* [PATCH 0/2] Couple of efivarfs fixes
@ 2020-05-28 19:49 Tony Luck
2020-05-28 19:49 ` [PATCH 1/2] efivarfs: Update inode modification time for successful writes Tony Luck
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: Tony Luck @ 2020-05-28 19:49 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Tony Luck, Matthew Garrett, Jeremy Kerr, linux-efi, linux-kernel
1) Some apps want to monitor changes in EFI variables, but reading the
file and comparing is inefficient. Just have Linnux update the
modification time when a file is written
2) A rate limited read can return -EINTR ... very suprising to apps.
Tony Luck (2):
efivarfs: Update inode modification time for successful writes
efivarfs: Don't return -EINTR when rate-limiting reads
fs/efivarfs/file.c | 7 +++----
1 file changed, 3 insertions(+), 4 deletions(-)
--
2.21.1
^ permalink raw reply [flat|nested] 6+ messages in thread
* [PATCH 1/2] efivarfs: Update inode modification time for successful writes
2020-05-28 19:49 [PATCH 0/2] Couple of efivarfs fixes Tony Luck
@ 2020-05-28 19:49 ` Tony Luck
2020-06-19 16:46 ` [tip: efi/urgent] " tip-bot2 for Tony Luck
2020-05-28 19:49 ` [PATCH 2/2] efivarfs: Don't return -EINTR when rate-limiting reads Tony Luck
2020-06-15 9:50 ` [PATCH 0/2] Couple of efivarfs fixes Ard Biesheuvel
2 siblings, 1 reply; 6+ messages in thread
From: Tony Luck @ 2020-05-28 19:49 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Tony Luck, Lennart Poettering, Matthew Garrett, Jeremy Kerr,
linux-efi, linux-kernel
Some applications want to be able to see when EFI variables
have been updated.
Update the modification time for successful writes.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
fs/efivarfs/file.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index e9e27a271af0..4b8bc4560d70 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -51,6 +51,7 @@ static ssize_t efivarfs_file_write(struct file *file,
} else {
inode_lock(inode);
i_size_write(inode, datasize + sizeof(attributes));
+ inode->i_mtime = current_time(inode);
inode_unlock(inode);
}
--
2.21.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [PATCH 2/2] efivarfs: Don't return -EINTR when rate-limiting reads
2020-05-28 19:49 [PATCH 0/2] Couple of efivarfs fixes Tony Luck
2020-05-28 19:49 ` [PATCH 1/2] efivarfs: Update inode modification time for successful writes Tony Luck
@ 2020-05-28 19:49 ` Tony Luck
2020-06-19 16:46 ` [tip: efi/urgent] " tip-bot2 for Tony Luck
2020-06-15 9:50 ` [PATCH 0/2] Couple of efivarfs fixes Ard Biesheuvel
2 siblings, 1 reply; 6+ messages in thread
From: Tony Luck @ 2020-05-28 19:49 UTC (permalink / raw)
To: Ard Biesheuvel
Cc: Tony Luck, Lennart Poettering, Matthew Garrett, Jeremy Kerr,
linux-efi, linux-kernel
Applications that read EFI variables may see a return
value of -EINTR if they exceed the rate limit and a
signal delivery is attempted while the process is sleeping.
This is quite surprising to the application, which probably
doesn't have code to handle it.
Change the interruptible sleep to a non-interruptible one.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
---
fs/efivarfs/file.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 4b8bc4560d70..feaa5e182b7b 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -73,10 +73,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
ssize_t size = 0;
int err;
- while (!__ratelimit(&file->f_cred->user->ratelimit)) {
- if (!msleep_interruptible(50))
- return -EINTR;
- }
+ while (!__ratelimit(&file->f_cred->user->ratelimit))
+ msleep(50);
err = efivar_entry_size(var, &datasize);
--
2.21.1
^ permalink raw reply related [flat|nested] 6+ messages in thread
* Re: [PATCH 0/2] Couple of efivarfs fixes
2020-05-28 19:49 [PATCH 0/2] Couple of efivarfs fixes Tony Luck
2020-05-28 19:49 ` [PATCH 1/2] efivarfs: Update inode modification time for successful writes Tony Luck
2020-05-28 19:49 ` [PATCH 2/2] efivarfs: Don't return -EINTR when rate-limiting reads Tony Luck
@ 2020-06-15 9:50 ` Ard Biesheuvel
2 siblings, 0 replies; 6+ messages in thread
From: Ard Biesheuvel @ 2020-06-15 9:50 UTC (permalink / raw)
To: Tony Luck
Cc: Matthew Garrett, Jeremy Kerr, linux-efi, Linux Kernel Mailing List
On Thu, 28 May 2020 at 21:49, Tony Luck <tony.luck@intel.com> wrote:
>
> 1) Some apps want to monitor changes in EFI variables, but reading the
> file and comparing is inefficient. Just have Linnux update the
> modification time when a file is written
>
> 2) A rate limited read can return -EINTR ... very suprising to apps.
