--- /dev/null
+From 2ebd1704ded88a8ae29b5f3998b13959c715c4be Mon Sep 17 00:00:00 2001
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Date: Wed, 5 Sep 2012 01:27:50 -0400
+Subject: ext4: avoid duplicate writes of the backup bg descriptor blocks
+
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+
+commit 2ebd1704ded88a8ae29b5f3998b13959c715c4be upstream.
+
+The resize code was needlessly writing the backup block group
+descriptor blocks multiple times (once per block group) during an
+online resize.
+
+Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/resize.c | 10 ++++++----
+ 1 file changed, 6 insertions(+), 4 deletions(-)
+
+--- a/fs/ext4/resize.c
++++ b/fs/ext4/resize.c
+@@ -1302,13 +1302,15 @@ exit_journal:
+ err = err2;
+
+ if (!err) {
+- int i;
++ int gdb_num = group / EXT4_DESC_PER_BLOCK(sb);
++ int gdb_num_end = ((group + flex_gd->count - 1) /
++ EXT4_DESC_PER_BLOCK(sb));
++
+ update_backups(sb, sbi->s_sbh->b_blocknr, (char *)es,
+ sizeof(struct ext4_super_block));
+- for (i = 0; i < flex_gd->count; i++, group++) {
++ for (; gdb_num <= gdb_num_end; gdb_num++) {
+ struct buffer_head *gdb_bh;
+- int gdb_num;
+- gdb_num = group / EXT4_BLOCKS_PER_GROUP(sb);
++
+ gdb_bh = sbi->s_group_desc[gdb_num];
+ update_backups(sb, gdb_bh->b_blocknr, gdb_bh->b_data,
+ gdb_bh->b_size);
--- /dev/null
+From 6df935ad2fced9033ab52078825fcaf6365f34b7 Mon Sep 17 00:00:00 2001
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Date: Wed, 5 Sep 2012 01:25:50 -0400
+Subject: ext4: don't copy non-existent gdt blocks when resizing
+
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+
+commit 6df935ad2fced9033ab52078825fcaf6365f34b7 upstream.
+
+The resize code was copying blocks at the beginning of each block
+group in order to copy the superblock and block group descriptor table
+(gdt) blocks. This was, unfortunately, being done even for block
+groups that did not have super blocks or gdt blocks. This is a
+complete waste of perfectly good I/O bandwidth, to skip writing those
+blocks for sparse bg's.
+
+Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/resize.c | 4 ++++
+ 1 file changed, 4 insertions(+)
+
+--- a/fs/ext4/resize.c
++++ b/fs/ext4/resize.c
+@@ -456,6 +456,9 @@ static int setup_new_flex_group_blocks(s
+ gdblocks = ext4_bg_num_gdb(sb, group);
+ start = ext4_group_first_block_no(sb, group);
+
++ if (!ext4_bg_has_super(sb, group))
++ goto handle_itb;
++
+ /* Copy all of the GDT blocks into the backup in this group */
+ for (j = 0, block = start + 1; j < gdblocks; j++, block++) {
+ struct buffer_head *gdb;
+@@ -498,6 +501,7 @@ static int setup_new_flex_group_blocks(s
+ goto out;
+ }
+
++handle_itb:
+ /* Initialize group tables of the grop @group */
+ if (!(bg_flags[i] & EXT4_BG_INODE_ZEROED))
+ goto handle_bb;
--- /dev/null
+From 00d4e7362ed01987183e9528295de3213031309c Mon Sep 17 00:00:00 2001
+From: Theodore Ts'o <tytso@mit.edu>
+Date: Wed, 19 Sep 2012 22:42:36 -0400
+Subject: ext4: fix potential deadlock in ext4_nonda_switch()
+
+From: Theodore Ts'o <tytso@mit.edu>
+
+commit 00d4e7362ed01987183e9528295de3213031309c upstream.
+
+In ext4_nonda_switch(), if the file system is getting full we used to
+call writeback_inodes_sb_if_idle(). The problem is that we can be
+holding i_mutex already, and this causes a potential deadlock when
+writeback_inodes_sb_if_idle() when it tries to take s_umount. (See
+lockdep output below).
+
+As it turns out we don't need need to hold s_umount; the fact that we
+are in the middle of the write(2) system call will keep the superblock
+pinned. Unfortunately writeback_inodes_sb() checks to make sure
+s_umount is taken, and the VFS uses a different mechanism for making
+sure the file system doesn't get unmounted out from under us. The
+simplest way of dealing with this is to just simply grab s_umount
+using a trylock, and skip kicking the writeback flusher thread in the
+very unlikely case that we can't take a read lock on s_umount without
+blocking.
