In the filesystem context, we must allocate memory by GFP_NOFS,
or we may start another filesystem operation and make kswap thread hang up.
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
---
fs/btrfs/extent-tree.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index f1db57d..42061d2 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -471,7 +471,7 @@ static int cache_block_group(struct btrfs_block_group_cache
*cache,
if (load_cache_only)
return 0;
- caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL);
+ caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS);
BUG_ON(!caching_ctl);
INIT_LIST_HEAD(&caching_ctl->list);
@@ -1743,7 +1743,7 @@ static int remove_extent_backref(struct btrfs_trans_handle
*trans,
static void btrfs_issue_discard(struct block_device *bdev,
u64 start, u64 len)
{
- blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL,
+ blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS,
BLKDEV_IFL_WAIT | BLKDEV_IFL_BARRIER);
}
--
1.7.3.1
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David Sterba
2011-Mar-24 23:07 UTC
Re: [PATCH V5 1/2] btrfs: use GFP_NOFS instead of GFP_KERNEL
Hi, On Thu, Mar 24, 2011 at 07:41:21PM +0800, Miao Xie wrote:> In the filesystem context, we must allocate memory by GFP_NOFS, > or we may start another filesystem operation and make kswap thread hang up.indeed. Did you check for other GFP_KERNEL allocations? I''ve found 8 more them and at least these look like candidates for GFP_NOFS too: diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c index de34bfa..76b9218 100644 --- a/fs/btrfs/acl.c +++ b/fs/btrfs/acl.c @@ -289,7 +289,7 @@ int btrfs_acl_chmod(struct inode *inode) if (IS_ERR(acl) || !acl) return PTR_ERR(acl); - clone = posix_acl_clone(acl, GFP_KERNEL); + clone = posix_acl_clone(acl, GFP_NOFS); posix_acl_release(acl); if (!clone) return -ENOMEM; diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f447b78..eb5c01d 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -998,7 +998,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) / PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / (sizeof(struct page *))); - pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); + pages = kmalloc(nrptrs * sizeof(struct page *), GFP_NOFS); if (!pages) { ret = -ENOMEM; goto out; diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c index d1bace3..e9b9648 100644 --- a/fs/btrfs/ioctl.c +++ b/fs/btrfs/ioctl.c @@ -1644,7 +1644,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) goto out; } - range = kzalloc(sizeof(*range), GFP_KERNEL); + range = kzalloc(sizeof(*range), GFP_NOFS); if (!range) { ret = -ENOMEM; goto out; diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c index d39a989..5e0fff7 100644 --- a/fs/btrfs/super.c +++ b/fs/btrfs/super.c @@ -399,7 +399,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, * strsep changes the string, duplicate it because parse_options * gets called twice */ - opts = kstrdup(options, GFP_KERNEL); + opts = kstrdup(options, GFP_NOFS); if (!opts) return -ENOMEM; orig = opts; @@ -446,7 +446,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, * mount path doesn''t care if it''s the default volume or another one. */ if (!*subvol_name) { - *subvol_name = kstrdup(".", GFP_KERNEL); + *subvol_name = kstrdup(".", GFP_NOFS); if (!*subvol_name) return -ENOMEM; } dave -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Miao Xie
2011-Mar-25 01:56 UTC
Re: [PATCH V5 1/2] btrfs: use GFP_NOFS instead of GFP_KERNEL
On Fri, 25 Mar 2011 00:07:59 +0100, David Sterba wrote:> On Thu, Mar 24, 2011 at 07:41:21PM +0800, Miao Xie wrote: >> In the filesystem context, we must allocate memory by GFP_NOFS, >> or we may start another filesystem operation and make kswap thread hang up. > > indeed. Did you check for other GFP_KERNEL allocations? I''ve found 8 more > them and at least these look like candidates for GFP_NOFS too:I just fix the ones, which should use GFP_NOFS. I think not all of the GFP_KERNEL allocations are wrong, if we don''t hold any btrfs''s lock except relative inode''s i_mutex and not in the context of the transaction, we can use GFP_KERNEL. So the following GFP_KERNEL allocations are right, I think. Thanks Miao> > diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c > index de34bfa..76b9218 100644 > --- a/fs/btrfs/acl.c > +++ b/fs/btrfs/acl.c > @@ -289,7 +289,7 @@ int btrfs_acl_chmod(struct inode *inode) > if (IS_ERR(acl) || !acl) > return PTR_ERR(acl); > > - clone = posix_acl_clone(acl, GFP_KERNEL); > + clone = posix_acl_clone(acl, GFP_NOFS); > posix_acl_release(acl); > if (!clone) > return -ENOMEM; > diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c > index f447b78..eb5c01d 100644 > --- a/fs/btrfs/file.c > +++ b/fs/btrfs/file.c > @@ -998,7 +998,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, > nrptrs = min((iov_iter_count(&i) + PAGE_CACHE_SIZE - 1) / > PAGE_CACHE_SIZE, PAGE_CACHE_SIZE / > (sizeof(struct page *))); > - pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL); > + pages = kmalloc(nrptrs * sizeof(struct page *), GFP_NOFS); > if (!pages) { > ret = -ENOMEM; > goto out; > diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c > index d1bace3..e9b9648 100644 > --- a/fs/btrfs/ioctl.c > +++ b/fs/btrfs/ioctl.c > @@ -1644,7 +1644,7 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp) > goto out; > } > > - range = kzalloc(sizeof(*range), GFP_KERNEL); > + range = kzalloc(sizeof(*range), GFP_NOFS); > if (!range) { > ret = -ENOMEM; > goto out; > diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c > index d39a989..5e0fff7 100644 > --- a/fs/btrfs/super.c > +++ b/fs/btrfs/super.c > @@ -399,7 +399,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, > * strsep changes the string, duplicate it because parse_options > * gets called twice > */ > - opts = kstrdup(options, GFP_KERNEL); > + opts = kstrdup(options, GFP_NOFS); > if (!opts) > return -ENOMEM; > orig = opts; > @@ -446,7 +446,7 @@ static int btrfs_parse_early_options(const char *options, fmode_t flags, > * mount path doesn''t care if it''s the default volume or another one. > */ > if (!*subvol_name) { > - *subvol_name = kstrdup(".", GFP_KERNEL); > + *subvol_name = kstrdup(".", GFP_NOFS); > if (!*subvol_name) > return -ENOMEM; > } > > > dave >-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html