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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-20 09:03:55 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-20 09:03:55 -0700 |
commit | 46ee9645094ad1eb5b4888882ecaa1fb87dcd2a3 (patch) | |
tree | d0a48e993568b6a2415cfc21fc06eaa2fd886429 /fs | |
parent | fa5312d9e87e7222c6c384c4e930dc149bc1178d (diff) | |
parent | 25f3a5a2854dce8b8413fd24cc9d5b9e3632be54 (diff) | |
download | kernel_samsung_espresso10-46ee9645094ad1eb5b4888882ecaa1fb87dcd2a3.zip kernel_samsung_espresso10-46ee9645094ad1eb5b4888882ecaa1fb87dcd2a3.tar.gz kernel_samsung_espresso10-46ee9645094ad1eb5b4888882ecaa1fb87dcd2a3.tar.bz2 |
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/suspend-2.6:
PM: PM QOS update fix
Freezer / cgroup freezer: Update stale locking comments
PM / platform_bus: Allow runtime PM by default
i2c: Fix bus-level power management callbacks
PM QOS update
PM / Hibernate: Fix block_io.c printk warning
PM / Hibernate: Group swap ops
PM / Hibernate: Move the first_sector out of swsusp_write
PM / Hibernate: Separate block_io
PM / Hibernate: Snapshot cleanup
FS / libfs: Implement simple_write_to_buffer
PM / Hibernate: document open(/dev/snapshot) side effects
PM / Runtime: Add sysfs debug files
PM: Improve device power management document
PM: Update device power management document
PM: Allow runtime_suspend methods to call pm_schedule_suspend()
PM: pm_wakeup - switch to using bool
Diffstat (limited to 'fs')
-rw-r--r-- | fs/libfs.c | 35 |
1 files changed, 35 insertions, 0 deletions
@@ -547,6 +547,40 @@ ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos, } /** + * simple_write_to_buffer - copy data from user space to the buffer + * @to: the buffer to write to + * @available: the size of the buffer + * @ppos: the current position in the buffer + * @from: the user space buffer to read from + * @count: the maximum number of bytes to read + * + * The simple_write_to_buffer() function reads up to @count bytes from the user + * space address starting at @from into the buffer @to at offset @ppos. + * + * On success, the number of bytes written is returned and the offset @ppos is + * advanced by this number, or negative value is returned on error. + **/ +ssize_t simple_write_to_buffer(void *to, size_t available, loff_t *ppos, + const void __user *from, size_t count) +{ + loff_t pos = *ppos; + size_t res; + + if (pos < 0) + return -EINVAL; + if (pos >= available || !count) + return 0; + if (count > available - pos) + count = available - pos; + res = copy_from_user(to + pos, from, count); + if (res == count) + return -EFAULT; + count -= res; + *ppos = pos + count; + return count; +} + +/** * memory_read_from_buffer - copy data from the buffer * @to: the kernel space buffer to read to * @count: the maximum number of bytes to read @@ -864,6 +898,7 @@ EXPORT_SYMBOL(simple_statfs); EXPORT_SYMBOL(simple_sync_file); EXPORT_SYMBOL(simple_unlink); EXPORT_SYMBOL(simple_read_from_buffer); +EXPORT_SYMBOL(simple_write_to_buffer); EXPORT_SYMBOL(memory_read_from_buffer); EXPORT_SYMBOL(simple_transaction_set); EXPORT_SYMBOL(simple_transaction_get); |