Unlink test for FAT file system seems to fail at test_unlink2. (When I added this test, I haven't seen any errors though.) for example, ===8<=== fs_obj_unlink = ['fat', '/home/akashi/tmp/uboot_sandbox_test/128MB.fat32.img']
def test_unlink2(self, u_boot_console, fs_obj_unlink): """ Test Case 2 - delete many files """ fs_type,fs_img = fs_obj_unlink with u_boot_console.log.section('Test Case 2 - unlink (many)'): output = u_boot_console.run_command('host bind 0 %s' % fs_img)
for i in range(0, 20): output = u_boot_console.run_command_list([ '%srm host 0:0 dir2/0123456789abcdef%02x' % (fs_type, i), '%sls host 0:0 dir2/0123456789abcdef%02x' % (fs_type, i)]) assert('' == ''.join(output))
output = u_boot_console.run_command( '%sls host 0:0 dir2' % fs_type)
assert('0 file(s), 2 dir(s)' in output)
E AssertionError: assert '0 file(s), 2 dir(s)' in ' ./\r\r\n ../\r\r\n 0 0123456789abcdef11\r\r\n\r\r\n1 file(s), 2 dir(s)'
test/py/tests/test_fs/test_unlink.py:52: AssertionError ===>8===
This can happen when fat_itr_next() wrongly detects an already- deleted directory entry.
File deletion, which was added in the commit f8240ce95d64 ("fs: fat: support unlink"), is implemented by marking its entry for a short name with DELETED_FLAG, but related entry slots for a long file name are kept unmodified. (So entries will never be actually deleted from media.)
To handle this case correctly, an additional check for a directory slot will be needed in fat_itr_next().
In addition, I added extra comments about long file name and short file name format in FAT file system. Although they are not directly related to the issue, I hope it will be helpful for better understandings in general.
Signed-off-by: AKASHI Takahiro takahiro.akashi@linaro.org --- fs/fat/fat.c | 33 ++++++++++++++++++++++++++++++++- 1 file changed, 32 insertions(+), 1 deletion(-)
diff --git a/fs/fat/fat.c b/fs/fat/fat.c index 9e1b842dac6b..68ce65838678 100644 --- a/fs/fat/fat.c +++ b/fs/fat/fat.c @@ -869,6 +869,14 @@ static dir_entry *extract_vfat_name(fat_itr *itr) return NULL; }
+ /* + * We are now at the short file name entry. + * If it is marked as deleted, just skip it. + */ + if (dent->name[0] == DELETED_FLAG || + dent->name[0] == aRING) + return NULL; + itr->l_name[n] = '\0';
chksum = mkcksum(dent->name, dent->ext); @@ -898,6 +906,16 @@ static int fat_itr_next(fat_itr *itr)
itr->name = NULL;
+ /* + * One logical directory entry consist of following slots: + * name[0] Attributes + * dent[N - N]: LFN[N - 1] N|0x40 ATTR_VFAT + * ... + * dent[N - 2]: LFN[1] 2 ATTR_VFAT + * dent[N - 1]: LFN[0] 1 ATTR_VFAT + * dent[N]: SFN ATTR_ARCH + */ + while (1) { dent = next_dent(itr); if (!dent) @@ -910,7 +928,17 @@ static int fat_itr_next(fat_itr *itr) if (dent->attr & ATTR_VOLUME) { if ((dent->attr & ATTR_VFAT) == ATTR_VFAT && (dent->name[0] & LAST_LONG_ENTRY_MASK)) { + /* long file name */ dent = extract_vfat_name(itr); + /* + * If succeeded, dent has a valid short file + * name entry for the current entry. + * If failed, itr points to a current bogus + * entry. So after fetching a next one, + * it may have a short file name entry + * for this bogus entry so that we can still + * check for a short name. + */ if (!dent) continue; itr->name = itr->l_name; @@ -919,8 +947,11 @@ static int fat_itr_next(fat_itr *itr) /* Volume label or VFAT entry, skip */ continue; } - } + } else if (!(dent->attr & ATTR_ARCH) && + !(dent->attr & ATTR_DIR)) + continue;
+ /* short file name */ break; }