* [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context
@ 2019-03-20 14:44 David Howells
2019-03-20 14:45 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
` (5 more replies)
0 siblings, 6 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:44 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Here's a set of patches that convert romfs, cramfs, jffs2 and squashfs to
use the new fs_context struct and replace mount_mtd(). They have
prerequisite commits (such as replacing mount_bdev()) that can be found in
the branch detailed below.
(1) Provide a replacement for mount_mtd() that takes an fs_context to
specify the parameters.
I also put an mtd device pointer into the fs_context struct for use in
the sget_fc() test and set functions plus a destructor because
put_fs_context() can't reach into the mtd module.
(2) Convert romfs.
(3) Convert cramfs.
(4) Convert jffs2.
(5) Get rid of the now-obsolete mount_mtd() function.
(6) Convert squashfs.
These can be found in the following branch:
http://git.kernel.org/cgit/linux/kernel/git/dhowells/linux-fs.git/log/?h=mount-api-viro
Thanks,
David
---
David Howells (6):
mtd: Provide fs_context-aware mount_mtd() replacement
romfs: Convert to fs_context
cramfs: Convert to fs_context
jffs2: Convert to fs_context
mtd: Kill off mount_mtd()
squashfs: Convert to fs_context
drivers/mtd/mtdcore.h | 1
drivers/mtd/mtdsuper.c | 181 ++++++++++++++++++++++----------------------
fs/cramfs/inode.c | 69 +++++++++--------
fs/fs_context.c | 2
fs/jffs2/fs.c | 21 +++--
fs/jffs2/os-linux.h | 4 -
fs/jffs2/super.c | 172 ++++++++++++++++++++----------------------
fs/romfs/super.c | 46 +++++++----
fs/squashfs/super.c | 100 +++++++++++++-----------
include/linux/fs_context.h | 2
include/linux/mtd/super.h | 6 +
11 files changed, 316 insertions(+), 288 deletions(-)
^ permalink raw reply [flat|nested] 9+ messages in thread
* [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
@ 2019-03-20 14:45 ` David Howells
2019-03-20 14:45 ` [RFC PATCH 2/6] romfs: Convert to fs_context David Howells
` (4 subsequent siblings)
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Provide a function, vfs_get_mtd_super(), to replace mount_mtd(), using an
fs_context struct to hold the parameters. The mtd device pointer is cached
in the struct, along with a destructor pointer as the mtd core may be in a
module and, as such, unreachable by the core code that would release the
fs_context.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---
drivers/mtd/mtdcore.h | 1
drivers/mtd/mtdsuper.c | 192 ++++++++++++++++++++++++++++++++++++++++++++
fs/fs_context.c | 2
include/linux/fs_context.h | 2
include/linux/mtd/super.h | 3 +
5 files changed, 198 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index b31c868019ad..b5eefeabf310 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -5,6 +5,7 @@
*/
extern struct mutex mtd_table_mutex;
+extern struct backing_dev_info *mtd_bdi;
struct mtd_info *__mtd_next_device(int i);
int __must_check add_mtd_device(struct mtd_info *mtd);
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index d58a61c09304..cf223c4aa862 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -19,6 +19,196 @@
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include "mtdcore.h"
+
+static void mtd_fc_destructor(struct fs_context *fc)
+{
+ if (fc->mtd)
+ put_mtd_device(fc->mtd);
+}
+
+/*
+ * compare superblocks to see if they're equivalent
+ * - they are if the underlying MTD device is the same
+ */
+static int mtd_test_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ if (sb->s_mtd == mtd) {
+ pr_debug("MTDSB: Match on device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+ return 1;
+ }
+
+ pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
+ sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
+ return 0;
+}
+
+/*
+ * mark the superblock by the MTD device it is using
+ * - set the device number to be the correct MTD block device for pesuperstence
+ * of NFS exports
+ */
+static int mtd_set_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ sb->s_mtd = mtd;
+ sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
+ sb->s_bdi = bdi_get(mtd_bdi);
+ fc->mtd = NULL;
+ return 0;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem
+ */
+static int mtd_get_sb(struct fs_context *fc,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct super_block *sb;
+ struct mtd_info *mtd = fc->mtd;
+ int ret;
+
+ sb = sget_fc(fc, mtd_test_super, mtd_set_super);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+
+ if (sb->s_root) {
+ /* new mountpoint for an already mounted superblock */
+ pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
+ mtd->index, mtd->name);
+ put_mtd_device(mtd);
+ } else {
+ /* fresh new superblock */
+ pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+
+ ret = fill_super(sb, fc);
+ if (ret < 0)
+ goto error_sb;
+
+ sb->s_flags |= SB_ACTIVE;
+ }
+
+ BUG_ON(fc->root);
+ fc->root = dget(sb->s_root);
+ return 0;
+
+error_sb:
+ deactivate_locked_super(sb);
+ return ret;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem by MTD device number
+ */
+static int mtd_get_sb_by_nr(struct fs_context *fc, int mtdnr,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct mtd_info *mtd;
+
+ mtd = get_mtd_device(NULL, mtdnr);
+ if (IS_ERR(mtd)) {
+ errorf(fc, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
+ return PTR_ERR(mtd);
+ }
+
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+}
+
+/**
+ * vfs_get_mtd_super - Get a superblock based on a single MTD device
+ * @fc: The filesystem context holding the parameters
+ * @fill_super: Helper to initialise a new superblock
+ */
+int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+#ifdef CONFIG_BLOCK
+ struct block_device *bdev;
+ int ret, major;
+#endif
+ int mtdnr;
+
+ if (!fc->source)
+ return invalf(fc, "No source specified");
+
+ pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);
+
+ /* the preferred way of mounting in future; especially when
+ * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
+ * by name, so that we don't require block device support to be present
+ * in the kernel.
