linux/fs/erofs/xattr.c

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// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Copyright (C) 2021-2022, Alibaba Cloud
*/
#include <linux/security.h>
#include "xattr.h"
struct erofs_xattr_iter {
struct super_block *sb;
struct erofs_buf buf;
erofs_off_t pos;
void *kaddr;
char *buffer;
int buffer_size, buffer_ofs;
/* getxattr */
int index, infix_len;
struct qstr name;
/* listxattr */
struct dentry *dentry;
};
static int erofs_init_inode_xattrs(struct inode *inode)
{
struct erofs_inode *const vi = EROFS_I(inode);
struct erofs_xattr_iter it;
unsigned int i;
struct erofs_xattr_ibody_header *ih;
struct super_block *sb = inode->i_sb;
int ret = 0;
/* the most case is that xattrs of this inode are initialized. */
if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags)) {
/*
* paired with smp_mb() at the end of the function to ensure
* fields will only be observed after the bit is set.
*/
smp_mb();
return 0;
}
if (wait_on_bit_lock(&vi->flags, EROFS_I_BL_XATTR_BIT, TASK_KILLABLE))
return -ERESTARTSYS;
/* someone has initialized xattrs for us? */
if (test_bit(EROFS_I_EA_INITED_BIT, &vi->flags))
goto out_unlock;
staging: erofs: fix fast symlink w/o xattr when fs xattr is on Currently, this will hit a BUG_ON for these symlinks as follows: - kernel message ------------[ cut here ]------------ kernel BUG at drivers/staging/erofs/xattr.c:59! SMP PTI CPU: 1 PID: 1170 Comm: getllxattr Not tainted 4.20.0-rc6+ #92 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:init_inode_xattrs+0x22b/0x270 Code: 48 0f 45 ea f0 ff 4d 34 74 0d 41 83 4c 24 e0 01 31 c0 e9 00 fe ff ff 48 89 ef e8 e0 31 9e ff eb e9 89 e8 e9 ef fd ff ff 0f 0$ <0f> 0b 48 89 ef e8 fb f6 9c ff 48 8b 45 08 a8 01 75 24 f0 ff 4d 34 RSP: 0018:ffffa03ac026bdf8 EFLAGS: 00010246 ------------[ cut here ]------------ ... Call Trace: erofs_listxattr+0x30/0x2c0 ? selinux_inode_listxattr+0x5a/0x80 ? kmem_cache_alloc+0x33/0x170 ? security_inode_listxattr+0x27/0x40 listxattr+0xaf/0xc0 path_listxattr+0x5a/0xa0 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... ---[ end trace 3c24b49408dc0c72 ]--- Fix it by checking ->xattr_isize in init_inode_xattrs(), and it also fixes improper return value -ENOTSUPP (it should be -ENODATA if xattr is enabled) for those inodes. Fixes: b17500a0fdba ("staging: erofs: introduce xattr & acl support") Cc: <stable@vger.kernel.org> # 4.19+ Reported-by: Li Guifu <bluce.liguifu@huawei.com> Tested-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14 11:40:23 +00:00
/*
* bypass all xattr operations if ->xattr_isize is not greater than
* sizeof(struct erofs_xattr_ibody_header), in detail:
* 1) it is not enough to contain erofs_xattr_ibody_header then
* ->xattr_isize should be 0 (it means no xattr);
* 2) it is just to contain erofs_xattr_ibody_header, which is on-disk
* undefined right now (maybe use later with some new sb feature).
