The patch is simplified defensive backport of upstream commit 4bacc9c9234c7c8eec44f5ed4e960d9f96fa0f01:
> overlayfs: Make f_path always point to the overlay and f_inode to the > underlay > > Make file->f_path always point to the overlay dentry so that the path in > /proc/pid/fd is correct and to ensure that label-based LSMs have access to > the > overlay as well as the underlay (path-based LSMs probably don't need it). > ... > Signed-off-by: David Howells <dhowe...@redhat.com> > Signed-off-by: Al Viro <v...@zeniv.linux.org.uk> Original patch is prone to errors because other parts of linux kernel are not prepared to such a change of semantics of f_path and f_inode. So, we only backport simplified d_select_inode keeping f_path and f_inode intact. https://jira.sw.ru/browse/PSBM-47981 Signed-off-by: Maxim Patlasov <mpatla...@virtuozzo.com> --- fs/dcache.c | 5 ++++- fs/overlayfs/inode.c | 15 +++++++++++++++ fs/overlayfs/overlayfs.h | 1 + fs/overlayfs/super.c | 2 ++ include/linux/dcache.h | 2 ++ 5 files changed, 24 insertions(+), 1 deletion(-) diff --git a/fs/dcache.c b/fs/dcache.c index 6433814..7db8aef 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1635,7 +1635,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) DCACHE_OP_COMPARE | DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE | - DCACHE_OP_DELETE )); + DCACHE_OP_DELETE | + DCACHE_OP_SELECT_INODE)); dentry->d_op = op; if (!op) return; @@ -1651,6 +1652,8 @@ void d_set_d_op(struct dentry *dentry, const struct dentry_operations *op) dentry->d_flags |= DCACHE_OP_DELETE; if (op->d_prune) dentry->d_flags |= DCACHE_OP_PRUNE; + if (op->d_select_inode) + dentry->d_flags |= DCACHE_OP_SELECT_INODE; } EXPORT_SYMBOL(d_set_d_op); diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c index 1d2c32f..5fe7acf 100644 --- a/fs/overlayfs/inode.c +++ b/fs/overlayfs/inode.c @@ -368,6 +368,21 @@ out: return err; } +struct inode *ovl_d_select_inode(struct dentry *dentry) +{ + struct path realpath; + + if (d_is_dir(dentry)) + return d_backing_inode(dentry); + + ovl_path_real(dentry, &realpath); + + if (realpath.dentry->d_flags & DCACHE_OP_SELECT_INODE) + return realpath.dentry->d_op->d_select_inode(realpath.dentry); + + return d_backing_inode(realpath.dentry); +} + static const struct inode_operations_wrapper ovl_file_inode_operations = { .ops = { .setattr = ovl_setattr, diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h index 45d183b..8da9684 100644 --- a/fs/overlayfs/overlayfs.h +++ b/fs/overlayfs/overlayfs.h @@ -173,6 +173,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, const char *name, void *value, size_t size); ssize_t ovl_listxattr(struct dentry *dentry, char *list, size_t size); int ovl_removexattr(struct dentry *dentry, const char *name); +struct inode *ovl_d_select_inode(struct dentry *dentry); struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, struct ovl_entry *oe); diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index d5c57b4..24ec90b 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -316,10 +316,12 @@ static int ovl_dentry_weak_revalidate(struct dentry *dentry, unsigned int flags) static const struct dentry_operations ovl_dentry_operations = { .d_release = ovl_dentry_release, + .d_select_inode = ovl_d_select_inode, }; static const struct dentry_operations ovl_reval_dentry_operations = { .d_release = ovl_dentry_release, + .d_select_inode = ovl_d_select_inode, .d_revalidate = ovl_dentry_revalidate, .d_weak_revalidate = ovl_dentry_weak_revalidate, }; diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 2f6e4d8..267dbc6 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -160,6 +160,7 @@ struct dentry_operations { char *(*d_dname)(struct dentry *, char *, int); struct vfsmount *(*d_automount)(struct path *); int (*d_manage)(struct dentry *, bool); + struct inode *(*d_select_inode)(struct dentry *); } ____cacheline_aligned; /* @@ -221,6 +222,7 @@ struct dentry_operations { #define DCACHE_FILE_TYPE 0x04000000 /* Other file type */ #define DCACHE_MAY_FREE 0x00800000 +#define DCACHE_OP_SELECT_INODE 0x20000000 /* Unioned entry: dcache op selects inode */ extern seqlock_t rename_lock; _______________________________________________ Devel mailing list Devel@openvz.org https://lists.openvz.org/mailman/listinfo/devel