e0f526b01b
When using sdcardfs, some more vfs symbols are needed to be exported to
the filesystem namespace, in order for it to build properly and to
prevent drivers from accessing them.
Like commit 0a77fca3aafc ("ANDROID: GKI: set vfs-only exports into their
own namespace"), move them to the vfs-only namespace so that builds work
properly.
Bug: 157965270
Bug: 210074446
Bug: 317479303
Change-Id: I915402a03712241bdf48681e3fb46aa33dcff305
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
77 lines
2.6 KiB
C
77 lines
2.6 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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#include <linux/export.h>
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#include <linux/fs.h>
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#include <linux/fs_stack.h>
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/* does _NOT_ require i_mutex to be held.
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*
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* This function cannot be inlined since i_size_{read,write} is rather
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* heavy-weight on 32-bit systems
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*/
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void fsstack_copy_inode_size(struct inode *dst, struct inode *src)
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{
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loff_t i_size;
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blkcnt_t i_blocks;
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/*
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* i_size_read() includes its own seqlocking and protection from
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* preemption (see include/linux/fs.h): we need nothing extra for
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* that here, and prefer to avoid nesting locks than attempt to keep
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* i_size and i_blocks in sync together.
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*/
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i_size = i_size_read(src);
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/*
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* But on 32-bit, we ought to make an effort to keep the two halves of
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* i_blocks in sync despite SMP or PREEMPTION - though stat's
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* generic_fillattr() doesn't bother, and we won't be applying quotas
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* (where i_blocks does become important) at the upper level.
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*
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* We don't actually know what locking is used at the lower level;
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* but if it's a filesystem that supports quotas, it will be using
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* i_lock as in inode_add_bytes().
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*/
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if (sizeof(i_blocks) > sizeof(long))
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spin_lock(&src->i_lock);
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i_blocks = src->i_blocks;
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if (sizeof(i_blocks) > sizeof(long))
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spin_unlock(&src->i_lock);
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/*
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* If CONFIG_SMP or CONFIG_PREEMPTION on 32-bit, it's vital for
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* fsstack_copy_inode_size() to hold some lock around
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* i_size_write(), otherwise i_size_read() may spin forever (see
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* include/linux/fs.h). We don't necessarily hold i_mutex when this
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* is called, so take i_lock for that case.
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*
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* And if on 32-bit, continue our effort to keep the two halves of
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* i_blocks in sync despite SMP or PREEMPTION: use i_lock for that case
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* too, and do both at once by combining the tests.
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*
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* There is none of this locking overhead in the 64-bit case.
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*/
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if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long))
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spin_lock(&dst->i_lock);
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i_size_write(dst, i_size);
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dst->i_blocks = i_blocks;
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if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long))
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spin_unlock(&dst->i_lock);
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}
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EXPORT_SYMBOL_NS_GPL(fsstack_copy_inode_size, ANDROID_GKI_VFS_EXPORT_ONLY);
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/* copy all attributes */
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void fsstack_copy_attr_all(struct inode *dest, const struct inode *src)
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{
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dest->i_mode = src->i_mode;
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dest->i_uid = src->i_uid;
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dest->i_gid = src->i_gid;
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dest->i_rdev = src->i_rdev;
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inode_set_atime_to_ts(dest, inode_get_atime(src));
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inode_set_mtime_to_ts(dest, inode_get_mtime(src));
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inode_set_ctime_to_ts(dest, inode_get_ctime(src));
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dest->i_blkbits = src->i_blkbits;
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dest->i_flags = src->i_flags;
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set_nlink(dest, src->i_nlink);
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}
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EXPORT_SYMBOL_GPL(fsstack_copy_attr_all);
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