+ */
+ if (fc->source[0] == 'm' &&
+ fc->source[1] == 't' &&
+ fc->source[2] == 'd') {
+ if (fc->source[3] == ':') {
+ struct mtd_info *mtd;
+
+ /* mount by MTD device name */
+ pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
+ fc->source + 4);
+
+ mtd = get_mtd_device_nm(fc->source + 4);
+ if (!IS_ERR(mtd)) {
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+ }
+
+ errorf(fc, "MTD: MTD device with name \"%s\" not found",
+ fc->source + 4);
+
+ } else if (isdigit(fc->source[3])) {
+ /* mount by MTD device number name */
+ char *endptr;
+
+ mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);
+ if (!*endptr) {
+ /* It was a valid number */
+ pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+ }
+ }
+ }
+
+#ifdef CONFIG_BLOCK
+ /* try the old way - the hack where we allowed users to mount
+ * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
+ */
+ bdev = lookup_bdev(fc->source);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);
+ return ret;
+ }
+ pr_debug("MTDSB: lookup_bdev() returned 0\n");
+
+ major = MAJOR(bdev->bd_dev);
+ mtdnr = MINOR(bdev->bd_dev);
+ bdput(bdev);
+
+ if (major == MTD_BLOCK_MAJOR)
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+
+#endif /* CONFIG_BLOCK */
+
+ if (!(fc->sb_flags & SB_SILENT))
+ errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",
+ fc->source);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
/*
* compare superblocks to see if they're equivalent
@@ -39,8 +229,6 @@ static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
return 0;
}
-extern struct backing_dev_info *mtd_bdi;
-
/*
* mark the superblock by the MTD device it is using
* - set the device number to be the correct MTD block device for pesuperstence
diff --git a/fs/fs_context.c b/fs/fs_context.c
index 3325b435cb6f..65e705d02521 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -427,6 +427,8 @@ void put_fs_context(struct fs_context *fc)
fc->ops->free(fc);
if (fc->bdev)
blkdev_put(fc->bdev, fc->bdev_mode);
+ if (fc->destructor)
+ fc->destructor(fc);
security_free_mnt_opts(&fc->security);
put_net(fc->net_ns);
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 524963c0cedb..8233c873af73 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -77,6 +77,7 @@ struct fs_context {
struct file_system_type *fs_type;
void *fs_private; /* The filesystem's context */
struct block_device *bdev; /* The backing blockdev (if applicable) */
+ struct mtd_info *mtd; /* The backing mtd (if applicable) */
struct dentry *root; /* The root and superblock */
struct user_namespace *user_ns; /* The user namespace for this mount */
struct net *net_ns; /* The network namespace for this mount */
@@ -92,6 +93,7 @@ struct fs_context {
enum fs_context_purpose purpose:8;
bool need_free:1; /* Need to call ops->free() */
bool global:1; /* Goes into &init_user_ns */
+ void (*destructor)(struct fs_context *fc); /* For mtd */
};
struct fs_context_operations {
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index f456230f9330..7ebd69e5c640 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -18,6 +18,9 @@
#include <linux/fs.h>
#include <linux/mount.h>
+extern int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 2/6] romfs: Convert to fs_context
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
2019-03-20 14:45 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
@ 2019-03-20 14:45 ` David Howells
2019-03-20 14:45 ` [RFC PATCH 3/6] cramfs: " David Howells
` (3 subsequent siblings)
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Signed-off-by: David Howells <dhowells@redhat.com>
cc: linux-mtd@lists.infradead.org
cc: linux-block@vger.kernel.org
---
fs/romfs/super.c | 46 ++++++++++++++++++++++++++++------------------
1 file changed, 28 insertions(+), 18 deletions(-)
diff --git a/fs/romfs/super.c b/fs/romfs/super.c
index 6ccb51993a76..627c2b64ff03 100644
--- a/fs/romfs/super.c
+++ b/fs/romfs/super.c
@@ -65,7 +65,7 @@
#include <linux/slab.h>
#include <linux/init.h>
#include <linux/blkdev.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/statfs.h>
@@ -430,10 +430,10 @@ static int romfs_statfs(struct dentry *dentry, struct kstatfs *buf)
/*
* remounting must involve read-only
*/
-static int romfs_remount(struct super_block *sb, int *flags, char *data)
+static int romfs_reconfigure(struct fs_context *fc)
{
- sync_filesystem(sb);
- *flags |= SB_RDONLY;
+ sync_filesystem(fc->root->d_sb);
+ fc->sb_flags |= SB_RDONLY;
return 0;
}
@@ -441,7 +441,6 @@ static const struct super_operations romfs_super_ops = {
.alloc_inode = romfs_alloc_inode,
.destroy_inode = romfs_destroy_inode,
.statfs = romfs_statfs,
- .remount_fs = romfs_remount,
};
/*
@@ -464,7 +463,7 @@ static __u32 romfs_checksum(const void *data, int size)
/*
* fill in the superblock
*/
-static int romfs_fill_super(struct super_block *sb, void *data, int silent)
+static int romfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct romfs_super_block *rsb;
struct inode *root;
@@ -511,8 +510,8 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
if (rsb->word0 != ROMSB_WORD0 || rsb->word1 != ROMSB_WORD1 ||
img_size < ROMFH_SIZE) {
- if (!silent)
- pr_warn("VFS: Can't find a romfs filesystem on dev %s.\n",
+ if (!(fc->sb_flags & SB_SILENT))
+ errorf(fc, "VFS: Can't find a romfs filesystem on dev %s.\n",
sb->s_id);
goto error_rsb_inval;
}
@@ -525,7 +524,7 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
storage = sb->s_mtd ? "MTD" : "the block layer";
len = strnlen(rsb->name, ROMFS_MAXFN);
- if (!silent)
+ if (!(fc->sb_flags & SB_SILENT))
pr_notice("Mounting image '%*.*s' through %s\n",
(unsigned) len, (unsigned) len, rsb->name, storage);
@@ -555,23 +554,34 @@ static int romfs_fill_super(struct super_block *sb, void *data, int silent)
/*
* get a superblock for mounting
*/
-static struct dentry *romfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *data)
+static int romfs_get_tree(struct fs_context *fc)
{
- struct dentry *ret = ERR_PTR(-EINVAL);
+ int ret = -EINVAL;
#ifdef CONFIG_ROMFS_ON_MTD
- ret = mount_mtd(fs_type, flags, dev_name, data, romfs_fill_super);
+ ret = vfs_get_mtd_super(fc, romfs_fill_super);
#endif
#ifdef CONFIG_ROMFS_ON_BLOCK
- if (ret == ERR_PTR(-EINVAL))
- ret = mount_bdev(fs_type, flags, dev_name, data,
- romfs_fill_super);
+ if (ret == -EINVAL)
+ ret = vfs_get_block_super(fc, romfs_fill_super);
#endif
return ret;
}
+static const struct fs_context_operations romfs_context_ops = {
+ .get_tree = romfs_get_tree,
+ .reconfigure = romfs_reconfigure,
+};
+
+/*
+ * Set up the filesystem mount context.
+ */
+static int romfs_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &romfs_context_ops;
+ return 0;
+}
+
/*
* destroy a romfs superblock in the appropriate manner
*/
@@ -594,7 +604,7 @@ static void romfs_kill_sb(struct super_block *sb)
static struct file_system_type romfs_fs_type = {
.owner = THIS_MODULE,
.name = "romfs",
- .mount = romfs_mount,
+ .init_fs_context = romfs_init_fs_context,
.kill_sb = romfs_kill_sb,
.fs_flags = FS_REQUIRES_DEV,
};
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 3/6] cramfs: Convert to fs_context
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
2019-03-20 14:45 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
2019-03-20 14:45 ` [RFC PATCH 2/6] romfs: Convert to fs_context David Howells
@ 2019-03-20 14:45 ` David Howells
2019-03-20 14:45 ` [RFC PATCH 4/6] jffs2: " David Howells
` (2 subsequent siblings)
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
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,
};
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 4/6] jffs2: Convert to fs_context
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
` (2 preceding siblings ...)
