March 2025 - Linux-stable-mirror

FAILED: patch "[PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x a562d0c4a893eae3ea51d512c4d90ab858a6b7ec # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030437-chloride-stargazer-d3b6@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a562d0c4a893eae3ea51d512c4d90ab858a6b7ec Mon Sep 17 00:00:00 2001 From: Wei Fang <wei.fang(a)nxp.com> Date: Mon, 24 Feb 2025 19:12:47 +0800 Subject: [PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC Actually ENETC VFs do not support HWTSTAMP_TX_ONESTEP_SYNC because only ENETC PF can access PMa_SINGLE_STEP registers. And there will be a crash if VFs are used to test one-step timestamp, the crash log as follows. [ 129.110909] Unable to handle kernel paging request at virtual address 00000000000080c0 [ 129.287769] Call trace: [ 129.290219] enetc_port_mac_wr+0x30/0xec (P) [ 129.294504] enetc_start_xmit+0xda4/0xe74 [ 129.298525] enetc_xmit+0x70/0xec [ 129.301848] dev_hard_start_xmit+0x98/0x118 Fixes: 41514737ecaa ("enetc: add get_ts_info interface for ethtool") Cc: stable(a)vger.kernel.org Signed-off-by: Wei Fang <wei.fang(a)nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Tested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Link: https://patch.msgid.link/20250224111251.1061098-5-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 3cb9ebb13b19..e946d8652790 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -3244,6 +3244,9 @@ static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr) new_offloads |= ENETC_F_TX_TSTAMP; break; case HWTSTAMP_TX_ONESTEP_SYNC: + if (!enetc_si_is_pf(priv->si)) + return -EOPNOTSUPP; + new_offloads &= ~ENETC_F_TX_TSTAMP_MASK; new_offloads |= ENETC_F_TX_ONESTEP_SYNC_TSTAMP; break; diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c index bf34b5bb1e35..ece3ae28ba82 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c @@ -832,6 +832,7 @@ static int enetc_set_coalesce(struct net_device *ndev, static int enetc_get_ts_info(struct net_device *ndev, struct kernel_ethtool_ts_info *info) { + struct enetc_ndev_priv *priv = netdev_priv(ndev); int *phc_idx; phc_idx = symbol_get(enetc_phc_index); @@ -852,8 +853,10 @@ static int enetc_get_ts_info(struct net_device *ndev, SOF_TIMESTAMPING_TX_SOFTWARE; info->tx_types = (1 << HWTSTAMP_TX_OFF) | - (1 << HWTSTAMP_TX_ON) | - (1 << HWTSTAMP_TX_ONESTEP_SYNC); + (1 << HWTSTAMP_TX_ON); + + if (enetc_si_is_pf(priv->si)) + info->tx_types |= (1 << HWTSTAMP_TX_ONESTEP_SYNC); info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_ALL);

