From 3f649ab728cda8038259d8f14492fe400fbab911 Mon Sep 17 00:00:00 2001 From: Kees Cook Date: Wed, 3 Jun 2020 13:09:38 -0700 Subject: treewide: Remove uninitialized_var() usage Using uninitialized_var() is dangerous as it papers over real bugs[1] (or can in the future), and suppresses unrelated compiler warnings (e.g. "unused variable"). If the compiler thinks it is uninitialized, either simply initialize the variable or make compiler changes. In preparation for removing[2] the[3] macro[4], remove all remaining needless uses with the following script: git grep '\buninitialized_var\b' | cut -d: -f1 | sort -u | \ xargs perl -pi -e \ 's/\buninitialized_var\(([^\)]+)\)/\1/g; s:\s*/\* (GCC be quiet|to make compiler happy) \*/$::g;' drivers/video/fbdev/riva/riva_hw.c was manually tweaked to avoid pathological white-space. No outstanding warnings were found building allmodconfig with GCC 9.3.0 for x86_64, i386, arm64, arm, powerpc, powerpc64le, s390x, mips, sparc64, alpha, and m68k. [1] https://lore.kernel.org/lkml/20200603174714.192027-1-glider@google.com/ [2] https://lore.kernel.org/lkml/CA+55aFw+Vbj0i=1TGqCR5vQkCzWJ0QxK6CernOU6eedsudAixw@mail.gmail.com/ [3] https://lore.kernel.org/lkml/CA+55aFwgbgqhbp1fkxvRKEpzyR5J8n1vKT1VZdz9knmPuXhOeg@mail.gmail.com/ [4] https://lore.kernel.org/lkml/CA+55aFz2500WfbKXAx8s67wrm9=yVJu65TpLgN_ybYNv0VEOKA@mail.gmail.com/ Reviewed-by: Leon Romanovsky # drivers/infiniband and mlx4/mlx5 Acked-by: Jason Gunthorpe # IB Acked-by: Kalle Valo # wireless drivers Reviewed-by: Chao Yu # erofs Signed-off-by: Kees Cook --- fs/gfs2/bmap.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/gfs2/bmap.c') diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 6306eaae378b..8dfe09f52cbc 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1761,7 +1761,7 @@ static int punch_hole(struct gfs2_inode *ip, u64 offset, u64 length) u64 lblock = (offset + (1 << bsize_shift) - 1) >> bsize_shift; __u16 start_list[GFS2_MAX_META_HEIGHT]; __u16 __end_list[GFS2_MAX_META_HEIGHT], *end_list = NULL; - unsigned int start_aligned, uninitialized_var(end_aligned); + unsigned int start_aligned, end_aligned; unsigned int strip_h = ip->i_height - 1; u32 btotal = 0; int ret, state; -- cgit From 70499cdfeb3625c87eebe4f7a7ea06fa7447e5df Mon Sep 17 00:00:00 2001 From: Bob Peterson Date: Fri, 24 Jul 2020 12:06:31 -0500 Subject: gfs2: Never call gfs2_block_zero_range with an open transaction Before this patch, some functions started transactions then they called gfs2_block_zero_range. However, gfs2_block_zero_range, like writes, can start transactions, which results in a recursive transaction error. For example: do_shrink trunc_start gfs2_trans_begin <------------------------------------------------ gfs2_block_zero_range iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops); iomap_apply ... iomap_zero_range_actor iomap_begin gfs2_iomap_begin gfs2_iomap_begin_write actor (iomap_zero_range_actor) iomap_zero iomap_write_begin gfs2_iomap_page_prepare gfs2_trans_begin <------------------------ This patch reorders the callers of gfs2_block_zero_range so that they only start their transactions after the call. It also adds a BUG_ON to ensure this doesn't happen again. Fixes: 2257e468a63b ("gfs2: implement gfs2_block_zero_range using iomap_zero_range") Cc: stable@vger.kernel.org # v5.5+ Signed-off-by: Bob Peterson