From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from lists.ozlabs.org (lists.ozlabs.org [112.213.38.117]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id C136EC433FE for ; Tue, 29 Nov 2022 06:02:51 +0000 (UTC) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4NLsFP30zwz3cM6 for ; Tue, 29 Nov 2022 17:02:49 +1100 (AEDT) Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=j9LcpASE; dkim-atps=neutral Authentication-Results: lists.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:4864:20::52d; helo=mail-pg1-x52d.google.com; envelope-from=zbestahu@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256 header.s=20210112 header.b=j9LcpASE; dkim-atps=neutral Received: from mail-pg1-x52d.google.com (mail-pg1-x52d.google.com [IPv6:2607:f8b0:4864:20::52d]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 4NLsFJ0sK9z2xVr for ; Tue, 29 Nov 2022 17:02:42 +1100 (AEDT) Received: by mail-pg1-x52d.google.com with SMTP id 82so4595189pgc.0 for ; Mon, 28 Nov 2022 22:02:41 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:from:to:cc:subject:date :message-id:reply-to; bh=PVtzVdKQv0g30oBa2Hz1NU30m+9ocKEMSrHBOpASCUE=; b=j9LcpASEEyHQAPpIMEFvOUJvC+/+L7+Egwuy6+yuaS9x/mxTiuACj6WfmV5YClhJ1V dRhQuSyt02Pflr4KKi3oZ+m6nr/97LiTNFOKmp6bzL0QpevsVX6jAug3bB6mMGqsxMRF 8Nt35dJoPmOpaCMT7uW1OaOE/1HwHUuSbgJO5yhZa7DCb/4FXOvAaZA3Lwuv2LK4w+yw 9GbEJbuE4OiV4z2d9u8rd7pMNvAwo+JFWC7LEIfOBDQHQyA0/MAPYI8UtzOq4JcCPzwT x4u/rhiwlZODchxIDyyJyQulZriKyzf/EqOzx+vEtH72WO3jtVKTlo487yEDqrSHQBOR bSuQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:subject:cc:to:from:date:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=PVtzVdKQv0g30oBa2Hz1NU30m+9ocKEMSrHBOpASCUE=; b=ChzYtl6kRF7S/Wugfjx3W74PTVGL2owAoxOTOZkIIszGZm0rs5572l+Wc4DeH7MdoF Gtfffyer3kLDOK2Speif6NKA/3hkgouUj8+uL+5vno5wGs5nT/rgWwni2HW7F6Uli3ZY oOkOPC2jb/xzIaCiPEt6zlDAAZ8yFYJ774CZKOPxonZodkEeeGFOYtGEpPpaQHKEuSQX 6gUinohAJttjvwT9/i83ov96cuBZqUY8HpXaL5lhcf3gvToMp5R/yMdNa5E2T5/Sle31 iurkBTvcHbTPfKX+bHaZ2ldd5c1QnxvOFugcI3OlFmyawwlRgL9yIRuSs6NwMY+/N5lZ +dxQ== X-Gm-Message-State: ANoB5pmEY4P5KaE8GQBr4wFhu4g2uGAzuZ4c5g790G4Jzq8/OBV/trO/ F51i9z5Px13YNIA/y/i6f8A= X-Google-Smtp-Source: AA0mqf4l6ME8PYNcrt8deR/IeLaZMF5UfzXRh4SYlgZ+XwFaBygdcPLCmFpItIqHInhJ1FsXZUVOvg== X-Received: by 2002:a63:1054:0:b0:42b:9219:d14e with SMTP id 20-20020a631054000000b0042b9219d14emr31169155pgq.176.1669701756450; Mon, 28 Nov 2022 22:02:36 -0800 (PST) Received: from localhost ([156.236.96.165]) by smtp.gmail.com with ESMTPSA id pm9-20020a17090b3c4900b00210c84b8ae5sm481443pjb.35.2022.11.28.22.02.34 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Mon, 28 Nov 2022 22:02:36 -0800 (PST) Date: Tue, 29 Nov 2022 14:06:44 +0800 From: Yue Hu To: Gao Xiang Subject: Re: [RFC][PATCH v2] erofs-utils: mkfs: support fragment deduplication Message-ID: <20221129140644.00003cb2.zbestahu@gmail.com> In-Reply-To: References: <20221123131916.20782-1-zbestahu@gmail.com> X-Mailer: Claws Mail 3.17.3 (GTK+ 2.24.32; i686-w64-mingw32) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Yue Hu , linux-erofs@lists.ozlabs.org, shaojunjun@coolpad.com, zhangwen@coolpad.com Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" On Tue, 29 Nov 2022 09:43:37 +0800 Gao