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x a562d0c4a893eae3ea51d512c4d90ab858a6b7ec # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030436-frightful-royal-6797@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a562d0c4a893eae3ea51d512c4d90ab858a6b7ec Mon Sep 17 00:00:00 2001 From: Wei Fang <wei.fang(a)nxp.com> Date: Mon, 24 Feb 2025 19:12:47 +0800 Subject: [PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC Actually ENETC VFs do not support HWTSTAMP_TX_ONESTEP_SYNC because only ENETC PF can access PMa_SINGLE_STEP registers. And there will be a crash if VFs are used to test one-step timestamp, the crash log as follows. [ 129.110909] Unable to handle kernel paging request at virtual address 00000000000080c0 [ 129.287769] Call trace: [ 129.290219] enetc_port_mac_wr+0x30/0xec (P) [ 129.294504] enetc_start_xmit+0xda4/0xe74 [ 129.298525] enetc_xmit+0x70/0xec [ 129.301848] dev_hard_start_xmit+0x98/0x118 Fixes: 41514737ecaa ("enetc: add get_ts_info interface for ethtool") Cc: stable(a)vger.kernel.org Signed-off-by: Wei Fang <wei.fang(a)nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Tested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Link: https://patch.msgid.link/20250224111251.1061098-5-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 3cb9ebb13b19..e946d8652790 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -3244,6 +3244,9 @@ static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr) new_offloads |= ENETC_F_TX_TSTAMP; break; case HWTSTAMP_TX_ONESTEP_SYNC: + if (!enetc_si_is_pf(priv->si)) + return -EOPNOTSUPP; + new_offloads &= ~ENETC_F_TX_TSTAMP_MASK; new_offloads |= ENETC_F_TX_ONESTEP_SYNC_TSTAMP; break; diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c index bf34b5bb1e35..ece3ae28ba82 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c @@ -832,6 +832,7 @@ static int enetc_set_coalesce(struct net_device *ndev, static int enetc_get_ts_info(struct net_device *ndev, struct kernel_ethtool_ts_info *info) { + struct enetc_ndev_priv *priv = netdev_priv(ndev); int *phc_idx; phc_idx = symbol_get(enetc_phc_index); @@ -852,8 +853,10 @@ static int enetc_get_ts_info(struct net_device *ndev, SOF_TIMESTAMPING_TX_SOFTWARE; info->tx_types = (1 << HWTSTAMP_TX_OFF) | - (1 << HWTSTAMP_TX_ON) | - (1 << HWTSTAMP_TX_ONESTEP_SYNC); + (1 << HWTSTAMP_TX_ON); + + if (enetc_si_is_pf(priv->si)) + info->tx_types |= (1 << HWTSTAMP_TX_ONESTEP_SYNC); info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_ALL);

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x a562d0c4a893eae3ea51d512c4d90ab858a6b7ec # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030436-plural-dislodge-e1b9@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From a562d0c4a893eae3ea51d512c4d90ab858a6b7ec Mon Sep 17 00:00:00 2001 From: Wei Fang <wei.fang(a)nxp.com> Date: Mon, 24 Feb 2025 19:12:47 +0800 Subject: [PATCH] net: enetc: VFs do not support HWTSTAMP_TX_ONESTEP_SYNC Actually ENETC VFs do not support HWTSTAMP_TX_ONESTEP_SYNC because only ENETC PF can access PMa_SINGLE_STEP registers. And there will be a crash if VFs are used to test one-step timestamp, the crash log as follows. [ 129.110909] Unable to handle kernel paging request at virtual address 00000000000080c0 [ 129.287769] Call trace: [ 129.290219] enetc_port_mac_wr+0x30/0xec (P) [ 129.294504] enetc_start_xmit+0xda4/0xe74 [ 129.298525] enetc_xmit+0x70/0xec [ 129.301848] dev_hard_start_xmit+0x98/0x118 Fixes: 41514737ecaa ("enetc: add get_ts_info interface for ethtool") Cc: stable(a)vger.kernel.org Signed-off-by: Wei Fang <wei.fang(a)nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Tested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Link: https://patch.msgid.link/20250224111251.1061098-5-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 3cb9ebb13b19..e946d8652790 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -3244,6 +3244,9 @@ static int enetc_hwtstamp_set(struct net_device *ndev, struct ifreq *ifr) new_offloads |= ENETC_F_TX_TSTAMP; break; case HWTSTAMP_TX_ONESTEP_SYNC: + if (!enetc_si_is_pf(priv->si)) + return -EOPNOTSUPP; + new_offloads &= ~ENETC_F_TX_TSTAMP_MASK; new_offloads |= ENETC_F_TX_ONESTEP_SYNC_TSTAMP; break; diff --git a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c index bf34b5bb1e35..ece3ae28ba82 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c +++ b/drivers/net/ethernet/freescale/enetc/enetc_ethtool.c @@ -832,6 +832,7 @@ static int enetc_set_coalesce(struct net_device *ndev, static int enetc_get_ts_info(struct net_device *ndev, struct kernel_ethtool_ts_info *info) { + struct enetc_ndev_priv *priv = netdev_priv(ndev); int *phc_idx; phc_idx = symbol_get(enetc_phc_index); @@ -852,8 +853,10 @@ static int enetc_get_ts_info(struct net_device *ndev, SOF_TIMESTAMPING_TX_SOFTWARE; info->tx_types = (1 << HWTSTAMP_TX_OFF) | - (1 << HWTSTAMP_TX_ON) | - (1 << HWTSTAMP_TX_ONESTEP_SYNC); + (1 << HWTSTAMP_TX_ON); + + if (enetc_si_is_pf(priv->si)) + info->tx_types |= (1 << HWTSTAMP_TX_ONESTEP_SYNC); info->rx_filters = (1 << HWTSTAMP_FILTER_NONE) | (1 << HWTSTAMP_FILTER_ALL);

