diff options
| -rw-r--r-- | fs/libfs.c | 37 |
1 files changed, 21 insertions, 16 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 8c9364a0174c..47399f90511a 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -245,9 +245,15 @@ const struct inode_operations simple_dir_inode_operations = { }; EXPORT_SYMBOL(simple_dir_inode_operations); -/* 0 is '.', 1 is '..', so always start with offset 2 or more */ +/* simple_offset_add() never assigns these to a dentry */ enum { - DIR_OFFSET_MIN = 2, + DIR_OFFSET_EOD = S32_MAX, +}; + +/* simple_offset_add() allocation range */ +enum { + DIR_OFFSET_MIN = 2, + DIR_OFFSET_MAX = DIR_OFFSET_EOD - 1, }; static void offset_set(struct dentry *dentry, long offset) @@ -291,7 +297,8 @@ int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry) return -EBUSY; ret = mtree_alloc_cyclic(&octx->mt, &offset, dentry, DIR_OFFSET_MIN, - LONG_MAX, &octx->next_offset, GFP_KERNEL); + DIR_OFFSET_MAX, &octx->next_offset, + GFP_KERNEL); if (unlikely(ret < 0)) return ret == -EBUSY ? -ENOSPC : ret; @@ -447,8 +454,6 @@ 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, LONG_MAX); } @@ -458,7 +463,7 @@ static struct dentry *offset_find_next(struct offset_ctx *octx, loff_t offset) struct dentry *child, *found = NULL; rcu_read_lock(); - child = mas_find(&mas, LONG_MAX); + child = mas_find(&mas, DIR_OFFSET_MAX); if (!child) goto out; spin_lock(&child->d_lock); @@ -479,7 +484,7 @@ 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 *octx = inode->i_op->get_offset_ctx(inode); struct dentry *dentry; @@ -487,7 +492,7 @@ static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx) while (true) { dentry = offset_find_next(octx, ctx->pos); if (!dentry) - return ERR_PTR(-ENOENT); + goto out_eod; if (!offset_dir_emit(ctx, dentry)) { dput(dentry); @@ -497,7 +502,10 @@ static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx) ctx->pos = dentry2offset(dentry) + 1; dput(dentry); } - return NULL; + return; + +out_eod: + ctx->pos = DIR_OFFSET_EOD; } /** @@ -517,6 +525,8 @@ static void *offset_iterate_dir(struct inode *inode, struct dir_context *ctx) * * On return, @ctx->pos contains an offset that will read the next entry * in this directory when offset_readdir() is called again with @ctx. + * Caller places this value in the d_off field of the last entry in the + * user's buffer. * * Return values: * %0 - Complete @@ -529,13 +539,8 @@ static int offset_readdir(struct file *file, struct dir_context *ctx) if (!dir_emit_dots(file, ctx)) return 0; - - /* In this case, ->private_data is protected by f_pos_lock */ - if (ctx->pos == DIR_OFFSET_MIN) - file->private_data = NULL; - else if (file->private_data == ERR_PTR(-ENOENT)) - return 0; - file->private_data = offset_iterate_dir(d_inode(dir), ctx); + if (ctx->pos != DIR_OFFSET_EOD) + offset_iterate_dir(d_inode(dir), ctx); return 0; } |