Xiang wrote: > Hi Yue, > > On Wed, Nov 23, 2022 at 09:19:16PM +0800, Yue Hu wrote: > > From: Yue Hu > > > > Previously, there's no fragment deduplication when this feature is > > introduced. Let's support it now. > > > > Suggested-by: Gao Xiang > > Signed-off-by: Yue Hu > > --- > > v2: mainly improve the logic in compression > > > > include/erofs/fragments.h | 3 +- > > lib/compress.c | 122 +++++++++++++++++++++---- > > lib/fragments.c | 188 +++++++++++++++++++++++++++++++++++++- > > lib/inode.c | 12 ++- > > 4 files changed, 302 insertions(+), 23 deletions(-) > > > > diff --git a/include/erofs/fragments.h b/include/erofs/fragments.h > > index 5444384..6c51fc9 100644 > > --- a/include/erofs/fragments.h > > +++ b/include/erofs/fragments.h > > @@ -15,8 +15,9 @@ extern "C" > > extern const char *frags_packedname; > > #define EROFS_PACKED_INODE frags_packedname > > > > +int z_erofs_fragments_dedupe(struct erofs_inode *inode, int fd, u32 *crc); > > int z_erofs_pack_fragments(struct erofs_inode *inode, void *data, > > - unsigned int len); > > + unsigned int len, u32 crc); > > struct erofs_inode *erofs_mkfs_build_fragments(void); > > int erofs_fragments_init(void); > > void erofs_fragments_exit(void); > > diff --git a/lib/compress.c b/lib/compress.c > > index 17b3213..7a133fd 100644 > > --- a/lib/compress.c > > +++ b/lib/compress.c > > @@ -33,6 +33,10 @@ struct z_erofs_vle_compress_ctx { > > unsigned int head, tail; > > erofs_blk_t blkaddr; /* pointing to the next blkaddr */ > > u16 clusterofs; > > + > > + u32 crc; > > + unsigned int pclustersize; > > + erofs_off_t remaining; > > }; > > > > #define Z_EROFS_LEGACY_MAP_HEADER_SIZE \ > > @@ -162,10 +166,10 @@ static void z_erofs_write_indexes(struct z_erofs_vle_compress_ctx *ctx) > > ctx->clusterofs = clusterofs + count; > > } > > > > -static int z_erofs_compress_dedupe(struct erofs_inode *inode, > > - struct z_erofs_vle_compress_ctx *ctx, > > +static int z_erofs_compress_dedupe(struct z_erofs_vle_compress_ctx *ctx, > > unsigned int *len) > > { > > + struct erofs_inode *inode = ctx->inode; > > int ret = 0; > > > > do { > > @@ -319,30 +323,83 @@ static void tryrecompress_trailing(void *in, unsigned int *insize, > > *compressedsize = ret; > > } > > > > -static int vle_compress_one(struct z_erofs_vle_compress_ctx *ctx, > > - bool final) > > +static void z_erofs_fragments_dedupe_reduce(struct z_erofs_vle_compress_ctx *ctx, > > + unsigned int *len) > > +{ > > + struct erofs_inode *inode = ctx->inode; > > + const unsigned int remaining = ctx->remaining + *len; > > + > > + if (!inode->fragment_size || !ctx->e.compressedblks) > > + return; > > + > > + /* try to close the gap if it gets larger (should be rare) */ > > + if (inode->fragment_size < remaining) { > > + z_erofs_write_indexes(ctx); > > + ctx->e.compressedblks = > > + BLK_ROUND_UP(remaining - inode->fragment_size); > > + return; > > + } > > + > > + inode->fragmentoff += inode->fragment_size - remaining; > > + inode->fragment_size = remaining; > > + > > + erofs_dbg("Reducing fragment size to %u at %lu", > > + inode->fragment_size, inode->fragmentoff); > > + > > + /* it's ending */ > > + ctx->head += remaining; > > + ctx->remaining = 0; > > + *len = 