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] net: enetc: fix the off-by-one issue in enetc_map_tx_buffs()" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 39ab773e4c120f7f98d759415ccc2aca706bbc10 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030409-primp-ripcord-cc40@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 39ab773e4c120f7f98d759415ccc2aca706bbc10 Mon Sep 17 00:00:00 2001 From: Wei Fang <wei.fang(a)nxp.com> Date: Mon, 24 Feb 2025 19:12:44 +0800 Subject: [PATCH] net: enetc: fix the off-by-one issue in enetc_map_tx_buffs() When a DMA mapping error occurs while processing skb frags, it will free one more tx_swbd than expected, so fix this off-by-one issue. Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers") Cc: stable(a)vger.kernel.org Suggested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Suggested-by: Michal Swiatkowski <michal.swiatkowski(a)linux.intel.com> Signed-off-by: Wei Fang <wei.fang(a)nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Reviewed-by: Claudiu Manoil <claudiu.manoil(a)nxp.com> Link: https://patch.msgid.link/20250224111251.1061098-2-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 6a6fc819dfde..55ad31a5073e 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -167,6 +167,24 @@ static bool enetc_skb_is_tcp(struct sk_buff *skb) return skb->csum_offset == offsetof(struct tcphdr, check); } +/** + * enetc_unwind_tx_frame() - Unwind the DMA mappings of a multi-buffer Tx frame + * @tx_ring: Pointer to the Tx ring on which the buffer descriptors are located + * @count: Number of Tx buffer descriptors which need to be unmapped + * @i: Index of the last successfully mapped Tx buffer descriptor + */ +static void enetc_unwind_tx_frame(struct enetc_bdr *tx_ring, int count, int i) +{ + while (count--) { + struct enetc_tx_swbd *tx_swbd = &tx_ring->tx_swbd[i]; + + enetc_free_tx_frame(tx_ring, tx_swbd); + if (i == 0) + i = tx_ring->bd_count; + i--; + } +} + static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb) { bool do_vlan, do_onestep_tstamp = false, do_twostep_tstamp = false; @@ -372,13 +390,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb) dma_err: dev_err(tx_ring->dev, "DMA map error"); - do { - tx_swbd = &tx_ring->tx_swbd[i]; - enetc_free_tx_frame(tx_ring, tx_swbd); - if (i == 0) - i = tx_ring->bd_count; - i--; - } while (count--); + enetc_unwind_tx_frame(tx_ring, count, i); return 0; }

