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affs: store cookie in private data

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Store the cookie to detect concurrent seeks on directories in
file->private_data.

Link: https://lore.kernel.org/r/20240830-vfs-file-f_version-v1-9-6d3e4816aa7b@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2024-08-30 15:04:50 +02:00
parent d688d65a84
commit bad74142a0
No known key found for this signature in database
GPG Key ID: 91C61BC06578DCA2
1 changed files with 38 additions and 6 deletions
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44
fs/affs/dir.c
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@ -17,13 +17,44 @@
#include <linux/iversion.h>
#include "affs.h"
struct affs_dir_data {
unsigned long ino;
u64 cookie;
};
static int affs_readdir(struct file *, struct dir_context *);
static loff_t affs_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct affs_dir_data *data = file->private_data;
return generic_llseek_cookie(file, offset, whence, &data->cookie);
}
static int affs_dir_open(struct inode *inode, struct file *file)
{
struct affs_dir_data *data;
data = kzalloc(sizeof(struct affs_dir_data), GFP_KERNEL);
if (!data)
return -ENOMEM;
file->private_data = data;
return 0;
}
static int affs_dir_release(struct inode *inode, struct file *file)
{
kfree(file->private_data);
return 0;
}
const struct file_operations affs_dir_operations = {
.open = affs_dir_open,
.read = generic_read_dir,
.llseek = generic_file_llseek,
.llseek = affs_dir_llseek,
.iterate_shared = affs_readdir,
.fsync = affs_file_fsync,
.release = affs_dir_release,
};
/*
@ -45,6 +76,7 @@ static int
affs_readdir(struct file *file, struct dir_context *ctx)
{
struct inode *inode = file_inode(file);
struct affs_dir_data *data = file->private_data;
struct super_block *sb = inode->i_sb;
struct buffer_head *dir_bh = NULL;
struct buffer_head *fh_bh = NULL;
@ -59,7 +91,7 @@ affs_readdir(struct file *file, struct dir_context *ctx)
pr_debug("%s(ino=%lu,f_pos=%llx)\n", __func__, inode->i_ino, ctx->pos);
if (ctx->pos < 2) {
file->private_data = (void *)0;
data->ino = 0;
if (!dir_emit_dots(file, ctx))
return 0;
}
@ -80,8 +112,8 @@ affs_readdir(struct file *file, struct dir_context *ctx)
/* If the directory hasn't changed since the last call to readdir(),
* we can jump directly to where we left off.
*/
ino = (u32)(long)file->private_data;
if (ino && inode_eq_iversion(inode, file->f_version)) {
ino = data->ino;
if (ino && inode_eq_iversion(inode, data->cookie)) {
pr_debug("readdir() left off=%d\n", ino);
goto inside;
}
@ -131,8 +163,8 @@ inside:
} while (ino);
}
done:
file->f_version = inode_query_iversion(inode);
file->private_data = (void *)(long)ino;
data->cookie = inode_query_iversion(inode);
data->ino = ino;
affs_brelse(fh_bh);
out_brelse_dir: