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Subject[PATCH] vfs: Convert coda to fs_context
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Convert coda to fs_context.  Note this is slightly tricky as coda currently
only has a binary mount data interface. This is handled through the
parse_monolithic hook.

Also add a more conventional interface with a parameter named "fd" that
takes an fd that refers to a coda psdev, thereby specifying the index to
use.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Jan Harkes <jaharkes@cs.cmu.edu>
cc: coda@cs.cmu.edu
---

fs/coda/inode.c | 171 +++++++++++++++++++++++++++++++++++++------------------
1 file changed, 116 insertions(+), 55 deletions(-)

diff --git a/fs/coda/inode.c b/fs/coda/inode.c
index 97424cf206c0..aaed68ba960b 100644
--- a/fs/coda/inode.c
+++ b/fs/coda/inode.c
@@ -2,9 +2,9 @@
/*
* Super block/filesystem wide operations
*
- * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
- * Michael Callahan <callahan@maths.ox.ac.uk>
- *
+ * Copyright (C) 1996 Peter J. Braam <braam@maths.ox.ac.uk> and
+ * Michael Callahan <callahan@maths.ox.ac.uk>
+ *
* Rewritten for Linux 2.1. Peter Braam <braam@cs.cmu.edu>
* Copyright (C) Carnegie Mellon University
*/
@@ -24,6 +24,8 @@
#include <linux/pid_namespace.h>
#include <linux/uaccess.h>
#include <linux/fs.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
#include <linux/vmalloc.h>

#include <linux/coda.h>
@@ -93,10 +95,10 @@ void coda_destroy_inodecache(void)
kmem_cache_destroy(coda_inode_cachep);
}

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

@@ -108,78 +110,111 @@ static const struct super_operations coda_super_operations =
.evict_inode = coda_evict_inode,
.put_super = coda_put_super,
.statfs = coda_statfs,
- .remount_fs = coda_remount,
};

-static int get_device_index(struct coda_mount_data *data)
+struct coda_fs_context {
+ int idx;
+};
+
+enum {
+ Opt_fd,
+};
+
+static const struct fs_parameter_spec coda_param_specs[] = {
+ fsparam_fd ("fd", Opt_fd),
+ {}
+};
+
+static const struct fs_parameter_description coda_fs_parameters = {
+ .name = "coda",
+ .specs = coda_param_specs,
+};
+
+static int coda_parse_fd(struct fs_context *fc, int fd)
{
+ struct coda_fs_context *ctx = fc->fs_private;
struct fd f;
struct inode *inode;
int idx;

- if (data == NULL) {
- pr_warn("%s: Bad mount data\n", __func__);
- return -1;
- }
-
- if (data->version != CODA_MOUNT_VERSION) {
- pr_warn("%s: Bad mount version\n", __func__);
- return -1;
- }
-
- f = fdget(data->fd);
+ f = fdget(fd);
if (!f.file)
- goto Ebadf;
+ return -EBADF;
+
inode = file_inode(f.file);
if (!S_ISCHR(inode->i_mode) || imajor(inode) != CODA_PSDEV_MAJOR) {
fdput(f);
- goto Ebadf;
+ return invalf(fc, "code: Not coda psdev");
}

idx = iminor(inode);
fdput(f);

- if (idx < 0 || idx >= MAX_CODADEVS) {
- pr_warn("%s: Bad minor number\n", __func__);
- return -1;
+ if (idx < 0 || idx >= MAX_CODADEVS)
+ return invalf(fc, "coda: Bad minor number");
+ ctx->idx = idx;
+ return 0;
+}
+
+static int coda_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct fs_parse_result result;
+ int opt;
+
+ opt = fs_parse(fc, &coda_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_fd:
+ return coda_parse_fd(fc, result.uint_32);
+ }
+
+ return 0;
+}
+
+/*
+ * Parse coda's binary mount data form. We ignore any errors and go with index
+ * 0 if we get one for backward compatibility.
+ */
+static int coda_parse_monolithic(struct fs_context *fc, void *_data)
+{
+ struct coda_mount_data *data = _data;
+
+ if (!data) {
+ invalf(fc, "coda: Bad mount data");
+ return 0;
+ }
+ if (data->version != CODA_MOUNT_VERSION) {
+ invalf(fc, "coda: Bad mount version");
+ return 0;
}

- return idx;
-Ebadf:
- pr_warn("%s: Bad file\n", __func__);
- return -1;
+ coda_parse_fd(fc, data->fd);
+ return 0;
}

-static int coda_fill_super(struct super_block *sb, void *data, int silent)
+static int coda_fill_super(struct super_block *sb, struct fs_context *fc)
{
+ struct coda_fs_context *ctx = fc->fs_private;
struct inode *root = NULL;
struct venus_comm *vc;
struct CodaFid fid;
int error;
- int idx;

- if (task_active_pid_ns(current) != &init_pid_ns)
- return -EINVAL;
+ infof(fc, "coda: device index: %i\n", ctx->idx);

- idx = get_device_index((struct coda_mount_data *) data);
-
- /* Ignore errors in data, for backward compatibility */
- if(idx == -1)
- idx = 0;
-
- pr_info("%s: device index: %i\n", __func__, idx);
-
- vc = &coda_comms[idx];
+ vc = &coda_comms[ctx->idx];
mutex_lock(&vc->vc_mutex);

if (!vc->vc_inuse) {
- pr_warn("%s: No pseudo device\n", __func__);
+ errorf(fc, "coda: No pseudo device");
error = -EINVAL;
goto unlock_out;
}

if (vc->vc_sb) {
- pr_warn("%s: Device already mounted\n", __func__);
+ errorf(fc, "coda: Device already mounted");
error = -EBUSY;
goto unlock_out;
}
@@ -207,7 +242,7 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
goto error;
}
pr_info("%s: rootfid is %s\n", __func__, coda_f2s(&fid));
-
+
/* make root inode */
root = coda_cnode_make(&fid, sb);
if (IS_ERR(root)) {
@@ -215,7 +250,7 @@ static int coda_fill_super(struct super_block *sb, void *data, int silent)
pr_warn("Failure of coda_cnode_make for root: error %d\n",
error);
goto error;
- }
+ }

pr_info("%s: rootinode is %ld dev %s\n",
__func__, root->i_ino, root->i_sb->s_id);
@@ -268,7 +303,7 @@ int coda_setattr(struct dentry *de, struct iattr *iattr)
struct coda_vattr vattr;
int error;

- memset(&vattr, 0, sizeof(vattr));
+ memset(&vattr, 0, sizeof(vattr));

inode->i_ctime = current_time(inode);
coda_iattr_to_vattr(iattr, &vattr);
@@ -278,7 +313,7 @@ int coda_setattr(struct dentry *de, struct iattr *iattr)
error = venus_setattr(inode->i_sb, coda_i2f(inode), &vattr);

if (!error) {
- coda_vattr_to_iattr(inode, &vattr);
+ coda_vattr_to_iattr(inode, &vattr);
coda_cache_clear_inode(inode);
}
return error;
@@ -293,7 +328,7 @@ const struct inode_operations coda_file_inode_operations = {
static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
{
int error;
-
+
error = venus_statfs(dentry, buf);

if (error) {
@@ -310,23 +345,49 @@ static int coda_statfs(struct dentry *dentry, struct kstatfs *buf)
buf->f_bsize = 4096;
buf->f_namelen = CODA_MAXNAMLEN;

- return 0;
+ return 0;
}

-/* init_coda: used by filesystems.c to register coda */
+static int coda_get_tree(struct fs_context *fc)
+{
+ if (task_active_pid_ns(current) != &init_pid_ns)
+ return -EINVAL;
+
+ return vfs_get_super(fc, vfs_get_independent_super, coda_fill_super);
+}
+
+static void coda_free_fc(struct fs_context *fc)
+{
+ kfree(fc->fs_private);
+}

-static struct dentry *coda_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
+static const struct fs_context_operations coda_context_ops = {
+ .free = coda_free_fc,
+ .parse_param = coda_parse_param,
+ .parse_monolithic = coda_parse_monolithic,
+ .get_tree = coda_get_tree,
+ .reconfigure = coda_reconfigure,
+};
+
+static int coda_init_fs_context(struct fs_context *fc)
{
- return mount_nodev(fs_type, flags, data, coda_fill_super);
+ struct coda_fs_context *ctx;
+
+ ctx = kzalloc(sizeof(struct coda_fs_context), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ fc->fs_private = ctx;
+ fc->ops = &coda_context_ops;
+ return 0;
}

struct file_system_type coda_fs_type = {
.owner = THIS_MODULE,
.name = "coda",
- .mount = coda_mount,
+ .init_fs_context = coda_init_fs_context,
+ .parameters = &coda_fs_parameters,
.kill_sb = kill_anon_super,
.fs_flags = FS_BINARY_MOUNTDATA,
};
MODULE_ALIAS_FS("coda");
-
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