kata-containers/s390-tools
1
0
Fork 0
mirror of https://github.com/ibm-s390-linux/s390-tools.git synced 2026-08-05 02:14:52 +00:00
Code Issues Packages Projects Releases Wiki Activity

cmsfs-fuse: fix pointer block level calculation

Browse Source 
Adding one to the pointer per block value results in a wrong
calculation of pointer block levels. When writing a file that
would result in about 454MB size, the code would calculate that
it needs a two level pointer directory but correct would be a three
level pointer directory. This causes an invalid filesystem state:
besides missing all the records of one top level pointer directory
entry, it would also record a higher record number in the FST than
what is present in the pointer blocks.

Note that this bug only hits when the file is about 454MB and the write
is stopped (means the file is closed) - if file writing continues the
problem doesn't happen because at some point in time cmsfs-fuse would
switch to three levels of pointer blocks anyways as the file grows.

Signed-off-by: Sven Schnelle <svens@linux.ibm.com>
Signed-off-by: Jan Höppner <hoeppner@linux.ibm.com>
This commit is contained in:
Sven Schnelle
2020-11-02 14:48:20 +01:00
committed by Jan Höppner
parent 148d3f9b64
commit 2f154fa49d
1 changed files with 2 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
cmsfs-fuse/cmsfs-fuse.c
View File

@@ -2050,7 +2050,7 @@ static int update_dir_levels(int blocks)
if (blocks < 2)
return 0;
while (blocks / (PTRS_PER_BLOCK + 1)) {
while (blocks / PTRS_PER_BLOCK) {
levels++;
blocks /= PTRS_PER_BLOCK;
}
@@ -3103,7 +3103,7 @@ static void update_levels(struct file *f)
return;
}
while (blocks / (per_block + 1)) {
while (blocks / per_block) {
levels++;
blocks /= per_block;
}