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ext4: Implement ext4_group_block_valid() as common function

RFC In review Ritesh Harjani 2 participants 18 messages Jan 31, 2022 – Feb 5, 2022 1 message not in the archive

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A message that is not in the archive (sent off-list or not yet received): [email protected]

Ritesh Harjani

author
#1 lore raw

RFC 1/6 ext4: Fixes ext4_mb_mark_bb() with flex_bg with fast_commit

In case of flex_bg feature (which is by default enabled), extents for any given inode might span across blocks from two different block group. ext4_mb_mark_bb() only reads the buffer_head of block bitmap once for the starting block group, but it fails to read it again when the extent length boundary overflows to another block group. Then in this below loop it accesses memory beyond the block group bitmap buffer_head and results into a data abort.

	for (i = 0; i < clen; i++)
		if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state)
			already++;

This patch adds this functionality for checking block group boundary in ext4_mb_mark_bb() and update the buffer_head(bitmap_bh) for every different block group.

w/o this patch, I was easily able to hit a data access abort using Power platform.

<...>

[   74.327662] EXT4-fs error (device loop3): ext4_mb_generate_buddy:1141: group 11, block bitmap and bg descriptor inconsistent: 21248 vs 23294 free clusters
[   74.533214] EXT4-fs (loop3): shut down requested (2)
[   74.536705] Aborting journal on device loop3-8.
[   74.702705] BUG: Unable to handle kernel data access on read at 0xc00000005e980000
[   74.703727] Faulting instruction address: 0xc0000000007bffb8
cpu 0xd: Vector: 300 (Data Access) at [c000000015db7060]
    pc: c0000000007bffb8: ext4_mb_mark_bb+0x198/0x5a0
    lr: c0000000007bfeec: ext4_mb_mark_bb+0xcc/0x5a0
    sp: c000000015db7300
   msr: 800000000280b033
   dar: c00000005e980000
 dsisr: 40000000
  current = 0xc000000027af6880
  paca    = 0xc00000003ffd5200   irqmask: 0x03   irq_happened: 0x01
    pid   = 5167, comm = mount

<...>
enter ? for help
[c000000015db7380] c000000000782708 ext4_ext_clear_bb+0x378/0x410 [c000000015db7400] c000000000813f14 ext4_fc_replay+0x1794/0x2000 [c000000015db7580] c000000000833f7c do_one_pass+0xe9c/0x12a0 [c000000015db7710] c000000000834504 jbd2_journal_recover+0x184/0x2d0 [c000000015db77c0] c000000000841398 jbd2_journal_load+0x188/0x4a0 [c000000015db7880] c000000000804de8 ext4_fill_super+0x2638/0x3e10 [c000000015db7a40] c0000000005f8404 get_tree_bdev+0x2b4/0x350 [c000000015db7ae0] c0000000007ef058 ext4_get_tree+0x28/0x40 [c000000015db7b00] c0000000005f6344 vfs_get_tree+0x44/0x100 [c000000015db7b70] c00000000063c408 path_mount+0xdd8/0xe70 [c000000015db7c40] c00000000063c8f0 sys_mount+0x450/0x550 [c000000015db7d50] c000000000035770 system_call_exception+0x4a0/0x4e0 [c000000015db7e10] c00000000000c74c system_call_common+0xec/0x250 --- Exception: c00 (System Call) at 00007ffff7dbfaa4

Fixes 8016e29f4362e28 ("ext4: fast commit recovery path")
Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)
fs/ext4/mballoc.c +27 -3
index c781974df9d0..8d23108cf9d7 100644
@@ -3899,12 +3899,29 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	struct ext4_sb_info *sbi = EXT4_SB(sb);
 	ext4_group_t group;
 	ext4_grpblk_t blkoff;
-	int i, clen, err;
+	int i, err;
 	int already;
+	unsigned int clen, overflow;
 
-	clen = EXT4_B2C(sbi, len);
-
+again:
+	overflow = 0;
 	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
+
+	/*
+	 * Check to see if we are freeing blocks across a group
+	 * boundary.
+	 * In case of flex_bg, this can happen that (block, len) may span across
+	 * more than one group. In that case we need to get the corresponding
+	 * group metadata to work with. For this we have goto again loop.
+	 */
+	if (EXT4_C2B(sbi, blkoff) + len > EXT4_BLOCKS_PER_GROUP(sb)) {
+		overflow = EXT4_C2B(sbi, blkoff) + len -
+			EXT4_BLOCKS_PER_GROUP(sb);
+		len -= overflow;
+	}
+
+	clen = EXT4_NUM_B2C(sbi, len);
+
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
 	if (IS_ERR(bitmap_bh)) {
 		err = PTR_ERR(bitmap_bh);

@@ -3960,6 +3977,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
 	sync_dirty_buffer(gdp_bh);
 
+	if (overflow && !err) {
+		block += len;
+		len = overflow;
+		put_bh(bitmap_bh);
+		goto again;
+	}
+
 out_err:
 	brelse(bitmap_bh);
 }
Signature · 1 line
2.31.1
reviewer
#2 lore raw

Re: [RFC 1/6] ext4: Fixes ext4_mb_mark_bb() with flex_bg with fast_commit

Quoted 63 lines · Ritesh Harjani

In case of flex_bg feature (which is by default enabled), extents for any given inode might span across blocks from two different block group. ext4_mb_mark_bb() only reads the buffer_head of block bitmap once for the starting block group, but it fails to read it again when the extent length boundary overflows to another block group. Then in this below loop it accesses memory beyond the block group bitmap buffer_head and results into a data abort.

	for (i = 0; i < clen; i++)
		if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state)
			already++;

This patch adds this functionality for checking block group boundary in ext4_mb_mark_bb() and update the buffer_head(bitmap_bh) for every different block group.

w/o this patch, I was easily able to hit a data access abort using Power platform.

