From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.sourceforge.net (lists.sourceforge.net [216.105.38.7]) (using TLSv1.2 with cipher ECDHE-ECDSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id DBE8B606A31A for ; Thu, 22 Oct 2026 16:56:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=lists.sourceforge.net header.i=@lists.sourceforge.net header.a=rsa-sha256 header.s=beta header.b=HUiuxYmF; dkim=fail reason="signature verification failed" (1024-bit key, unprotected) header.d=sourceforge.net header.i=@sourceforge.net header.a=rsa-sha256 header.s=x header.b=EQp4D8b6; dkim=fail reason="signature verification failed" (1024-bit key, unprotected) header.d=sf.net header.i=@sf.net header.a=rsa-sha256 header.s=x header.b=lZVUuOSF; dkim=neutral header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20251104 header.b=TKeU8/Ul DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.sourceforge.net; s=beta; h=Content-Transfer-Encoding:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: Subject:MIME-Version:Message-ID:Date:To:From:Sender:Reply-To:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Unsubscribe-Post:List-Owner; bh=VBh7a4tuVhnYO9y5ZMldg/xHxrY82WB16tXd779Kij0=; b=HUiuxYmFYVq13mS8hU5Q+Fd6/f QZUOz2Ixt11FNLQLbu7JiM2RVuELzbYuF9AQp6n0LGBJ5zkSSHcvG2BkwVuPiwO1bcHmFohGPGq5F vW5A2S5An5jmmV5rOm9qtGE0kZOcN0Iv7BRfiwt8rkKMSd+KSFIf1d2/WWDii8pW1MF4=; Received: from [127.0.0.1] (helo=sfs-ml-3.v29.lw.sourceforge.com) by sfs-ml-3.v29.lw.sourceforge.com with esmtp (Exim 4.100.1) (envelope-from ) id 1xJw5U-000000004Py-1iTf; Thu, 22 Oct 2026 16:56:20 +0000 Received: from [172.30.29.66] (helo=mx.sourceforge.net) by sfs-ml-3.v29.lw.sourceforge.com with esmtps (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.100.1) (envelope-from ) id 1xJw4w-000000004PO-09DR for linux-f2fs-devel@lists.sourceforge.net; Thu, 22 Oct 2026 16:55:46 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sourceforge.net; s=x; h=Content-Transfer-Encoding:MIME-Version:Message-ID: Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:In-Reply-To:References:List-Id:List-Help:List-Unsubscribe: List-Unsubscribe-Post:List-Subscribe:List-Post:List-Owner:List-Archive; bh=cGA7aNtopU1D3jFV3b7MKOoXob/OOTqjubBjksI2s90=; b=EQp4D8b65MDY22tacoYjee1pxS x6zhvb8tcl9svXFkVe0DNZtN8XdG3J50Rw/EvD4nX/KiryrpzT9zoeVRZXPmWjw8244CiUz33gXTu V7t6+VljVSwknKx83b80FcCDACvUsrlzSFy3MdmZjMZAwiClnUMneQuLKQcn8nx4wrdk=; DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sf.net; s=x ; h=Content-Transfer-Encoding:MIME-Version:Message-ID:Date:Subject:Cc:To:From :Sender:Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To: References:List-Id:List-Help:List-Unsubscribe:List-Unsubscribe-Post: List-Subscribe:List-Post:List-Owner:List-Archive; bh=cGA7aNtopU1D3jFV3b7MKOoXob/OOTqjubBjksI2s90=; b=lZVUuOSFRnFBeKvAq0/hPrtzf4 38FNEKFkhZAECmMxhTy+L02GnFLTaBqq+R25vmNiu+vvIIkMRqUl1PdZz6zbVv23l121sqcMOSzsh 5oEHv7jxJdpYPMDf8IFHFsoQjMUKtqZBHbWYq5qq1g2WykGjLI36atL/MWfqgwTv6uhY=; Received: from mail-pj1-f44.google.com ([209.85.216.44]) by sfi-mx-2.v28.lw.sourceforge.com with esmtps (TLS1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.100.1) id 1xJw4u-0000000008K-1lZc for linux-f2fs-devel@lists.sourceforge.net; Thu, 22 Oct 2026 16:55:45 +0000 Received: by mail-pj1-f44.google.com with SMTP id 98e67ed59e1d1-398b3c37877so38876a91.0 for ; Thu, 22 Oct 2026 09:55:44 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1792688139; x=1793292939; darn=lists.sourceforge.net; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:from:to:cc:subject:date:message-id:reply-to:content-type; bh=cGA7aNtopU1D3jFV3b7MKOoXob/OOTqjubBjksI2s90=; b=TKeU8/Ul6dpRYsDOl37kCEp8Q0KTAfjnoHwttSu3yqcmUiIFLTc+DE5Ig9zHvisp8I