[PATCH 03/12] fs: introduce f_op->mmap_capabilities for nommu mmap support

Christoph Hellwig
2015-01-08T17:45:24Z

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>
---
Documentation/nommu-mmap.txt | 8 +--
block/blk-core.c | 2 +-
drivers/char/mem.c | 64 ++++++++++----------
drivers/mtd/mtdchar.c | 72 ++++------------------
drivers/mtd/mtdconcat.c | 10 ----
drivers/mtd/mtdcore.c | 80 +++++++------------------
drivers/mtd/mtdpart.c | 1 -
drivers/staging/lustre/lustre/llite/llite_lib.c | 2 +-
fs/9p/v9fs.c | 2 +-
fs/afs/volume.c | 2 +-
fs/aio.c | 14 +----
fs/btrfs/disk-io.c | 3 +-
fs/char_dev.c | 24 --------
fs/cifs/connect.c | 2 +-
fs/coda/inode.c | 2 +-
fs/configfs/configfs_internal.h | 2 -
fs/configfs/inode.c | 18 +-----
fs/configfs/mount.c | 11 +---
fs/ecryptfs/main.c | 2 +-
fs/exofs/super.c | 2 +-
fs/ncpfs/inode.c | 2 +-
fs/ramfs/file-nommu.c | 7 +++
fs/ramfs/inode.c | 22 +------
fs/romfs/mmap-nommu.c | 10 ++++
fs/ubifs/super.c | 2 +-
include/linux/backing-dev.h | 33 ++--------
include/linux/cdev.h | 2 -
include/linux/fs.h | 23 +++++++
include/linux/mtd/mtd.h | 2 +
mm/backing-dev.c | 7 +--
mm/nommu.c | 69 ++++++++++-----------
security/security.c | 13 ++--
32 files changed, 169 insertions(+), 346 deletions(-)

diff --git a/Documentation/nommu-mmap.txt b/Documentation/nommu-mmap.txt
index 8e1ddec..ae57b9e 100644
--- a/Documentation/nommu-mmap.txt
+++ b/Documentation/nommu-mmap.txt
@@ -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:
diff --git a/block/blk-core.c b/block/blk-core.c
index 30f6153..56bc2b8 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -588,7 +588,7 @@ 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;

diff --git a/drivers/char/mem.c b/drivers/char/mem.c
index 4c58333..9a6b637 100644
--- a/drivers/char/mem.c
+++ b/drivers/char/mem.c
@@ -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);
diff --git a/drivers/mtd/mtdchar.c b/drivers/mtd/mtdchar.c
index 5356395..55fa27e 100644
--- a/drivers/mtd/mtdchar.c
+++ b/drivers/mtd/mtdchar.c
@@ -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");
}

diff --git a/drivers/mtd/mtdconcat.c b/drivers/mtd/mtdconcat.c
index b900056..eacc3aa 100644
--- a/drivers/mtd/mtdconcat.c
+++ b/drivers/mtd/mtdconcat.c
@@ -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;
diff --git a/drivers/mtd/mtdcore.c b/drivers/mtd/mtdcore.c
index 4c61187..ff38a1d 100644
--- a/drivers/mtd/mtdcore.c
+++ b/drivers/mtd/mtdcore.c
@@ -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");
- 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");
+ ret = mtd_bdi_init(&mtd_bdi, "mtd");
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);
diff --git a/drivers/mtd/mtdpart.c b/drivers/mtd/mtdpart.c
index a3e3a7d..e779de3 100644
--- a/drivers/mtd/mtdpart.c
+++ b/drivers/mtd/mtdpart.c
@@ -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.
diff --git a/drivers/staging/lustre/lustre/llite/llite_lib.c b/drivers/staging/lustre/lustre/llite/llite_lib.c
index a3367bf..d5b149c 100644
--- a/drivers/staging/lustre/lustre/llite/llite_lib.c
+++ b/drivers/staging/lustre/lustre/llite/llite_lib.c
@@ -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;
diff --git a/fs/9p/v9fs.c b/fs/9p/v9fs.c
index 6894b08..620d934 100644
--- a/fs/9p/v9fs.c
+++ b/fs/9p/v9fs.c
@@ -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);
diff --git a/fs/afs/volume.c b/fs/afs/volume.c
index 2b60725..d142a24 100644
--- a/fs/afs/volume.c
+++ b/fs/afs/volume.c
@@ -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;

diff --git a/fs/aio.c b/fs/aio.c
index 1b7893e..6f13d3f 100644
--- a/fs/aio.c
+++ b/fs/aio.c
@@ -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);

