The patch titled
knfsd: exportfs: remove iget abuse
has been added to the -mm tree. Its filename is
knfsd-exportfs-remove-iget-abuse.patch
*** Remember to use Documentation/SubmitChecklist when testing your code ***
See http://www.zip.com.au/~akpm/linux/patches/stuff/added-to-mm.txt to find
out what to do about this
------------------------------------------------------
Subject: knfsd: exportfs: remove iget abuse
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
When the exportfs interface was added the expectation was that filesystems
provide an operation to convert from a file handle to an inode/dentry, but it
kept a backwards compat option that still calls into iget.
Calling into iget from non-filesystem code is very bad, because it gives too
little information to filesystem, and simply crashes if the filesystem doesn't
implement the ->read_inode routine.
Fortunately there are only two filesystems left using this fallback: efs and
jfs. This patch moves a copy of export_iget to each of those to implement the
get_dentry method.
While this is a temporary increase of lines of code in the kernel it allows
for a much cleaner interface and important code restructuring in later
patches.
Cc: <shaggy@xxxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Signed-off-by: Neil Brown <neilb@xxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/efs/namei.c | 32 ++++++++++++++++++++++
fs/efs/super.c | 1
fs/exportfs/expfs.c | 56 ++-------------------------------------
fs/jfs/jfs_inode.h | 2 -
fs/jfs/namei.c | 32 ++++++++++++++++++++++
fs/jfs/super.c | 1
include/linux/efs_fs.h | 1
7 files changed, 71 insertions(+), 54 deletions(-)
diff -puN fs/efs/namei.c~knfsd-exportfs-remove-iget-abuse fs/efs/namei.c
--- a/fs/efs/namei.c~knfsd-exportfs-remove-iget-abuse
+++ a/fs/efs/namei.c
@@ -75,6 +75,38 @@ struct dentry *efs_lookup(struct inode *
return NULL;
}
+struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp)
+{
+ __u32 *objp = vobjp;
+ unsigned long ino = objp[0];
+ __u32 generation = objp[1];
+ struct inode *inode;
+ struct dentry *result;
+
+ if (ino == 0)
+ return ERR_PTR(-ESTALE);
+ inode = iget(sb, ino);
+ if (inode == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ if (is_bad_inode(inode) ||
+ (generation && inode->i_generation != generation)) {
+ result = ERR_PTR(-ESTALE);
+ goto out_iput;
+ }
+
+ result = d_alloc_anon(inode);
+ if (!result) {
+ result = ERR_PTR(-ENOMEM);
+ goto out_iput;
+ }
+ return result;
+
+ out_iput:
+ iput(inode);
+ return result;
+}
+
struct dentry *efs_get_parent(struct dentry *child)
{
struct dentry *parent;
diff -puN fs/efs/super.c~knfsd-exportfs-remove-iget-abuse fs/efs/super.c
--- a/fs/efs/super.c~knfsd-exportfs-remove-iget-abuse
+++ a/fs/efs/super.c
@@ -114,6 +114,7 @@ static const struct super_operations efs
};
static struct export_operations efs_export_ops = {
+ .get_dentry = efs_get_dentry,
.get_parent = efs_get_parent,
};
diff -puN fs/exportfs/expfs.c~knfsd-exportfs-remove-iget-abuse fs/exportfs/expfs.c
--- a/fs/exportfs/expfs.c~knfsd-exportfs-remove-iget-abuse
+++ a/fs/exportfs/expfs.c
@@ -391,61 +391,11 @@ out:
return error;
}
-
-static struct dentry *export_iget(struct super_block *sb, unsigned long ino, __u32 generation)
+static struct dentry *get_dentry(struct super_block *sb, void *vobjp)
{
-
- /* iget isn't really right if the inode is currently unallocated!!
- * This should really all be done inside each filesystem
- *
- * ext2fs' read_inode has been strengthed to return a bad_inode if
- * the inode had been deleted.
- *
- * Currently we don't know the generation for parent directory, so
- * a generation of 0 means "accept any"
- */
- struct inode *inode;
- struct dentry *result;
- if (ino == 0)
- return ERR_PTR(-ESTALE);
- inode = iget(sb, ino);
- if (inode == NULL)
- return ERR_PTR(-ENOMEM);
- if (is_bad_inode(inode)
- || (generation && inode->i_generation != generation)
- ) {
- /* we didn't find the right inode.. */
- dprintk("fh_verify: Inode %lu, Bad count: %d %d or version %u %u\n",
- inode->i_ino,
- inode->i_nlink, atomic_read(&inode->i_count),
- inode->i_generation,
- generation);
-
- iput(inode);
- return ERR_PTR(-ESTALE);
- }
- /* now to find a dentry.