*/
if (vi->xattr_isize == sizeof(struct erofs_xattr_ibody_header)) {
erofs_err(sb,
"xattr_isize %d of nid %llu is not supported yet",
vi->xattr_isize, vi->nid);
ret = -EOPNOTSUPP;
goto out_unlock;
staging: erofs: fix fast symlink w/o xattr when fs xattr is on Currently, this will hit a BUG_ON for these symlinks as follows: - kernel message ------------[ cut here ]------------ kernel BUG at drivers/staging/erofs/xattr.c:59! SMP PTI CPU: 1 PID: 1170 Comm: getllxattr Not tainted 4.20.0-rc6+ #92 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:init_inode_xattrs+0x22b/0x270 Code: 48 0f 45 ea f0 ff 4d 34 74 0d 41 83 4c 24 e0 01 31 c0 e9 00 fe ff ff 48 89 ef e8 e0 31 9e ff eb e9 89 e8 e9 ef fd ff ff 0f 0$ <0f> 0b 48 89 ef e8 fb f6 9c ff 48 8b 45 08 a8 01 75 24 f0 ff 4d 34 RSP: 0018:ffffa03ac026bdf8 EFLAGS: 00010246 ------------[ cut here ]------------ ... Call Trace: erofs_listxattr+0x30/0x2c0 ? selinux_inode_listxattr+0x5a/0x80 ? kmem_cache_alloc+0x33/0x170 ? security_inode_listxattr+0x27/0x40 listxattr+0xaf/0xc0 path_listxattr+0x5a/0xa0 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... ---[ end trace 3c24b49408dc0c72 ]--- Fix it by checking ->xattr_isize in init_inode_xattrs(), and it also fixes improper return value -ENOTSUPP (it should be -ENODATA if xattr is enabled) for those inodes. Fixes: b17500a0fdba ("staging: erofs: introduce xattr & acl support") Cc: <stable@vger.kernel.org> # 4.19+ Reported-by: Li Guifu <bluce.liguifu@huawei.com> Tested-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14 11:40:23 +00:00
} else if (vi->xattr_isize < sizeof(struct erofs_xattr_ibody_header)) {
if (vi->xattr_isize) {
erofs_err(sb, "bogus xattr ibody @ nid %llu", vi->nid);
staging: erofs: fix fast symlink w/o xattr when fs xattr is on Currently, this will hit a BUG_ON for these symlinks as follows: - kernel message ------------[ cut here ]------------ kernel BUG at drivers/staging/erofs/xattr.c:59! SMP PTI CPU: 1 PID: 1170 Comm: getllxattr Not tainted 4.20.0-rc6+ #92 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:init_inode_xattrs+0x22b/0x270 Code: 48 0f 45 ea f0 ff 4d 34 74 0d 41 83 4c 24 e0 01 31 c0 e9 00 fe ff ff 48 89 ef e8 e0 31 9e ff eb e9 89 e8 e9 ef fd ff ff 0f 0$ <0f> 0b 48 89 ef e8 fb f6 9c ff 48 8b 45 08 a8 01 75 24 f0 ff 4d 34 RSP: 0018:ffffa03ac026bdf8 EFLAGS: 00010246 ------------[ cut here ]------------ ... Call Trace: erofs_listxattr+0x30/0x2c0 ? selinux_inode_listxattr+0x5a/0x80 ? kmem_cache_alloc+0x33/0x170 ? security_inode_listxattr+0x27/0x40 listxattr+0xaf/0xc0 path_listxattr+0x5a/0xa0 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... ---[ end trace 3c24b49408dc0c72 ]--- Fix it by checking ->xattr_isize in init_inode_xattrs(), and it also fixes improper return value -ENOTSUPP (it should be -ENODATA if xattr is enabled) for those inodes. Fixes: b17500a0fdba ("staging: erofs: introduce xattr & acl support") Cc: <stable@vger.kernel.org> # 4.19+ Reported-by: Li Guifu <bluce.liguifu@huawei.com> Tested-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14 11:40:23 +00:00
DBG_BUGON(1);
ret = -EFSCORRUPTED;
goto out_unlock; /* xattr ondisk layout error */
