On Fri 30-08-24 15:04:52, Christian Brauner wrote:
> Store the cookie to detect concurrent seeks on directories in
> file->private_data.
>
> Signed-off-by: Christian Brauner <brauner@xxxxxxxxxx>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@xxxxxxx>
Honza
> ---
> fs/ext4/dir.c | 50 ++++++++++++++++++++++++++++----------------------
> fs/ext4/ext4.h | 2 ++
> fs/ext4/inline.c | 7 ++++---
> 3 files changed, 34 insertions(+), 25 deletions(-)
>
> diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
> index ff4514e4626b..13196afe55ce 100644
> --- a/fs/ext4/dir.c
> +++ b/fs/ext4/dir.c
> @@ -133,6 +133,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
> struct super_block *sb = inode->i_sb;
> struct buffer_head *bh = NULL;
> struct fscrypt_str fstr = FSTR_INIT(NULL, 0);
> + struct dir_private_info *info = file->private_data;
>
> err = fscrypt_prepare_readdir(inode);
> if (err)
> @@ -229,7 +230,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
> * readdir(2), then we might be pointing to an invalid
> * dirent right now. Scan from the start of the block
> * to make sure. */
> - if (!inode_eq_iversion(inode, file->f_version)) {
> + if (!inode_eq_iversion(inode, info->cookie)) {
> for (i = 0; i < sb->s_blocksize && i < offset; ) {
> de = (struct ext4_dir_entry_2 *)
> (bh->b_data + i);
> @@ -249,7 +250,7 @@ static int ext4_readdir(struct file *file, struct dir_context *ctx)
> offset = i;
> ctx->pos = (ctx->pos & ~(sb->s_blocksize - 1))
> | offset;
> - file->f_version = inode_query_iversion(inode);
> + info->cookie = inode_query_iversion(inode);
> }
>
> while (ctx->pos < inode->i_size
> @@ -384,6 +385,7 @@ static inline loff_t ext4_get_htree_eof(struct file *filp)
> static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
> {
> struct inode *inode = file->f_mapping->host;
> + struct dir_private_info *info = file->private_data;
> int dx_dir = is_dx_dir(inode);
> loff_t ret, htree_max = ext4_get_htree_eof(file);
>
> @@ -392,7 +394,7 @@ static loff_t ext4_dir_llseek(struct file *file, loff_t offset, int whence)
> htree_max, htree_max);
> else
> ret = ext4_llseek(file, offset, whence);
> - file->f_version = inode_peek_iversion(inode) - 1;
> + info->cookie = inode_peek_iversion(inode) - 1;
> return ret;
> }
>
> @@ -429,18 +431,15 @@ static void free_rb_tree_fname(struct rb_root *root)
> *root = RB_ROOT;
> }
>
> -
> -static struct dir_private_info *ext4_htree_create_dir_info(struct file *filp,
> - loff_t pos)
> +static void ext4_htree_init_dir_info(struct file *filp, loff_t pos)
> {
> - struct dir_private_info *p;
> -
> - p = kzalloc(sizeof(*p), GFP_KERNEL);
> - if (!p)
> - return NULL;
> - p->curr_hash = pos2maj_hash(filp, pos);
> - p->curr_minor_hash = pos2min_hash(filp, pos);
> - return p;
> + struct dir_private_info *p = filp->private_data;
> +
> + if (is_dx_dir(file_inode(filp)) && !p->initialized) {
> + p->curr_hash = pos2maj_hash(filp, pos);
> + p->curr_minor_hash = pos2min_hash(filp, pos);
> + p->initialized = true;
> + }
> }
>
> void ext4_htree_free_dir_info(struct dir_private_info *p)
> @@ -552,12 +551,7 @@ static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
> struct fname *fname;
> int ret = 0;
>
> - if (!info) {
> - info = ext4_htree_create_dir_info(file, ctx->pos);
> - if (!info)
> - return -ENOMEM;
> - file->private_data = info;
> - }
> + ext4_htree_init_dir_info(file, ctx->pos);
>
> if (ctx->pos == ext4_get_htree_eof(file))
> return 0; /* EOF */
> @@ -590,10 +584,10 @@ static int ext4_dx_readdir(struct file *file, struct dir_context *ctx)
> * cached entries.
> */
> if ((!info->curr_node) ||
> - !inode_eq_iversion(inode, file->f_version)) {
> + !inode_eq_iversion(inode, info->cookie)) {
> info->curr_node = NULL;
> free_rb_tree_fname(&info->root);
> - file->f_version = inode_query_iversion(inode);
> + info->cookie = inode_query_iversion(inode);
> ret = ext4_htree_fill_tree(file, info->curr_hash,
> info->curr_minor_hash,
> &info->next_hash);
> @@ -664,7 +658,19 @@ int ext4_check_all_de(struct inode *dir, struct buffer_head *bh, void *buf,
> return 0;
> }
>
> +static int ext4_dir_open(struct inode *inode, struct file *file)
> +{
> + struct dir_private_info *info;
> +
> + info = kzalloc(sizeof(*info), GFP_KERNEL);
> + if (!info)
> + return -ENOMEM;
> + file->private_data = info;
> + return 0;
> +}
> +
> const struct file_operations ext4_dir_operations = {
> + .open = ext4_dir_open,
> .llseek = ext4_dir_llseek,
> .read = generic_read_dir,
> .iterate_shared = ext4_readdir,
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 08acd152261e..d62a4b9b26ce 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2553,6 +2553,8 @@ struct dir_private_info {
> __u32 curr_hash;
> __u32 curr_minor_hash;
> __u32 next_hash;
> + u64 cookie;
> + bool initialized;
> };
>
> /* calculate the first block number of the group */
> diff --git a/fs/ext4/inline.c b/fs/ext4/inline.c
> index e7a09a99837b..4282e12dc405 100644
> --- a/fs/ext4/inline.c
> +++ b/fs/ext4/inline.c
> @@ -1460,6 +1460,7 @@ int ext4_read_inline_dir(struct file *file,
> struct ext4_iloc iloc;
> void *dir_buf = NULL;
> int dotdot_offset, dotdot_size, extra_offset, extra_size;
> + struct dir_private_info *info = file->private_data;
>
> ret = ext4_get_inode_loc(inode, &iloc);
> if (ret)
> @@ -1503,12 +1504,12 @@ int ext4_read_inline_dir(struct file *file,
> extra_size = extra_offset + inline_size;
>
> /*
> - * If the version has changed since the last call to
> + * If the cookie has changed since the last call to
> * readdir(2), then we might be pointing to an invalid
> * dirent right now. Scan from the start of the inline
> * dir to make sure.
> */
> - if (!inode_eq_iversion(inode, file->f_version)) {
> + if (!inode_eq_iversion(inode, info->cookie)) {
> for (i = 0; i < extra_size && i < offset;) {
> /*
> * "." is with offset 0 and
> @@ -1540,7 +1541,7 @@ int ext4_read_inline_dir(struct file *file,
> }
> offset = i;
> ctx->pos = offset;
> - file->f_version = inode_query_iversion(inode);
> + info->cookie = inode_query_iversion(inode);
> }
>
> while (ctx->pos < extra_size) {
>
> --
> 2.45.2
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR
