[RFC PATCH 3/6] cramfs: Convert to fs_context

David Howells
2019-03-21T11:50:53Z

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Nicolas Pitre <nico@linaro.org>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
---

fs/cramfs/inode.c | 69 ++++++++++++++++++++++++++++++-----------------------
1 file changed, 39 insertions(+), 30 deletions(-)

diff --git a/fs/cramfs/inode.c b/fs/cramfs/inode.c
index 9352487bd0fc..2ee89a353d64 100644
--- a/fs/cramfs/inode.c
+++ b/fs/cramfs/inode.c
@@ -24,6 +24,7 @@
#include <linux/blkdev.h>
#include <linux/mtd/mtd.h>
#include <linux/mtd/super.h>
+#include <linux/fs_context.h>
#include <linux/slab.h>
#include <linux/vfs.h>
#include <linux/mutex.h>
@@ -506,18 +507,19 @@ static void cramfs_kill_sb(struct super_block *sb)
kfree(sbi);
}

-static int cramfs_remount(struct super_block *sb, int *flags, char *data)
+static int cramfs_reconfigure(struct fs_context *fc)
{
- sync_filesystem(sb);
- *flags |= SB_RDONLY;
+ sync_filesystem(fc->root->d_sb);
+ fc->sb_flags |= SB_RDONLY;
return 0;
}

-static int cramfs_read_super(struct super_block *sb,
- struct cramfs_super *super, int silent)
+static int cramfs_read_super(struct super_block *sb, struct fs_context *fc,
+ struct cramfs_super *super)
{
struct cramfs_sb_info *sbi = CRAMFS_SB(sb);
unsigned long root_offset;
+ bool silent = fc->sb_flags & SB_SILENT;

/* We don't know the real size yet */
sbi->size = PAGE_SIZE;
@@ -532,7 +534,7 @@ static int cramfs_read_super(struct super_block *sb,
/* check for wrong endianness */
if (super->magic == CRAMFS_MAGIC_WEND) {
if (!silent)
- pr_err("wrong endianness\n");
+ errorf(fc, "cramfs: wrong endianness");
return -EINVAL;
}

@@ -544,22 +546,22 @@ static int cramfs_read_super(struct super_block *sb,
mutex_unlock(&read_mutex);
if (super->magic != CRAMFS_MAGIC) {
if (super->magic == CRAMFS_MAGIC_WEND && !silent)
- pr_err("wrong endianness\n");
+ errorf(fc, "cramfs: wrong endianness");
else if (!silent)
- pr_err("wrong magic\n");
+ errorf(fc, "cramfs: wrong magic");
return -EINVAL;
}
}

/* get feature flags first */
if (super->flags & ~CRAMFS_SUPPORTED_FLAGS) {
- pr_err("unsupported filesystem features\n");
+ errorf(fc, "cramfs: unsupported filesystem features");
return -EINVAL;
}

/* Check that the root inode is in a sane state */
if (!S_ISDIR(super->root.mode)) {
- pr_err("root is not a directory\n");
+ errorf(fc, "cramfs: root is not a directory");
return -EINVAL;
}
/* correct strange, hard-coded permissions of mkcramfs */
@@ -578,12 +580,12 @@ static int cramfs_read_super(struct super_block *sb,
sbi->magic = super->magic;
sbi->flags = super->flags;
if (root_offset == 0)
- pr_info("empty filesystem");
+ infof(fc, "cramfs: empty filesystem");
else if (!(super->flags & CRAMFS_FLAG_SHIFTED_ROOT_OFFSET) &&
((root_offset != sizeof(struct cramfs_super)) &&
(root_offset != 512 + sizeof(struct cramfs_super))))
{
- pr_err("bad root offset %lu\n", root_offset);
+ errorf(fc, "cramfs: bad root offset %lu", root_offset);
return -EINVAL;
}

@@ -607,8 +609,7 @@ static int cramfs_finalize_super(struct super_block *sb,
return 0;
}

-static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
- int silent)
+static int cramfs_blkdev_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct cramfs_sb_info *sbi;
struct cramfs_super super;
@@ -623,14 +624,13 @@ static int cramfs_blkdev_fill_super(struct super_block *sb, void *data,
for (i = 0; i < READ_BUFFERS; i++)
buffer_blocknr[i] = -1;

- err = cramfs_read_super(sb, &super, silent);
+ err = cramfs_read_super(sb, fc, &super);
if (err)
return err;
return cramfs_finalize_super(sb, &super.root);
}

-static int cramfs_mtd_fill_super(struct super_block *sb, void *data,
- int silent)
+static int cramfs_mtd_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct cramfs_sb_info *sbi;
struct cramfs_super super;
@@ -652,7 +652,7 @@ static int cramfs_mtd_fill_super(struct super_block *sb, void *data,

pr_info("checking physical address %pap for linear cramfs image\n",
&sbi->linear_phys_addr);
- err = cramfs_read_super(sb, &super, silent);
+ err = cramfs_read_super(sb, fc, &super);
if (err)
return err;

@@ -947,32 +947,41 @@ static const struct inode_operations cramfs_dir_inode_operations = {
};

static const struct super_operations cramfs_ops = {
- .remount_fs = cramfs_remount,
.statfs = cramfs_statfs,
};

-static struct dentry *cramfs_mount(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data)
+static int cramfs_get_tree(struct fs_context *fc)
{
- struct dentry *ret = ERR_PTR(-ENOPROTOOPT);
+ int ret = -ENOPROTOOPT;

if (IS_ENABLED(CONFIG_CRAMFS_MTD)) {
- ret = mount_mtd(fs_type, flags, dev_name, data,
- cramfs_mtd_fill_super);
- if (!IS_ERR(ret))
+ ret = vfs_get_mtd_super(fc, cramfs_mtd_fill_super);
+ if (ret < 0)
return ret;
}
- if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV)) {
- ret = mount_bdev(fs_type, flags, dev_name, data,
- cramfs_blkdev_fill_super);
- }
+ if (IS_ENABLED(CONFIG_CRAMFS_BLOCKDEV))
+ ret = vfs_get_block_super(fc, cramfs_blkdev_fill_super);
return ret;
}

+static const struct fs_context_operations cramfs_context_ops = {
+ .get_tree = cramfs_get_tree,
+ .reconfigure = cramfs_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int cramfs_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &cramfs_context_ops;
+ return 0;
+}
+
static struct file_system_type cramfs_fs_type = {
.owner = THIS_MODULE,
.name = "cramfs",
- .mount = cramfs_mount,
+ .init_fs_context = cramfs_init_fs_context,
.kill_sb = cramfs_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};