From eba67eb6de441909a22090bc77206c91134cd58c Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Tue, 13 Jun 2023 15:41:10 +0800 Subject: [PATCH] erofs: use absolute position in xattr iterator Replace blkaddr/ofs with pos in 'struct erofs_xattr_iter'. After erofs_bread() is introduced to replace raw page cache APIs for metadata I/Os handling, xattr_iter_fixup() is no longer needed anymore. In addition, it is also unnecessary to check if the iterated position is span over the block boundary as absolute offset is used instead of blkaddr + offset pairs. Signed-off-by: Jingbo Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20230613074114.120115-2-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/xattr.c | 162 ++++++++++++++++++++++--------------------------------- 1 file changed, 65 insertions(+), 97 deletions(-) diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index d9e041d..4c11d4f 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -7,26 +7,11 @@ #include #include "xattr.h" -static inline erofs_blk_t erofs_xattr_blkaddr(struct super_block *sb, - unsigned int xattr_id) -{ - return EROFS_SB(sb)->xattr_blkaddr + - erofs_blknr(sb, xattr_id * sizeof(__u32)); -} - -static inline unsigned int erofs_xattr_blkoff(struct super_block *sb, - unsigned int xattr_id) -{ - return erofs_blkoff(sb, xattr_id * sizeof(__u32)); -} - struct xattr_iter { struct super_block *sb; struct erofs_buf buf; + erofs_off_t pos; void *kaddr; - - erofs_blk_t blkaddr; - unsigned int ofs; }; static int erofs_init_inode_xattrs(struct inode *inode) @@ -82,17 +67,16 @@ static int erofs_init_inode_xattrs(struct inode *inode) it.buf = __EROFS_BUF_INITIALIZER; erofs_init_metabuf(&it.buf, sb); - it.blkaddr = erofs_blknr(sb, erofs_iloc(inode) + vi->inode_isize); - it.ofs = erofs_blkoff(sb, erofs_iloc(inode) + vi->inode_isize); + it.pos = erofs_iloc(inode) + vi->inode_isize; /* read in shared xattr array (non-atomic, see kmalloc below) */ - it.kaddr = erofs_bread(&it.buf, it.blkaddr, EROFS_KMAP); + it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), EROFS_KMAP); if (IS_ERR(it.kaddr)) { ret = PTR_ERR(it.kaddr); goto out_unlock; } - ih = (struct erofs_xattr_ibody_header *)(it.kaddr + it.ofs); + ih = it.kaddr + erofs_blkoff(sb, it.pos); vi->xattr_shared_count = ih->h_shared_count; vi->xattr_shared_xattrs = kmalloc_array(vi->xattr_shared_count, sizeof(uint), GFP_KERNEL); @@ -103,25 +87,20 @@ static int erofs_init_inode_xattrs(struct inode *inode) } /* let's skip ibody header */ - it.ofs += sizeof(struct erofs_xattr_ibody_header); + it.pos += sizeof(struct erofs_xattr_ibody_header); for (i = 0; i < vi->xattr_shared_count; ++i) { - if (it.ofs >= sb->s_blocksize) { - /* cannot be unaligned */ - DBG_BUGON(it.ofs != sb->s_blocksize); - - it.kaddr = erofs_bread(&it.buf, ++it.blkaddr, EROFS_KMAP); - if (IS_ERR(it.kaddr)) { - kfree(vi->xattr_shared_xattrs); - vi->xattr_shared_xattrs = NULL; - ret = PTR_ERR(it.kaddr); - goto out_unlock; - } - it.ofs = 0; + it.kaddr = erofs_bread(&it.buf, erofs_blknr(sb, it.pos), + EROFS_KMAP); + if (IS_ERR(it.kaddr)) { + kfree(vi->xattr_shared_xattrs); + vi->xattr_shared_xattrs = NULL; + ret = PTR_ERR(it.kaddr); + goto out_unlock; } - vi->xattr_shared_xattrs[i] = - le32_to_cpu(*(__le32 *)(it.kaddr + it.ofs)); - it.ofs += sizeof(__le32); + vi->xattr_shared_xattrs[i] = le32_to_cpu(*(__le32 *) + (it.kaddr + erofs_blkoff(sb, it.pos))); + it.pos += sizeof(__le32); } erofs_put_metabuf(&it.buf); @@ -150,24 +129,11 @@ struct xattr_iter_handlers { unsigned int len); }; -static inline int xattr_iter_fixup(struct xattr_iter *it) -{ - if (it->ofs < it->sb->s_blocksize) - return 0; - - it->blkaddr += erofs_blknr(it->sb, it->ofs); - it->kaddr = erofs_bread(&it->buf, it->blkaddr, EROFS_KMAP); - if (IS_ERR(it->kaddr)) - return PTR_ERR(it->kaddr); - it->ofs = erofs_blkoff(it->sb, it->ofs); - return 0; -} - static int inline_xattr_iter_begin(struct xattr_iter *it, struct inode *inode) { struct erofs_inode *const vi = EROFS_I(inode); - unsigned int xattr_header_sz, inline_xattr_ofs; + unsigned int xattr_header_sz; xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + sizeof(u32) * vi->xattr_shared_count; @@ -176,11 +142,9 @@ static int inline_xattr_iter_begin(struct xattr_iter *it, return -ENOATTR; } - inline_xattr_ofs = vi->inode_isize + xattr_header_sz; - - it->blkaddr = erofs_blknr(it->sb, erofs_iloc(inode) + inline_xattr_ofs); - it->ofs = erofs_blkoff(it->sb, erofs_iloc(inode) + inline_xattr_ofs); - it->kaddr = erofs_bread(&it->buf, it->blkaddr, EROFS_KMAP); + it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; + it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos), + EROFS_KMAP); if (IS_ERR(it->kaddr)) return PTR_ERR(it->kaddr); return vi->xattr_isize - xattr_header_sz; @@ -188,27 +152,29 @@ static int inline_xattr_iter_begin(struct xattr_iter *it, /* * Regardless of success or failure, `xattr_foreach' will end up with - * `ofs' pointing to the next xattr item rather than an arbitrary position. + * `pos' pointing to the next xattr item rather than an arbitrary position. */ static int xattr_foreach(struct xattr_iter *it, const struct xattr_iter_handlers *op, unsigned int *tlimit) { struct erofs_xattr_entry entry; + struct super_block *sb = it->sb; unsigned int value_sz, processed, slice; int err; - /* 0. fixup blkaddr, ofs, ipage */ - err = xattr_iter_fixup(it); - if (err) - return err; + /* 0. fixup blkaddr, pos */ + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); /* * 1. read xattr entry to the memory, * since we do EROFS_XATTR_ALIGN * therefore entry should be in the page */ - entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs); + entry = *(struct erofs_xattr_entry *) + (it->kaddr + erofs_blkoff(sb, it->pos)); if (tlimit) { unsigned int entry_sz = erofs_xattr_entry_size(&entry); @@ -220,40 +186,40 @@ static int xattr_foreach(struct xattr_iter *it, *tlimit -= entry_sz; } - it->ofs += sizeof(struct erofs_xattr_entry); + it->pos += sizeof(struct erofs_xattr_entry); value_sz = le16_to_cpu(entry.e_value_size); /* handle entry */ err = op->entry(it, &entry); if (err) { - it->ofs += entry.e_name_len + value_sz; + it->pos += entry.e_name_len + value_sz; goto out; } - /* 2. handle xattr name (ofs will finally be at the end of name) */ + /* 2. handle xattr name (pos will finally be at the end of name) */ processed = 0; while (processed < entry.e_name_len) { - if (it->ofs >= it->sb->s_blocksize) { - DBG_BUGON(it->ofs > it->sb->s_blocksize); - - err = xattr_iter_fixup(it); - if (err) - goto