<...>

[   74.327662] EXT4-fs error (device loop3): ext4_mb_generate_buddy:1141: group 11, block bitmap and bg descriptor inconsistent: 21248 vs 23294 free clusters
[   74.533214] EXT4-fs (loop3): shut down requested (2)
[   74.536705] Aborting journal on device loop3-8.
[   74.702705] BUG: Unable to handle kernel data access on read at 0xc00000005e980000
[   74.703727] Faulting instruction address: 0xc0000000007bffb8
cpu 0xd: Vector: 300 (Data Access) at [c000000015db7060]
    pc: c0000000007bffb8: ext4_mb_mark_bb+0x198/0x5a0
    lr: c0000000007bfeec: ext4_mb_mark_bb+0xcc/0x5a0
    sp: c000000015db7300
   msr: 800000000280b033
   dar: c00000005e980000
 dsisr: 40000000
  current = 0xc000000027af6880
  paca    = 0xc00000003ffd5200   irqmask: 0x03   irq_happened: 0x01
    pid   = 5167, comm = mount

<...>
enter ? for help
[c000000015db7380] c000000000782708 ext4_ext_clear_bb+0x378/0x410 [c000000015db7400] c000000000813f14 ext4_fc_replay+0x1794/0x2000 [c000000015db7580] c000000000833f7c do_one_pass+0xe9c/0x12a0 [c000000015db7710] c000000000834504 jbd2_journal_recover+0x184/0x2d0 [c000000015db77c0] c000000000841398 jbd2_journal_load+0x188/0x4a0 [c000000015db7880] c000000000804de8 ext4_fill_super+0x2638/0x3e10 [c000000015db7a40] c0000000005f8404 get_tree_bdev+0x2b4/0x350 [c000000015db7ae0] c0000000007ef058 ext4_get_tree+0x28/0x40 [c000000015db7b00] c0000000005f6344 vfs_get_tree+0x44/0x100 [c000000015db7b70] c00000000063c408 path_mount+0xdd8/0xe70 [c000000015db7c40] c00000000063c8f0 sys_mount+0x450/0x550 [c000000015db7d50] c000000000035770 system_call_exception+0x4a0/0x4e0 [c000000015db7e10] c00000000000c74c system_call_common+0xec/0x250 --- Exception: c00 (System Call) at 00007ffff7dbfaa4

Fixes 8016e29f4362e28 ("ext4: fast commit recovery path")
Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)
fs/ext4/mballoc.c +0 -0
index c781974df9d0..8d23108cf9d7 100644
@@ -3899,12 +3899,29 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	struct ext4_sb_info *sbi = EXT4_SB(sb);

fs/ext4/mballoc.c void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, · line 3906

Quoted 10 lines
fs/ext4/mballoc.c +3 -3
 	ext4_group_t group;
 	ext4_grpblk_t blkoff;
-	int i, clen, err;
+	int i, err;
 	int already;
+	unsigned int clen, overflow;
 
-	clen = EXT4_B2C(sbi, len);
-
+again:

And maybe structure this as a while loop? Like:

	while (len > 0) {
		...
	}
Quoted 4 lines
fs/ext4/mballoc.c +3 -0
+	overflow = 0;
 	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
+
+	/*

fs/ext4/mballoc.c void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, · line 3920

Quoted 10 lines
fs/ext4/mballoc.c +10 -0
+	 * Check to see if we are freeing blocks across a group
+	 * boundary.
+	 * In case of flex_bg, this can happen that (block, len) may span across
+	 * more than one group. In that case we need to get the corresponding
+	 * group metadata to work with. For this we have goto again loop.
+	 */
+	if (EXT4_C2B(sbi, blkoff) + len > EXT4_BLOCKS_PER_GROUP(sb)) {
+		overflow = EXT4_C2B(sbi, blkoff) + len -
+			EXT4_BLOCKS_PER_GROUP(sb);
+		len -= overflow;

Why not just:

	thisgrp_len = min_t(int, len,
			EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
	clen = EXT4_NUM_B2C(sbi, thisgrp_len);

It seems easier to understand to me.

Honza

Quoted 24 lines
fs/ext4/mballoc.c +11 -0
+	}
+
+	clen = EXT4_NUM_B2C(sbi, len);
+
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
 	if (IS_ERR(bitmap_bh)) {
 		err = PTR_ERR(bitmap_bh);

@@ -3960,6 +3977,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	err = ext4_handle_dirty_metadata(NULL, NULL, gdp_bh);
 	sync_dirty_buffer(gdp_bh);
 
+	if (overflow && !err) {
+		block += len;
+		len = overflow;
+		put_bh(bitmap_bh);
+		goto again;
+	}
+
 out_err:
 	brelse(bitmap_bh);
 }
Signature · 1 line
2.31.1
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#3 lore raw

Re: [RFC 1/6] ext4: Fixes ext4_mb_mark_bb() with flex_bg with fast_commit

Quoted 77 lines · Jan Kara
Quoted 63 lines · Ritesh Harjani

In case of flex_bg feature (which is by default enabled), extents for any given inode might span across blocks from two different block group. ext4_mb_mark_bb() only reads the buffer_head of block bitmap once for the starting block group, but it fails to read it again when the extent length boundary overflows to another block group. Then in this below loop it accesses memory beyond the block group bitmap buffer_head and results into a data abort.

	for (i = 0; i < clen; i++)
		if (!mb_test_bit(blkoff + i, bitmap_bh->b_data) == !state)
			already++;

This patch adds this functionality for checking block group boundary in ext4_mb_mark_bb() and update the buffer_head(bitmap_bh) for every different block group.

w/o this patch, I was easily able to hit a data access abort using Power platform.

<...>

[   74.327662] EXT4-fs error (device loop3): ext4_mb_generate_buddy:1141: group 11, block bitmap and bg descriptor inconsistent: 21248 vs 23294 free clusters
[   74.533214] EXT4-fs (loop3): shut down requested (2)
[   74.536705] Aborting journal on device loop3-8.
[   74.702705] BUG: Unable to handle kernel data access on read at 0xc00000005e980000
[   74.703727] Faulting instruction address: 0xc0000000007bffb8
cpu 0xd: Vector: 300 (Data Access) at [c000000015db7060]
    pc: c0000000007bffb8: ext4_mb_mark_bb+0x198/0x5a0
    lr: c0000000007bfeec: ext4_mb_mark_bb+0xcc/0x5a0
    sp: c000000015db7300
   msr: 800000000280b033
   dar: c00000005e980000
 dsisr: 40000000
  current = 0xc000000027af6880
  paca    = 0xc00000003ffd5200   irqmask: 0x03   irq_happened: 0x01
    pid   = 5167, comm = mount

