diff options
author | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 12:17:53 -0700 |
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committer | Yunhong Jiang <yunhong.jiang@intel.com> | 2015-08-04 15:44:42 -0700 |
commit | 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 (patch) | |
tree | 1c9cafbcd35f783a87880a10f85d1a060db1a563 /kernel/fs/stack.c | |
parent | 98260f3884f4a202f9ca5eabed40b1354c489b29 (diff) |
Add the rt linux 4.1.3-rt3 as base
Import the rt linux 4.1.3-rt3 as OPNFV kvm base.
It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and
the base is:
commit 0917f823c59692d751951bf5ea699a2d1e2f26a2
Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Sat Jul 25 12:13:34 2015 +0200
Prepare v4.1.3-rt3
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
We lose all the git history this way and it's not good. We
should apply another opnfv project repo in future.
Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423
Signed-off-by: Yunhong Jiang <yunhong.jiang@intel.com>
Diffstat (limited to 'kernel/fs/stack.c')
-rw-r--r-- | kernel/fs/stack.c | 76 |
1 files changed, 76 insertions, 0 deletions
diff --git a/kernel/fs/stack.c b/kernel/fs/stack.c new file mode 100644 index 000000000..a54e33ed1 --- /dev/null +++ b/kernel/fs/stack.c @@ -0,0 +1,76 @@ +#include <linux/export.h> +#include <linux/fs.h> +#include <linux/fs_stack.h> + +/* does _NOT_ require i_mutex to be held. + * + * This function cannot be inlined since i_size_{read,write} is rather + * heavy-weight on 32-bit systems + */ +void fsstack_copy_inode_size(struct inode *dst, struct inode *src) +{ + loff_t i_size; + blkcnt_t i_blocks; + + /* + * i_size_read() includes its own seqlocking and protection from + * preemption (see include/linux/fs.h): we need nothing extra for + * that here, and prefer to avoid nesting locks than attempt to keep + * i_size and i_blocks in sync together. + */ + i_size = i_size_read(src); + + /* + * But if CONFIG_LBDAF (on 32-bit), we ought to make an effort to + * keep the two halves of i_blocks in sync despite SMP or PREEMPT - + * though stat's generic_fillattr() doesn't bother, and we won't be + * applying quotas (where i_blocks does become important) at the + * upper level. + * + * We don't actually know what locking is used at the lower level; + * but if it's a filesystem that supports quotas, it will be using + * i_lock as in inode_add_bytes(). + */ + if (sizeof(i_blocks) > sizeof(long)) + spin_lock(&src->i_lock); + i_blocks = src->i_blocks; + if (sizeof(i_blocks) > sizeof(long)) + spin_unlock(&src->i_lock); + + /* + * If CONFIG_SMP or CONFIG_PREEMPT on 32-bit, it's vital for + * fsstack_copy_inode_size() to hold some lock around + * i_size_write(), otherwise i_size_read() may spin forever (see + * include/linux/fs.h). We don't necessarily hold i_mutex when this + * is called, so take i_lock for that case. + * + * And if CONFIG_LBDAF (on 32-bit), continue our effort to keep the + * two halves of i_blocks in sync despite SMP or PREEMPT: use i_lock + * for that case too, and do both at once by combining the tests. + * + * There is none of this locking overhead in the 64-bit case. + */ + if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long)) + spin_lock(&dst->i_lock); + i_size_write(dst, i_size); + dst->i_blocks = i_blocks; + if (sizeof(i_size) > sizeof(long) || sizeof(i_blocks) > sizeof(long)) + spin_unlock(&dst->i_lock); +} +EXPORT_SYMBOL_GPL(fsstack_copy_inode_size); + +/* copy all attributes */ +void fsstack_copy_attr_all(struct inode *dest, const struct inode *src) +{ + dest->i_mode = src->i_mode; + dest->i_uid = src->i_uid; + dest->i_gid = src->i_gid; + dest->i_rdev = src->i_rdev; + dest->i_atime = src->i_atime; + dest->i_mtime = src->i_mtime; + dest->i_ctime = src->i_ctime; + dest->i_blkbits = src->i_blkbits; + dest->i_flags = src->i_flags; + set_nlink(dest, src->i_nlink); +} +EXPORT_SYMBOL_GPL(fsstack_copy_attr_all); |