out; - it->ofs = 0; + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) { + err = PTR_ERR(it->kaddr); + goto out; } - slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs, + slice = min_t(unsigned int, + sb->s_blocksize - erofs_blkoff(sb, it->pos), entry.e_name_len - processed); /* handle name */ - err = op->name(it, processed, it->kaddr + it->ofs, slice); + err = op->name(it, processed, + it->kaddr + erofs_blkoff(sb, it->pos), slice); if (err) { - it->ofs += entry.e_name_len - processed + value_sz; + it->pos += entry.e_name_len - processed + value_sz; goto out; } - it->ofs += slice; + it->pos += slice; processed += slice; } @@ -263,31 +229,31 @@ static int xattr_foreach(struct xattr_iter *it, if (op->alloc_buffer) { err = op->alloc_buffer(it, value_sz); if (err) { - it->ofs += value_sz; + it->pos += value_sz; goto out; } } while (processed < value_sz) { - if (it->ofs >= it->sb->s_blocksize) { - DBG_BUGON(it->ofs > it->sb->s_blocksize); - - err = xattr_iter_fixup(it); - if (err) - goto out; - it->ofs = 0; + it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) { + err = PTR_ERR(it->kaddr); + goto out; } - slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs, + slice = min_t(unsigned int, + sb->s_blocksize - erofs_blkoff(sb, it->pos), value_sz - processed); - op->value(it, processed, it->kaddr + it->ofs, slice); - it->ofs += slice; + op->value(it, processed, it->kaddr + erofs_blkoff(sb, it->pos), + slice); + it->pos += slice; processed += slice; } out: /* xattrs should be 4-byte aligned (on-disk constraint) */ - it->ofs = EROFS_XATTR_ALIGN(it->ofs); + it->pos = EROFS_XATTR_ALIGN(it->pos); return err < 0 ? err : 0; } @@ -394,14 +360,15 @@ static int shared_getxattr(struct inode *inode, struct getxattr_iter *it) { struct erofs_inode *const vi = EROFS_I(inode); struct super_block *const sb = it->it.sb; - unsigned int i, xsid; + struct erofs_sb_info *sbi = EROFS_SB(sb); + unsigned int i; int ret = -ENOATTR; for (i = 0; i < vi->xattr_shared_count; ++i) { - xsid = vi->xattr_shared_xattrs[i]; - it->it.blkaddr = erofs_xattr_blkaddr(sb, xsid); - it->it.ofs = erofs_xattr_blkoff(sb, xsid); - it->it.kaddr = erofs_bread(&it->it.buf, it->it.blkaddr, EROFS_KMAP); + it->it.pos = erofs_pos(sb, sbi->xattr_blkaddr) + + vi->xattr_shared_xattrs[i] * sizeof(__le32); + it->it.kaddr = erofs_bread(&it->it.buf, + erofs_blknr(sb, it->it.pos), EROFS_KMAP); if (IS_ERR(it->it.kaddr)) return PTR_ERR(it->it.kaddr); @@ -599,14 +566,15 @@ static int shared_listxattr(struct listxattr_iter *it) struct inode *const inode = d_inode(it->dentry); struct erofs_inode *const vi = EROFS_I(inode); struct super_block *const sb = it->it.sb; - unsigned int i, xsid; + struct erofs_sb_info *sbi = EROFS_SB(sb); + unsigned int i; int ret = 0; for (i = 0; i < vi->xattr_shared_count; ++i) { - xsid = vi->xattr_shared_xattrs[i]; - it->it.blkaddr = erofs_xattr_blkaddr(sb, xsid); - it->it.ofs = erofs_xattr_blkoff(sb, xsid); - it->it.kaddr = erofs_bread(&it->it.buf, it->it.blkaddr, EROFS_KMAP); + it->it.pos = erofs_pos(sb, sbi->xattr_blkaddr) + + vi->xattr_shared_xattrs[i] * sizeof(__le32); + it->it.kaddr = erofs_bread(&it->it.buf, + erofs_blknr(sb, it->it.pos), EROFS_KMAP); if (IS_ERR(it->it.kaddr)) return PTR_ERR(it->it.kaddr); -- 2.7.4