<...>
enter ? for help
[c000000015db7380] c000000000782708 ext4_ext_clear_bb+0x378/0x410 [c000000015db7400] c000000000813f14 ext4_fc_replay+0x1794/0x2000 [c000000015db7580] c000000000833f7c do_one_pass+0xe9c/0x12a0 [c000000015db7710] c000000000834504 jbd2_journal_recover+0x184/0x2d0 [c000000015db77c0] c000000000841398 jbd2_journal_load+0x188/0x4a0 [c000000015db7880] c000000000804de8 ext4_fill_super+0x2638/0x3e10 [c000000015db7a40] c0000000005f8404 get_tree_bdev+0x2b4/0x350 [c000000015db7ae0] c0000000007ef058 ext4_get_tree+0x28/0x40 [c000000015db7b00] c0000000005f6344 vfs_get_tree+0x44/0x100 [c000000015db7b70] c00000000063c408 path_mount+0xdd8/0xe70 [c000000015db7c40] c00000000063c8f0 sys_mount+0x450/0x550 [c000000015db7d50] c000000000035770 system_call_exception+0x4a0/0x4e0 [c000000015db7e10] c00000000000c74c system_call_common+0xec/0x250 --- Exception: c00 (System Call) at 00007ffff7dbfaa4

Fixes 8016e29f4362e28 ("ext4: fast commit recovery path")
Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 30 +++++++++++++++++++++++++++---
 1 file changed, 27 insertions(+), 3 deletions(-)
fs/ext4/mballoc.c +0 -0
index c781974df9d0..8d23108cf9d7 100644
@@ -3899,12 +3899,29 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	struct ext4_sb_info *sbi = EXT4_SB(sb);

fs/ext4/mballoc.c void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, · line 3906

Quoted 10 lines
fs/ext4/mballoc.c +3 -3
 	ext4_group_t group;
 	ext4_grpblk_t blkoff;
-	int i, clen, err;
+	int i, err;
 	int already;
+	unsigned int clen, overflow;
 
-	clen = EXT4_B2C(sbi, len);
-
+again:

And maybe structure this as a while loop? Like:

Quoted 3 lines
	while (len > 0) {
		...
	}

Sure, will check.

Quoted 18 lines
Quoted 5 lines
fs/ext4/mballoc.c +3 -0
+	overflow = 0;
 	ext4_get_group_no_and_offset(sb, block, &group, &blkoff);
+
+	/*

fs/ext4/mballoc.c void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block, · line 3920

Quoted 10 lines
fs/ext4/mballoc.c +10 -0
+	 * Check to see if we are freeing blocks across a group
+	 * boundary.
+	 * In case of flex_bg, this can happen that (block, len) may span across
+	 * more than one group. In that case we need to get the corresponding
+	 * group metadata to work with. For this we have goto again loop.
+	 */
+	if (EXT4_C2B(sbi, blkoff) + len > EXT4_BLOCKS_PER_GROUP(sb)) {
+		overflow = EXT4_C2B(sbi, blkoff) + len -
+			EXT4_BLOCKS_PER_GROUP(sb);
+		len -= overflow;

Why not just:

Quoted 5 lines
	thisgrp_len = min_t(int, len,
			EXT4_BLOCKS_PER_GROUP(sb) - EXT4_C2B(sbi, blkoff));
	clen = EXT4_NUM_B2C(sbi, thisgrp_len);

It seems easier to understand to me.

Agree, will make this change.

-ritesh

author
#4 lore raw

RFC 2/6 ext4: Implement ext4_group_block_valid() as common function

In reply to a message not in the archive

This patch implements ext4_group_block_valid() check functionality, and refactors all the callers to use this common function instead.

Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/block_validity.c | 31 +++++++++++++++++++++++++++++++
 fs/ext4/ext4.h           |  3 +++
 fs/ext4/mballoc.c        | 16 +++-------------
 3 files changed, 37 insertions(+), 13 deletions(-)
fs/ext4/block_validity.c +31 -0
index 4666b55b736e..01d822c664df 100644
@@ -361,3 +361,34 @@ int ext4_check_blockref(const char *function, unsigned int line,
 	return 0;
 }
 
+/*
+ * ext4_group_block_valid - This checks if any of FS metadata blocks of a
+ * given group (@bg) lies in the given range [block, block + count - 1]
+ * or not.
+ *
+ * Return -
+ * - false if it does
+ * - else true
+ */
+bool ext4_group_block_valid(struct super_block *sb, ext4_group_t bg,
+			    ext4_fsblk_t block, unsigned int count)
+{
+	struct ext4_group_desc *gdp;
+	bool ret = true;
+
+	gdp = ext4_get_group_desc(sb, bg, NULL);
+	if (!gdp) {
+		ret = false;
+		goto out;
+	}
+
+	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
+	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
+	    in_range(block, ext4_inode_table(sb, gdp),
+		    EXT4_SB(sb)->s_itb_per_group) ||
+	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
+		    EXT4_SB(sb)->s_itb_per_group))
+		ret = false;
+out:
+	return ret;
+}
fs/ext4/ext4.h +3 -0
index 18cd5b3b4815..fc7aa4b3e415 100644
@@ -3706,6 +3706,9 @@ extern int ext4_inode_block_valid(struct inode *inode,
 				  unsigned int count);
 extern int ext4_check_blockref(const char *, unsigned int,
 			       struct inode *, __le32 *, unsigned int);
+extern bool ext4_group_block_valid(struct super_block *sb, ext4_group_t bg,
+				   ext4_fsblk_t block, unsigned int count);
+
 
 /* extents.c */
 struct ext4_ext_path;
fs/ext4/mballoc.c +3 -13
index 8d23108cf9d7..60d32d3d8dc4 100644
@@ -6001,13 +6001,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		goto error_return;
 	}
 
-	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-	    in_range(block, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group)) {
-
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);
 		/* err = 0. ext4_std_error should be a no op */

@@ -6078,7 +6072,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 						 NULL);
 			if (err && err != -EOPNOTSUPP)
 				ext4_msg(sb, KERN_WARNING, "discard request in"
-					 " group:%d block:%d count:%lu failed"
+					 " group:%u block:%d count:%lu failed"
 					 " with %d", block_group, bit, count,
 					 err);
 		} else

@@ -6194,11 +6188,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 		goto error_return;
 	}
 
-	if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, desc), block, count) ||
-	    in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, desc),
-		     sbi->s_itb_per_group)) {
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Adding blocks in system zones - "
 			   "Block = %llu, count = %lu",
 			   block, count);
Signature · 1 line
2.31.1
reviewer
#5 lore raw
Quoted 4 lines · Ritesh Harjani

This patch implements ext4_group_block_valid() check functionality, and refactors all the callers to use this common function instead.

Signed-off-by Ritesh Harjani <[email protected]>

...

Quoted 9 lines
fs/ext4/mballoc.c +0 -1
index 8d23108cf9d7..60d32d3d8dc4 100644
@@ -6001,13 +6001,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		goto error_return;
 	}
 
-	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||

fs/ext4/mballoc.c void ext4_free_blocks(handle_t *handle, struct inode *inode, · line 6007

Quoted 10 lines
fs/ext4/mballoc.c +1 -6
-	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-	    in_range(block, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group)) {
-
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);
 		/* err = 0. ext4_std_error should be a no op */

When doing this, why not rather directly use ext4_inode_block_valid() here?

fs/ext4/mballoc.c int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, · line 6194

Quoted 13 lines
fs/ext4/mballoc.c +1 -5
@@ -6194,11 +6188,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 		goto error_return;
 	}
 
-	if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, desc), block, count) ||
-	    in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, desc),
-		     sbi->s_itb_per_group)) {
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Adding blocks in system zones - "
 			   "Block = %llu, count = %lu",
 			   block, count);

And here I'd rather refactor ext4_inode_block_valid() a bit to provide a more generic helper not requiring an inode and use it here...

Honza

Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#6 lore raw
Quoted 15 lines · Jan Kara
Quoted 4 lines · Ritesh Harjani

This patch implements ext4_group_block_valid() check functionality, and refactors all the callers to use this common function instead.

Signed-off-by Ritesh Harjani <[email protected]>

...

Quoted 8 lines
fs/ext4/mballoc.c +0 -0
index 8d23108cf9d7..60d32d3d8dc4 100644
@@ -6001,13 +6001,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		goto error_return;
 	}
Quoted 13 lines

fs/ext4/mballoc.c void ext4_free_blocks(handle_t *handle, struct inode *inode, · line 6007

Quoted 11 lines
fs/ext4/mballoc.c +1 -7
-	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-	    in_range(block, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group)) {
-
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);
 		/* err = 0. ext4_std_error should be a no op */

When doing this, why not rather directly use ext4_inode_block_valid() here?

This is because while freeing these blocks we have their's corresponding block group too. So there is little point in checking FS Metadata of all block groups v/s FS Metadata of just this block group, no?

Also, I am not sure if we changing this to check against system-zone's blocks (which has FS Metadata blocks from all block groups), can add any additional penalty?

-riteshh

Quoted 22 lines
Quoted 4 lines
fs/ext4/mballoc.c +0 -0
@@ -6194,11 +6188,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
 		goto error_return;
 	}

fs/ext4/mballoc.c int ext4_group_add_blocks(handle_t *handle, struct super_block *sb, · line 6194

Quoted 10 lines
fs/ext4/mballoc.c +1 -5
 
-	if (in_range(ext4_block_bitmap(sb, desc), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, desc), block, count) ||
-	    in_range(block, ext4_inode_table(sb, desc), sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, desc),
-		     sbi->s_itb_per_group)) {
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Adding blocks in system zones - "
 			   "Block = %llu, count = %lu",
 			   block, count);

And here I'd rather refactor ext4_inode_block_valid() a bit to provide a more generic helper not requiring an inode and use it here...

Honza
--
Jan Kara <[email protected]>
SUSE Labs, CR

reviewer
#7 lore raw
Quoted 30 lines · Ritesh Harjani
Quoted 15 lines · Jan Kara
Quoted 4 lines · Ritesh Harjani

This patch implements ext4_group_block_valid() check functionality, and refactors all the callers to use this common function instead.

Signed-off-by Ritesh Harjani <[email protected]>

...

Quoted 8 lines
fs/ext4/mballoc.c +0 -0
index 8d23108cf9d7..60d32d3d8dc4 100644
@@ -6001,13 +6001,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		goto error_return;
 	}
Quoted 13 lines

fs/ext4/mballoc.c void ext4_free_blocks(handle_t *handle, struct inode *inode, · line 6007

Quoted 11 lines
fs/ext4/mballoc.c +1 -7
-	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-	    in_range(block, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group)) {
-
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);
 		/* err = 0. ext4_std_error should be a no op */

When doing this, why not rather directly use ext4_inode_block_valid() here?

Quoted 7 lines

This is because while freeing these blocks we have their's corresponding block group too. So there is little point in checking FS Metadata of all block groups v/s FS Metadata of just this block group, no?

Also, I am not sure if we changing this to check against system-zone's blocks (which has FS Metadata blocks from all block groups), can add any additional penalty?

I agree the check will be somewhat more costly (rbtree lookup). OTOH with more complex fs structure (like flexbg which is default for quite some time), this is by far not checking the only metadata blocks, that can overlap the freed range. Also this is not checking for freeing journal blocks. So I'd either got for no check (if we really want performance) or full check (if we care more about detecting fs errors early). Because these half-baked checks do not bring much value these days...

Honza

Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#8 lore raw
Quoted 39 lines · Jan Kara
Quoted 30 lines · Ritesh Harjani
Quoted 15 lines · Jan Kara
Quoted 4 lines · Ritesh Harjani

This patch implements ext4_group_block_valid() check functionality, and refactors all the callers to use this common function instead.

Signed-off-by Ritesh Harjani <[email protected]>

...

Quoted 8 lines
fs/ext4/mballoc.c +0 -0
index 8d23108cf9d7..60d32d3d8dc4 100644
@@ -6001,13 +6001,7 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 		goto error_return;
 	}
Quoted 13 lines

fs/ext4/mballoc.c void ext4_free_blocks(handle_t *handle, struct inode *inode, · line 6007

Quoted 11 lines
fs/ext4/mballoc.c +1 -7
-	if (in_range(ext4_block_bitmap(sb, gdp), block, count) ||
-	    in_range(ext4_inode_bitmap(sb, gdp), block, count) ||
-	    in_range(block, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group) ||
-	    in_range(block + count - 1, ext4_inode_table(sb, gdp),
-		     sbi->s_itb_per_group)) {
-
+	if (!ext4_group_block_valid(sb, block_group, block, count)) {
 		ext4_error(sb, "Freeing blocks in system zone - "
 			   "Block = %llu, count = %lu", block, count);
 		/* err = 0. ext4_std_error should be a no op */

When doing this, why not rather directly use ext4_inode_block_valid() here?

Quoted 7 lines

This is because while freeing these blocks we have their's corresponding block group too. So there is little point in checking FS Metadata of all block groups v/s FS Metadata of just this block group, no?

Also, I am not sure if we changing this to check against system-zone's blocks (which has FS Metadata blocks from all block groups), can add any additional penalty?

Quoted 7 lines

I agree the check will be somewhat more costly (rbtree lookup). OTOH with more complex fs structure (like flexbg which is default for quite some time), this is by far not checking the only metadata blocks, that can overlap the freed range. Also this is not checking for freeing journal blocks. So I'd either got for no check (if we really want performance) or full check (if we care more about detecting fs errors early). Because these half-baked checks do not bring much value these days...

Agreed. Thanks for putting out your points.
I am making these suggested changes to add stricter checking via ext4_inode_block_valid() and will be sending out v1 soon.

-ritesh

author
#9 lore raw

RFC 3/6 ext4: Use in_range() for range checking in ext4_fc_replay_check_excluded

In reply to a message not in the archive

Instead of open coding it, use in_range() function instead.

Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/fast_commit.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
fs/ext4/fast_commit.c +2 -2
index 5934c23e153e..bd6a47d18716 100644
@@ -1874,8 +1874,8 @@ bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t blk)
 		if (state->fc_regions[i].ino == 0 ||
 			state->fc_regions[i].len == 0)
 			continue;
-		if (blk >= state->fc_regions[i].pblk &&
-		    blk < state->fc_regions[i].pblk + state->fc_regions[i].len)
+		if (in_range(blk, state->fc_regions[i].pblk,
+					state->fc_regions[i].len))
 			return true;
 	}
 	return false;
Signature · 1 line
2.31.1
reviewer Reviewed-by on v1 3/6
#10 lore raw

Re: [RFC 3/6] ext4: Use in_range() for range checking in ext4_fc_replay_check_excluded

Quoted 3 lines · Ritesh Harjani

Instead of open coding it, use in_range() function instead.

Signed-off-by Ritesh Harjani <[email protected]>

Looks good. Feel free to add:

Reviewed-by Jan Kara <[email protected]>

Honza

Quoted 22 lines
---
 fs/ext4/fast_commit.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)
fs/ext4/fast_commit.c +2 -2
index 5934c23e153e..bd6a47d18716 100644
@@ -1874,8 +1874,8 @@ bool ext4_fc_replay_check_excluded(struct super_block *sb, ext4_fsblk_t blk)
 		if (state->fc_regions[i].ino == 0 ||
 			state->fc_regions[i].len == 0)
 			continue;
-		if (blk >= state->fc_regions[i].pblk &&
-		    blk < state->fc_regions[i].pblk + state->fc_regions[i].len)
+		if (in_range(blk, state->fc_regions[i].pblk,
+					state->fc_regions[i].len))
 			return true;
 	}
 	return false;
Signature · 1 line
2.31.1
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#11 lore raw

RFC 4/6 ext4: No need to test for block bitmap bits in ext4_mb_mark_bb()

In reply to a message not in the archive

We don't need the return value of mb_test_and_clear_bits() in ext4_mb_mark_bb() So simply use mb_clear_bits() instead.

Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/ext4/mballoc.c +1 -1
index 60d32d3d8dc4..2f931575e6c2 100644
@@ -3943,7 +3943,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	if (state)
 		ext4_set_bits(bitmap_bh->b_data, blkoff, clen);
 	else
-		mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen);
+		mb_clear_bits(bitmap_bh->b_data, blkoff, clen);
 	if (ext4_has_group_desc_csum(sb) &&
 	    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
 		gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
Signature · 1 line
2.31.1
reviewer Reviewed-by on v1 4/6
#12 lore raw

Re: [RFC 4/6] ext4: No need to test for block bitmap bits in ext4_mb_mark_bb()

Quoted 4 lines · Ritesh Harjani

We don't need the return value of mb_test_and_clear_bits() in ext4_mb_mark_bb() So simply use mb_clear_bits() instead.

Signed-off-by Ritesh Harjani <[email protected]>

Looks good. I'm rather confused by ext4_set_bits() vs mb_clear_bits() asymetry but that's not directly related to this patch. Just another cleanup to do. Feel free to add:

Reviewed-by Jan Kara <[email protected]>

Honza

Quoted 20 lines
---
 fs/ext4/mballoc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/ext4/mballoc.c +1 -1
index 60d32d3d8dc4..2f931575e6c2 100644
@@ -3943,7 +3943,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	if (state)
 		ext4_set_bits(bitmap_bh->b_data, blkoff, clen);
 	else
-		mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen);
+		mb_clear_bits(bitmap_bh->b_data, blkoff, clen);
 	if (ext4_has_group_desc_csum(sb) &&
 	    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
 		gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
Signature · 1 line
2.31.1
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#13 lore raw

Re: [RFC 4/6] ext4: No need to test for block bitmap bits in ext4_mb_mark_bb()

Quoted 9 lines · Jan Kara
Quoted 4 lines · Ritesh Harjani

We don't need the return value of mb_test_and_clear_bits() in ext4_mb_mark_bb() So simply use mb_clear_bits() instead.

Signed-off-by Ritesh Harjani <[email protected]>

Looks good. I'm rather confused by ext4_set_bits() vs mb_clear_bits() asymetry but that's not directly related to this patch. Just another cleanup to do. Feel free to add:

Yes, make sense. Looking at ext4_set_bits(), I think it should be renamed to mb_set_bits() for uniform API conventions.

Quoted 3 lines
Reviewed-by Jan Kara <[email protected]>

Thanks :)

Quoted 25 lines

Honza

Quoted 18 lines
---
 fs/ext4/mballoc.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
fs/ext4/mballoc.c +1 -2
index 60d32d3d8dc4..2f931575e6c2 100644
@@ -3943,7 +3943,7 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 	if (state)
 		ext4_set_bits(bitmap_bh->b_data, blkoff, clen);
 	else
-		mb_test_and_clear_bits(bitmap_bh->b_data, blkoff, clen);
+		mb_clear_bits(bitmap_bh->b_data, blkoff, clen);
 	if (ext4_has_group_desc_csum(sb) &&
 	    (gdp->bg_flags & cpu_to_le16(EXT4_BG_BLOCK_UNINIT))) {
 		gdp->bg_flags &= cpu_to_le16(~EXT4_BG_BLOCK_UNINIT);
--
Quoted 2 lines

2.31.1

--
Jan Kara <[email protected]>
SUSE Labs, CR

author
#14 lore raw

RFC 5/6 ext4: Refactor ext4_free_blocks() to pull out ext4_mb_clear_bb()

In reply to a message not in the archive

ext4_free_blocks() function became too long and confusing, this patch just pulls out the ext4_mb_clear_bb() function logic from it which clears the block bitmap and frees it.

No functionality change in this patch

Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 180 ++++++++++++++++++++++++++--------------------
 1 file changed, 102 insertions(+), 78 deletions(-)
fs/ext4/mballoc.c +102 -78
index 2f931575e6c2..5f20e355d08c 100644
@@ -5870,7 +5870,8 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
 }
 
 /**
- * ext4_free_blocks() -- Free given blocks and update quota
+ * ext4_mb_clear_bb() -- helper function for freeing blocks.
+ * 			Used by ext4_free_blocks()
  * @handle:		handle for this transaction
  * @inode:		inode
  * @bh:			optional buffer of the block to be freed

@@ -5878,9 +5879,9 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
  * @count:		number of blocks to be freed
  * @flags:		flags used by ext4_free_blocks
  */
-void ext4_free_blocks(handle_t *handle, struct inode *inode,
-		      struct buffer_head *bh, ext4_fsblk_t block,
-		      unsigned long count, int flags)
+static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
+			       ext4_fsblk_t block, unsigned long count,
+			       int flags)
 {
 	struct buffer_head *bitmap_bh = NULL;
 	struct super_block *sb = inode->i_sb;

@@ -5897,80 +5898,6 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 
 	sbi = EXT4_SB(sb);
 
-	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
-		ext4_free_blocks_simple(inode, block, count);
-		return;
-	}
-
-	might_sleep();
-	if (bh) {
-		if (block)
-			BUG_ON(block != bh->b_blocknr);
-		else
-			block = bh->b_blocknr;
-	}
-
-	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
-	    !ext4_inode_block_valid(inode, block, count)) {
-		ext4_error(sb, "Freeing blocks not in datazone - "
-			   "block = %llu, count = %lu", block, count);
-		goto error_return;
-	}
-
-	ext4_debug("freeing block %llu\n", block);
-	trace_ext4_free_blocks(inode, block, count, flags);
-
-	if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
-		BUG_ON(count > 1);
-
-		ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
-			    inode, bh, block);
-	}
-
-	/*
-	 * If the extent to be freed does not begin on a cluster
-	 * boundary, we need to deal with partial clusters at the
-	 * beginning and end of the extent.  Normally we will free
-	 * blocks at the beginning or the end unless we are explicitly
-	 * requested to avoid doing so.
-	 */
-	overflow = EXT4_PBLK_COFF(sbi, block);
-	if (overflow) {
-		if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
-			overflow = sbi->s_cluster_ratio - overflow;
-			block += overflow;
-			if (count > overflow)
-				count -= overflow;
-			else
-				return;
-		} else {
-			block -= overflow;
-			count += overflow;
-		}
-	}
-	overflow = EXT4_LBLK_COFF(sbi, count);
-	if (overflow) {
-		if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
-			if (count > overflow)
-				count -= overflow;
-			else
-				return;
-		} else
-			count += sbi->s_cluster_ratio - overflow;
-	}
-
-	if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
-		int i;
-		int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
-
-		for (i = 0; i < count; i++) {
-			cond_resched();
-			if (is_metadata)
-				bh = sb_find_get_block(inode->i_sb, block + i);
-			ext4_forget(handle, is_metadata, inode, bh, block + i);
-		}
-	}
-
 do_more:
 	overflow = 0;
 	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);

@@ -6132,6 +6059,103 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 	return;
 }
 
+/**
+ * ext4_free_blocks() -- Free given blocks and update quota
+ * @handle:		handle for this transaction
+ * @inode:		inode
+ * @bh:			optional buffer of the block to be freed
+ * @block:		starting physical block to be freed
+ * @count:		number of blocks to be freed
+ * @flags:		flags used by ext4_free_blocks
+ */
+void ext4_free_blocks(handle_t *handle, struct inode *inode,
+		      struct buffer_head *bh, ext4_fsblk_t block,
+		      unsigned long count, int flags)
+{
+	struct super_block *sb = inode->i_sb;
+	unsigned int overflow;
+	struct ext4_sb_info *sbi;
+
+	sbi = EXT4_SB(sb);
+
+	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
+		ext4_free_blocks_simple(inode, block, count);
+		return;
+	}
+
+	might_sleep();
+	if (bh) {
+		if (block)
+			BUG_ON(block != bh->b_blocknr);
+		else
+			block = bh->b_blocknr;
+	}
+
+	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
+	    !ext4_inode_block_valid(inode, block, count)) {
+		ext4_error(sb, "Freeing blocks not in datazone - "
+			   "block = %llu, count = %lu", block, count);
+		return;
+	}
+
+	ext4_debug("freeing block %llu\n", block);
+	trace_ext4_free_blocks(inode, block, count, flags);
+
+	if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+		BUG_ON(count > 1);
+
+		ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
+			    inode, bh, block);
+	}
+
+	/*
+	 * If the extent to be freed does not begin on a cluster
+	 * boundary, we need to deal with partial clusters at the
+	 * beginning and end of the extent.  Normally we will free
+	 * blocks at the beginning or the end unless we are explicitly
+	 * requested to avoid doing so.
+	 */
+	overflow = EXT4_PBLK_COFF(sbi, block);
+	if (overflow) {
+		if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
+			overflow = sbi->s_cluster_ratio - overflow;
+			block += overflow;
+			if (count > overflow)
+				count -= overflow;
+			else
+				return;
+		} else {
+			block -= overflow;
+			count += overflow;
+		}
+	}
+	overflow = EXT4_LBLK_COFF(sbi, count);
+	if (overflow) {
+		if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
+			if (count > overflow)
+				count -= overflow;
+			else
+				return;
+		} else
+			count += sbi->s_cluster_ratio - overflow;
+	}
+
+	if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+		int i;
+		int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
+
+		for (i = 0; i < count; i++) {
+			cond_resched();
+			if (is_metadata)
+				bh = sb_find_get_block(inode->i_sb, block + i);
+			ext4_forget(handle, is_metadata, inode, bh, block + i);
+		}
+	}
+
+	ext4_mb_clear_bb(handle, inode, block, count, flags);
+	return;
+}
+
 /**
  * ext4_group_add_blocks() -- Add given blocks to an existing group
  * @handle:			handle to this transaction
Signature · 1 line
2.31.1
reviewer Reviewed-by on v1 5/6
#15 lore raw