2019-03-20 14:45 ` [RFC PATCH 3/6] cramfs: " David Howells
@ 2019-03-20 14:45 ` David Howells
2019-03-20 14:45 ` [RFC PATCH 5/6] mtd: Kill off mount_mtd() David Howells
2019-03-20 14:45 ` [RFC PATCH 6/6] squashfs: Convert to fs_context David Howells
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: linux-mtd@lists.infradead.org
---
fs/jffs2/fs.c | 21 +++---
fs/jffs2/os-linux.h | 4 +
fs/jffs2/super.c | 172 +++++++++++++++++++++++++--------------------------
3 files changed, 96 insertions(+), 101 deletions(-)
diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c
index eab04eca95a3..d79734bd7650 100644
--- a/fs/jffs2/fs.c
+++ b/fs/jffs2/fs.c
@@ -17,6 +17,7 @@
#include <linux/sched.h>
#include <linux/cred.h>
#include <linux/fs.h>
+#include <linux/fs_context.h>
#include <linux/list.h>
#include <linux/mtd/mtd.h>
#include <linux/pagemap.h>
@@ -184,7 +185,7 @@ int jffs2_do_setattr (struct inode *inode, struct iattr *iattr)
if (ivalid & ATTR_SIZE && inode->i_size > iattr->ia_size) {
truncate_setsize(inode, iattr->ia_size);
inode->i_blocks = (inode->i_size + 511) >> 9;
- }
+ }
return 0;
}
@@ -390,7 +391,7 @@ void jffs2_dirty_inode(struct inode *inode, int flags)
jffs2_do_setattr(inode, &iattr);
}
-int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
+int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc)
{
struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
@@ -408,10 +409,10 @@ int jffs2_do_remount_fs(struct super_block *sb, int *flags, char *data)
mutex_unlock(&c->alloc_sem);
}
- if (!(*flags & SB_RDONLY))
+ if (!(fc->sb_flags & SB_RDONLY))
jffs2_start_garbage_collect_thread(c);
- *flags |= SB_NOATIME;
+ fc->sb_flags |= SB_NOATIME;
return 0;
}
@@ -508,7 +509,7 @@ static int calculate_inocache_hashsize(uint32_t flash_size)
return hashsize;
}
-int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
+int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct jffs2_sb_info *c;
struct inode *root_i;
@@ -523,11 +524,11 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
#ifndef CONFIG_JFFS2_FS_WRITEBUFFER
if (c->mtd->type == MTD_NANDFLASH) {
- pr_err("Cannot operate on NAND flash unless jffs2 NAND support is compiled in\n");
+ errorf(fc, "Cannot operate on NAND flash unless jffs2 NAND support is compiled in");
return -EINVAL;
}
if (c->mtd->type == MTD_DATAFLASH) {
- pr_err("Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in\n");
+ errorf(fc, "Cannot operate on DataFlash unless jffs2 DataFlash support is compiled in");
return -EINVAL;
}
#endif
@@ -541,12 +542,12 @@ int jffs2_do_fill_super(struct super_block *sb, void *data, int silent)
*/
if ((c->sector_size * blocks) != c->flash_size) {
c->flash_size = c->sector_size * blocks;
- pr_info("Flash size not aligned to erasesize, reducing to %dKiB\n",
- c->flash_size / 1024);
+ infof(fc, "Flash size not aligned to erasesize, reducing to %dKiB",
+ c->flash_size / 1024);
}
if (c->flash_size < 5*c->sector_size) {
- pr_err("Too few erase blocks (%d)\n",
+ errorf(fc, "Too few erase blocks (%d)",
c->flash_size / c->sector_size);
return -EINVAL;
}
diff --git a/fs/jffs2/os-linux.h b/fs/jffs2/os-linux.h
index a2dbbb3f4c74..ac23ae5cdb54 100644
--- a/fs/jffs2/os-linux.h
+++ b/fs/jffs2/os-linux.h
@@ -172,8 +172,8 @@ void jffs2_dirty_inode(struct inode *inode, int flags);
struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode,
struct jffs2_raw_inode *ri);
int jffs2_statfs (struct dentry *, struct kstatfs *);
-int jffs2_do_remount_fs(struct super_block *, int *, char *);
-int jffs2_do_fill_super(struct super_block *sb, void *data, int silent);
+int jffs2_do_remount_fs(struct super_block *sb, struct fs_context *fc);
+int jffs2_do_fill_super(struct super_block *sb, struct fs_context *fc);
void jffs2_gc_release_inode(struct jffs2_sb_info *c,
struct jffs2_inode_info *f);
struct jffs2_inode_info *jffs2_gc_fetch_inode(struct jffs2_sb_info *c,
diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c
index bb6ae387469f..69dcc4e0b243 100644
--- a/fs/jffs2/super.c
+++ b/fs/jffs2/super.c
@@ -19,7 +19,8 @@
#include <linux/fs.h>
#include <linux/err.h>
#include <linux/mount.h>
-#include <linux/parser.h>
+#include <linux/fs_context.h>
+#include <linux/fs_parser.h>
#include <linux/jffs2.h>
#include <linux/pagemap.h>
#include <linux/mtd/super.h>
@@ -160,96 +161,77 @@ static const struct export_operations jffs2_export_ops = {
/*
* JFFS2 mount options.
*
+ * Opt_source: The source device
* Opt_override_compr: override default compressor
* Opt_rp_size: size of reserved pool in KiB
- * Opt_err: just end of array marker
*/
enum {
+ Opt_source,
Opt_override_compr,
Opt_rp_size,
- Opt_err,
};
-static const match_table_t tokens = {
- {Opt_override_compr, "compr=%s"},
- {Opt_rp_size, "rp_size=%u"},
- {Opt_err, NULL},
+static const struct fs_parameter_spec jffs2_param_specs[] = {
+ fsparam_string ("source", Opt_source),
+ fsparam_enum ("compr", Opt_override_compr),
+ fsparam_u32 ("rp_size", Opt_rp_size),
+ {}
};
-static int jffs2_parse_options(struct jffs2_sb_info *c, char *data)
-{
- substring_t args[MAX_OPT_ARGS];
- char *p, *name;
- unsigned int opt;
-
- if (!data)
- return 0;
-
- while ((p = strsep(&data, ","))) {
- int token;
-
- if (!*p)
- continue;
-
- token = match_token(p, tokens, args);
- switch (token) {
- case Opt_override_compr:
- name = match_strdup(&args[0]);
-
- if (!name)
- return -ENOMEM;
- if (!strcmp(name, "none"))
- c->mount_opts.compr = JFFS2_COMPR_MODE_NONE;
+static const struct fs_parameter_enum jffs2_param_enums[] = {
+ { Opt_override_compr, "none", JFFS2_COMPR_MODE_NONE },
#ifdef CONFIG_JFFS2_LZO
- else if (!strcmp(name, "lzo"))
- c->mount_opts.compr = JFFS2_COMPR_MODE_FORCELZO;
+ { Opt_override_compr, "lzo", JFFS2_COMPR_MODE_FORCELZO },
#endif
#ifdef CONFIG_JFFS2_ZLIB
- else if (!strcmp(name, "zlib"))
- c->mount_opts.compr =
- JFFS2_COMPR_MODE_FORCEZLIB;
+ { Opt_override_compr, "zlib", JFFS2_COMPR_MODE_FORCEZLIB },
#endif
- else {
- pr_err("Error: unknown compressor \"%s\"\n",
- name);
- kfree(name);
- return -EINVAL;
- }
- kfree(name);
- c->mount_opts.override_compr = true;
- break;
- case Opt_rp_size:
- if (match_int(&args[0], &opt))
- return -EINVAL;
- opt *= 1024;
- if (opt > c->mtd->size) {
- pr_warn("Too large reserve pool specified, max "
- "is %llu KB\n", c->mtd->size / 1024);
- return -EINVAL;
- }
- c->mount_opts.rp_size = opt;
- break;
- default:
- pr_err("Error: unrecognized mount option '%s' or missing value\n",
- p);
- return -EINVAL;
- }
+ {}
+};
+
+const struct fs_parameter_description jffs2_fs_parameters = {
+ .name = "jffs2",
+ .specs = jffs2_param_specs,
+ .enums = jffs2_param_enums,
+};
+
+static int jffs2_parse_param(struct fs_context *fc, struct fs_parameter *param)
+{
+ struct fs_parse_result result;
+ struct jffs2_sb_info *c = fc->s_fs_info;
+ int opt;
+
+ opt = fs_parse(fc, &jffs2_fs_parameters, param, &result);
+ if (opt < 0)
+ return opt;
+
+ switch (opt) {
+ case Opt_override_compr:
+ c->mount_opts.compr = result.uint_32;
+ c->mount_opts.override_compr = true;
+ break;
+ case Opt_rp_size:
+ if (result.uint_32 > UINT_MAX / 1024)
+ return invalf(fc, "jffs2: rp_size unrepresentable");
+ opt = result.uint_32 * 1024;
+ if (opt > c->mtd->size)
+ return invalf(fc, "jffs2: Too large reserve pool specified, max is %llu KB",
+ c->mtd->size / 1024);
+ c->mount_opts.rp_size = opt;
+ break;
+ default:
+ return -EINVAL;
}
return 0;
}
-static int jffs2_remount_fs(struct super_block *sb, int *flags, char *data)
+static int jffs2_reconfigure(struct fs_context *fc)
{
- struct jffs2_sb_info *c = JFFS2_SB_INFO(sb);
- int err;
+ struct super_block *sb = fc->root->d_sb;
sync_filesystem(sb);
- err = jffs2_parse_options(c, data);
- if (err)
- return -EINVAL;
-
- return jffs2_do_remount_fs(sb, flags, data);
+ return jffs2_do_remount_fs(sb, fc);
}
static const struct super_operations jffs2_super_operations =
@@ -258,7 +240,6 @@ static const struct super_operations jffs2_super_operations =
.destroy_inode =jffs2_destroy_inode,
.put_super = jffs2_put_super,
.statfs = jffs2_statfs,
- .remount_fs = jffs2_remount_fs,
.evict_inode = jffs2_evict_inode,
.dirty_inode = jffs2_dirty_inode,
.show_options = jffs2_show_options,
@@ -268,26 +249,16 @@ static const struct super_operations jffs2_super_operations =
/*
* fill in the superblock
*/
