Messages in this thread Patch in this message | | | From | Hongnan Li <> | Subject | [PATCH v2 resend] erofs: make filesystem exportable | Date | Mon, 25 Apr 2022 12:07:12 +0800 |
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Implement export operations in order to make EROFS support accessing inodes with filehandles so that it can be exported via NFS and used by overlayfs.
Without this patch, 'exportfs -rv' will report: exportfs: /root/erofs_mp does not support NFS export
Also tested with unionmount-testsuite and the testcase below passes now: ./run --ov --erofs --verify hard-link
For more details about the testcase, see: https://github.com/amir73il/unionmount-testsuite/pull/6
Signed-off-by: Hongnan Li <hongnan.li@linux.alibaba.com> --- fs/erofs/internal.h | 2 +- fs/erofs/namei.c | 5 ++--- fs/erofs/super.c | 40 ++++++++++++++++++++++++++++++++++++++++ 3 files changed, 43 insertions(+), 4 deletions(-)
diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h index 5298c4ee277d..12c65f647324 100644 --- a/fs/erofs/internal.h +++ b/fs/erofs/internal.h @@ -509,7 +509,7 @@ int erofs_getattr(struct user_namespace *mnt_userns, const struct path *path, /* namei.c */ extern const struct inode_operations erofs_dir_iops; -int erofs_namei(struct inode *dir, struct qstr *name, +int erofs_namei(struct inode *dir, const struct qstr *name, erofs_nid_t *nid, unsigned int *d_type); /* dir.c */ diff --git a/fs/erofs/namei.c b/fs/erofs/namei.c index 554efa363317..fd75506799c4 100644 --- a/fs/erofs/namei.c +++ b/fs/erofs/namei.c @@ -165,9 +165,8 @@ static void *find_target_block_classic(struct erofs_buf *target, return candidate; } -int erofs_namei(struct inode *dir, - struct qstr *name, - erofs_nid_t *nid, unsigned int *d_type) +int erofs_namei(struct inode *dir, const struct qstr *name, erofs_nid_t *nid, + unsigned int *d_type) { int ndirents; struct erofs_buf buf = __EROFS_BUF_INITIALIZER; diff --git a/fs/erofs/super.c b/fs/erofs/super.c index 0c4b41130c2f..1c77b7acabd0 100644 --- a/fs/erofs/super.c +++ b/fs/erofs/super.c @@ -13,6 +13,7 @@ #include <linux/fs_context.h> #include <linux/fs_parser.h> #include <linux/dax.h> +#include <linux/exportfs.h> #include "xattr.h" #define CREATE_TRACE_POINTS @@ -577,6 +578,44 @@ static int erofs_init_managed_cache(struct super_block *sb) static int erofs_init_managed_cache(struct super_block *sb) { return 0; } #endif +static struct inode *erofs_nfs_get_inode(struct super_block *sb, + u64 ino, u32 generation) +{ + return erofs_iget(sb, ino, false); +} + +static struct dentry *erofs_fh_to_dentry(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + return generic_fh_to_dentry(sb, fid, fh_len, fh_type, + erofs_nfs_get_inode); +} + +static struct dentry *erofs_fh_to_parent(struct super_block *sb, struct fid *fid, + int fh_len, int fh_type) +{ + return generic_fh_to_parent(sb, fid, fh_len, fh_type, + erofs_nfs_get_inode); +} + +static struct dentry *erofs_get_parent(struct dentry *child) +{ + erofs_nid_t nid; + unsigned int d_type; + int err; + + err = erofs_namei(d_inode(child), &dotdot_name, &nid, &d_type); + if (err) + return ERR_PTR(err); + return d_obtain_alias(erofs_iget(child->d_sb, nid, d_type == FT_DIR)); +} + +static const struct export_operations erofs_export_ops = { + .fh_to_dentry = erofs_fh_to_dentry, + .fh_to_parent = erofs_fh_to_parent, + .get_parent = erofs_get_parent, +}; + static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) { struct inode *inode; @@ -618,6 +657,7 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc) sb->s_time_gran = 1; sb->s_op = &erofs_sops; + sb->s_export_op = &erofs_export_ops; sb->s_xattr = erofs_xattr_handlers; if (test_opt(&sbi->opt, POSIX_ACL)) -- 2.19.1.6.gb485710b
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