0; > > +} > > + > > +static void z_erofs_fragments_dedupe_end(struct z_erofs_vle_compress_ctx *ctx) > > +{ > > + struct erofs_inode *inode = ctx->inode; > > + > > + if (inode->fragment_size && ctx->e.compressedblks) { > > + inode->z_advise |= Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; > > + z_erofs_write_indexes(ctx); > > + > > + ctx->e.length = inode->fragment_size; > > + ctx->e.compressedblks = 0; > > + ctx->e.raw = true; > > + ctx->e.partial = false; > > + ctx->e.blkaddr = ctx->blkaddr; > > + } > > + z_erofs_write_indexes(ctx); > > + z_erofs_write_indexes_final(ctx); > > +} > > + > > +static int vle_compress_one(struct z_erofs_vle_compress_ctx *ctx, bool fixing) > > { > > static char dstbuf[EROFS_CONFIG_COMPR_MAX_SZ + EROFS_BLKSIZ]; > > struct erofs_inode *inode = ctx->inode; > > char *const dst = dstbuf + EROFS_BLKSIZ; > > struct erofs_compress *const h = &compresshandle; > > unsigned int len = ctx->tail - ctx->head; > > + bool final = !ctx->remaining; > > int ret; > > > > while (len) { > > - unsigned int pclustersize = > > - z_erofs_get_max_pclusterblks(inode) * EROFS_BLKSIZ; > > + unsigned int pclustersize = !fixing ? ctx->pclustersize : > > + ctx->e.compressedblks * EROFS_BLKSIZ; > > I have to think more about this. i will set "ctx->pcluster" when recompressing directly. > > > bool may_inline = (cfg.c_ztailpacking && final); > > bool may_packing = (cfg.c_fragments && final && > > !erofs_is_packed_inode(inode)); > > > > - if (z_erofs_compress_dedupe(inode, ctx, &len) && !final) > > + if (z_erofs_compress_dedupe(ctx, &len) && !final) > > break; > > > > if (len <= pclustersize) { > > if (!final || !len) > > break; > > if (may_packing) { > > + if (inode->fragment_size && !fixing) { > > + ctx->remaining = inode->fragment_size; > > + ctx->e.length = 0; > > + ctx->e.compressedblks = BLK_ROUND_UP(len); > > + return -EAGAIN; > > + } > > ctx->e.length = len; > > goto frag_packing; > > } > > @@ -385,11 +442,11 @@ nocompression: > > ctx->e.compressedblks = 1; > > ctx->e.raw = true; > > } else if (may_packing && len == ctx->e.length && > > - ret < pclustersize) { > > + ret < pclustersize && !inode->fragment_size) { > > frag_packing: > > ret = z_erofs_pack_fragments(inode, > > ctx->queue + ctx->head, > > - len); > > + len, ctx->crc); > > if (ret < 0) > > return ret; > > ctx->e.compressedblks = 0; /* indicate a fragment */ > > @@ -425,6 +482,20 @@ frag_packing: > > DBG_BUGON(ctx->e.compressedblks * EROFS_BLKSIZ >= > > ctx->e.length); > > > > + /* > > + * Try to recompress a litte more if there's space left > > + * for fragment deduplication. > > + */ > > + if (may_packing && len == ctx->e.length && tailused) { > > + DBG_BUGON(!inode->fragment_size); > > + if (fixing) > > + goto frag_packing; > > + > > + ctx->remaining = inode->fragment_size; > > + ctx->e.length = 0; > > + return -EAGAIN; > > + } > > + > > /* zero out garbage trailing data for non-0padding */ > > if (!erofs_sb_has_lz4_0padding()) > > memset(dst + ret, 0, > > @@ -454,6 +525,9 @@ frag_packing: > > ctx->head += ctx->e.length; > > len -= ctx->e.length; > > > > + if (fixing) > > + z_erofs_fragments_dedupe_reduce(ctx, &len); > > + > > if (!final && ctx->head >= EROFS_CONFIG_COMPR_MAX_SZ) { > > const unsigned int qh_aligned = > > round_down(ctx->head, EROFS_BLKSIZ); > > @@ -736,7 +810,6 @@ int erofs_write_compressed_file(struct erofs_inode *inode, int fd) > > { > > struct erofs_buffer_head *bh; > > static struct z_erofs_vle_compress_ctx ctx; > > - erofs_off_t remaining; > > erofs_blk_t blkaddr, compressed_blocks; > > unsigned int legacymetasize; > > int ret; > > @@ -775,6 +848,16 @@ int erofs_write_compressed_file(struct erofs_inode *inode, int fd) > > inode->idata_size = 0; > > inode->fragment_size = 0; > > > > + /* > > + * Dedupe fragments before compression to avoid writing duplicate parts > > + * into packed inode. > > + */ > > + if (cfg.c_fragments && !erofs_is_packed_inode(inode)) { > > + ret = z_erofs_fragments_dedupe(inode, fd, &ctx.crc); > > + if (ret < 0) > > + goto err_bdrop; > > + } > > + > > blkaddr = erofs_mapbh(bh->block); /* start_blkaddr */ > > ctx.inode = inode; > > ctx.blkaddr = blkaddr; > > @@ -782,22 +865,26 @@ int erofs_write_compressed_file(struct erofs_inode *inode, int fd) > > ctx.head = ctx.tail = 0; > > ctx.clusterofs = 0; > > ctx.e.length = 0; > > - remaining = inode->i_size; > > + ctx.e.compressedblks = 0; > > + ctx.pclustersize = z_erofs_get_max_pclusterblks(inode) * EROFS_BLKSIZ; > > + ctx.remaining = inode->i_size - inode->fragment_size; > > > > - while (remaining) { > > - const u64 readcount = min_t(u64, remaining, > > + ret = 0; > > + while (ctx.remaining) { > > + const u64 readcount = min_t(u64, ctx.remaining, > > sizeof(ctx.queue) - ctx.tail); > > + bool fixing = !!ret; > > > > ret = read(fd, ctx.queue + ctx.tail, readcount); > > if (ret != readcount) { > > ret = -errno; > > goto err_bdrop; > > } > > - remaining -= readcount; > > + ctx.remaining -= readcount; > > ctx.tail += readcount; > > > > - ret = vle_compress_one(&ctx, !remaining); > > - if (ret) > > + ret = vle_compress_one(&ctx, fixing); > > + if (ret && ret != -EAGAIN) > > goto err_free_idata; > > } > > DBG_BUGON(ctx.head != ctx.tail); > > @@ -807,8 +894,7 @@ int erofs_write_compressed_file(struct erofs_inode *inode, int fd) > > DBG_BUGON(compressed_blocks < !!inode->idata_size); > > compressed_blocks -= !!inode->idata_size; > > > > - z_erofs_write_indexes(&ctx); > > - z_erofs_write_indexes_final(&ctx); > > + z_erofs_fragments_dedupe_end(&ctx); > > legacymetasize = ctx.metacur - compressmeta; > > /* estimate if data compression saves space or not */ > > if (!inode->fragment_size && > > diff --git a/lib/fragments.c b/lib/fragments.c > > index b8c37d5..550c888 100644 > > --- a/lib/fragments.c > > +++ b/lib/fragments.c > > @@ -10,14 +10,191 @@ > > #include "erofs/inode.h" > > #include "erofs/compress.h" > > #include "erofs/print.h" > > +#include "erofs/internal.h" > > #include "erofs/fragments.h" > > > > +struct fragment_dedupe_item { > > + struct list_head list; > > + unsigned int length, nr_dup; > > + erofs_off_t pos; > > + u8 data[]; > > +}; > > + > > +#define FRAGMENT_HASHTABLE_SIZE 65536 > > +#define FRAGMENT_HASH(crc) (crc & (FRAGMENT_HASHTABLE_SIZE - 1)) > > + > > +static struct list_head di_hashtable[FRAGMENT_HASHTABLE_SIZE]; > > what does "di_hashtable" mean? What about "dedupe_fragments" or "dupli_fragments"? > > > +static