-static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
+static int jffs2_fill_super(struct super_block *sb, struct fs_context *fc)
{
- struct jffs2_sb_info *c;
- int ret;
+ struct jffs2_sb_info *c = sb->s_fs_info;
jffs2_dbg(1, "jffs2_get_sb_mtd():"
" New superblock for device %d (\"%s\")\n",
sb->s_mtd->index, sb->s_mtd->name);
- c = kzalloc(sizeof(*c), GFP_KERNEL);
- if (!c)
- return -ENOMEM;
-
c->mtd = sb->s_mtd;
c->os_priv = sb;
- sb->s_fs_info = c;
-
- ret = jffs2_parse_options(c, data);
- if (ret)
- return -EINVAL;
/* Initialize JFFS2 superblock locks, the further initialization will
* be done later */
@@ -305,15 +276,37 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent)
#ifdef CONFIG_JFFS2_FS_POSIX_ACL
sb->s_flags |= SB_POSIXACL;
#endif
- ret = jffs2_do_fill_super(sb, data, silent);
- return ret;
+ return jffs2_do_fill_super(sb, fc);
}
-static struct dentry *jffs2_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name,
- void *data)
+static int jffs2_get_tree(struct fs_context *fc)
{
- return mount_mtd(fs_type, flags, dev_name, data, jffs2_fill_super);
+ return vfs_get_mtd_super(fc, jffs2_fill_super);
+}
+
+static void jffs2_free_fc(struct fs_context *fc)
+{
+ kfree(fc->s_fs_info);
+}
+
+static const struct fs_context_operations jffs2_context_ops = {
+ .free = jffs2_free_fc,
+ .parse_param = jffs2_parse_param,
+ .get_tree = jffs2_get_tree,
+ .reconfigure = jffs2_reconfigure,
+};
+
+static int jffs2_init_fs_context(struct fs_context *fc)
+{
+ struct jffs2_sb_info *ctx;
+
+ ctx = kzalloc(sizeof(struct jffs2_sb_info), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+
+ fc->s_fs_info = ctx;
+ fc->ops = &jffs2_context_ops;
+ return 0;
}
static void jffs2_put_super (struct super_block *sb)
@@ -350,7 +343,8 @@ static void jffs2_kill_sb(struct super_block *sb)
static struct file_system_type jffs2_fs_type = {
.owner = THIS_MODULE,
.name = "jffs2",
- .mount = jffs2_mount,
+ .init_fs_context = jffs2_init_fs_context,
+ .parameters = &jffs2_fs_parameters,
.kill_sb = jffs2_kill_sb,
};
MODULE_ALIAS_FS("jffs2");
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 5/6] mtd: Kill off mount_mtd()
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
` (3 preceding siblings ...)
2019-03-20 14:45 ` [RFC PATCH 4/6] jffs2: " David Howells
@ 2019-03-20 14:45 ` David Howells
2019-03-20 14:45 ` [RFC PATCH 6/6] squashfs: Convert to fs_context David Howells
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Kill off mount_mtd() as it has now been replaced and nothing now uses it.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---
drivers/mtd/mtdsuper.c | 189 ---------------------------------------------
include/linux/mtd/super.h | 3 -
2 files changed, 192 deletions(-)
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index cf223c4aa862..b5db8baab3d3 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -210,195 +210,6 @@ int vfs_get_mtd_super(struct fs_context *fc,
}
EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
-/*
- * compare superblocks to see if they're equivalent
- * - they are if the underlying MTD device is the same
- */
-static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
-{
- struct mtd_info *mtd = _mtd;
-
- if (sb->s_mtd == mtd) {
- pr_debug("MTDSB: Match on device %d (\"%s\")\n",
- mtd->index, mtd->name);
- return 1;
- }
-
- pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
- sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
- return 0;
-}
-
-/*
- * mark the superblock by the MTD device it is using
- * - set the device number to be the correct MTD block device for pesuperstence
- * of NFS exports
- */
-static int get_sb_mtd_set(struct super_block *sb, void *_mtd)
-{
- struct mtd_info *mtd = _mtd;
-
- sb->s_mtd = mtd;
- sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
- sb->s_bdi = bdi_get(mtd_bdi);
-
- return 0;
-}
-
-/*
- * get a superblock on an MTD-backed filesystem
- */
-static struct dentry *mount_mtd_aux(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data,
- struct mtd_info *mtd,
- int (*fill_super)(struct super_block *, void *, int))
-{
- struct super_block *sb;
- int ret;
-
- sb = sget(fs_type, get_sb_mtd_compare, get_sb_mtd_set, flags, mtd);
- if (IS_ERR(sb))
- goto out_error;
-
- if (sb->s_root)
- goto already_mounted;
-
- /* fresh new superblock */
- pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
- mtd->index, mtd->name);
-
- ret = fill_super(sb, data, flags & SB_SILENT ? 1 : 0);
- if (ret < 0) {
- deactivate_locked_super(sb);
- return ERR_PTR(ret);
- }
-
- /* go */
- sb->s_flags |= SB_ACTIVE;
- return dget(sb->s_root);
-
- /* new mountpoint for an already mounted superblock */
-already_mounted:
- pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
- mtd->index, mtd->name);
- put_mtd_device(mtd);
- return dget(sb->s_root);
-
-out_error:
- put_mtd_device(mtd);
- return ERR_CAST(sb);
-}
-
-/*
- * get a superblock on an MTD-backed filesystem by MTD device number
- */
-static struct dentry *mount_mtd_nr(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data, int mtdnr,
- int (*fill_super)(struct super_block *, void *, int))
-{
- struct mtd_info *mtd;
-
- mtd = get_mtd_device(NULL, mtdnr);
- if (IS_ERR(mtd)) {
- pr_debug("MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
- return ERR_CAST(mtd);
- }
-
- return mount_mtd_aux(fs_type, flags, dev_name, data, mtd, fill_super);
-}
-
-/*
- * set up an MTD-based superblock
- */
-struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data,
- int (*fill_super)(struct super_block *, void *, int))
-{
-#ifdef CONFIG_BLOCK
- struct block_device *bdev;
- int ret, major;
-#endif
- int mtdnr;
-
- if (!dev_name)
- return ERR_PTR(-EINVAL);
-
- pr_debug("MTDSB: dev_name \"%s\"\n", dev_name);
-
- /* the preferred way of mounting in future; especially when
- * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
- * by name, so that we don't require block device support to be present
- * in the kernel. */
- if (dev_name[0] == 'm' && dev_name[1] == 't' && dev_name[2] == 'd') {
- if (dev_name[3] == ':') {
- struct mtd_info *mtd;
-
- /* mount by MTD device name */
- pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
- dev_name + 4);
-
- mtd = get_mtd_device_nm(dev_name + 4);
- if (!IS_ERR(mtd))
- return mount_mtd_aux(
- fs_type, flags,
- dev_name, data, mtd,
- fill_super);
-
- printk(KERN_NOTICE "MTD:"
- " MTD device with name \"%s\" not found.\n",
- dev_name + 4);
-
- } else if (isdigit(dev_name[3])) {
- /* mount by MTD device number name */
- char *endptr;
-
- mtdnr = simple_strtoul(dev_name + 3, &endptr, 0);
- if (!*endptr) {
- /* It was a valid number */
- pr_debug("MTDSB: mtd%%d, mtdnr %d\n",
- mtdnr);
- return mount_mtd_nr(fs_type, flags,
- dev_name, data,
- mtdnr, fill_super);
- }
- }
- }
-
-#ifdef CONFIG_BLOCK
- /* try the old way - the hack where we allowed users to mount
- * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
- */
- bdev = lookup_bdev(dev_name);
- if (IS_ERR(bdev)) {
- ret = PTR_ERR(bdev);
- pr_debug("MTDSB: lookup_bdev() returned %d\n", ret);
- return ERR_PTR(ret);
- }
- pr_debug("MTDSB: lookup_bdev() returned 0\n");
-
- ret = -EINVAL;
-
- major = MAJOR(bdev->bd_dev);
- mtdnr = MINOR(bdev->bd_dev);
- bdput(bdev);
-
- if (major != MTD_BLOCK_MAJOR)
- goto not_an_MTD_device;
-
- return mount_mtd_nr(fs_type, flags, dev_name, data, mtdnr, fill_super);
-
-not_an_MTD_device:
-#endif /* CONFIG_BLOCK */
-
- if (!(flags & SB_SILENT))
- printk(KERN_NOTICE
- "MTD: Attempt to mount non-MTD device \"%s\"\n",
- dev_name);
- return ERR_PTR(-EINVAL);
-}
-
-EXPORT_SYMBOL_GPL(mount_mtd);
-
/*
* destroy an MTD-based superblock
*/
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index 7ebd69e5c640..c8bfaf0b8fe7 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -21,9 +21,6 @@
extern int vfs_get_mtd_super(struct fs_context *fc,
int (*fill_super)(struct super_block *sb,
struct fs_context *fc));
-extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
- const char *dev_name, void *data,
- int (*fill_super)(struct super_block *, void *, int));
extern void kill_mtd_super(struct super_block *sb);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 6/6] squashfs: Convert to fs_context
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
` (4 preceding siblings ...)
2019-03-20 14:45 ` [RFC PATCH 5/6] mtd: Kill off mount_mtd() David Howells
@ 2019-03-20 14:45 ` David Howells
5 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-20 14:45 UTC (permalink / raw)
To: viro; +Cc: linux-fsdevel, linux-kernel, dhowells
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Phillip Lougher <phillip@squashfs.org.uk>
cc: squashfs-devel@lists.sourceforge.net
---
fs/squashfs/super.c | 100 ++++++++++++++++++++++++++++-----------------------
1 file changed, 55 insertions(+), 45 deletions(-)
diff --git a/fs/squashfs/super.c b/fs/squashfs/super.c
index 40e657386fa5..672011725eb2 100644
--- a/fs/squashfs/super.c
+++ b/fs/squashfs/super.c
@@ -30,6 +30,7 @@
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/fs.h>
+#include <linux/fs_context.h>
#include <linux/vfs.h>
#include <linux/slab.h>
#include <linux/mutex.h>
@@ -49,26 +50,27 @@
static struct file_system_type squashfs_fs_type;
static const struct super_operations squashfs_super_ops;
-static const struct squashfs_decompressor *supported_squashfs_filesystem(short
- major, short minor, short id)
+static const struct squashfs_decompressor *supported_squashfs_filesystem(
+ struct fs_context *fc,
+ short major, short minor, short id)
{
const struct squashfs_decompressor *decompressor;
if (major < SQUASHFS_MAJOR) {
- ERROR("Major/Minor mismatch, older Squashfs %d.%d "
- "filesystems are unsupported\n", major, minor);
+ errorf(fc, "Major/Minor mismatch, older Squashfs %d.%d "
+ "filesystems are unsupported", major, minor);
return NULL;
} else if (major > SQUASHFS_MAJOR || minor > SQUASHFS_MINOR) {
- ERROR("Major/Minor mismatch, trying to mount newer "
- "%d.%d filesystem\n", major, minor);
- ERROR("Please update your kernel\n");
+ errorf(fc, "Major/Minor mismatch, trying to mount newer "
+ "%d.%d filesystem", major, minor);
+ errorf(fc, "Please update your kernel");
return NULL;
}
decompressor = squashfs_lookup_decompressor(id);
if (!decompressor->supported) {
- ERROR("Filesystem uses \"%s\" compression. This is not "
- "supported\n", decompressor->name);
+ errorf(fc, "Filesystem uses \"%s\" compression. This is not supported",
+ decompressor->name);
return NULL;
}
@@ -76,7 +78,7 @@ static const struct squashfs_decompressor *supported_squashfs_filesystem(short
}
-static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
+static int squashfs_fill_super(struct super_block *sb, struct fs_context *fc)
{
struct squashfs_sb_info *msblk;
struct squashfs_super_block *sblk = NULL;
@@ -111,7 +113,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
sblk = squashfs_read_table(sb, SQUASHFS_START, sizeof(*sblk));
if (IS_ERR(sblk)) {
- ERROR("unable to read squashfs_super_block\n");
+ errorf(fc, "unable to read squashfs_super_block");
err = PTR_ERR(sblk);
sblk = NULL;
goto failed_mount;
@@ -122,14 +124,15 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
/* Check it is a SQUASHFS superblock */
sb->s_magic = le32_to_cpu(sblk->s_magic);
if (sb->s_magic != SQUASHFS_MAGIC) {
- if (!silent)
- ERROR("Can't find a SQUASHFS superblock on %pg\n",
- sb->s_bdev);
+ if (!(fc->sb_flags & SB_SILENT))
+ errorf(fc, "Can't find a SQUASHFS superblock on %pg",
+ sb->s_bdev);
goto failed_mount;
}
/* Check the MAJOR & MINOR versions and lookup compression type */
msblk->decompressor = supported_squashfs_filesystem(
+ fc,
le16_to_cpu(sblk->s_major),
le16_to_cpu(sblk->s_minor),
le16_to_cpu(sblk->compression));
@@ -146,15 +149,15 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
/* Check block size for sanity */
msblk->block_size = le32_to_cpu(sblk->block_size);
if (msblk->block_size > SQUASHFS_FILE_MAX_SIZE)
- goto failed_mount;
+ goto insanity;
/*
* Check the system page size is not larger than the filesystem
* block size (by default 128K). This is currently not supported.