staging: erofs: fix fast symlink w/o xattr when fs xattr is on Currently, this will hit a BUG_ON for these symlinks as follows: - kernel message ------------[ cut here ]------------ kernel BUG at drivers/staging/erofs/xattr.c:59! SMP PTI CPU: 1 PID: 1170 Comm: getllxattr Not tainted 4.20.0-rc6+ #92 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:init_inode_xattrs+0x22b/0x270 Code: 48 0f 45 ea f0 ff 4d 34 74 0d 41 83 4c 24 e0 01 31 c0 e9 00 fe ff ff 48 89 ef e8 e0 31 9e ff eb e9 89 e8 e9 ef fd ff ff 0f 0$ <0f> 0b 48 89 ef e8 fb f6 9c ff 48 8b 45 08 a8 01 75 24 f0 ff 4d 34 RSP: 0018:ffffa03ac026bdf8 EFLAGS: 00010246 ------------[ cut here ]------------ ... Call Trace: erofs_listxattr+0x30/0x2c0 ? selinux_inode_listxattr+0x5a/0x80 ? kmem_cache_alloc+0x33/0x170 ? security_inode_listxattr+0x27/0x40 listxattr+0xaf/0xc0 path_listxattr+0x5a/0xa0 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... ---[ end trace 3c24b49408dc0c72 ]--- Fix it by checking ->xattr_isize in init_inode_xattrs(), and it also fixes improper return value -ENOTSUPP (it should be -ENODATA if xattr is enabled) for those inodes. Fixes: b17500a0fdba ("staging: erofs: introduce xattr & acl support") Cc: <stable@vger.kernel.org> # 4.19+ Reported-by: Li Guifu <bluce.liguifu@huawei.com> Tested-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14 11:40:23 +00:00
}
ret = -ENOATTR;
goto out_unlock;
staging: erofs: fix fast symlink w/o xattr when fs xattr is on Currently, this will hit a BUG_ON for these symlinks as follows: - kernel message ------------[ cut here ]------------ kernel BUG at drivers/staging/erofs/xattr.c:59! SMP PTI CPU: 1 PID: 1170 Comm: getllxattr Not tainted 4.20.0-rc6+ #92 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-2.fc27 04/01/2014 RIP: 0010:init_inode_xattrs+0x22b/0x270 Code: 48 0f 45 ea f0 ff 4d 34 74 0d 41 83 4c 24 e0 01 31 c0 e9 00 fe ff ff 48 89 ef e8 e0 31 9e ff eb e9 89 e8 e9 ef fd ff ff 0f 0$ <0f> 0b 48 89 ef e8 fb f6 9c ff 48 8b 45 08 a8 01 75 24 f0 ff 4d 34 RSP: 0018:ffffa03ac026bdf8 EFLAGS: 00010246 ------------[ cut here ]------------ ... Call Trace: erofs_listxattr+0x30/0x2c0 ? selinux_inode_listxattr+0x5a/0x80 ? kmem_cache_alloc+0x33/0x170 ? security_inode_listxattr+0x27/0x40 listxattr+0xaf/0xc0 path_listxattr+0x5a/0xa0 do_syscall_64+0x43/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 ... ---[ end trace 3c24b49408dc0c72 ]--- Fix it by checking ->xattr_isize in init_inode_xattrs(), and it also fixes improper return value -ENOTSUPP (it should be -ENODATA if xattr is enabled) for those inodes. Fixes: b17500a0fdba ("staging: erofs: introduce xattr & acl support") Cc: <stable@vger.kernel.org> # 4.19+ Reported-by: Li Guifu <bluce.liguifu@huawei.com> Tested-by: Li Guifu <bluce.liguifu@huawei.com> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Gao Xiang <gaoxiang25@huawei.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-01-14 11:40:23 +00:00
}
it.buf = __EROFS_BUF_INITIALIZER;
erofs_init_metabuf(&it.buf, sb);
it.pos = erofs_iloc(inode) + vi->inode_isize;
/* read in shared xattr array (non-atomic, see kmalloc below) */
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 = 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);
if (!vi->xattr_shared_xattrs) {
erofs_put_metabuf(&it.buf);
ret = -ENOMEM;
goto out_unlock;
}
/* let's skip ibody header */
it.pos += sizeof(struct erofs_xattr_ibody_header);
for (i = 0; i < vi->xattr_shared_count; ++i) {
