From: Chuck Lever Date: Sun, 19 Nov 2023 23:56:17 +0000 (-0500) Subject: libfs: getdents() should return 0 after reaching EOD X-Git-Tag: v6.6.17~2489 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=53da7fe847d58e771ee9b01ea14e3a94ff60cd7d;p=platform%2Fkernel%2Flinux-rpi.git libfs: getdents() should return 0 after reaching EOD [ Upstream commit 796432efab1e372d404e7a71cc6891a53f105051 ] The new directory offset helpers don't conform with the convention of getdents() returning no more entries once a directory file descriptor has reached the current end-of-directory. To address this, copy the logic from dcache_readdir() to mark the open directory file descriptor once EOD has been reached. Seeking resets the mark. Reported-by: Tavian Barnes Closes: https://lore.kernel.org/linux-fsdevel/20231113180616.2831430-1-tavianator@tavianator.com/ Fixes: 6faddda69f62 ("libfs: Add directory operations for stable offsets") Signed-off-by: Chuck Lever Link: https://lore.kernel.org/r/170043792492.4628.15646203084646716134.stgit@bazille.1015granger.net Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- diff --git a/fs/libfs.c b/fs/libfs.c index 37f2d34..189447c 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -396,6 +396,8 @@ static loff_t offset_dir_llseek(struct file *file, loff_t offset, int whence) return -EINVAL; } + /* In this case, ->private_data is protected by f_pos_lock */ + file->private_data = NULL; return vfs_setpos(file, offset, U32_MAX); } @@ -425,7 +427,7 @@ static bool offset_dir_emit(struct dir_context *ctx, struct dentry *dentry) inode->i_ino, fs_umode_to_dtype(inode->i_mode)); } -static void offset_iterate_dir(struct inode *inode, struct dir_context *ctx) +static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx) { struct offset_ctx *so_ctx = inode->i_op->get_offset_ctx(inode); XA_STATE(xas, &so_ctx->xa, ctx->pos); @@ -434,7 +436,7 @@ static void offset_iterate_dir(struct inode *inode, struct dir_context *ctx) while (true) { dentry = offset_find_next(&xas); if (!dentry) - break; + return ERR_PTR(-ENOENT); if (!offset_dir_emit(ctx, dentry)) { dput(dentry); @@ -444,6 +446,7 @@ static void offset_iterate_dir(struct inode *inode, struct dir_context *ctx) dput(dentry); ctx->pos = xas.xa_index + 1; } + return NULL; } /** @@ -476,7 +479,12 @@ static int offset_readdir(struct file *file, struct dir_context *ctx) if (!dir_emit_dots(file, ctx)) return 0; - offset_iterate_dir(d_inode(dir), ctx); + /* In this case, ->private_data is protected by f_pos_lock */ + if (ctx->pos == 2) + file->private_data = NULL; + else if (file->private_data == ERR_PTR(-ENOENT)) + return 0; + file->private_data = offset_iterate_dir(d_inode(dir), ctx); return 0; }