*/
if (PAGE_SIZE > msblk->block_size) {
- ERROR("Page size > filesystem block size (%d). This is "
- "currently not supported!\n", msblk->block_size);
+ errorf(fc, "Page size > filesystem block size (%d). This is "
+ "currently not supported!", msblk->block_size);
goto failed_mount;
}
@@ -165,12 +168,12 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
/* Check that block_size and block_log match */
if (msblk->block_size != (1 << msblk->block_log))
- goto failed_mount;
+ goto insanity;
/* Check the root inode for sanity */
root_inode = le64_to_cpu(sblk->root_inode);
if (SQUASHFS_INODE_OFFSET(root_inode) > SQUASHFS_METADATA_SIZE)
- goto failed_mount;
+ goto insanity;
msblk->inode_table = le64_to_cpu(sblk->inode_table_start);
msblk->directory_table = le64_to_cpu(sblk->directory_table_start);
@@ -210,7 +213,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
msblk->read_page = squashfs_cache_init("data",
squashfs_max_decompressors(), msblk->block_size);
if (msblk->read_page == NULL) {
- ERROR("Failed to allocate read_page block\n");
+ errorf(fc, "Failed to allocate read_page block");
goto failed_mount;
}
@@ -218,7 +221,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
if (IS_ERR(msblk->stream)) {
err = PTR_ERR(msblk->stream);
msblk->stream = NULL;
- goto failed_mount;
+ goto insanity;
}
/* Handle xattrs */
@@ -233,7 +236,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
if (IS_ERR(msblk->xattr_id_table)) {
- ERROR("unable to read xattr id index table\n");
+ errorf(fc, "unable to read xattr id index table");
err = PTR_ERR(msblk->xattr_id_table);
msblk->xattr_id_table = NULL;
if (err != -ENOTSUPP)
@@ -247,7 +250,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
le64_to_cpu(sblk->id_table_start), next_table,
le16_to_cpu(sblk->no_ids));
if (IS_ERR(msblk->id_table)) {
- ERROR("unable to read id index table\n");
+ errorf(fc, "unable to read id index table");
err = PTR_ERR(msblk->id_table);
msblk->id_table = NULL;
goto failed_mount;
@@ -263,7 +266,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
lookup_table_start, next_table, msblk->inodes);
if (IS_ERR(msblk->inode_lookup_table)) {
- ERROR("unable to read inode lookup table\n");
+ errorf(fc, "unable to read inode lookup table");
err = PTR_ERR(msblk->inode_lookup_table);
msblk->inode_lookup_table = NULL;
goto failed_mount;
@@ -288,7 +291,7 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
msblk->fragment_index = squashfs_read_fragment_index_table(sb,
le64_to_cpu(sblk->fragment_table_start), next_table, fragments);
if (IS_ERR(msblk->fragment_index)) {
- ERROR("unable to read fragment index table\n");
+ errorf(fc, "unable to read fragment index table");
err = PTR_ERR(msblk->fragment_index);
msblk->fragment_index = NULL;
goto failed_mount;
@@ -299,13 +302,13 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
/* Sanity check directory_table */
if (msblk->directory_table > next_table) {
err = -EINVAL;
- goto failed_mount;
+ goto insanity;
}
/* Sanity check inode_table */
if (msblk->inode_table >= msblk->directory_table) {
err = -EINVAL;
- goto failed_mount;
+ goto insanity;
}
/* allocate root */
@@ -334,6 +337,8 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
kfree(sblk);
return 0;
+insanity:
+ errorf(fc, "squashfs image failed sanity check");
failed_mount:
squashfs_cache_delete(msblk->block_cache);
squashfs_cache_delete(msblk->fragment_cache);
@@ -349,6 +354,28 @@ static int squashfs_fill_super(struct super_block *sb, void *data, int silent)
return err;
}
+static int squashfs_get_tree(struct fs_context *fc)
+{
+ return vfs_get_block_super(fc, squashfs_fill_super);
+}
+
+static int squashfs_reconfigure(struct fs_context *fc)
+{
+ sync_filesystem(fc->root->d_sb);
+ fc->sb_flags |= SB_RDONLY;
+ return 0;
+}
+
+static const struct fs_context_operations squashfs_context_ops = {
+ .get_tree = squashfs_get_tree,
+ .reconfigure = squashfs_reconfigure,
+};
+
+static int squashfs_init_fs_context(struct fs_context *fc)
+{
+ fc->ops = &squashfs_context_ops;
+ return 0;
+}
static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
{
@@ -371,14 +398,6 @@ static int squashfs_statfs(struct dentry *dentry, struct kstatfs *buf)
}
-static int squashfs_remount(struct super_block *sb, int *flags, char *data)
-{
- sync_filesystem(sb);
- *flags |= SB_RDONLY;
- return 0;
-}
-
-
static void squashfs_put_super(struct super_block *sb)
{
if (sb->s_fs_info) {
@@ -397,14 +416,6 @@ static void squashfs_put_super(struct super_block *sb)
}
}
-
-static struct dentry *squashfs_mount(struct file_system_type *fs_type,
- int flags, const char *dev_name, void *data)
-{
- return mount_bdev(fs_type, flags, dev_name, data, squashfs_fill_super);
-}
-
-
static struct kmem_cache *squashfs_inode_cachep;
@@ -488,7 +499,7 @@ static void squashfs_destroy_inode(struct inode *inode)
static struct file_system_type squashfs_fs_type = {
.owner = THIS_MODULE,
.name = "squashfs",
- .mount = squashfs_mount,
+ .init_fs_context = squashfs_init_fs_context,
.kill_sb = kill_block_super,
.fs_flags = FS_REQUIRES_DEV
};
@@ -499,7 +510,6 @@ static const struct super_operations squashfs_super_ops = {
.destroy_inode = squashfs_destroy_inode,
.statfs = squashfs_statfs,
.put_super = squashfs_put_super,
- .remount_fs = squashfs_remount
};
module_init(init_squashfs_fs);
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement
2019-03-21 11:51 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
@ 2019-03-21 11:52 ` David Howells
0 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-21 11:52 UTC (permalink / raw)
To: viro
Cc: David Woodhouse, Brian Norris, Boris Brezillon, Marek Vasut,
Richard Weinberger, linux-mtd, linux-fsdevel, linux-kernel,
dhowells
Provide a function, vfs_get_mtd_super(), to replace mount_mtd(), using an
fs_context struct to hold the parameters. The mtd device pointer is cached
in the struct, along with a destructor pointer as the mtd core may be in a
module and, as such, unreachable by the core code that would release the
fs_context.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---
drivers/mtd/mtdcore.h | 1
drivers/mtd/mtdsuper.c | 192 ++++++++++++++++++++++++++++++++++++++++++++
fs/fs_context.c | 2
include/linux/fs_context.h | 2
include/linux/mtd/super.h | 3 +
5 files changed, 198 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index b31c868019ad..b5eefeabf310 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -5,6 +5,7 @@
*/
extern struct mutex mtd_table_mutex;
+extern struct backing_dev_info *mtd_bdi;
struct mtd_info *__mtd_next_device(int i);
int __must_check add_mtd_device(struct mtd_info *mtd);
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index d58a61c09304..cf223c4aa862 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -19,6 +19,196 @@
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include "mtdcore.h"
+
+static void mtd_fc_destructor(struct fs_context *fc)
+{
+ if (fc->mtd)
+ put_mtd_device(fc->mtd);
+}
+
+/*
+ * compare superblocks to see if they're equivalent
+ * - they are if the underlying MTD device is the same
+ */
+static int mtd_test_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ if (sb->s_mtd == mtd) {
+ pr_debug("MTDSB: Match on device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+ return 1;
+ }
+
+ pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
+ sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
+ return 0;
+}
+
+/*
+ * mark the superblock by the MTD device it is using
+ * - set the device number to be the correct MTD block device for pesuperstence
+ * of NFS exports
+ */
+static int mtd_set_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ sb->s_mtd = mtd;
+ sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
+ sb->s_bdi = bdi_get(mtd_bdi);
+ fc->mtd = NULL;
+ return 0;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem
+ */
+static int mtd_get_sb(struct fs_context *fc,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct super_block *sb;
+ struct mtd_info *mtd = fc->mtd;
+ int ret;
+
+ sb = sget_fc(fc, mtd_test_super, mtd_set_super);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+
+ if (sb->s_root) {
+ /* new mountpoint for an already mounted superblock */
+ pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
+ mtd->index, mtd->name);
+ put_mtd_device(mtd);
+ } else {
+ /* fresh new superblock */
+ pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+
+ ret = fill_super(sb, fc);
+ if (ret < 0)
+ goto error_sb;
+
+ sb->s_flags |= SB_ACTIVE;
+ }
+
+ BUG_ON(fc->root);
+ fc->root = dget(sb->s_root);
+ return 0;
+
+error_sb:
+ deactivate_locked_super(sb);
+ return ret;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem by MTD device number
+ */
+static int mtd_get_sb_by_nr(struct fs_context *fc, int mtdnr,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct mtd_info *mtd;
+
+ mtd = get_mtd_device(NULL, mtdnr);
+ if (IS_ERR(mtd)) {
+ errorf(fc, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
+ return PTR_ERR(mtd);
+ }
+
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+}
+
+/**
+ * vfs_get_mtd_super - Get a superblock based on a single MTD device
+ * @fc: The filesystem context holding the parameters
+ * @fill_super: Helper to initialise a new superblock
+ */
+int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+#ifdef CONFIG_BLOCK
+ struct block_device *bdev;
+ int ret, major;
+#endif
+ int mtdnr;
+
+ if (!fc->source)
+ return invalf(fc, "No source specified");
+
+ pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);
+
+ /* the preferred way of mounting in future; especially when
+ * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
+ * by name, so that we don't require block device support to be present
+ * in the kernel.