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 + erofs_blkoff(sb, it.pos)));
it.pos += sizeof(__le32);
}
erofs_put_metabuf(&it.buf);
/* paired with smp_mb() at the beginning of the function. */
smp_mb();
set_bit(EROFS_I_EA_INITED_BIT, &vi->flags);
out_unlock:
clear_and_wake_up_bit(EROFS_I_BL_XATTR_BIT, &vi->flags);
return ret;
}
static bool erofs_xattr_user_list(struct dentry *dentry)
{
return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER);
}
static bool erofs_xattr_trusted_list(struct dentry *dentry)
{
return capable(CAP_SYS_ADMIN);
}
static int erofs_xattr_generic_get(const struct xattr_handler *handler,
struct dentry *unused, struct inode *inode,
const char *name, void *buffer, size_t size)
{
if (handler->flags == EROFS_XATTR_INDEX_USER &&
!test_opt(&EROFS_I_SB(inode)->opt, XATTR_USER))
return -EOPNOTSUPP;
return erofs_getxattr(inode, handler->flags, name, buffer, size);
}
const struct xattr_handler erofs_xattr_user_handler = {
.prefix = XATTR_USER_PREFIX,
.flags = EROFS_XATTR_INDEX_USER,
.list = erofs_xattr_user_list,
.get = erofs_xattr_generic_get,
};
const struct xattr_handler erofs_xattr_trusted_handler = {
.prefix = XATTR_TRUSTED_PREFIX,
.flags = EROFS_XATTR_INDEX_TRUSTED,
.list = erofs_xattr_trusted_list,
.get = erofs_xattr_generic_get,
};
#ifdef CONFIG_EROFS_FS_SECURITY
const struct xattr_handler __maybe_unused erofs_xattr_security_handler = {
.prefix = XATTR_SECURITY_PREFIX,
.flags = EROFS_XATTR_INDEX_SECURITY,
.get = erofs_xattr_generic_get,
};
#endif
const struct xattr_handler *erofs_xattr_handlers[] = {
&erofs_xattr_user_handler,
&erofs_xattr_trusted_handler,
#ifdef CONFIG_EROFS_FS_SECURITY
&erofs_xattr_security_handler,
#endif
NULL,
};
static int erofs_xattr_copy_to_buffer(struct erofs_xattr_iter *it,
unsigned int len)
{
unsigned int slice, processed;
struct super_block *sb = it->sb;
void *src;
for (processed = 0; processed < len; processed += slice) {
it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
EROFS_KMAP);
if (IS_ERR(it->kaddr))
return PTR_ERR(it->kaddr);
src = it->kaddr + erofs_blkoff(sb, it->pos);
slice = min_t(unsigned int, sb->s_blocksize -
erofs_blkoff(sb, it->pos), len - processed);
memcpy(it->buffer + it->buffer_ofs, src, slice);
it->buffer_ofs += slice;
it->pos += slice;
}
return 0;
}
static int erofs_listxattr_foreach(struct erofs_xattr_iter *it)
{
struct erofs_xattr_entry entry;
unsigned int base_index, name_total, prefix_len, infix_len = 0;
const char *prefix, *infix = NULL;
int err;
/* 1. handle xattr entry */
entry = *(struct erofs_xattr_entry *)
(it->kaddr + erofs_blkoff(it->sb, it->pos));
it->pos += sizeof(struct erofs_xattr_entry);
base_index = entry.e_name_index;
if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
struct erofs_sb_info *sbi = EROFS_SB(it->sb);
struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
(entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
return 0;
infix = pf->prefix->infix;
infix_len = pf->infix_len;
base_index = pf->prefix->base_index;
}