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] net: enetc: fix the off-by-one issue in enetc_map_tx_buffs()" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 39ab773e4c120f7f98d759415ccc2aca706bbc10 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030409-kiln-astound-cb63@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 39ab773e4c120f7f98d759415ccc2aca706bbc10 Mon Sep 17 00:00:00 2001 From: Wei Fang <wei.fang(a)nxp.com> Date: Mon, 24 Feb 2025 19:12:44 +0800 Subject: [PATCH] net: enetc: fix the off-by-one issue in enetc_map_tx_buffs() When a DMA mapping error occurs while processing skb frags, it will free one more tx_swbd than expected, so fix this off-by-one issue. Fixes: d4fd0404c1c9 ("enetc: Introduce basic PF and VF ENETC ethernet drivers") Cc: stable(a)vger.kernel.org Suggested-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Suggested-by: Michal Swiatkowski <michal.swiatkowski(a)linux.intel.com> Signed-off-by: Wei Fang <wei.fang(a)nxp.com> Reviewed-by: Vladimir Oltean <vladimir.oltean(a)nxp.com> Reviewed-by: Claudiu Manoil <claudiu.manoil(a)nxp.com> Link: https://patch.msgid.link/20250224111251.1061098-2-wei.fang@nxp.com Signed-off-by: Jakub Kicinski <kuba(a)kernel.org> diff --git a/drivers/net/ethernet/freescale/enetc/enetc.c b/drivers/net/ethernet/freescale/enetc/enetc.c index 6a6fc819dfde..55ad31a5073e 100644 --- a/drivers/net/ethernet/freescale/enetc/enetc.c +++ b/drivers/net/ethernet/freescale/enetc/enetc.c @@ -167,6 +167,24 @@ static bool enetc_skb_is_tcp(struct sk_buff *skb) return skb->csum_offset == offsetof(struct tcphdr, check); } +/** + * enetc_unwind_tx_frame() - Unwind the DMA mappings of a multi-buffer Tx frame + * @tx_ring: Pointer to the Tx ring on which the buffer descriptors are located + * @count: Number of Tx buffer descriptors which need to be unmapped + * @i: Index of the last successfully mapped Tx buffer descriptor + */ +static void enetc_unwind_tx_frame(struct enetc_bdr *tx_ring, int count, int i) +{ + while (count--) { + struct enetc_tx_swbd *tx_swbd = &tx_ring->tx_swbd[i]; + + enetc_free_tx_frame(tx_ring, tx_swbd); + if (i == 0) + i = tx_ring->bd_count; + i--; + } +} + static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb) { bool do_vlan, do_onestep_tstamp = false, do_twostep_tstamp = false; @@ -372,13 +390,7 @@ static int enetc_map_tx_buffs(struct enetc_bdr *tx_ring, struct sk_buff *skb) dma_err: dev_err(tx_ring->dev, "DMA map error"); - do { - tx_swbd = &tx_ring->tx_swbd[i]; - enetc_free_tx_frame(tx_ring, tx_swbd); - if (i == 0) - i = tx_ring->bd_count; - i--; - } while (count--); + enetc_unwind_tx_frame(tx_ring, count, i); return 0; }

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix data overwriting bug during buffered write when" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x efa11fd269c139e29b71ec21bc9c9c0063fde40d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030420-underfeed-siren-2384@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From efa11fd269c139e29b71ec21bc9c9c0063fde40d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 19 Feb 2025 09:06:33 +1030 Subject: [PATCH] btrfs: fix data overwriting bug during buffered write when block size < page size [BUG] When running generic/418 with a btrfs whose block size < page size (subpage cases), it always fails. And the following minimal reproducer is more than enough to trigger it reliably: workload() { mkfs.btrfs -s 4k -f $dev > /dev/null dmesg -C mount $dev $mnt $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest ret=$? umount $mnt stop_trace if [ $ret -ne 0 ]; then fail fi } for (( i = 0; i < 1024; i++)); do echo "=== $i/$runtime ===" workload done [CAUSE] With extra trace printk added to the following functions: - btrfs_buffered_write() * Which folio is touched * The file offset (start) where the buffered write is at * How many bytes are copied * The content of the write (the first 2 bytes) - submit_one_sector() * Which folio is touched * The position inside the folio * The content of the page cache (the first 2 bytes) - pagecache_isize_extended() * The parameters of the function itself * The parameters of the folio_zero_range() Which are enough to show the problem: 22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101 22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101 22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101 22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101 22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192 22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000 22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101 The tool dio-invalidate-cache will start 3 threads, each doing a buffered write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read, and compare the read buffer with the write buffer. Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into the page cache. But at submit_one_sector(), at file offset 4096, the content is zeroed out, by pagecache_isize_extended(). The race happens like this: Thread A is writing into range [4K, 8K). Thread B is writing into range [8K, 12k). Thread A | Thread B -------------------------------------+------------------------------------ btrfs_buffered_write() | btrfs_buffered_write() |- old_isize = 4K; | |- old_isize = 4096; |- btrfs_inode_lock() | | |- write into folio range [4K, 8K) | | |- pagecache_isize_extended() | | | extend isize from 4096 to 8192 | | | no folio_zero_range() called | | |- btrfs_inode_lock() | | | |- btrfs_inode_lock() | |- write into folio range [8K, 12K) | |- pagecache_isize_extended() | | calling folio_zero_range(4K, 8K) | | This is caused by the old_isize is | | grabbed too early, without any | | inode lock. | |- btrfs_inode_unlock() The @old_isize is grabbed without inode lock, causing race between two buffered write threads and making pagecache_isize_extended() to zero range which is still containing cached data. And this is only affecting subpage btrfs, because for regular blocksize == page size case, the function pagecache_isize_extended() will do nothing if the block size >= page size. [FIX] Grab the old i_size while holding the inode lock. This means each buffered write thread will have a stable view of the old inode size, thus avoid the above race. CC: stable(a)vger.kernel.org # 5.15+ Fixes: 5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write") Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed3c0d6546c5..0b568c8d24cb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1090,7 +1090,7 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) u64 lockend; size_t num_written = 0; ssize_t ret; - loff_t old_isize = i_size_read(inode); + loff_t old_isize; unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); @@ -1103,6 +1103,13 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret < 0) return ret; + /* + * We can only trust the isize with inode lock held, or it can race with + * other buffered writes and cause incorrect call of + * pagecache_isize_extended() to overwrite existing data. + */ + old_isize = i_size_read(inode); + ret = generic_write_checks(iocb, i); if (ret <= 0) goto out;

