path: root/mkfs
diff options
authorQu Wenruo <>2018-03-28 14:39:09 +0800
committerDavid Sterba <>2018-03-30 22:15:55 +0200
commit4e6e5804f2153efc85cfd1efaeabbaa5b7e8c02e (patch)
tree05b1f34d96d64e5f64eafd67280096279aa1499c /mkfs
parent3fd6a955f91cfd0fabdab8ab441938879f7d692d (diff)
btrfs-progs: mkfs/rootdir: Don't follow symbolic link when calcuating size
[BUG] If we have a symbolic link in rootdir pointing to non-existing location, mkfs.btrfs --rootdir will just fail: ------ $ mkfs.btrfs -f --rootdir /tmp/rootdir/ /dev/data/btrfs btrfs-progs v4.15.1 See for more information. ERROR: ftw subdir walk of /tmp/rootdir/ failed: No such file or directory ------ [CAUSE] Commit 599a0abed564 ("btrfs-progs: mkfs/rootdir: Use over-reserve method to make size estimate easier") add extra ftw walk to estimate the filesystem size. Such default ftw walk will follow symbolic link and gives ENOENT error. [FIX] Use nftw() to specify FTW_PHYS so we won't follow symbolic link for size calculation. Issue: #109 Reported-by: Alexander Kanavin <> Fixes: 599a0abed564 ("btrfs-progs: mkfs/rootdir: Use over-reserve method to make size estimate easier") Signed-off-by: Qu Wenruo <> Signed-off-by: David Sterba <>
Diffstat (limited to 'mkfs')
1 files changed, 7 insertions, 2 deletions
diff --git a/mkfs/rootdir.c b/mkfs/rootdir.c
index a1d223a2..33c3ff1e 100644
--- a/mkfs/rootdir.c
+++ b/mkfs/rootdir.c
@@ -696,7 +696,7 @@ out:
static int ftw_add_entry_size(const char *fpath, const struct stat *st,
- int type)
+ int type, struct FTW *ftwbuf)
* Failed to read the directory, mostly due to EPERM. Abort ASAP, so
@@ -731,7 +731,12 @@ u64 btrfs_mkfs_size_dir(const char *dir_name, u32 sectorsize, u64 min_dev_size,
fs_block_size = sectorsize;
ftw_data_size = 0;
ftw_meta_nr_inode = 0;
- ret = ftw(dir_name, ftw_add_entry_size, 10);
+ /*
+ * Symbolic link is not followed when creating files, so no need to
+ * follow them here.
+ */
+ ret = nftw(dir_name, ftw_add_entry_size, 10, FTW_PHYS);
if (ret < 0) {
error("ftw subdir walk of %s failed: %s", dir_name,