+ */
+ if (fc->source[0] == 'm' &&
+ fc->source[1] == 't' &&
+ fc->source[2] == 'd') {
+ if (fc->source[3] == ':') {
+ struct mtd_info *mtd;
+
+ /* mount by MTD device name */
+ pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
+ fc->source + 4);
+
+ mtd = get_mtd_device_nm(fc->source + 4);
+ if (!IS_ERR(mtd)) {
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+ }
+
+ errorf(fc, "MTD: MTD device with name \"%s\" not found",
+ fc->source + 4);
+
+ } else if (isdigit(fc->source[3])) {
+ /* mount by MTD device number name */
+ char *endptr;
+
+ mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);
+ if (!*endptr) {
+ /* It was a valid number */
+ pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+ }
+ }
+ }
+
+#ifdef CONFIG_BLOCK
+ /* try the old way - the hack where we allowed users to mount
+ * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
+ */
+ bdev = lookup_bdev(fc->source);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);
+ return ret;
+ }
+ pr_debug("MTDSB: lookup_bdev() returned 0\n");
+
+ major = MAJOR(bdev->bd_dev);
+ mtdnr = MINOR(bdev->bd_dev);
+ bdput(bdev);
+
+ if (major == MTD_BLOCK_MAJOR)
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+
+#endif /* CONFIG_BLOCK */
+
+ if (!(fc->sb_flags & SB_SILENT))
+ errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",
+ fc->source);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
/*
* compare superblocks to see if they're equivalent
@@ -39,8 +229,6 @@ static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
return 0;
}
-extern struct backing_dev_info *mtd_bdi;
-
/*
* mark the superblock by the MTD device it is using
* - set the device number to be the correct MTD block device for pesuperstence
diff --git a/fs/fs_context.c b/fs/fs_context.c
index ee727665d7f6..b191d215057d 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -429,6 +429,8 @@ void put_fs_context(struct fs_context *fc)
if (fc->bdev)
blkdev_put(fc->bdev, fc->bdev_mode);
#endif
+ if (fc->destructor)
+ fc->destructor(fc);
security_free_mnt_opts(&fc->security);
put_net(fc->net_ns);
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 524963c0cedb..8233c873af73 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -77,6 +77,7 @@ struct fs_context {
struct file_system_type *fs_type;
void *fs_private; /* The filesystem's context */
struct block_device *bdev; /* The backing blockdev (if applicable) */
+ struct mtd_info *mtd; /* The backing mtd (if applicable) */
struct dentry *root; /* The root and superblock */
struct user_namespace *user_ns; /* The user namespace for this mount */
struct net *net_ns; /* The network namespace for this mount */
@@ -92,6 +93,7 @@ struct fs_context {
enum fs_context_purpose purpose:8;
bool need_free:1; /* Need to call ops->free() */
bool global:1; /* Goes into &init_user_ns */
+ void (*destructor)(struct fs_context *fc); /* For mtd */
};
struct fs_context_operations {
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index f456230f9330..7ebd69e5c640 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -18,6 +18,9 @@
#include <linux/fs.h>
#include <linux/mount.h>
+extern int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
^ permalink raw reply related [flat|nested] 9+ messages in thread
* [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement
2019-03-21 11:50 [RFC PATCH 0/6] Convert mount_single-using filesystems " David Howells
@ 2019-03-21 11:50 ` David Howells
0 siblings, 0 replies; 9+ messages in thread
From: David Howells @ 2019-03-21 11:50 UTC (permalink / raw)
To: viro
Cc: David Woodhouse, Brian Norris, Boris Brezillon, Marek Vasut,
Richard Weinberger, linux-mtd, linux-fsdevel, linux-kernel,
dhowells
Provide a function, vfs_get_mtd_super(), to replace mount_mtd(), using an
fs_context struct to hold the parameters. The mtd device pointer is cached
in the struct, along with a destructor pointer as the mtd core may be in a
module and, as such, unreachable by the core code that would release the
fs_context.
Signed-off-by: David Howells <dhowells@redhat.com>
cc: David Woodhouse <dwmw2@infradead.org>
cc: Brian Norris <computersforpeace@gmail.com>
cc: Boris Brezillon <bbrezillon@kernel.org>
cc: Marek Vasut <marek.vasut@gmail.com>
cc: Richard Weinberger <richard@nod.at>
cc: linux-mtd@lists.infradead.org
---
drivers/mtd/mtdcore.h | 1
drivers/mtd/mtdsuper.c | 192 ++++++++++++++++++++++++++++++++++++++++++++
fs/fs_context.c | 2
include/linux/fs_context.h | 2
include/linux/mtd/super.h | 3 +
5 files changed, 198 insertions(+), 2 deletions(-)
diff --git a/drivers/mtd/mtdcore.h b/drivers/mtd/mtdcore.h
index b31c868019ad..b5eefeabf310 100644
--- a/drivers/mtd/mtdcore.h
+++ b/drivers/mtd/mtdcore.h
@@ -5,6 +5,7 @@
*/
extern struct mutex mtd_table_mutex;
+extern struct backing_dev_info *mtd_bdi;
struct mtd_info *__mtd_next_device(int i);
int __must_check add_mtd_device(struct mtd_info *mtd);
diff --git a/drivers/mtd/mtdsuper.c b/drivers/mtd/mtdsuper.c
index d58a61c09304..cf223c4aa862 100644
--- a/drivers/mtd/mtdsuper.c
+++ b/drivers/mtd/mtdsuper.c
@@ -19,6 +19,196 @@
#include <linux/slab.h>
#include <linux/major.h>
#include <linux/backing-dev.h>
+#include <linux/fs_context.h>
+#include "mtdcore.h"
+
+static void mtd_fc_destructor(struct fs_context *fc)
+{
+ if (fc->mtd)
+ put_mtd_device(fc->mtd);
+}
+
+/*
+ * compare superblocks to see if they're equivalent
+ * - they are if the underlying MTD device is the same
+ */
+static int mtd_test_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ if (sb->s_mtd == mtd) {
+ pr_debug("MTDSB: Match on device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+ return 1;
+ }
+
+ pr_debug("MTDSB: No match, device %d (\"%s\"), device %d (\"%s\")\n",
+ sb->s_mtd->index, sb->s_mtd->name, mtd->index, mtd->name);
+ return 0;
+}
+
+/*
+ * mark the superblock by the MTD device it is using
+ * - set the device number to be the correct MTD block device for pesuperstence
+ * of NFS exports
+ */
+static int mtd_set_super(struct super_block *sb, struct fs_context *fc)
+{
+ struct mtd_info *mtd = fc->mtd;
+
+ sb->s_mtd = mtd;
+ sb->s_dev = MKDEV(MTD_BLOCK_MAJOR, mtd->index);
+ sb->s_bdi = bdi_get(mtd_bdi);
+ fc->mtd = NULL;
+ return 0;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem
+ */
+static int mtd_get_sb(struct fs_context *fc,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct super_block *sb;
+ struct mtd_info *mtd = fc->mtd;
+ int ret;
+
+ sb = sget_fc(fc, mtd_test_super, mtd_set_super);
+ if (IS_ERR(sb))
+ return PTR_ERR(sb);
+
+ if (sb->s_root) {
+ /* new mountpoint for an already mounted superblock */
+ pr_debug("MTDSB: Device %d (\"%s\") is already mounted\n",
+ mtd->index, mtd->name);
+ put_mtd_device(mtd);
+ } else {
+ /* fresh new superblock */
+ pr_debug("MTDSB: New superblock for device %d (\"%s\")\n",
+ mtd->index, mtd->name);
+
+ ret = fill_super(sb, fc);
+ if (ret < 0)
+ goto error_sb;
+
+ sb->s_flags |= SB_ACTIVE;
+ }
+
+ BUG_ON(fc->root);
+ fc->root = dget(sb->s_root);
+ return 0;
+
+error_sb:
+ deactivate_locked_super(sb);
+ return ret;
+}
+
+/*
+ * get a superblock on an MTD-backed filesystem by MTD device number
+ */
+static int mtd_get_sb_by_nr(struct fs_context *fc, int mtdnr,
+ int (*fill_super)(struct super_block *,
+ struct fs_context *))
+{
+ struct mtd_info *mtd;
+
+ mtd = get_mtd_device(NULL, mtdnr);
+ if (IS_ERR(mtd)) {
+ errorf(fc, "MTDSB: Device #%u doesn't appear to exist\n", mtdnr);
+ return PTR_ERR(mtd);
+ }
+
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+}
+
+/**
+ * vfs_get_mtd_super - Get a superblock based on a single MTD device
+ * @fc: The filesystem context holding the parameters
+ * @fill_super: Helper to initialise a new superblock
+ */
+int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc))
+{
+#ifdef CONFIG_BLOCK
+ struct block_device *bdev;
+ int ret, major;
+#endif
+ int mtdnr;
+
+ if (!fc->source)
+ return invalf(fc, "No source specified");
+
+ pr_debug("MTDSB: dev_name \"%s\"\n", fc->source);
+
+ /* the preferred way of mounting in future; especially when
+ * CONFIG_BLOCK=n - we specify the underlying MTD device by number or
+ * by name, so that we don't require block device support to be present
+ * in the kernel.