>
> Tony Luck (2):
> efivarfs: Update inode modification time for successful writes
> efivarfs: Don't return -EINTR when rate-limiting reads
>
> fs/efivarfs/file.c | 7 +++----
> 1 file changed, 3 insertions(+), 4 deletions(-)
>
Queued in efi/urgent
Thanks,
^ permalink raw reply [flat|nested] 6+ messages in thread
* [tip: efi/urgent] efivarfs: Update inode modification time for successful writes
2020-05-28 19:49 ` [PATCH 1/2] efivarfs: Update inode modification time for successful writes Tony Luck
@ 2020-06-19 16:46 ` tip-bot2 for Tony Luck
0 siblings, 0 replies; 6+ messages in thread
From: tip-bot2 for Tony Luck @ 2020-06-19 16:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: Lennart Poettering, Tony Luck, Ard Biesheuvel, x86, LKML
The following commit has been merged into the efi/urgent branch of tip:
Commit-ID: 2096721f1577b51b574fa06a7d91823dffe7267a
Gitweb: https://git.kernel.org/tip/2096721f1577b51b574fa06a7d91823dffe7267a
Author: Tony Luck <tony.luck@intel.com>
AuthorDate: Thu, 28 May 2020 12:49:04 -07:00
Committer: Ard Biesheuvel <ardb@kernel.org>
CommitterDate: Mon, 15 Jun 2020 14:38:56 +02:00
efivarfs: Update inode modification time for successful writes
Some applications want to be able to see when EFI variables
have been updated.
Update the modification time for successful writes.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200528194905.690-2-tony.luck@intel.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
fs/efivarfs/file.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index e9e27a2..4b8bc45 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -51,6 +51,7 @@ static ssize_t efivarfs_file_write(struct file *file,
} else {
inode_lock(inode);
i_size_write(inode, datasize + sizeof(attributes));
+ inode->i_mtime = current_time(inode);
inode_unlock(inode);
}
^ permalink raw reply related [flat|nested] 6+ messages in thread
* [tip: efi/urgent] efivarfs: Don't return -EINTR when rate-limiting reads
2020-05-28 19:49 ` [PATCH 2/2] efivarfs: Don't return -EINTR when rate-limiting reads Tony Luck
@ 2020-06-19 16:46 ` tip-bot2 for Tony Luck
0 siblings, 0 replies; 6+ messages in thread
From: tip-bot2 for Tony Luck @ 2020-06-19 16:46 UTC (permalink / raw)
To: linux-tip-commits
Cc: Lennart Poettering, Tony Luck, Ard Biesheuvel, x86, LKML
The following commit has been merged into the efi/urgent branch of tip:
Commit-ID: 4353f03317fd3eb0bd803b61bdb287b68736a728
Gitweb: https://git.kernel.org/tip/4353f03317fd3eb0bd803b61bdb287b68736a728
Author: Tony Luck <tony.luck@intel.com>
AuthorDate: Thu, 28 May 2020 12:49:05 -07:00
Committer: Ard Biesheuvel <ardb@kernel.org>
CommitterDate: Mon, 15 Jun 2020 14:38:56 +02:00
efivarfs: Don't return -EINTR when rate-limiting reads
Applications that read EFI variables may see a return
value of -EINTR if they exceed the rate limit and a
signal delivery is attempted while the process is sleeping.
This is quite surprising to the application, which probably
doesn't have code to handle it.
Change the interruptible sleep to a non-interruptible one.
Reported-by: Lennart Poettering <mzxreary@0pointer.de>
Signed-off-by: Tony Luck <tony.luck@intel.com>
Link: https://lore.kernel.org/r/20200528194905.690-3-tony.luck@intel.com
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
fs/efivarfs/file.c | 6 ++----
1 file changed, 2 insertions(+), 4 deletions(-)
diff --git a/fs/efivarfs/file.c b/fs/efivarfs/file.c
index 4b8bc45..feaa5e1 100644
--- a/fs/efivarfs/file.c
+++ b/fs/efivarfs/file.c
@@ -73,10 +73,8 @@ static ssize_t efivarfs_file_read(struct file *file, char __user *userbuf,
ssize_t size = 0;
int err;
- while (!__ratelimit(&file->f_cred->user->ratelimit)) {
- if (!msleep_interruptible(50))
- return -EINTR;
- }
+ while (!__ratelimit(&file->f_cred->user->ratelimit))
+ msleep(50);
err = efivar_entry_size(var, &datasize);
^ permalink raw reply related [flat|nested] 6+ messages in thread
end of thread, other threads:[~2020-06-19 16:53 UTC | newest]
Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed)
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2020-05-28 19:49 [PATCH 0/2] Couple of efivarfs fixes Tony Luck
2020-05-28 19:49 ` [PATCH 1/2] efivarfs: Update inode modification time for successful writes Tony Luck
2020-06-19 16:46 ` [tip: efi/urgent] " tip-bot2 for Tony Luck
2020-05-28 19:49 ` [PATCH 2/2] efivarfs: Don't return -EINTR when rate-limiting reads Tony Luck
2020-06-19 16:46 ` [tip: efi/urgent] " tip-bot2 for Tony Luck
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