Re: [RFC 5/6] ext4: Refactor ext4_free_blocks() to pull out ext4_mb_clear_bb()

Quoted 7 lines · Ritesh Harjani

ext4_free_blocks() function became too long and confusing, this patch just pulls out the ext4_mb_clear_bb() function logic from it which clears the block bitmap and frees it.

No functionality change in this patch

Signed-off-by Ritesh Harjani <[email protected]>

Yeah, the function was rather long. Feel free to add:

Reviewed-by Jan Kara <[email protected]>

Honza

Quoted 219 lines
---
 fs/ext4/mballoc.c | 180 ++++++++++++++++++++++++++--------------------
 1 file changed, 102 insertions(+), 78 deletions(-)
fs/ext4/mballoc.c +102 -78
index 2f931575e6c2..5f20e355d08c 100644
@@ -5870,7 +5870,8 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
 }
 
 /**
- * ext4_free_blocks() -- Free given blocks and update quota
+ * ext4_mb_clear_bb() -- helper function for freeing blocks.
+ * 			Used by ext4_free_blocks()
  * @handle:		handle for this transaction
  * @inode:		inode
  * @bh:			optional buffer of the block to be freed

@@ -5878,9 +5879,9 @@ static void ext4_free_blocks_simple(struct inode *inode, ext4_fsblk_t block,
  * @count:		number of blocks to be freed
  * @flags:		flags used by ext4_free_blocks
  */
-void ext4_free_blocks(handle_t *handle, struct inode *inode,
-		      struct buffer_head *bh, ext4_fsblk_t block,
-		      unsigned long count, int flags)
+static void ext4_mb_clear_bb(handle_t *handle, struct inode *inode,
+			       ext4_fsblk_t block, unsigned long count,
+			       int flags)
 {
 	struct buffer_head *bitmap_bh = NULL;
 	struct super_block *sb = inode->i_sb;

@@ -5897,80 +5898,6 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 
 	sbi = EXT4_SB(sb);
 
-	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
-		ext4_free_blocks_simple(inode, block, count);
-		return;
-	}
-
-	might_sleep();
-	if (bh) {
-		if (block)
-			BUG_ON(block != bh->b_blocknr);
-		else
-			block = bh->b_blocknr;
-	}
-
-	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
-	    !ext4_inode_block_valid(inode, block, count)) {
-		ext4_error(sb, "Freeing blocks not in datazone - "
-			   "block = %llu, count = %lu", block, count);
-		goto error_return;
-	}
-
-	ext4_debug("freeing block %llu\n", block);
-	trace_ext4_free_blocks(inode, block, count, flags);
-
-	if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
-		BUG_ON(count > 1);
-
-		ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
-			    inode, bh, block);
-	}
-
-	/*
-	 * If the extent to be freed does not begin on a cluster
-	 * boundary, we need to deal with partial clusters at the
-	 * beginning and end of the extent.  Normally we will free
-	 * blocks at the beginning or the end unless we are explicitly
-	 * requested to avoid doing so.
-	 */
-	overflow = EXT4_PBLK_COFF(sbi, block);
-	if (overflow) {
-		if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
-			overflow = sbi->s_cluster_ratio - overflow;
-			block += overflow;
-			if (count > overflow)
-				count -= overflow;
-			else
-				return;
-		} else {
-			block -= overflow;
-			count += overflow;
-		}
-	}
-	overflow = EXT4_LBLK_COFF(sbi, count);
-	if (overflow) {
-		if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
-			if (count > overflow)
-				count -= overflow;
-			else
-				return;
-		} else
-			count += sbi->s_cluster_ratio - overflow;
-	}
-
-	if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
-		int i;
-		int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
-
-		for (i = 0; i < count; i++) {
-			cond_resched();
-			if (is_metadata)
-				bh = sb_find_get_block(inode->i_sb, block + i);
-			ext4_forget(handle, is_metadata, inode, bh, block + i);
-		}
-	}
-
 do_more:
 	overflow = 0;
 	ext4_get_group_no_and_offset(sb, block, &block_group, &bit);

@@ -6132,6 +6059,103 @@ void ext4_free_blocks(handle_t *handle, struct inode *inode,
 	return;
 }
 