EuFKonktiV41xGrdwp9a1EbnEWqbSgKBAyAXdEqPl16Xhrs4t7kaN25LE4oasQOlw5aN dWoQP3mFOGzz8hLpKU9n2/8ZBnVP+80SevZqUojHl0EzcFdzbxzSx3r0vvRD9xqI01AP cuCDjRxylT29CEjx2IJvRk5abIWtrQ5wW9uaPM3EydgzVRNH4WcozQpQgIFfISVejHcH B5xaQFAQmBFGy47kp8X6AYzs+TpgMj9hCKoEKHlftotkn8o7Wb7XpVfAhI27DEgJsyZ1 pYEA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20260707; t=1792688139; x=1793292939; h=content-transfer-encoding:mime-version:message-id:date:subject:cc :to:from:x-gm-gg:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to:content-type; bh=cGA7aNtopU1D3jFV3b7MKOoXob/OOTqjubBjksI2s90=; b=f1ES6tEIiHAIyb/Vn3ZT4ITJo51tFIHOP0fEq4lU+S+y/QgE5+MsXMRzjrPRQxm5Nd X/B1YbNLWZlMC4+ZiNGN8Nra1UXKdjktDQHICUF5jocTop8wqZREDocOnrEGeDcYliQb XVFkwUQAbjuJLK+gIJCYxx64jqRhnMmH7hS1iFQ2ID38CzixW0fEzGeLFDD/RZxcWsYO Bvt4S6+nko4feIhvyRAWLkicFE/2G3gyDuRV7nSnnztdBryoQf3d1Aa8zTzxdDr76oUq AZi/T51mnRxFAvNRlCD5g9oIwoUoWVPjgv8EMYYnnjBN9v6ZxrvRUIjKeUVKiFJ4YTyK GQ/w== X-Forwarded-Encrypted: i=1; AKwUvBzuy4rFg4OrmFsAkY8wE2B4hjrF6yveSgUMR6+TTQcXH9Q5Ejg1+P/vB4l+qbch0BTj/MS64CeS9hAnz9uh4ma1@lists.sourceforge.net X-Gm-Message-State: AFq9FYJM4ez8kDa/L5IMl2JPf+BkeUE/eMbKo1zfm3NZUWK+0Ructj1v 8Ya5/lXoBO0IseFUxyZyaucKGsZ6qNhS3sMHGvcp+fyZyDgCWPIkBUu3Re0XDg== X-Gm-Gg: AYBFou2OosRtIt4nJy0UaJQKY7Te0TktWsH49nx7ghp7dI0f2Pxu69+LPvbb7/CazH2 U+HgnCAQjpKg1RKGGaxeqH8eiPkqtvL7+CNEMxWYQ335i6VrOGxM6GgmY2tybEm960rcgtewHUi XWiCxdAeOPmHcoBbt8N8k5aLxPLOBhUcUQzdvJ0vfkHNJudGpLEGoFBT2a8me2juoZgUoFcqtJT F9IxjqwdRqYh5j0Ow5k3G6JcPlIHFFdTOruZHdOogH1940zaxOdv9YRgIeUvuUAqNJUy6z0IkXc TtHWr++KrvtElSFwEBkTuvXsXExddo6GzhIr+kCs4rVf32Mjgy1iT+o9I7EaCU+kTiKwvdT0GCp 7tA31fghyOB+OAcVeh/J5/LLb22OZ8uuJfUDc2cOsuPOQat/iA2cZUPs1LoqvM8qRkvTuzOaADt bT/UQKMuubgklIt3GpjE9UckPB1KsX/B1bdpfa9BP/Sh94EZ0590vzlz/PSFlOFYEexLAHf+UXJ yhUAjC7Waa/bFWRYybiaHUNYmPZFkuz2La3OUsbg2baMuSmg3qdecoMMNAODlaHyRfH4HwJ7+h7 yQ9TmtTWPHxykMpiLQ7D0C1z7oVQMr5jZlYFquzGLH1GyNxAJDFpH+K7tbURpO66Dfw+R1LZeg= = X-Received: by 2002:a17:90b:3bcc:b0:3ac:b3c7:de14 with SMTP id 98e67ed59e1d1-3ad86d6cd8fmr4895188a91.61.1792688138335; Thu, 22 Oct 2026 09:55:38 -0700 (PDT) Received: from f2fs-test.c.googlers.com.com (225.134.16.34.bc.googleusercontent.com. [34.16.134.225]) by smtp.gmail.com with ESMTPSA id 98e67ed59e1d1-3ada48879a0sm5057688a91.4.2026.10.22.09.55.37 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Oct 2026 09:55:37 -0700 (PDT) From: Daeho Jeong To: linux-kernel@vger.kernel.org, linux-f2fs-devel@lists.sourceforge.net, kernel-team@android.com Date: Thu, 22 Oct 2026 16:55:26 +0000 Message-ID: <20261022165526.1539629-1-daeho43@gmail.com> X-Mailer: git-send-email 2.56.0.218.g1ec904b173-goog X-Archived-By: MIME-Version: 1.0 X-Spam-Score: 1.1 (+) X-Headers-End: 1xJw4u-0000000008K-1lZc Subject: [f2fs-dev] [PATCH v2] f2fs: reserve space to be shrunk during resize_fs X-BeenThere: linux-f2fs-devel@lists.sourceforge.net X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Daeho Jeong Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-13.8 required=3.0 tests=BAYES_00, DKIM_ADSP_CUSTOM_MED,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_EF, FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_PASS, SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=4.0.1 X-Spam-Checker-Version: SpamAssassin 4.0.1 (2024-03-26) on aws-us-west-2-korg-listserv-alma10-1 From: Daeho Jeong f2fs_resize_fs() drops gc_lock and the cp lock between the free space check and freeze_super(). In that window, others can allocate the free space, so the second check after freeze_super() fails with -ENOSPC. This is easy to hit on a busy filesystem, e.g. at OTA install time. Reserve the space to be shrunk via resize_reserved_blocks once the first check passes, and deduct it in __get_available_block_count() like alias_reserved_blocks. Release it on success or on error. With the reservation, the second check should not fail anymore, so: - allow root reserved blocks, which root may use in the meantime, - recheck DISABLE_CHECKPOINT, which remount may set in the meantime, since freeze_super() fails only when the fs is still dirty, - keep the check only as a WARN_ON_ONCE() safety net. Also exclude the alias/resize reservations when updating current_reserved_blocks via sysfs, otherwise it can underflow __get_available_block_count(). Suggested-by: Chao Yu Signed-off-by: Daeho Jeong --- Changes in v2: - Exclude alias/resize reservations from current_reserved_blocks. - Allow root reserved blocks in the second check, with WARN_ON_ONCE(). - Recheck DISABLE_CHECKPOINT after freeze_super(). --- fs/f2fs/f2fs.h | 18 +++++++++++++---- fs/f2fs/gc.c | 54 ++++++++++++++++++++++++++++++++++++++----------- fs/f2fs/super.c | 1 + fs/f2fs/sysfs.c | 12 ++++++++++- 4 files changed, 68 insertions(+), 17 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 089a62c054e..6b9e1d0e71c 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -1897,6 +1897,7 @@ struct f2fs_sb_info { block_t reserved_blocks; /* configurable reserved blocks */ block_t current_reserved_blocks; /* current reserved blocks */ block_t alias_reserved_blocks; /* reserved blocks for device alias */ + block_t resize_reserved_blocks; /* reserved blocks for resize_fs */ /* Additional tracking for no checkpoint mode */ block_t unusable_block_count; /* # of blocks saved by last cp */ @@ -2666,16 +2667,18 @@ static inline bool __allow_reserved_root(struct f2fs_sb_info *sbi, return false; } -static inline unsigned int get_available_block_count(struct f2fs_sb_info *sbi, - struct inode *inode, bool cap) +static inline unsigned int __get_available_block_count( + struct f2fs_sb_info *sbi, + bool allow_root) { block_t avail_user_block_count; avail_user_block_count = sbi->user_block_count - sbi->current_reserved_blocks - - sbi->alias_reserved_blocks; + sbi->alias_reserved_blocks - + sbi->resize_reserved_blocks; - if (test_opt(sbi, RESERVE_ROOT) && !__allow_reserved_root(sbi, inode, cap)) + if (test_opt(sbi, RESERVE_ROOT) && !allow_root) avail_user_block_count -= F2FS_OPTION(sbi).root_reserved_blocks; if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) { @@ -2688,6 +2691,13 @@ static inline unsigned int get_available_block_count(struct f2fs_sb_info *sbi, return avail_user_block_count; } +static inline unsigned int get_available_block_count(struct f2fs_sb_info *sbi, + struct inode *inode, bool cap) +{ + return __get_available_block_count(sbi, + __allow_reserved_root(sbi, inode, cap)); +} + static inline void f2fs_i_blocks_write(struct inode *, block_t, bool, bool); static inline int inc_valid_block_count(struct f2fs_sb_info *sbi, struct inode *inode, blkcnt_t *count, diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c index 926e6976bc2..955224f4166 100644 --- a/fs/f2fs/gc.c +++ b/fs/f2fs/gc.c @@ -2374,6 +2374,7 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count) struct f2fs_lock_context glc; struct f2fs_lock_context clc; unsigned int secs; + bool reserved = false; int err = 0; __u32 rem; @@ -2425,10 +2426,17 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count) f2fs_lock_op(sbi, &lc); spin_lock(&sbi->stat_lock); - if (shrunk_blocks + valid_user_blocks(sbi) + - sbi->current_reserved_blocks + sbi->unusable_block_count + - F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count) + if (shrunk_blocks + valid_user_blocks(sbi) > + __get_available_block_count(sbi, false)) { err = -ENOSPC; + } else { + /* + * Reserve the space to be shrunk so that no one, including + * root, can