From 0f63c0e88f76878a55b375f81e8b326a21dee2ef Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 14 May 2017 09:17:29 +0000 Subject: [PATCH] introduce ->iterate(), ctx->pos, dir_emit() New method - ->iterate(file, ctx). That's the replacement for ->readdir(); it takes callback from ctx->actor, uses ctx->pos instead of file->f_pos and calls dir_emit(ctx, ...) instead of filldir(data, ...). It does *not* update file->f_pos (or look at it, for that matter); iterate_dir() does the update. Note that dir_emit() takes the offset from ctx->pos (and eventually filldir_t will lose that argument). Signed-off-by: Al Viro --- arch/parisc/hpux/fs.c | 2 +- fs/coda/dir.c | 19 +++++++++++++++---- fs/compat.c | 4 ++-- fs/exportfs/expfs.c | 2 +- fs/nfsd/nfs4recover.c | 12 +++++++----- fs/readdir.c | 15 +++++++++++---- include/linux/fs.h | 9 +++++++++ 7 files changed, 46 insertions(+), 17 deletions(-) diff --git a/arch/parisc/hpux/fs.c b/arch/parisc/hpux/fs.c index fc2cbee86e34..eca8230267cc 100644 --- a/arch/parisc/hpux/fs.c +++ b/arch/parisc/hpux/fs.c @@ -129,7 +129,7 @@ int hpux_getdents(unsigned int fd, struct hpux_dirent __user *dirent, unsigned i error = buf.error; lastdirent = buf.previous; if (lastdirent) { - if (put_user(arg.file->f_pos, &lastdirent->d_off)) + if (put_user(buf.ctx.pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; diff --git a/fs/coda/dir.c b/fs/coda/dir.c index b7d3a05c062c..fc66861b3598 100644 --- a/fs/coda/dir.c +++ b/fs/coda/dir.c @@ -391,8 +391,7 @@ static int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir) if (!host_file->f_op) return -ENOTDIR; - if (host_file->f_op->readdir) - { + if (host_file->f_op->readdir) { /* potemkin case: we were handed a directory inode. * We can't use vfs_readdir because we have to keep the file * position in sync between the coda_file and the host_file. @@ -410,8 +409,20 @@ static int coda_readdir(struct file *coda_file, void *buf, filldir_t filldir) coda_file->f_pos = host_file->f_pos; mutex_unlock(&host_inode->i_mutex); - } - else /* Venus: we must read Venus dirents from a file */ + } else if (host_file->f_op->iterate) { + struct inode *host_inode = file_inode(host_file); + struct dir_context *ctx = buf; + + mutex_lock(&host_inode->i_mutex); + ret = -ENOENT; + if (!IS_DEADDIR(host_inode)) { + ret = host_file->f_op->iterate(host_file, ctx); + file_accessed(host_file); + } + mutex_unlock(&host_inode->i_mutex); + + coda_file->f_pos = ctx->pos; + } else /* Venus: we must read Venus dirents from a file */ ret = coda_venus_readdir(coda_file, buf, filldir); return ret; diff --git a/fs/compat.c b/fs/compat.c index 2279b59e81f2..69ca1e301766 100644 --- a/fs/compat.c +++ b/fs/compat.c @@ -975,7 +975,7 @@ asmlinkage long compat_sys_getdents(unsigned int fd, error = buf.error; lastdirent = buf.previous; if (lastdirent) { - if (put_user(f.file->f_pos, &lastdirent->d_off)) + if (put_user(buf.ctx.pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; @@ -1062,7 +1062,7 @@ asmlinkage long compat_sys_getdents64(unsigned int fd, error = buf.error; lastdirent = buf.previous; if (lastdirent) { - typeof(lastdirent->d_off) d_off = f.file->f_pos; + typeof(lastdirent->d_off) d_off = buf.ctx.pos; if (__put_user_unaligned(d_off, &lastdirent->d_off)) error = -EFAULT; else diff --git a/fs/exportfs/expfs.c b/fs/exportfs/expfs.c index 95b32a6fb3b7..34e0905df1cb 100644 --- a/fs/exportfs/expfs.c +++ b/fs/exportfs/expfs.c @@ -272,7 +272,7 @@ static int get_name(const struct path *path, char *name, struct dentry *child) goto out; error = -EINVAL; - if (!file->f_op->readdir) + if (!file->f_op->readdir && !file->f_op->iterate) goto