Re: [PATCH 1/3] smb: client: do not defer close open handles to deleted files

From: Steve French
Date: Sat Feb 10 2024 - 00:59:52 EST

could we make the "file_is_deleted" a boolean instead of using up more
space making it an int?

Alternatively - would it be possible to simply look at the file
attributes to see if it was marked as deleted (ie we should already be
setting ATTR_DELETE_ON_CLOSE)

On Fri, Feb 9, 2024 at 7:17 AM <meetakshisetiyaoss@xxxxxxxxx> wrote:
>
> From: Meetakshi Setiya <msetiya@xxxxxxxxxxxxx>
>
> When a file/dentry has been deleted before closing all its open handles,
> currently, closing them can add them to the deferred close list. This can
> lead to problems in creating file with the same name when the file is
> re-created before the deferred close completes. This issue was seen while
> reusing a client's already existing lease on a file for compound operations
> and xfstest 591 failed because of the deferred close handle that remained
> valid even after the file was deleted and was being reused to create a file
> with the same name. The server in this case returns an error on open with
> STATUS_DELETE_PENDING. Recreating the file would fail till the deferred
> handles are closed (duration specified in closetimeo).
>
> This patch fixes the issue by flagging all open handles for the deleted
> file (file path to be precise) with FILE_DELETED at the end of the unlink
> operation. A new field cflags has been introduced in the cifsFileInfo
> structure to set the FILE_DELETED flag without interfering with the f_flags
> field. This cflags field could be useful in the future for setting more
> flags specific to cfile.
> When doing close in cifs_close for each of these handles, check the
> FILE_DELETED flag and do not defer close these handles if the corresponding
> filepath has been deleted.
>
> Signed-off-by: Meetakshi Setiya <msetiya@xxxxxxxxxxxxx>
> ---
> fs/smb/client/cifsglob.h | 3 +++
> fs/smb/client/cifsproto.h | 4 ++++
> fs/smb/client/file.c | 3 ++-
> fs/smb/client/inode.c | 2 ++
> fs/smb/client/misc.c | 22 ++++++++++++++++++++++
> 5 files changed, 33 insertions(+), 1 deletion(-)
>
> diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
> index 16befff4cbb4..f6b4acdcdeb3 100644
> --- a/fs/smb/client/cifsglob.h
> +++ b/fs/smb/client/cifsglob.h
> @@ -1398,6 +1398,8 @@ struct cifs_fid_locks {
> struct list_head locks; /* locks held by fid above */
> };
>
> +#define FILE_DELETED 00000001
> +
> struct cifsFileInfo {
> /* following two lists are protected by tcon->open_file_lock */
> struct list_head tlist; /* pointer to next fid owned by tcon */
> @@ -1413,6 +1415,7 @@ struct cifsFileInfo {
> struct dentry *dentry;
> struct tcon_link *tlink;
> unsigned int f_flags;
> + unsigned int cflags; /* flags for this file */
> bool invalidHandle:1; /* file closed via session abend */
> bool swapfile:1;
> bool oplock_break_cancelled:1;
> diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
> index a841bf4967fa..f995b766b177 100644
> --- a/fs/smb/client/cifsproto.h
> +++ b/fs/smb/client/cifsproto.h
> @@ -296,6 +296,10 @@ extern void cifs_close_all_deferred_files(struct cifs_tcon *cifs_tcon);
>
> extern void cifs_close_deferred_file_under_dentry(struct cifs_tcon *cifs_tcon,
> const char *path);
> +
> +extern void cifs_mark_open_handles_for_deleted_file(struct cifs_tcon
> + *cifs_tcon, const char *path);
> +
> extern struct TCP_Server_Info *
> cifs_get_tcp_session(struct smb3_fs_context *ctx,
> struct TCP_Server_Info *primary_server);
> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
> index b75282c204da..91cf4d2df4de 100644
> --- a/fs/smb/client/file.c
> +++ b/fs/smb/client/file.c
> @@ -483,6 +483,7 @@ struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file *file,
> cfile->uid = current_fsuid();
> cfile->dentry = dget(dentry);
> cfile->f_flags = file->f_flags;
> + cfile->cflags = 0;
> cfile->invalidHandle = false;
> cfile->deferred_close_scheduled = false;
> cfile->tlink = cifs_get_tlink(tlink);
> @@ -1085,7 +1086,7 @@ int cifs_close(struct inode *inode, struct file *file)
> if ((cifs_sb->ctx->closetimeo && cinode->oplock == CIFS_CACHE_RHW_FLG)
> && cinode->lease_granted &&
> !test_bit(CIFS_INO_CLOSE_ON_LOCK, &cinode->flags) &&
> - dclose) {
> + dclose && !(cfile->cflags & FILE_DELETED)) {
> if (test_and_clear_bit(CIFS_INO_MODIFIED_ATTR, &cinode->flags)) {
> inode_set_mtime_to_ts(inode,
> inode_set_ctime_current(inode));
> diff --git a/fs/smb/client/inode.c b/fs/smb/client/inode.c
> index d02f8ba29cb5..8121b5b1aa22 100644
> --- a/fs/smb/client/inode.c
> +++ b/fs/smb/client/inode.c
> @@ -1900,6 +1900,8 @@ int cifs_unlink(struct inode *dir, struct dentry *dentry)
> cifs_inode = CIFS_I(dir);
> CIFS_I(dir)->time = 0; /* force revalidate of dir as well */
> unlink_out:
> + if (rc == 0)
> + cifs_mark_open_handles_for_deleted_file(tcon, full_path);
> free_dentry_path(page);
> kfree(attrs);
> free_xid(xid);
> diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c
> index 0748d7b757b9..8e46dee1a36c 100644
> --- a/fs/smb/client/misc.c
> +++ b/fs/smb/client/misc.c
> @@ -853,6 +853,28 @@ cifs_close_deferred_file_under_dentry(struct cifs_tcon *tcon, const char *path)
> free_dentry_path(page);
> }
>
> +/*
> + * If a dentry has been deleted, all corresponding open handles should know that
> + * so that we do not defer close them.
> + */
> +void cifs_mark_open_handles_for_deleted_file(struct cifs_tcon *tcon,
> + const char *path)
> +{
> + struct cifsFileInfo *cfile;
> + void *page;
> + const char *full_path;
> +
> + page = alloc_dentry_path();
> + spin_lock(&tcon->open_file_lock);
> + list_for_each_entry(cfile, &tcon->openFileList, tlist) {
> + full_path = build_path_from_dentry(cfile->dentry, page);
> + if (strcmp(full_path, path) == 0)
> + cfile->cflags |= FILE_DELETED;
> + }
> + spin_unlock(&tcon->open_file_lock);
> + free_dentry_path(page);
> +}
> +
> /* parses DFS referral V3 structure
> * caller is responsible for freeing target_nodes
> * returns:
> --
> 2.39.2
>
>


--
Thanks,

Steve