allocate it until the shrink is done. + */ + sbi->resize_reserved_blocks += shrunk_blocks; + reserved = true; + } spin_unlock(&sbi->stat_lock); if (err) @@ -2442,29 +2450,45 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count) out_drop_write: mnt_drop_write_file(filp); if (err) - return err; + goto out_release; err = freeze_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL); if (err) - return err; + goto out_release; if (f2fs_readonly(sbi->sb)) { err = thaw_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL); - if (err) - return err; - return -EROFS; + if (!err) + err = -EROFS; + goto out_release; + } + + /* checkpoint can be disabled by remount before freeze_super() */ + if (test_opt(sbi, DISABLE_CHECKPOINT)) { + f2fs_err(sbi, "Checkpoint should be enabled."); + err = thaw_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL); + if (!err) + err = -EINVAL; + goto out_release; } f2fs_down_write_trace(&sbi->gc_lock, &glc); f2fs_down_write_trace(&sbi->cp_global_sem, &clc); spin_lock(&sbi->stat_lock); - if (shrunk_blocks + valid_user_blocks(sbi) + - sbi->current_reserved_blocks + sbi->unusable_block_count + - F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count) + /* + * shrunk_blocks is already accounted in resize_reserved_blocks, so + * this should not fail. Allow root reserved blocks here since root + * may have used them after the first check, regardless of resize. + */ + if (WARN_ON_ONCE(valid_user_blocks(sbi) > + __get_available_block_count(sbi, true))) { err = -ENOSPC; - else + } else { sbi->user_block_count -= shrunk_blocks; + sbi->resize_reserved_blocks -= shrunk_blocks; + reserved = false; + } spin_unlock(&sbi->stat_lock); if (err) goto out_err; @@ -2510,5 +2534,11 @@ int f2fs_resize_fs(struct file *filp, __u64 block_count) f2fs_up_write_trace(&sbi->cp_global_sem, &clc); f2fs_up_write_trace(&sbi->gc_lock, &glc); thaw_super(sbi->sb, FREEZE_HOLDER_KERNEL, NULL); +out_release: + if (reserved) { + spin_lock(&sbi->stat_lock); + sbi->resize_reserved_blocks -= shrunk_blocks; + spin_unlock(&sbi->stat_lock); + } return err; } diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c index d683240040f..28e49e8d71e 100644 --- a/fs/f2fs/super.c +++ b/fs/f2fs/super.c @@ -5345,6 +5345,7 @@ static int f2fs_fill_super(struct super_block *sb, struct fs_context *fc) sbi->reserved_blocks = 0; sbi->current_reserved_blocks = 0; sbi->alias_reserved_blocks = 0; + sbi->resize_reserved_blocks = 0; limit_reserve_root(sbi); adjust_unusable_cap_perc(sbi); diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c index 9749da70089..ce70d81eba3 100644 --- a/fs/f2fs/sysfs.c +++ b/fs/f2fs/sysfs.c @@ -594,6 +594,8 @@ static ssize_t __sbi_store(struct f2fs_attr *a, } #endif if (a->struct_type == RESERVED_BLOCKS) { + block_t avail, valid; + spin_lock(&sbi->stat_lock); if (t > (unsigned long)(sbi->user_block_count - F2FS_OPTION(sbi).root_reserved_blocks)) { @@ -601,8 +603,16 @@ static ssize_t __sbi_store(struct f2fs_attr *a, return -EINVAL; } *ui = t; + /* + * Exclude the space reserved for device aliasing and resize_fs, + * otherwise the reserved blocks can overlap with them and + * __get_available_block_count() can underflow. + */ + avail = sbi->user_block_count - sbi->alias_reserved_blocks - + sbi->resize_reserved_blocks; + valid = valid_user_blocks(sbi); sbi->current_reserved_blocks = min(sbi->reserved_blocks, - sbi->user_block_count - valid_user_blocks(sbi)); + avail > valid ? avail - valid : 0); spin_unlock(&sbi->stat_lock); return count; } -- 2.56.0.218.g1ec904b173-goog _______________________________________________ Linux-f2fs-devel mailing list Linux-f2fs-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/linux-f2fs-devel