+/**
+ * ext4_free_blocks() -- Free given blocks and update quota
+ * @handle:		handle for this transaction
+ * @inode:		inode
+ * @bh:			optional buffer of the block to be freed
+ * @block:		starting physical block to be freed
+ * @count:		number of blocks to be freed
+ * @flags:		flags used by ext4_free_blocks
+ */
+void ext4_free_blocks(handle_t *handle, struct inode *inode,
+		      struct buffer_head *bh, ext4_fsblk_t block,
+		      unsigned long count, int flags)
+{
+	struct super_block *sb = inode->i_sb;
+	unsigned int overflow;
+	struct ext4_sb_info *sbi;
+
+	sbi = EXT4_SB(sb);
+
+	if (sbi->s_mount_state & EXT4_FC_REPLAY) {
+		ext4_free_blocks_simple(inode, block, count);
+		return;
+	}
+
+	might_sleep();
+	if (bh) {
+		if (block)
+			BUG_ON(block != bh->b_blocknr);
+		else
+			block = bh->b_blocknr;
+	}
+
+	if (!(flags & EXT4_FREE_BLOCKS_VALIDATED) &&
+	    !ext4_inode_block_valid(inode, block, count)) {
+		ext4_error(sb, "Freeing blocks not in datazone - "
+			   "block = %llu, count = %lu", block, count);
+		return;
+	}
+
+	ext4_debug("freeing block %llu\n", block);
+	trace_ext4_free_blocks(inode, block, count, flags);
+
+	if (bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+		BUG_ON(count > 1);
+
+		ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
+			    inode, bh, block);
+	}
+
+	/*
+	 * If the extent to be freed does not begin on a cluster
+	 * boundary, we need to deal with partial clusters at the
+	 * beginning and end of the extent.  Normally we will free
+	 * blocks at the beginning or the end unless we are explicitly
+	 * requested to avoid doing so.
+	 */
+	overflow = EXT4_PBLK_COFF(sbi, block);
+	if (overflow) {
+		if (flags & EXT4_FREE_BLOCKS_NOFREE_FIRST_CLUSTER) {
+			overflow = sbi->s_cluster_ratio - overflow;
+			block += overflow;
+			if (count > overflow)
+				count -= overflow;
+			else
+				return;
+		} else {
+			block -= overflow;
+			count += overflow;
+		}
+	}
+	overflow = EXT4_LBLK_COFF(sbi, count);
+	if (overflow) {
+		if (flags & EXT4_FREE_BLOCKS_NOFREE_LAST_CLUSTER) {
+			if (count > overflow)
+				count -= overflow;
+			else
+				return;
+		} else
+			count += sbi->s_cluster_ratio - overflow;
+	}
+
+	if (!bh && (flags & EXT4_FREE_BLOCKS_FORGET)) {
+		int i;
+		int is_metadata = flags & EXT4_FREE_BLOCKS_METADATA;
+
+		for (i = 0; i < count; i++) {
+			cond_resched();
+			if (is_metadata)
+				bh = sb_find_get_block(inode->i_sb, block + i);
+			ext4_forget(handle, is_metadata, inode, bh, block + i);
+		}
+	}
+
+	ext4_mb_clear_bb(handle, inode, block, count, flags);
+	return;
+}
+
 /**
  * ext4_group_add_blocks() -- Add given blocks to an existing group
  * @handle:			handle to this transaction
Signature · 1 line
2.31.1
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#16 lore raw

RFC 6/6 ext4: Add extra check in ext4_mb_mark_bb() to prevent against possible corruption

In reply to a message not in the archive

This patch adds an extra checks in ext4_mb_mark_bb() function to make sure we mark & report error if we were to mark/clear any of the critical FS metadata specific bitmaps (&bail out) to prevent from any accidental corruption.

Signed-off-by Ritesh Harjani <[email protected]>
---
 fs/ext4/mballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)
fs/ext4/mballoc.c +7 -0
index 5f20e355d08c..c94888534caa 100644
@@ -3920,6 +3920,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 		len -= overflow;
 	}
 
+	if (!ext4_group_block_valid(sb, group, block, len)) {
+		ext4_error(sb, "Marking blocks in system zone - "
+			   "Block = %llu, len = %d", block, len);
+		bitmap_bh = NULL;
+		goto out_err;
+	}
+
 	clen = EXT4_NUM_B2C(sbi, len);
 
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
Signature · 1 line
2.31.1
reviewer
#17 lore raw

Re: [RFC 6/6] ext4: Add extra check in ext4_mb_mark_bb() to prevent against possible corruption

Quoted 6 lines · Ritesh Harjani

This patch adds an extra checks in ext4_mb_mark_bb() function to make sure we mark & report error if we were to mark/clear any of the critical FS metadata specific bitmaps (&bail out) to prevent from any accidental corruption.

Signed-off-by Ritesh Harjani <[email protected]>

Again please rather use ext4_inode_block_valid() here. All the callers of ext4_mb_mark_bb() have the information available.

Honza

Quoted 25 lines
---
 fs/ext4/mballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)
fs/ext4/mballoc.c +7 -0
index 5f20e355d08c..c94888534caa 100644
@@ -3920,6 +3920,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 		len -= overflow;
 	}
 
+	if (!ext4_group_block_valid(sb, group, block, len)) {
+		ext4_error(sb, "Marking blocks in system zone - "
+			   "Block = %llu, len = %d", block, len);
+		bitmap_bh = NULL;
+		goto out_err;
+	}
+
 	clen = EXT4_NUM_B2C(sbi, len);
 
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
Signature · 1 line
2.31.1
Signature · 2 lines
Jan Kara <[email protected]>
SUSE Labs, CR
author
#18 lore raw

Re: [RFC 6/6] ext4: Add extra check in ext4_mb_mark_bb() to prevent against possible corruption

Quoted 11 lines · Jan Kara
Quoted 6 lines · Ritesh Harjani

This patch adds an extra checks in ext4_mb_mark_bb() function to make sure we mark & report error if we were to mark/clear any of the critical FS metadata specific bitmaps (&bail out) to prevent from any accidental corruption.

Signed-off-by Ritesh Harjani <[email protected]>

Again please rather use ext4_inode_block_valid() here. All the callers of ext4_mb_mark_bb() have the information available.

Same reason here too, since we are already aware of the block group these blocks belong too, does it make any sense to check against the system-zone in that case?

-ritesh

Quoted 30 lines

Honza

Quoted 23 lines
---
 fs/ext4/mballoc.c | 7 +++++++
 1 file changed, 7 insertions(+)
fs/ext4/mballoc.c +7 -1
index 5f20e355d08c..c94888534caa 100644
@@ -3920,6 +3920,13 @@ void ext4_mb_mark_bb(struct super_block *sb, ext4_fsblk_t block,
 		len -= overflow;
 	}
 
+	if (!ext4_group_block_valid(sb, group, block, len)) {
+		ext4_error(sb, "Marking blocks in system zone - "
+			   "Block = %llu, len = %d", block, len);
+		bitmap_bh = NULL;
+		goto out_err;
+	}
+
 	clen = EXT4_NUM_B2C(sbi, len);
 
 	bitmap_bh = ext4_read_block_bitmap(sb, group);
--
Quoted 2 lines

2.31.1

--
Jan Kara <[email protected]>
SUSE Labs, CR