+ */
+ if (fc->source[0] == 'm' &&
+ fc->source[1] == 't' &&
+ fc->source[2] == 'd') {
+ if (fc->source[3] == ':') {
+ struct mtd_info *mtd;
+
+ /* mount by MTD device name */
+ pr_debug("MTDSB: mtd:%%s, name \"%s\"\n",
+ fc->source + 4);
+
+ mtd = get_mtd_device_nm(fc->source + 4);
+ if (!IS_ERR(mtd)) {
+ fc->mtd = mtd;
+ fc->destructor = mtd_fc_destructor;
+ return mtd_get_sb(fc, fill_super);
+ }
+
+ errorf(fc, "MTD: MTD device with name \"%s\" not found",
+ fc->source + 4);
+
+ } else if (isdigit(fc->source[3])) {
+ /* mount by MTD device number name */
+ char *endptr;
+
+ mtdnr = simple_strtoul(fc->source + 3, &endptr, 0);
+ if (!*endptr) {
+ /* It was a valid number */
+ pr_debug("MTDSB: mtd%%d, mtdnr %d\n", mtdnr);
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+ }
+ }
+ }
+
+#ifdef CONFIG_BLOCK
+ /* try the old way - the hack where we allowed users to mount
+ * /dev/mtdblock$(n) but didn't actually _use_ the blockdev
+ */
+ bdev = lookup_bdev(fc->source);
+ if (IS_ERR(bdev)) {
+ ret = PTR_ERR(bdev);
+ errorf(fc, "MTD: Couldn't look up '%s': %d", fc->source, ret);
+ return ret;
+ }
+ pr_debug("MTDSB: lookup_bdev() returned 0\n");
+
+ major = MAJOR(bdev->bd_dev);
+ mtdnr = MINOR(bdev->bd_dev);
+ bdput(bdev);
+
+ if (major == MTD_BLOCK_MAJOR)
+ return mtd_get_sb_by_nr(fc, mtdnr, fill_super);
+
+#endif /* CONFIG_BLOCK */
+
+ if (!(fc->sb_flags & SB_SILENT))
+ errorf(fc, "MTD: Attempt to mount non-MTD device \"%s\"",
+ fc->source);
+ return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(vfs_get_mtd_super);
/*
* compare superblocks to see if they're equivalent
@@ -39,8 +229,6 @@ static int get_sb_mtd_compare(struct super_block *sb, void *_mtd)
return 0;
}
-extern struct backing_dev_info *mtd_bdi;
-
/*
* mark the superblock by the MTD device it is using
* - set the device number to be the correct MTD block device for pesuperstence
diff --git a/fs/fs_context.c b/fs/fs_context.c
index ee727665d7f6..b191d215057d 100644
--- a/fs/fs_context.c
+++ b/fs/fs_context.c
@@ -429,6 +429,8 @@ void put_fs_context(struct fs_context *fc)
if (fc->bdev)
blkdev_put(fc->bdev, fc->bdev_mode);
#endif
+ if (fc->destructor)
+ fc->destructor(fc);
security_free_mnt_opts(&fc->security);
put_net(fc->net_ns);
diff --git a/include/linux/fs_context.h b/include/linux/fs_context.h
index 524963c0cedb..8233c873af73 100644
--- a/include/linux/fs_context.h
+++ b/include/linux/fs_context.h
@@ -77,6 +77,7 @@ struct fs_context {
struct file_system_type *fs_type;
void *fs_private; /* The filesystem's context */
struct block_device *bdev; /* The backing blockdev (if applicable) */
+ struct mtd_info *mtd; /* The backing mtd (if applicable) */
struct dentry *root; /* The root and superblock */
struct user_namespace *user_ns; /* The user namespace for this mount */
struct net *net_ns; /* The network namespace for this mount */
@@ -92,6 +93,7 @@ struct fs_context {
enum fs_context_purpose purpose:8;
bool need_free:1; /* Need to call ops->free() */
bool global:1; /* Goes into &init_user_ns */
+ void (*destructor)(struct fs_context *fc); /* For mtd */
};
struct fs_context_operations {
diff --git a/include/linux/mtd/super.h b/include/linux/mtd/super.h
index f456230f9330..7ebd69e5c640 100644
--- a/include/linux/mtd/super.h
+++ b/include/linux/mtd/super.h
@@ -18,6 +18,9 @@
#include <linux/fs.h>
#include <linux/mount.h>
+extern int vfs_get_mtd_super(struct fs_context *fc,
+ int (*fill_super)(struct super_block *sb,
+ struct fs_context *fc));
extern struct dentry *mount_mtd(struct file_system_type *fs_type, int flags,
const char *dev_name, void *data,
int (*fill_super)(struct super_block *, void *, int));
^ permalink raw reply related [flat|nested] 9+ messages in thread
end of thread, other threads:[~2019-03-21 11:52 UTC | newest]
Thread overview: 9+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2019-03-20 14:44 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
2019-03-20 14:45 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
2019-03-20 14:45 ` [RFC PATCH 2/6] romfs: Convert to fs_context David Howells
2019-03-20 14:45 ` [RFC PATCH 3/6] cramfs: " David Howells
2019-03-20 14:45 ` [RFC PATCH 4/6] jffs2: " David Howells
2019-03-20 14:45 ` [RFC PATCH 5/6] mtd: Kill off mount_mtd() David Howells
2019-03-20 14:45 ` [RFC PATCH 6/6] squashfs: Convert to fs_context David Howells
2019-03-21 11:50 [RFC PATCH 0/6] Convert mount_single-using filesystems " David Howells
2019-03-21 11:50 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
2019-03-21 11:51 [RFC PATCH 0/6] mtd, romfs, cramfs, jffs2, squashfs: Convert to fs_context David Howells
2019-03-21 11:52 ` [RFC PATCH 1/6] mtd: Provide fs_context-aware mount_mtd() replacement David Howells
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