+
+Also, we now check the cirteria for kicking the writeback thread
+before we decide to whether to fall back to non-delayed writeback, so
+if there are any outstanding delayed allocation writes, we try to get
+them resolved as soon as possible.
+
+ [ INFO: possible circular locking dependency detected ]
+ 3.6.0-rc1-00042-gce894ca #367 Not tainted
+ -------------------------------------------------------
+ dd/8298 is trying to acquire lock:
+ (&type->s_umount_key#18){++++..}, at: [<c02277d4>] writeback_inodes_sb_if_idle+0x28/0x46
+
+ but task is already holding lock:
+ (&sb->s_type->i_mutex_key#8){+.+...}, at: [<c01ddcce>] generic_file_aio_write+0x5f/0xd3
+
+ which lock already depends on the new lock.
+
+ 2 locks held by dd/8298:
+ #0: (sb_writers#2){.+.+.+}, at: [<c01ddcc5>] generic_file_aio_write+0x56/0xd3
+ #1: (&sb->s_type->i_mutex_key#8){+.+...}, at: [<c01ddcce>] generic_file_aio_write+0x5f/0xd3
+
+ stack backtrace:
+ Pid: 8298, comm: dd Not tainted 3.6.0-rc1-00042-gce894ca #367
+ Call Trace:
+ [<c015b79c>] ? console_unlock+0x345/0x372
+ [<c06d62a1>] print_circular_bug+0x190/0x19d
+ [<c019906c>] __lock_acquire+0x86d/0xb6c
+ [<c01999db>] ? mark_held_locks+0x5c/0x7b
+ [<c0199724>] lock_acquire+0x66/0xb9
+ [<c02277d4>] ? writeback_inodes_sb_if_idle+0x28/0x46
+ [<c06db935>] down_read+0x28/0x58
+ [<c02277d4>] ? writeback_inodes_sb_if_idle+0x28/0x46
+ [<c02277d4>] writeback_inodes_sb_if_idle+0x28/0x46
+ [<c026f3b2>] ext4_nonda_switch+0xe1/0xf4
+ [<c0271ece>] ext4_da_write_begin+0x27/0x193
+ [<c01dcdb0>] generic_file_buffered_write+0xc8/0x1bb
+ [<c01ddc47>] __generic_file_aio_write+0x1dd/0x205
+ [<c01ddce7>] generic_file_aio_write+0x78/0xd3
+ [<c026d336>] ext4_file_write+0x480/0x4a6
+ [<c0198c1d>] ? __lock_acquire+0x41e/0xb6c
+ [<c0180944>] ? sched_clock_cpu+0x11a/0x13e
+ [<c01967e9>] ? trace_hardirqs_off+0xb/0xd
+ [<c018099f>] ? local_clock+0x37/0x4e
+ [<c0209f2c>] do_sync_write+0x67/0x9d
+ [<c0209ec5>] ? wait_on_retry_sync_kiocb+0x44/0x44
+ [<c020a7b9>] vfs_write+0x7b/0xe6
+ [<c020a9a6>] sys_write+0x3b/0x64
+ [<c06dd4bd>] syscall_call+0x7/0xb
+
+Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/inode.c | 17 ++++++++++-------
+ fs/fs-writeback.c | 1 +
+ 2 files changed, 11 insertions(+), 7 deletions(-)
+
+--- a/fs/ext4/inode.c
++++ b/fs/ext4/inode.c
+@@ -2386,6 +2386,16 @@ static int ext4_nonda_switch(struct supe
+ free_blocks = EXT4_C2B(sbi,
+ percpu_counter_read_positive(&sbi->s_freeclusters_counter));
+ dirty_blocks = percpu_counter_read_positive(&sbi->s_dirtyclusters_counter);
++ /*
++ * Start pushing delalloc when 1/2 of free blocks are dirty.
++ */
++ if (dirty_blocks && (free_blocks < 2 * dirty_blocks) &&
++ !writeback_in_progress(sb->s_bdi) &&
++ down_read_trylock(&sb->s_umount)) {
++ writeback_inodes_sb(sb, WB_REASON_FS_FREE_SPACE);
++ up_read(&sb->s_umount);
++ }
++
+ if (2 * free_blocks < 3 * dirty_blocks ||
+ free_blocks < (dirty_blocks + EXT4_FREECLUSTERS_WATERMARK)) {
+ /*
+@@ -2394,13 +2404,6 @@ static int ext4_nonda_switch(struct supe
+ */
+ return 1;
+ }
+- /*
+- * Even if we don't switch but are nearing capacity,
+- * start pushing delalloc when 1/2 of free blocks are dirty.
+- */
+- if (free_blocks < 2 * dirty_blocks)
+- writeback_inodes_sb_if_idle(sb, WB_REASON_FS_FREE_SPACE);
+-
+ return 0;
+ }
+
+--- a/fs/fs-writeback.c
++++ b/fs/fs-writeback.c
+@@ -68,6 +68,7 @@ int writeback_in_progress(struct backing
+ {
+ return test_bit(BDI_writeback_running, &bdi->state);
+ }
++EXPORT_SYMBOL(writeback_in_progress);
+
+ static inline struct backing_dev_info *inode_to_bdi(struct inode *inode)
+ {
--- /dev/null
+From 03c1c29053f678234dbd51bf3d65f3b7529021de Mon Sep 17 00:00:00 2001
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Date: Wed, 5 Sep 2012 01:21:50 -0400
+Subject: ext4: ignore last group w/o enough space when resizing instead of BUG'ing
+
+From: Yongqiang Yang <xiaoqiangnk@gmail.com>
+
+commit 03c1c29053f678234dbd51bf3d65f3b7529021de upstream.
+
+If the last group does not have enough space for group tables, ignore
+it instead of calling BUG_ON().
+
+Reported-by: Daniel Drake <dsd@laptop.org>
+Signed-off-by: Yongqiang Yang <xiaoqiangnk@gmail.com>
+Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
+Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
+
+---
+ fs/ext4/resize.c | 12 +++++++++---
+ 1 file changed, 9 insertions(+), 3 deletions(-)
+
+--- a/fs/ext4/resize.c
++++ b/fs/ext4/resize.c
+@@ -200,8 +200,11 @@ static void free_flex_gd(struct ext4_new
+ * be a partial of a flex group.
+ *
+ * @sb: super block of fs to which the groups belongs
++ *
++ * Returns 0 on a successful allocation of the metadata blocks in the
++ * block group.
+ */
+-static void ext4_alloc_group_tables(struct super_block *sb,
++static int ext4_alloc_group_tables(struct super_block *sb,
+ struct ext4_new_flex_group_data *flex_gd,
+ int flexbg_size)
+ {
+@@ -226,6 +229,8 @@ static void ext4_alloc_group_tables(stru
+ (last_group & ~(flexbg_size - 1))));
+ next_group:
+ group = group_data[0].group;
++ if (src_group >= group_data[0].group + flex_gd->count)
++ return -ENOSPC;
+ start_blk = ext4_group_first_block_no(sb, src_group);
+ last_blk = start_blk + group_data[src_group - group].blocks_count;
+
+@@ -235,7 +240,6 @@ next_group:
+
+ start_blk += overhead;
+
+- BUG_ON(src_group >= group_data[0].group + flex_gd->count);
+ /* We collect contiguous blocks as much as possible. */
+ src_group++;
+ for (; src_group <= last_group; src_group++)
+@@ -300,6 +304,7 @@ next_group:
+ group_data[i].free_blocks_count);
+ }
+ }
++ return 0;
+ }
+
+ static struct buffer_head *bclean(handle_t *handle, struct super_block *sb,
+@@ -1676,7 +1681,8 @@ int ext4_resize_fs(struct super_block *s
+ */
+ while (ext4_setup_next_flex_gd(sb, flex_gd, n_blocks_count,
+ flexbg_size)) {
+- ext4_alloc_group_tables(sb, flex_gd, flexbg_size);
++ if (ext4_alloc_group_tables(sb, flex_gd, flexbg_size) != 0)
++ break;
+ err = ext4_flex_group_add(sb, resize_inode, flex_gd);
+ if (unlikely(err))
+ break;
scsi-zfcp-restore-refcount-check-on-port_remove.patch
scsi-zfcp-only-access-zfcp_scsi_dev-for-valid-scsi_device.patch
pci-check-p2p-bridge-for-invalid-secondary-subordinate-range.patch
+ext4-ignore-last-group-w-o-enough-space-when-resizing-instead-of-bug-ing.patch
+ext4-don-t-copy-non-existent-gdt-blocks-when-resizing.patch
+ext4-avoid-duplicate-writes-of-the-backup-bg-descriptor-blocks.patch
+ext4-fix-potential-deadlock-in-ext4_nonda_switch.patch
projects / thirdparty / kernel / stable-queue.git / commitdiff