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix data overwriting bug during buffered write when" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x efa11fd269c139e29b71ec21bc9c9c0063fde40d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030418-sharpness-steadier-31ea@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From efa11fd269c139e29b71ec21bc9c9c0063fde40d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 19 Feb 2025 09:06:33 +1030 Subject: [PATCH] btrfs: fix data overwriting bug during buffered write when block size < page size [BUG] When running generic/418 with a btrfs whose block size < page size (subpage cases), it always fails. And the following minimal reproducer is more than enough to trigger it reliably: workload() { mkfs.btrfs -s 4k -f $dev > /dev/null dmesg -C mount $dev $mnt $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest ret=$? umount $mnt stop_trace if [ $ret -ne 0 ]; then fail fi } for (( i = 0; i < 1024; i++)); do echo "=== $i/$runtime ===" workload done [CAUSE] With extra trace printk added to the following functions: - btrfs_buffered_write() * Which folio is touched * The file offset (start) where the buffered write is at * How many bytes are copied * The content of the write (the first 2 bytes) - submit_one_sector() * Which folio is touched * The position inside the folio * The content of the page cache (the first 2 bytes) - pagecache_isize_extended() * The parameters of the function itself * The parameters of the folio_zero_range() Which are enough to show the problem: 22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101 22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101 22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101 22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101 22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192 22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000 22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101 The tool dio-invalidate-cache will start 3 threads, each doing a buffered write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read, and compare the read buffer with the write buffer. Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into the page cache. But at submit_one_sector(), at file offset 4096, the content is zeroed out, by pagecache_isize_extended(). The race happens like this: Thread A is writing into range [4K, 8K). Thread B is writing into range [8K, 12k). Thread A | Thread B -------------------------------------+------------------------------------ btrfs_buffered_write() | btrfs_buffered_write() |- old_isize = 4K; | |- old_isize = 4096; |- btrfs_inode_lock() | | |- write into folio range [4K, 8K) | | |- pagecache_isize_extended() | | | extend isize from 4096 to 8192 | | | no folio_zero_range() called | | |- btrfs_inode_lock() | | | |- btrfs_inode_lock() | |- write into folio range [8K, 12K) | |- pagecache_isize_extended() | | calling folio_zero_range(4K, 8K) | | This is caused by the old_isize is | | grabbed too early, without any | | inode lock. | |- btrfs_inode_unlock() The @old_isize is grabbed without inode lock, causing race between two buffered write threads and making pagecache_isize_extended() to zero range which is still containing cached data. And this is only affecting subpage btrfs, because for regular blocksize == page size case, the function pagecache_isize_extended() will do nothing if the block size >= page size. [FIX] Grab the old i_size while holding the inode lock. This means each buffered write thread will have a stable view of the old inode size, thus avoid the above race. CC: stable(a)vger.kernel.org # 5.15+ Fixes: 5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write") Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed3c0d6546c5..0b568c8d24cb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1090,7 +1090,7 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) u64 lockend; size_t num_written = 0; ssize_t ret; - loff_t old_isize = i_size_read(inode); + loff_t old_isize; unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); @@ -1103,6 +1103,13 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret < 0) return ret; + /* + * We can only trust the isize with inode lock held, or it can race with + * other buffered writes and cause incorrect call of + * pagecache_isize_extended() to overwrite existing data. + */ + old_isize = i_size_read(inode); + ret = generic_write_checks(iocb, i); if (ret <= 0) goto out;