unsigned int keylen; /* the data length to crc for deduplication */ > > keylen? too generic name. Let me think again. > > > + > > static FILE *packedfile; > > const char *frags_packedname = "packed_file"; > > > > +static struct fragment_dedupe_item *find_duplicate(struct list_head *head, > > why not fold in this? Will fix it in v3. > > > + u8 *data, unsigned int len) > > +{ > > + struct fragment_dedupe_item *di, *candidate = NULL; > > + > > + list_for_each_entry(di, head, list) { > > + unsigned int e1, e2, i = 0; > > + > > + DBG_BUGON(di->length < keylen + 1); > > + DBG_BUGON(len < keylen + 1); > > + > > + e1 = di->length - keylen - 1; > > + e2 = len - keylen - 1; > > + > > + if (memcmp(di->data + e1 + 1, data + e2 + 1, keylen)) > > + continue; > > + > > + while (i <= min(e1, e2) && di->data[e1 - i] == data[e2 - i]) > > + i++; > > + > > + if (i && (!candidate || i + keylen > candidate->nr_dup)) { > > + di->nr_dup = i + keylen; > > + candidate = di; > > + > > + /* full match */ > > + if (i == min(e1, e2) + 1) > > + break; > > + } > > + } > > + return candidate; > > +} > > + > > +static int z_erofs_fragments_dedupe_find(struct erofs_inode *inode, int fd, > > + u32 crc) > > +{ > > + struct fragment_dedupe_item *di; > > + struct list_head *head; > > + u8 *data; > > + unsigned int length; > > + int ret; > > + > > + head = &di_hashtable[FRAGMENT_HASH(crc)]; > > + if (list_empty(head)) > > + return 0; > > + > > + if (inode->i_size < EROFS_CONFIG_COMPR_MAX_SZ) > > + length = inode->i_size; > > + else > > + length = EROFS_CONFIG_COMPR_MAX_SZ; > > + > > + data = malloc(length); > > + if (!data) > > + return -ENOMEM; > > + > > + ret = lseek(fd, inode->i_size - length, SEEK_SET); > > + if (ret == -1) { > > + ret = -errno; > > + goto out; > > + } > > + > > + ret = read(fd, data, length); > > + if (ret != length) { > > + ret = -errno; > > + goto out; > > + } > > + > > + di = find_duplicate(head, data, length); > > + if (!di) > > + goto out; > > + > > + DBG_BUGON(di->length < di->nr_dup); > > + > > + inode->fragment_size = di->nr_dup; > > + inode->fragmentoff = di->pos + di->length - di->nr_dup; > > + > > + erofs_dbg("Dedupe %u fragment data at %lu", inode->fragment_size, > > + inode->fragmentoff); > > +out: > > + free(data); > > + return ret; > > +} > > + > > + > > +int z_erofs_fragments_dedupe(struct erofs_inode *inode, int fd, u32 *crc_ret) > > +{ > > + u8 key[keylen]; > > + u32 crc; > > + int ret; > > + > > + if (inode->i_size <= keylen) > > + return 0; > > + > > + ret = lseek(fd, inode->i_size - keylen, SEEK_SET); > > + if (ret == -1) > > + return -errno; > > + > > + ret = read(fd, key, keylen); > > + if (ret != keylen) > > + return -errno; > > + > > + crc = erofs_crc32c(~0, key, keylen); > > + *crc_ret = crc; > > + > > + ret = z_erofs_fragments_dedupe_find(inode, fd, crc); > > + if (ret < 0) > > + return ret; > > + > > + ret = lseek(fd, 0, SEEK_SET); > > + if (ret == -1) > > + return -errno; > > + return 0; > > +} > > + > > +static int z_erofs_fragments_dedupe_insert(void *data, unsigned int len, > > + erofs_off_t pos, u32 crc) > > +{ > > + struct fragment_dedupe_item *di; > > erofs_fragment_dedupe_item? Okay. > > > + > > + if (len <= keylen) > > + return 0; > > + > > + di = malloc(sizeof(*di) + len); > > + if (!di) > > + return -ENOMEM; > > + > > + memcpy(di->data, data, len); > > + di->length = len; > > + di->pos = pos; > > + di->nr_dup = 0; > > + > > + list_add_tail(&di->list, &di_hashtable[FRAGMENT_HASH(crc)]); > > + return 0; > > +} > > + > > +static inline void z_erofs_fragments_dedupe_init(unsigned int clen) > > +{ > > + unsigned int i; > > + > > + for (i = 0; i < FRAGMENT_HASHTABLE_SIZE; ++i) > > + init_list_head(&di_hashtable[i]); > > + > > + keylen = clen; > > +} > > + > > +static void z_erofs_fragments_dedupe_exit(void) > > +{ > > + struct fragment_dedupe_item *di, *n; > > + struct list_head *head; > > + unsigned int i; > > + > > + for (i = 0; i < FRAGMENT_HASHTABLE_SIZE; ++i) { > > + head = &di_hashtable[i]; > > + > > + if (list_empty(head)) > > + continue; > > + > > + list_for_each_entry_safe(di, n, head, list) > > + free(di); > > + } > > +} > > + > > int z_erofs_pack_fragments(struct erofs_inode *inode, void *data, > > - unsigned int len) > > + unsigned int len, u32 crc) > > { > > + int ret; > > + > > inode->z_advise |= Z_EROFS_ADVISE_FRAGMENT_PCLUSTER; > > inode->fragmentoff = ftell(packedfile); > > inode->fragment_size = len; > > @@ -35,6 +212,11 @@ int z_erofs_pack_fragments(struct erofs_inode *inode, void *data, > > > > erofs_dbg("Recording %u fragment data at %lu", inode->fragment_size, > > inode->fragmentoff); > > + > > + ret = z_erofs_fragments_dedupe_insert(data, len, inode->fragmentoff, > > + crc); > > + if (ret) > > + return ret; > > return len; > > } > > > > @@ -50,6 +232,8 @@ void erofs_fragments_exit(void) > > { > > if (packedfile) > > fclose(packedfile); > > + > > + z_erofs_fragments_dedupe_exit(); > > } > > > > int erofs_fragments_init(void) > > @@ -61,5 +245,7 @@ int erofs_fragments_init(void) > > #endif > > if (!packedfile) > > return -ENOMEM; > > + > > + z_erofs_fragments_dedupe_init(16); > > return 0; > > } > > diff --git a/lib/inode.c b/lib/inode.c > > index 9de4dec..cb2e057 100644 > > --- a/lib/inode.c > > +++ b/lib/inode.c > > @@ -406,7 +406,7 @@ static int write_uncompressed_file_from_fd(struct erofs_inode *inode, int fd) > > return 0; > > } > > > > -int erofs_write_file(struct erofs_inode *inode) > > +static int erofs_write_file(struct erofs_inode *inode) > > Can we move this into a seperated patch? Sure. > > > { > > int ret, fd; > > > > @@ -1196,7 +1196,10 @@ struct erofs_inode *erofs_mkfs_build_special_from_fd(int fd, const char *name) > > struct erofs_inode *inode; > > int ret; > > > > - lseek(fd, 0, SEEK_SET); > > + ret = lseek(fd, 0, SEEK_SET); > > + if (ret == -1) > > + return ERR_PTR(-errno); > > Same here. Sure. > > > + > > ret = fstat64(fd, &st); > > if (ret) > > return ERR_PTR(-errno); > > @@ -1223,7 +1226,10 @@ struct erofs_inode *erofs_mkfs_build_special_from_fd(int fd, const char *name) > > > > ret = erofs_write_compressed_file(inode, fd); > > if (ret == -ENOSPC) { > > - lseek(fd, 0, SEEK_SET); > > + ret = lseek(fd, 0, SEEK_SET); > > + if (ret == -1) > > + return ERR_PTR(-errno); > > + > > Same here. Sure. > > Thanks, > Gao Xiang > > > > ret = write_uncompressed_file_from_fd(inode, fd); > > } > > > > -- > > 2.17.1