| Message ID | 1349459359-2298-1-git-send-email-jbacik@fusionio.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, Oct 05, 2012 at 01:49:19PM -0400, Josef Bacik wrote: > --- a/fs/btrfs/compression.c > +++ b/fs/btrfs/compression.c > @@ -577,6 +577,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, > u64 em_start; > struct extent_map *em; > int ret = -ENOMEM; > + int faili = 0; > u32 *sums; > > tree = &BTRFS_I(inode)->io_tree; > @@ -626,8 +627,11 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, > for (pg_index = 0; pg_index < nr_pages; pg_index++) { > cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS | > __GFP_HIGHMEM); > - if (!cb->compressed_pages[pg_index]) > + if (!cb->compressed_pages[pg_index]) { > + faili = pg_index - 1; > + ret = -ENOMEM; > goto fail2; > + } > } > cb->nr_pages = nr_pages; > > @@ -713,8 +717,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, > return 0; > > fail2: > - for (pg_index = 0; pg_index < nr_pages; pg_index++) > - free_page((unsigned long)cb->compressed_pages[pg_index]); > + while (faili >= 0) { > + __free_page(cb->compressed_pages[pg_index]); ^^^^^^^^ s/pg_index/faili/ Also, faili (how do you pronounce that?) is initialized to 0, the while loop will always fire (and burn a page), initialize it to -1. Other than that, I like the fix, thanks. > + faili--; > + } > > kfree(cb->compressed_pages); > fail1: david -- 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
On Fri, Oct 05, 2012 at 10:06:17PM +0200, David Sterba wrote: > Also, faili (how do you pronounce that?) is initialized to 0, the while > loop will always fire (and burn a page), initialize it to -1. My oversight sorry, it takes a different codepath and this will not happen. david -- 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
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 43d1c5a..36eb5f2 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -577,6 +577,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, u64 em_start; struct extent_map *em; int ret = -ENOMEM; + int faili = 0; u32 *sums; tree = &BTRFS_I(inode)->io_tree; @@ -626,8 +627,11 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, for (pg_index = 0; pg_index < nr_pages; pg_index++) { cb->compressed_pages[pg_index] = alloc_page(GFP_NOFS | __GFP_HIGHMEM); - if (!cb->compressed_pages[pg_index]) + if (!cb->compressed_pages[pg_index]) { + faili = pg_index - 1; + ret = -ENOMEM; goto fail2; + } } cb->nr_pages = nr_pages; @@ -713,8 +717,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, return 0; fail2: - for (pg_index = 0; pg_index < nr_pages; pg_index++) - free_page((unsigned long)cb->compressed_pages[pg_index]); + while (faili >= 0) { + __free_page(cb->compressed_pages[pg_index]); + faili--; + } kfree(cb->compressed_pages); fail1:
We were freeing non-existent pages which was causing a panic for a user who was suffering from ENOMEM. This patch fixes the problem. Thanks, Reported-by: Jérôme Poulin <jeromepoulin@gmail.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com> --- fs/btrfs/compression.c | 12 +++++++++--- 1 files changed, 9 insertions(+), 3 deletions(-)