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix data overwriting bug during buffered write when" failed to apply to 5.15-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.15-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.15.y git checkout FETCH_HEAD git cherry-pick -x efa11fd269c139e29b71ec21bc9c9c0063fde40d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030416-prong-outdated-7f45@gregkh' --subject-prefix 'PATCH 5.15.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From efa11fd269c139e29b71ec21bc9c9c0063fde40d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 19 Feb 2025 09:06:33 +1030 Subject: [PATCH] btrfs: fix data overwriting bug during buffered write when block size < page size [BUG] When running generic/418 with a btrfs whose block size < page size (subpage cases), it always fails. And the following minimal reproducer is more than enough to trigger it reliably: workload() { mkfs.btrfs -s 4k -f $dev > /dev/null dmesg -C mount $dev $mnt $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest ret=$? umount $mnt stop_trace if [ $ret -ne 0 ]; then fail fi } for (( i = 0; i < 1024; i++)); do echo "=== $i/$runtime ===" workload done [CAUSE] With extra trace printk added to the following functions: - btrfs_buffered_write() * Which folio is touched * The file offset (start) where the buffered write is at * How many bytes are copied * The content of the write (the first 2 bytes) - submit_one_sector() * Which folio is touched * The position inside the folio * The content of the page cache (the first 2 bytes) - pagecache_isize_extended() * The parameters of the function itself * The parameters of the folio_zero_range() Which are enough to show the problem: 22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101 22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101 22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101 22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101 22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192 22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000 22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101 The tool dio-invalidate-cache will start 3 threads, each doing a buffered write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read, and compare the read buffer with the write buffer. Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into the page cache. But at submit_one_sector(), at file offset 4096, the content is zeroed out, by pagecache_isize_extended(). The race happens like this: Thread A is writing into range [4K, 8K). Thread B is writing into range [8K, 12k). Thread A | Thread B -------------------------------------+------------------------------------ btrfs_buffered_write() | btrfs_buffered_write() |- old_isize = 4K; | |- old_isize = 4096; |- btrfs_inode_lock() | | |- write into folio range [4K, 8K) | | |- pagecache_isize_extended() | | | extend isize from 4096 to 8192 | | | no folio_zero_range() called | | |- btrfs_inode_lock() | | | |- btrfs_inode_lock() | |- write into folio range [8K, 12K) | |- pagecache_isize_extended() | | calling folio_zero_range(4K, 8K) | | This is caused by the old_isize is | | grabbed too early, without any | | inode lock. | |- btrfs_inode_unlock() The @old_isize is grabbed without inode lock, causing race between two buffered write threads and making pagecache_isize_extended() to zero range which is still containing cached data. And this is only affecting subpage btrfs, because for regular blocksize == page size case, the function pagecache_isize_extended() will do nothing if the block size >= page size. [FIX] Grab the old i_size while holding the inode lock. This means each buffered write thread will have a stable view of the old inode size, thus avoid the above race. CC: stable(a)vger.kernel.org # 5.15+ Fixes: 5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write") Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed3c0d6546c5..0b568c8d24cb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1090,7 +1090,7 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) u64 lockend; size_t num_written = 0; ssize_t ret; - loff_t old_isize = i_size_read(inode); + loff_t old_isize; unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); @@ -1103,6 +1103,13 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret < 0) return ret; + /* + * We can only trust the isize with inode lock held, or it can race with + * other buffered writes and cause incorrect call of + * pagecache_isize_extended() to overwrite existing data. + */ + old_isize = i_size_read(inode); + ret = generic_write_checks(iocb, i); if (ret <= 0) goto out;