Changes since last update: - Add sub-page block size support for uncompressed files; - Support flattened block device for multi-blob images to be attached into virtual machines (including cloud servers) and bare metals; - Support long xattr name prefixes to optimize images with common xattr namespaces (e.g. files with overlayfs xattrs) use cases; - Various minor cleanups & fixes. -----BEGIN PGP SIGNATURE----- iIcEABYIAC8WIQThPAmQN9sSA0DVxtI5NzHcH7XmBAUCZETCNREceGlhbmdAa2Vy bmVsLm9yZwAKCRA5NzHcH7XmBJCMAP9VkAPycbbqa6qWUASdyh/HGyuLJTHSfmsJ zO4y6hBgOwD9GXg55sY8ycvcOx9ayaUt5V5f9zhs4wdGcoPhj5fWzgA= =nUva -----END PGP SIGNATURE----- Merge tag 'erofs-for-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs Pull erofs updates from Gao Xiang: "In this cycle, sub-page block support for uncompressed files is available. It's mainly used to enable original signing ('golden') 4k-block images on arm64 with 16/64k pages. In addition, end users could also use this feature to build a manifest to directly refer to golden tar data. Besides, long xattr name prefix support is also introduced in this cycle to avoid too many xattrs with the same prefix (e.g. overlayfs xattrs). It's useful for erofs + overlayfs combination (like Composefs model): the image size is reduced by ~14% and runtime performance is also slightly improved. Others are random fixes and cleanups as usual. Summary: - Add sub-page block size support for uncompressed files - Support flattened block device for multi-blob images to be attached into virtual machines (including cloud servers) and bare metals - Support long xattr name prefixes to optimize images with common xattr namespaces (e.g. files with overlayfs xattrs) use cases - Various minor cleanups & fixes" * tag 'erofs-for-6.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/xiang/erofs: erofs: cleanup i_format-related stuffs erofs: sunset erofs_dbg() erofs: fix potential overflow calculating xattr_isize erofs: get rid of z_erofs_fill_inode() erofs: enable long extended attribute name prefixes erofs: handle long xattr name prefixes properly erofs: add helpers to load long xattr name prefixes erofs: introduce on-disk format for long xattr name prefixes erofs: move packed inode out of the compression part erofs: keep meta inode into erofs_buf erofs: initialize packed inode after root inode is assigned erofs: stop parsing non-compact HEAD index if clusterofs is invalid erofs: don't warn ztailpacking feature anymore erofs: simplify erofs_xattr_generic_get() erofs: rename init_inode_xattrs with erofs_ prefix erofs: move several xattr helpers into xattr.c erofs: tidy up EROFS on-disk naming erofs: support flattened block device for multi-blob images erofs: set block size to the on-disk block size erofs: avoid hardcoded blocksize for subpage block support
2023-04-24 21:25:39 +00:00
prefix = erofs_xattr_prefix(base_index, it->dentry);
if (!prefix)
return 0;
prefix_len = strlen(prefix);
name_total = prefix_len + infix_len + entry.e_name_len + 1;
if (!it->buffer) {
it->buffer_ofs += name_total;
return 0;
}
if (it->buffer_ofs + name_total > it->buffer_size)
return -ERANGE;
memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len);
memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len);
it->buffer_ofs += prefix_len + infix_len;
/* 2. handle xattr name */
err = erofs_xattr_copy_to_buffer(it, entry.e_name_len);
if (err)
return err;
it->buffer[it->buffer_ofs++] = '\0';
return 0;
}
static int erofs_getxattr_foreach(struct erofs_xattr_iter *it)
{
struct super_block *sb = it->sb;
struct erofs_xattr_entry entry;
unsigned int slice, processed, value_sz;
/* 1. handle xattr entry */
entry = *(struct erofs_xattr_entry *)
(it->kaddr + erofs_blkoff(sb, it->pos));
it->pos += sizeof(struct erofs_xattr_entry);
value_sz = le16_to_cpu(entry.e_value_size);
/* should also match the infix for long name prefixes */
if (entry.e_name_index & EROFS_XATTR_LONG_PREFIX) {
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes +
(entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK);
if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count)
return -ENOATTR;
if (it->index != pf->prefix->base_index ||
it->name.len != entry.e_name_len + pf->infix_len)
return -ENOATTR;
if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len))
return -ENOATTR;
it->infix_len = pf->infix_len;
} else {
if (it->index != entry.e_name_index ||
it->name.len != entry.e_name_len)
return -ENOATTR;
it->infix_len = 0;
}
/* 2. handle xattr name */
for (processed = 0; processed < entry.e_name_len; processed += slice) {
it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
EROFS_KMAP);
if (IS_ERR(it->kaddr))
return PTR_ERR(it->kaddr);
slice = min_t(unsigned int,
sb->s_blocksize - erofs_blkoff(sb, it->pos),
entry.e_name_len - processed);
if (memcmp(it->name.name + it->infix_len + processed,
it->kaddr + erofs_blkoff(sb, it->pos), slice))
return -ENOATTR;
it->pos += slice;
}
/* 3. handle xattr value */
if (!it->buffer) {
it->buffer_ofs = value_sz;
return 0;
}
if (it->buffer_size < value_sz)
return -ERANGE;
return erofs_xattr_copy_to_buffer(it, value_sz);
}
static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it,
struct inode *inode, bool getxattr)
{
struct erofs_inode *const vi = EROFS_I(inode);
unsigned int xattr_header_sz, remaining, entry_sz;
erofs_off_t next_pos;
int ret;
xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) +
sizeof(u32) * vi->xattr_shared_count;
if (xattr_header_sz >= vi->xattr_isize) {
DBG_BUGON(xattr_header_sz > vi->xattr_isize);
return -ENOATTR;
}
remaining = vi->xattr_isize - xattr_header_sz;
it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz;
while (remaining) {
it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos),
EROFS_KMAP);
if (IS_ERR(it->kaddr))
return PTR_ERR(it->kaddr);
entry_sz = erofs_xattr_entry_size(it->kaddr +
erofs_blkoff(it->sb, it->pos));
/* xattr on-disk corruption: xattr entry beyond xattr_isize */
if (remaining < entry_sz) {
DBG_BUGON(1);
return -EFSCORRUPTED;
}
remaining -= entry_sz;
next_pos = it->pos + entry_sz;
if (getxattr)
ret = erofs_getxattr_foreach(it);
else
ret = erofs_listxattr_foreach(it);
if ((getxattr && ret != -ENOATTR) || (!getxattr && ret))
break;
it->pos = next_pos;
}
return ret;
}
static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it,
struct inode *inode, bool getxattr)
{
struct erofs_inode *const vi = EROFS_I(inode);
struct super_block *const sb = it->sb;
struct erofs_sb_info *sbi = EROFS_SB(sb);
unsigned int i;
int ret = -ENOATTR;
for (i = 0; i < vi->xattr_shared_count; ++i) {
it->pos = erofs_pos(sb, sbi->xattr_blkaddr) +
vi->xattr_shared_xattrs[i] * sizeof(__le32);
it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos),
EROFS_KMAP);
if (IS_ERR(it->kaddr))
return PTR_ERR(it->kaddr);
if (getxattr)
ret = erofs_getxattr_foreach(it);
else
ret = erofs_listxattr_foreach(it);
if ((getxattr && ret != -ENOATTR) || (!getxattr && ret))
