The current memory copy function of nilfs2 ioctl has following
problems:
(1) It tries to allocate 128KB size of memory even for small objects.
(2) Though the function repeatedly tries large memory allocations
while reducing the size, GFP_NOWAIT flag is not specified.
This increases the possibility of system memory shortage.
(3) During the retries of (2), verbose warnings are printed
because _GFP_NOWARN flag is not used for the kmalloc calls.
This will fix these problems.
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@xxxxxxxxxxxxx>
---
fs/nilfs2/ioctl.c | 17 ++++++++++++-----
1 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index 35ba60e..5ba6e4e 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -51,13 +51,20 @@ static int nilfs_ioctl_wrap_copy(struct the_nilfs *nilfs,
if (argv->v_nmembs == 0)
return 0;
- for (ksize = KMALLOC_SIZE_MAX; ksize >= KMALLOC_SIZE_MIN; ksize /= 2) {
- buf = kmalloc(ksize, GFP_NOFS);
- if (buf != NULL)
- break;
+ ksize = min_t(unsigned long, argv->v_nmembs * argv->v_size,
+ KMALLOC_SIZE_MAX);
+ while (ksize >= KMALLOC_SIZE_MIN) {
+ buf = kmalloc(ksize, GFP_NOWAIT | __GFP_NOWARN);
+ if (buf)
+ goto allocated;
+ ksize >>= 1;
}
- if (ksize < KMALLOC_SIZE_MIN)
+ ksize = max_t(size_t, ksize, argv->v_size);
+ buf = kmalloc(ksize, GFP_NOFS);
+ if (unlikely(!buf))
return -ENOMEM;
+
+ allocated:
maxmembs = ksize / argv->v_size;
ret = 0;
--
1.5.6.5
--
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