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix data overwriting bug during buffered write when" failed to apply to 6.1-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.1-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.1.y git checkout FETCH_HEAD git cherry-pick -x efa11fd269c139e29b71ec21bc9c9c0063fde40d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030414-enroll-suitor-daa4@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From efa11fd269c139e29b71ec21bc9c9c0063fde40d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 19 Feb 2025 09:06:33 +1030 Subject: [PATCH] btrfs: fix data overwriting bug during buffered write when block size < page size [BUG] When running generic/418 with a btrfs whose block size < page size (subpage cases), it always fails. And the following minimal reproducer is more than enough to trigger it reliably: workload() { mkfs.btrfs -s 4k -f $dev > /dev/null dmesg -C mount $dev $mnt $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest ret=$? umount $mnt stop_trace if [ $ret -ne 0 ]; then fail fi } for (( i = 0; i < 1024; i++)); do echo "=== $i/$runtime ===" workload done [CAUSE] With extra trace printk added to the following functions: - btrfs_buffered_write() * Which folio is touched * The file offset (start) where the buffered write is at * How many bytes are copied * The content of the write (the first 2 bytes) - submit_one_sector() * Which folio is touched * The position inside the folio * The content of the page cache (the first 2 bytes) - pagecache_isize_extended() * The parameters of the function itself * The parameters of the folio_zero_range() Which are enough to show the problem: 22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101 22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101 22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101 22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101 22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192 22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000 22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101 The tool dio-invalidate-cache will start 3 threads, each doing a buffered write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read, and compare the read buffer with the write buffer. Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into the page cache. But at submit_one_sector(), at file offset 4096, the content is zeroed out, by pagecache_isize_extended(). The race happens like this: Thread A is writing into range [4K, 8K). Thread B is writing into range [8K, 12k). Thread A | Thread B -------------------------------------+------------------------------------ btrfs_buffered_write() | btrfs_buffered_write() |- old_isize = 4K; | |- old_isize = 4096; |- btrfs_inode_lock() | | |- write into folio range [4K, 8K) | | |- pagecache_isize_extended() | | | extend isize from 4096 to 8192 | | | no folio_zero_range() called | | |- btrfs_inode_lock() | | | |- btrfs_inode_lock() | |- write into folio range [8K, 12K) | |- pagecache_isize_extended() | | calling folio_zero_range(4K, 8K) | | This is caused by the old_isize is | | grabbed too early, without any | | inode lock. | |- btrfs_inode_unlock() The @old_isize is grabbed without inode lock, causing race between two buffered write threads and making pagecache_isize_extended() to zero range which is still containing cached data. And this is only affecting subpage btrfs, because for regular blocksize == page size case, the function pagecache_isize_extended() will do nothing if the block size >= page size. [FIX] Grab the old i_size while holding the inode lock. This means each buffered write thread will have a stable view of the old inode size, thus avoid the above race. CC: stable(a)vger.kernel.org # 5.15+ Fixes: 5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write") Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed3c0d6546c5..0b568c8d24cb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1090,7 +1090,7 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) u64 lockend; size_t num_written = 0; ssize_t ret; - loff_t old_isize = i_size_read(inode); + loff_t old_isize; unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); @@ -1103,6 +1103,13 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret < 0) return ret; + /* + * We can only trust the isize with inode lock held, or it can race with + * other buffered writes and cause incorrect call of + * pagecache_isize_extended() to overwrite existing data. + */ + old_isize = i_size_read(inode); + ret = generic_write_checks(iocb, i); if (ret <= 0) goto out;