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 8c63419..afc4092 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -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;

diff --git a/fs/char_dev.c b/fs/char_dev.c
index 67b2007..ea06a3d 100644
--- a/fs/char_dev.c
+++ b/fs/char_dev.c
@@ -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);
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 2a772da..d3aa999 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -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;

diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index b945410..82ec68b 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -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;

diff --git a/fs/configfs/configfs_internal.h b/fs/configfs/configfs_internal.h
index bd4a3c1..a315677 100644
--- a/fs/configfs/configfs_internal.h
+++ b/fs/configfs/configfs_internal.h
@@ -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 *,
diff --git a/fs/configfs/inode.c b/fs/configfs/inode.c
index 5946ad9..0ad6b4d 100644
--- a/fs/configfs/inode.c
+++ b/fs/configfs/inode.c
@@ -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);
-}
diff --git a/fs/configfs/mount.c b/fs/configfs/mount.c
index f6c2858..da94e41 100644
--- a/fs/configfs/mount.c
+++ b/fs/configfs/mount.c
@@ -145,19 +145,13 @@ static int __init configfs_init(void)
if (!config_kobj)
goto out2;

- err = configfs_inode_init();
- if (err)
- goto out3;
-
err = register_filesystem(&configfs_fs_type);
if (err)
- goto out4;
+ goto out3;

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");
diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c
index d9eb84b..1895d60 100644
--- a/fs/ecryptfs/main.c
+++ b/fs/ecryptfs/main.c
@@ -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;

diff --git a/fs/exofs/super.c b/fs/exofs/super.c
index 9596550..fcc2e56 100644
--- a/fs/exofs/super.c
+++ b/fs/exofs/super.c
@@ -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);
diff --git a/fs/ncpfs/inode.c b/fs/ncpfs/inode.c
index e31e589..a699a3f 100644
--- a/fs/ncpfs/inode.c
+++ b/fs/ncpfs/inode.c
@@ -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;

diff --git a/fs/ramfs/file-nommu.c b/fs/ramfs/file-nommu.c
index bbafbde..d1390b8d 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -33,8 +33,15 @@ static unsigned long ramfs_nommu_get_unmapped_area(struct file *file,
unsigned long pgoff,
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,
diff --git a/fs/ramfs/inode.c b/fs/ramfs/inode.c
index d365b1c..ad4d712 100644
--- a/fs/ramfs/inode.c
+++ b/fs/ramfs/inode.c
@@ -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);
diff --git a/fs/romfs/mmap-nommu.c b/fs/romfs/mmap-nommu.c
index ea06c75..7da9e21 100644
--- a/fs/romfs/mmap-nommu.c
+++ b/fs/romfs/mmap-nommu.c
@@ -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,
};
diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 106bf20..ed93dc6 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -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;
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index e936cea..478f95d 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -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;

diff --git a/include/linux/cdev.h b/include/linux/cdev.h
index fb45919..f876361 100644
--- a/include/linux/cdev.h
+++ b/include/linux/cdev.h
@@ -30,6 +30,4 @@ void cdev_del(struct cdev *);

void cd_forget(struct inode *);

-extern struct backing_dev_info directly_mappable_cdev_bdi;
-
#endif
diff --git a/include/linux/fs.h b/include/linux/fs.h
index f90c028..7939a2e 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -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 {
diff --git a/include/linux/mtd/mtd.h b/include/linux/mtd/mtd.h
index 031ff3a..3301c4c 100644
--- a/include/linux/mtd/mtd.h
+++ b/include/linux/mtd/mtd.h
@@ -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__ */
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 0ae0df5..16c6895 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -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;
diff --git a/mm/nommu.c b/mm/nommu.c
index b51eadf..13af96f3 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -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);
diff --git a/security/security.c b/security/security.c
index 18b35c6..a0442b2 100644
--- a/security/security.c
+++ b/security/security.c
@@ -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;
}
--
1.9.1