e86d1b2bb7
[ Upstream commit e874dcde1cbf82c786c0e7f2899811c02630cc52 ] UBIFS calculates available space by c->main_bytes - c->lst.total_used (which means non-index lebs' free and dirty space is accounted into total available), then index lebs and four lebs (one for gc_lnum, one for deletions, two for journal heads) are deducted. In following situation, ubifs may get -ENOSPC from make_reservation(): LEB 84: DATAHD free 122880 used 1920 dirty 2176 dark 6144 LEB 110:DELETION free 126976 used 0 dirty 0 dark 6144 (empty) LEB 201:gc_lnum free 126976 used 0 dirty 0 dark 6144 LEB 272:GCHD free 77824 used 47672 dirty 1480 dark 6144 LEB 356:BASEHD free 0 used 39776 dirty 87200 dark 6144 OTHERS: index lebs, zero-available non-index lebs UBIFS calculates the available bytes is 6888 (How to calculate it: 126976 * 5[remain main bytes] - 1920[used] - 47672[used] - 39776[used] - 126976 * 1[deletions] - 126976 * 1[gc_lnum] - 126976 * 2[journal heads] - 6144 * 5[dark] = 6888) after doing budget, however UBIFS cannot use BASEHD's dirty space(87200), because UBIFS cannot find next BASEHD to reclaim current BASEHD. (c->bi.min_idx_lebs equals to c->lst.idx_lebs, the empty leb won't be found by ubifs_find_free_space(), and dirty index lebs won't be picked as gced lebs. All non-index lebs has dirty space less then c->dead_wm, non-index lebs won't be picked as gced lebs either. So new free lebs won't be produced.). See more details in Link. To fix it, reserve one leb for each journal head while doing budget. Link: https://bugzilla.kernel.org/show_bug.cgi?id=216562 Fixes: 1e51764a3c2ac0 ("UBIFS: add new flash file system") Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com> Signed-off-by: Richard Weinberger <richard@nod.at> Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.