out_close; buffer.name = name; diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c index 4f8cc6ba7c28..45509c23c7a0 100644 --- a/fs/nfsd/nfs4recover.c +++ b/fs/nfsd/nfs4recover.c @@ -240,6 +240,11 @@ struct name_list { struct list_head list; }; +struct nfs4_dir_ctx { + struct dir_context ctx; + struct list_head names; +}; + static int nfsd4_build_namelist(void *arg, const char *name, int namlen, loff_t offset, u64 ino, unsigned int d_type) @@ -254,7 +259,7 @@ nfsd4_build_namelist(void *arg, const char *name, int namlen, return -ENOMEM; memcpy(entry->name, name, HEXDIR_LEN - 1); entry->name[HEXDIR_LEN - 1] = '\0'; - list_add(&entry->list, names); + list_add(&entry->list, &ctx->names); return 0; } @@ -263,10 +268,7 @@ nfsd4_list_rec_dir(recdir_func *f, struct nfsd_net *nn) { const struct cred *original_cred; struct dentry *dir = nn->rec_file->f_path.dentry; - struct { - struct dir_context ctx; - struct list_head names; - } ctx; + struct nfs4_dir_ctx ctx; int status; status = nfs4_save_creds(&original_cred); diff --git a/fs/readdir.c b/fs/readdir.c index 5b620a2b45e6..5d6578affbbf 100644 --- a/fs/readdir.c +++ b/fs/readdir.c @@ -24,7 +24,7 @@ int iterate_dir(struct file *file, struct dir_context *ctx) { struct inode *inode = file_inode(file); int res = -ENOTDIR; - if (!file->f_op || !file->f_op->readdir) + if (!file->f_op || (!file->f_op->readdir && !file->f_op->iterate)) goto out; res = security_file_permission(file, MAY_READ); @@ -37,7 +37,14 @@ int iterate_dir(struct file *file, struct dir_context *ctx) res = -ENOENT; if (!IS_DEADDIR(inode)) { - res = file->f_op->readdir(file, ctx, ctx->actor); + if (file->f_op->iterate) { + ctx->pos = file->f_pos; + res = file->f_op->iterate(file, ctx); + file->f_pos = ctx->pos; + } else { + res = file->f_op->readdir(file, ctx, ctx->actor); + ctx->pos = file->f_pos; + } file_accessed(file); } mutex_unlock(&inode->i_mutex); @@ -214,7 +221,7 @@ SYSCALL_DEFINE3(getdents, unsigned int, fd, error = buf.error; lastdirent = buf.previous; if (lastdirent) { - if (put_user(f.file->f_pos, &lastdirent->d_off)) + if (put_user(buf.ctx.pos, &lastdirent->d_off)) error = -EFAULT; else error = count - buf.count; @@ -296,7 +303,7 @@ SYSCALL_DEFINE3(getdents64, unsigned int, fd, error = buf.error; lastdirent = buf.previous; if (lastdirent) { - typeof(lastdirent->d_off) d_off = f.file->f_pos; + typeof(lastdirent->d_off) d_off = buf.ctx.pos; if (__put_user(d_off, &lastdirent->d_off)) error = -EFAULT; else diff --git a/include/linux/fs.h b/include/linux/fs.h index 75327e6dc2d8..3fe45fa4b78c 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1508,7 +1508,15 @@ int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags); typedef int (*filldir_t)(void *, const char *, int, loff_t, u64, unsigned); struct dir_context { filldir_t actor; + loff_t pos; }; + +static inline bool dir_emit(struct dir_context *ctx, + const char *name, int namelen, + u64 ino, unsigned type) +{ + return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0; +} struct block_device_operations; /* These macros are for out of kernel modules to test that @@ -1525,6 +1533,7 @@ struct file_operations { ssize_t (*aio_read) (struct kiocb *, const struct iovec *, unsigned long, loff_t); ssize_t (*aio_write) (struct kiocb *, const struct iovec *, unsigned long, loff_t); int (*readdir) (struct file *, void *, filldir_t); + int (*iterate) (struct file *, struct dir_context *); unsigned int (*poll) (struct file *, struct poll_table_struct *); long (*unlocked_ioctl) (struct file *, unsigned int, unsigned long); long (*compat_ioctl) (struct file *, unsigned int, unsigned long); -- 2.20.1