3 months, 1 week

1
0
0 0

FAILED: patch "[PATCH] btrfs: fix data overwriting bug during buffered write when" failed to apply to 6.6-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x efa11fd269c139e29b71ec21bc9c9c0063fde40d # <resolve conflicts, build, test, etc.> git commit -s git send-email --to '<stable(a)vger.kernel.org>' --in-reply-to '2025030412-gliding-oncoming-9727@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From efa11fd269c139e29b71ec21bc9c9c0063fde40d Mon Sep 17 00:00:00 2001 From: Qu Wenruo <wqu(a)suse.com> Date: Wed, 19 Feb 2025 09:06:33 +1030 Subject: [PATCH] btrfs: fix data overwriting bug during buffered write when block size < page size [BUG] When running generic/418 with a btrfs whose block size < page size (subpage cases), it always fails. And the following minimal reproducer is more than enough to trigger it reliably: workload() { mkfs.btrfs -s 4k -f $dev > /dev/null dmesg -C mount $dev $mnt $fsstree_dir/src/dio-invalidate-cache -r -b 4096 -n 3 -i 1 -f $mnt/diotest ret=$? umount $mnt stop_trace if [ $ret -ne 0 ]; then fail fi } for (( i = 0; i < 1024; i++)); do echo "=== $i/$runtime ===" workload done [CAUSE] With extra trace printk added to the following functions: - btrfs_buffered_write() * Which folio is touched * The file offset (start) where the buffered write is at * How many bytes are copied * The content of the write (the first 2 bytes) - submit_one_sector() * Which folio is touched * The position inside the folio * The content of the page cache (the first 2 bytes) - pagecache_isize_extended() * The parameters of the function itself * The parameters of the folio_zero_range() Which are enough to show the problem: 22.158114: btrfs_buffered_write: folio pos=0 start=0 copied=4096 content=0x0101 22.158161: submit_one_sector: r/i=5/257 folio=0 pos=0 content=0x0101 22.158609: btrfs_buffered_write: folio pos=0 start=4096 copied=4096 content=0x0101 22.158634: btrfs_buffered_write: folio pos=0 start=8192 copied=4096 content=0x0101 22.158650: pagecache_isize_extended: folio=0 from=4096 to=8192 bsize=4096 zero off=4096 len=8192 22.158682: submit_one_sector: r/i=5/257 folio=0 pos=4096 content=0x0000 22.158686: submit_one_sector: r/i=5/257 folio=0 pos=8192 content=0x0101 The tool dio-invalidate-cache will start 3 threads, each doing a buffered write with 0x01 at offset 0, 4096 and 8192, do a fsync, then do a direct read, and compare the read buffer with the write buffer. Note that all 3 btrfs_buffered_write() are writing the correct 0x01 into the page cache. But at submit_one_sector(), at file offset 4096, the content is zeroed out, by pagecache_isize_extended(). The race happens like this: Thread A is writing into range [4K, 8K). Thread B is writing into range [8K, 12k). Thread A | Thread B -------------------------------------+------------------------------------ btrfs_buffered_write() | btrfs_buffered_write() |- old_isize = 4K; | |- old_isize = 4096; |- btrfs_inode_lock() | | |- write into folio range [4K, 8K) | | |- pagecache_isize_extended() | | | extend isize from 4096 to 8192 | | | no folio_zero_range() called | | |- btrfs_inode_lock() | | | |- btrfs_inode_lock() | |- write into folio range [8K, 12K) | |- pagecache_isize_extended() | | calling folio_zero_range(4K, 8K) | | This is caused by the old_isize is | | grabbed too early, without any | | inode lock. | |- btrfs_inode_unlock() The @old_isize is grabbed without inode lock, causing race between two buffered write threads and making pagecache_isize_extended() to zero range which is still containing cached data. And this is only affecting subpage btrfs, because for regular blocksize == page size case, the function pagecache_isize_extended() will do nothing if the block size >= page size. [FIX] Grab the old i_size while holding the inode lock. This means each buffered write thread will have a stable view of the old inode size, thus avoid the above race. CC: stable(a)vger.kernel.org # 5.15+ Fixes: 5e8b9ef30392 ("btrfs: move pos increment and pagecache extension to btrfs_buffered_write") Reviewed-by: Filipe Manana <fdmanana(a)suse.com> Signed-off-by: Qu Wenruo <wqu(a)suse.com> Signed-off-by: David Sterba <dsterba(a)suse.com> diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index ed3c0d6546c5..0b568c8d24cb 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1090,7 +1090,7 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) u64 lockend; size_t num_written = 0; ssize_t ret; - loff_t old_isize = i_size_read(inode); + loff_t old_isize; unsigned int ilock_flags = 0; const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); @@ -1103,6 +1103,13 @@ ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) if (ret < 0) return ret; + /* + * We can only trust the isize with inode lock held, or it can race with + * other buffered writes and cause incorrect call of + * pagecache_isize_extended() to overwrite existing data. + */ + old_isize = i_size_read(inode); + ret = generic_write_checks(iocb, i); if (ret <= 0) goto out;

3 months, 1 week

1
0
0 0

2025

2024

2023

2022

2021

2020

2019

2018

2017

Linux-stable-mirror March 2025