- * If possible, get a well-connected one
- */
- result = d_alloc_anon(inode);
- if (!result) {
- iput(inode);
- return ERR_PTR(-ENOMEM);
- }
- return result;
+ return ERR_PTR(-ESTALE);
}
-
-static struct dentry *get_object(struct super_block *sb, void *vobjp)
-{
- __u32 *objp = vobjp;
- unsigned long ino = objp[0];
- __u32 generation = objp[1];
-
- return export_iget(sb, ino, generation);
-}
-
-
/**
* export_encode_fh - default export_operations->encode_fh function
* @dentry: the dentry to encode
@@ -524,7 +474,7 @@ struct export_operations export_op_defau
.get_name = get_name,
.get_parent = get_parent,
- .get_dentry = get_object,
+ .get_dentry = get_dentry,
};
EXPORT_SYMBOL(export_op_default);
diff -puN fs/jfs/jfs_inode.h~knfsd-exportfs-remove-iget-abuse fs/jfs/jfs_inode.h
--- a/fs/jfs/jfs_inode.h~knfsd-exportfs-remove-iget-abuse
+++ a/fs/jfs/jfs_inode.h
@@ -31,7 +31,7 @@ extern void jfs_truncate(struct inode *)
extern void jfs_truncate_nolock(struct inode *, loff_t);
extern void jfs_free_zero_link(struct inode *);
extern struct dentry *jfs_get_parent(struct dentry *dentry);
-extern void jfs_get_inode_flags(struct jfs_inode_info *);
+extern struct dentry *jfs_get_dentry(struct super_block *sb, void *vobjp);
extern void jfs_set_inode_flags(struct inode *);
extern int jfs_get_block(struct inode *, sector_t, struct buffer_head *, int);
diff -puN fs/jfs/namei.c~knfsd-exportfs-remove-iget-abuse fs/jfs/namei.c
--- a/fs/jfs/namei.c~knfsd-exportfs-remove-iget-abuse
+++ a/fs/jfs/namei.c
@@ -1477,6 +1477,38 @@ static struct dentry *jfs_lookup(struct
return dentry;
}
+struct dentry *jfs_get_dentry(struct super_block *sb, void *vobjp)
+{
+ __u32 *objp = vobjp;
+ unsigned long ino = objp[0];
+ __u32 generation = objp[1];
+ struct inode *inode;
+ struct dentry *result;
+
+ if (ino == 0)
+ return ERR_PTR(-ESTALE);
+ inode = iget(sb, ino);
+ if (inode == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ if (is_bad_inode(inode) ||
+ (generation && inode->i_generation != generation)) {
+ result = ERR_PTR(-ESTALE);
+ goto out_iput;
+ }
+
+ result = d_alloc_anon(inode);
+ if (!result) {
+ result = ERR_PTR(-ENOMEM);
+ goto out_iput;
+ }
+ return result;
+
+ out_iput:
+ iput(inode);
+ return result;
+}
+
struct dentry *jfs_get_parent(struct dentry *dentry)
{
struct super_block *sb = dentry->d_inode->i_sb;
diff -puN fs/jfs/super.c~knfsd-exportfs-remove-iget-abuse fs/jfs/super.c
--- a/fs/jfs/super.c~knfsd-exportfs-remove-iget-abuse
+++ a/fs/jfs/super.c
@@ -738,6 +738,7 @@ static const struct super_operations jfs
};
static struct export_operations jfs_export_operations = {
+ .get_dentry = jfs_get_dentry,
.get_parent = jfs_get_parent,
};
diff -puN include/linux/efs_fs.h~knfsd-exportfs-remove-iget-abuse include/linux/efs_fs.h
--- a/include/linux/efs_fs.h~knfsd-exportfs-remove-iget-abuse
+++ a/include/linux/efs_fs.h
@@ -45,6 +45,7 @@ extern efs_block_t efs_map_block(struct
extern int efs_get_block(struct inode *, sector_t, struct buffer_head *, int);
extern struct dentry *efs_lookup(struct inode *, struct dentry *, struct nameidata *);
+extern struct dentry *efs_get_dentry(struct super_block *sb, void *vobjp);
extern struct dentry *efs_get_parent(struct dentry *);
extern int efs_bmap(struct inode *, int);
_
Patches currently in -mm which might be from hch@xxxxxxxxxxxxx are
dvb_en_50221-convert-to-kthread-api.patch
git-nfs.patch
git-nfs-server-cluster-locking-api.patch
remove-pci_dac_dma_-apis.patch
git-xfs.patch
tidy-up-usermode-helper-waiting-a-bit.patch
knfsd-exportfs-add-exportfsh-header.patch
knfsd-exportfs-remove-iget-abuse.patch
knfsd-exportfs-add-procedural-interface-for-nfsd.patch
knfsd-exportfs-remove-call-macro.patch
knfsd-exportfs-untangle-isdir-logic-in-find_exported_dentry.patch
knfsd-exportfs-move-acceptable-check-into-find_acceptable_alias.patch
knfsd-exportfs-add-find_disconnected_root-helper.patch
knfsd-exportfs-split-out-reconnecting-a-dentry-from-find_exported_dentry.patch
-
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