Signed-off-by: Andreas Gruenbacher --- fs/gfs2/bmap.c | 69 +++++++++++++++++++++++++++++++++------------------------- 1 file changed, 39 insertions(+), 30 deletions(-) (limited to 'fs/gfs2/bmap.c') diff --git a/fs/gfs2/bmap.c b/fs/gfs2/bmap.c index 6306eaae378b..6d2ea788d0a1 100644 --- a/fs/gfs2/bmap.c +++ b/fs/gfs2/bmap.c @@ -1351,9 +1351,15 @@ int gfs2_extent_map(struct inode *inode, u64 lblock, int *new, u64 *dblock, unsi return ret; } +/* + * NOTE: Never call gfs2_block_zero_range with an open transaction because it + * uses iomap write to perform its actions, which begin their own transactions + * (iomap_begin, page_prepare, etc.) + */ static int gfs2_block_zero_range(struct inode *inode, loff_t from, unsigned int length) { + BUG_ON(current->journal_info); return iomap_zero_range(inode, from, length, NULL, &gfs2_iomap_ops); } @@ -1414,6 +1420,16 @@ static int trunc_start(struct inode *inode, u64 newsize) u64 oldsize = inode->i_size; int error; + if (!gfs2_is_stuffed(ip)) { + unsigned int blocksize = i_blocksize(inode); + unsigned int offs = newsize & (blocksize - 1); + if (offs) { + error = gfs2_block_zero_range(inode, newsize, + blocksize - offs); + if (error) + return error; + } + } if (journaled) error = gfs2_trans_begin(sdp, RES_DINODE + RES_JDATA, GFS2_JTRUNC_REVOKES); else @@ -1427,19 +1443,10 @@ static int trunc_start(struct inode *inode, u64 newsize) gfs2_trans_add_meta(ip->i_gl, dibh); - if (gfs2_is_stuffed(ip)) { + if (gfs2_is_stuffed(ip)) gfs2_buffer_clear_tail(dibh, sizeof(struct gfs2_dinode) + newsize); - } else { - unsigned int blocksize = i_blocksize(inode); - unsigned int offs = newsize & (blocksize - 1); - if (offs) { - error = gfs2_block_zero_range(inode, newsize, - blocksize - offs); - if (error) - goto out; - } + else ip->i_diskflags |= GFS2_DIF_TRUNC_IN_PROG; - } i_size_write(inode, newsize); ip->i_inode.i_mtime = ip->i_inode.i_ctime = current_time(&ip->i_inode); @@ -2448,25 +2455,7 @@ int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length) loff_t start, end; int error; - start = round_down(offset, blocksize); - end = round_up(offset + length, blocksize) - 1; - error = filemap_write_and_wait_range(inode->i_mapping, start, end); - if (error) - return error; - - if (gfs2_is_jdata(ip)) - error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA, - GFS2_JTRUNC_REVOKES); - else - error = gfs2_trans_begin(sdp, RES_DINODE, 0); - if (error) - return error; - - if (gfs2_is_stuffed(ip)) { - error = stuffed_zero_range(inode, offset, length); - if (error) - goto out; - } else { + if (!gfs2_is_stuffed(ip)) { unsigned int start_off, end_len; start_off = offset & (blocksize - 1); @@ -2489,6 +2478,26 @@ int __gfs2_punch_hole(struct file *file, loff_t offset, loff_t length) } } + start = round_down(offset, blocksize); + end = round_up(offset + length, blocksize) - 1; + error = filemap_write_and_wait_range(inode->i_mapping, start, end); + if (error) + return error; + + if (gfs2_is_jdata(ip)) + error = gfs2_trans_begin(sdp, RES_DINODE + 2 * RES_JDATA, + GFS2_JTRUNC_REVOKES); + else + error = gfs2_trans_begin(sdp, RES_DINODE, 0); + if (error) + return error; + + if (gfs2_is_stuffed(ip)) { + error = stuffed_zero_range(inode, offset, length); + if (error) + goto out; + } + if (gfs2_is_jdata(ip)) { BUG_ON(!current->journal_info); gfs2_journaled_truncate_range(inode, offset, length); -- cgit