break;
}
return ret;
}
int erofs_getxattr(struct inode *inode, int index, const char *name,
void *buffer, size_t buffer_size)
{
int ret;
struct erofs_xattr_iter it;
if (!name)
return -EINVAL;
ret = erofs_init_inode_xattrs(inode);
if (ret)
return ret;
it.index = index;
it.name = (struct qstr)QSTR_INIT(name, strlen(name));
if (it.name.len > EROFS_NAME_LEN)
return -ERANGE;
it.sb = inode->i_sb;
it.buf = __EROFS_BUF_INITIALIZER;
erofs_init_metabuf(&it.buf, it.sb);
it.buffer = buffer;
it.buffer_size = buffer_size;
it.buffer_ofs = 0;
ret = erofs_xattr_iter_inline(&it, inode, true);
if (ret == -ENOATTR)
ret = erofs_xattr_iter_shared(&it, inode, true);
erofs_put_metabuf(&it.buf);
return ret ? ret : it.buffer_ofs;
}
ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size)
{
int ret;
struct erofs_xattr_iter it;
struct inode *inode = d_inode(dentry);
ret = erofs_init_inode_xattrs(inode);
if (ret == -ENOATTR)
return 0;
if (ret)
return ret;
it.sb = dentry->d_sb;
it.buf = __EROFS_BUF_INITIALIZER;
erofs_init_metabuf(&it.buf, it.sb);
it.dentry = dentry;
it.buffer = buffer;
it.buffer_size = buffer_size;
it.buffer_ofs = 0;
ret = erofs_xattr_iter_inline(&it, inode, false);
if (!ret || ret == -ENOATTR)
ret = erofs_xattr_iter_shared(&it, inode, false);
if (ret == -ENOATTR)
ret = 0;
erofs_put_metabuf(&it.buf);
return ret ? ret : it.buffer_ofs;
}
void erofs_xattr_prefixes_cleanup(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
int i;
if (sbi->xattr_prefixes) {
for (i = 0; i < sbi->xattr_prefix_count; i++)
kfree(sbi->xattr_prefixes[i].prefix);
kfree(sbi->xattr_prefixes);
sbi->xattr_prefixes = NULL;
}
}
int erofs_xattr_prefixes_init(struct super_block *sb)
{
struct erofs_sb_info *sbi = EROFS_SB(sb);
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2;
struct erofs_xattr_prefix_item *pfs;
int ret = 0, i, len;
if (!sbi->xattr_prefix_count)
return 0;
pfs = kzalloc(sbi->xattr_prefix_count * sizeof(*pfs), GFP_KERNEL);
if (!pfs)
return -ENOMEM;
if (sbi->packed_inode)
buf.inode = sbi->packed_inode;
else
erofs_init_metabuf(&buf, sb);
for (i = 0; i < sbi->xattr_prefix_count; i++) {
void *ptr = erofs_read_metadata(sb, &buf, &pos, &len);
if (IS_ERR(ptr)) {
ret = PTR_ERR(ptr);
break;
} else if (len < sizeof(*pfs->prefix) ||
len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) {
kfree(ptr);
ret = -EFSCORRUPTED;
break;
}
pfs[i].prefix = ptr;
pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix);
}
erofs_put_metabuf(&buf);
sbi->xattr_prefixes = pfs;
if (ret)
erofs_xattr_prefixes_cleanup(sb);
return ret;
}
#ifdef CONFIG_EROFS_FS_POSIX_ACL
struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu)
{
struct posix_acl *acl;
int prefix, rc;
char *value = NULL;
if (rcu)
return ERR_PTR(-ECHILD);
switch (type) {
case ACL_TYPE_ACCESS:
prefix = EROFS_XATTR_INDEX_POSIX_ACL_ACCESS;
break;
case ACL_TYPE_DEFAULT:
prefix = EROFS_XATTR_INDEX_POSIX_ACL_DEFAULT;
break;
default:
return ERR_PTR(-EINVAL);
}
rc = erofs_getxattr(inode, prefix, "", NULL, 0);
if (rc > 0) {
value = kmalloc(rc, GFP_KERNEL);
if (!value)
return ERR_PTR(-ENOMEM);
rc = erofs_getxattr(inode, prefix, "", value, rc);
}
if (rc == -ENOATTR)
acl = NULL;
else if (rc < 0)
acl = ERR_PTR(rc);
else
acl = posix_acl_from_xattr(&init_user_ns, value, rc);
kfree(value);
return acl;
}
#endif