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>
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 @@
}
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 @@
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 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 @@
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 @@
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 @@
{
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 @@
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_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 @@
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 @@
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 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 @@
.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 @@
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 @@
}
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 @@
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 @@
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 @@
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 @@
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 @@
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..f6ab41b 100644
--- a/fs/ramfs/file-nommu.c
+++ b/fs/ramfs/file-nommu.c
@@ -34,7 +34,14 @@
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 @@
.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 @@
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 @@
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 @@
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 @@
.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 @@
* 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;