diff options
| author | Ritesh Harjani <riteshh@linux.ibm.com> | 2020-05-20 09:40:36 +0300 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2020-06-04 06:16:53 +0300 |
| commit | 993778306e7901a7286322f25c7c681dd47bede6 (patch) | |
| tree | 174a21ba354ba4162ee4c5da7dd6eefafdee6846 /fs/ext4/ext4.h | |
| parent | 8ef123fe02ca0923b01b57bdf639800a23a2faa8 (diff) | |
| download | linux-993778306e7901a7286322f25c7c681dd47bede6.tar.xz | |
ext4: mballoc: use lock for checking free blocks while retrying
Currently while doing block allocation grp->bb_free may be getting
modified if discard is happening in parallel.
For e.g. consider a case where there are lot of threads who have
preallocated lot of blocks and there is a thread which is trying
to discard all of this group's PA. Now it could happen that
we see all of those group's bb_free is zero and fail the allocation
while there is sufficient space if we free up all the PA.
So this patch adds another flag "EXT4_MB_STRICT_CHECK" which will be set
if we are unable to allocate any blocks in the first try (since we may
not have considered blocks about to be discarded from PA lists).
So during retry attempt to allocate blocks we will use ext4_lock_group()
for checking if the group is good or not.
Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com>
Link: https://lore.kernel.org/r/9cb740a117c958c36596f167b12af1beae9a68b7.1589955723.git.riteshh@linux.ibm.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index af60be906528..dbc36e377eb0 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -150,6 +150,8 @@ enum SHIFT_DIRECTION { #define EXT4_MB_USE_ROOT_BLOCKS 0x1000 /* Use blocks from reserved pool */ #define EXT4_MB_USE_RESERVED 0x2000 +/* Do strict check for free blocks while retrying block allocation */ +#define EXT4_MB_STRICT_CHECK 0x4000 struct ext4_allocation_request { /* target inode for block we're allocating */ |