@ static unsigned long determine_vm_flags(struct file *file,
/* overlay a shareable mapping on the backing device or inode
* if possible - used for chardevs, ramfs/tmpfs/shmfs and
* romfs/cramfs */
vm_flags |= VM_MAYSHARE | (capabilities & BDI_CAP_VMFLAGS);
vm_flags |= VM_MAYSHARE | (capabilities & NOMMU_VMFLAGS);
if (flags & MAP_SHARED)
vm_flags |= VM_SHARED;
}
@ -1157,7 +1148,7 @@ static int do_mmap_private(struct vm_area_struct *vma,
* shared mappings on devices or memory
* - VM_MAYSHARE will be set if it may attempt to share
*/
if (capabilities & BDI_CAP_MAP_DIRECT) {
if (capabilities & NOMMU_MAP_DIRECT) {
ret = vma->vm_file->f_op->mmap(vma->vm_file, vma);
if (ret == 0) {
/* shouldn't return success if we're not sharing */
@ -1346,7 +1337,7 @@ unsigned long do_mmap_pgoff(struct file *file,
if ((pregion->vm_pgoff != pgoff || rpglen != pglen) &&
!(pgoff >= pregion->vm_pgoff && pgend <= rpgend)) {
/* new mapping is not a subset of the region */
if (!(capabilities & BDI_CAP_MAP_DIRECT))
if (!(capabilities & NOMMU_MAP_DIRECT))
goto sharing_violation;
continue;
}
@ -1385,7 +1376,7 @@ unsigned long do_mmap_pgoff(struct file *file,
* - this is the hook for quasi-memory character devices to
* tell us the location of a shared mapping
*/
if (capabilities & BDI_CAP_MAP_DIRECT) {
if (capabilities & NOMMU_MAP_DIRECT) {
addr = file->f_op->get_unmapped_area(file, addr, len,
pgoff, flags);
if (IS_ERR_VALUE(addr)) {
@ -1397,10 +1388,10 @@ unsigned long do_mmap_pgoff(struct file *file,
* the mapping so we'll have to attempt to copy
* it */
ret = -ENODEV;
if (!(capabilities & BDI_CAP_MAP_COPY))
if (!(capabilities & NOMMU_MAP_COPY))
goto error_just_free;
capabilities &= ~BDI_CAP_MAP_DIRECT;
capabilities &= ~NOMMU_MAP_DIRECT;
} else {
vma->vm_start = region->vm_start = addr;
vma->vm_end = region->vm_end = addr + len;
@ -1411,7 +1402,7 @@ unsigned long do_mmap_pgoff(struct file *file,
vma->vm_region = region;
/* set up the mapping
* - the region is filled in if BDI_CAP_MAP_DIRECT is still set
* - the region is filled in if NOMMU_MAP_DIRECT is still set
*/
if (file && vma->vm_flags & VM_SHARED)
ret = do_mmap_shared_file(vma);

View file

@ -726,16 +726,15 @@ static inline unsigned long mmap_prot(struct file *file, unsigned long prot)
return prot | PROT_EXEC;
/*
* ditto if it's not on noexec mount, except that on !MMU we need
* BDI_CAP_EXEC_MMAP (== VM_MAYEXEC) in this case
* NOMMU_MAP_EXEC (== VM_MAYEXEC) in this case
*/
if (!(file->f_path.mnt->mnt_flags & MNT_NOEXEC)) {
#ifndef CONFIG_MMU
unsigned long caps = 0;
struct address_space *mapping = file->f_mapping;
if (mapping && mapping->backing_dev_info)
caps = mapping->backing_dev_info->capabilities;
if (!(caps & BDI_CAP_EXEC_MAP))
return prot;
if (file->f_op->mmap_capabilities) {
unsigned caps = file->f_op->mmap_capabilities(file);
if (!(caps & NOMMU_MAP_EXEC))
return prot;
}
#endif
return prot | PROT_EXEC;
}