[PATCH] man/man2/mount.2: add ENOSPC

[PATCH] man/man2/mount.2: add ENOSPC

[Chen Linxuan via B4 Relay]

From: Chen Linxuan <me@black-desk.cn>

After linux commit d29216842a85 ("mnt: Add a per mount namespace limit
on the number of mounts"), mount(2) might return ENOSPC.

---
Signed-off-by: Chen Linxuan <me@black-desk.cn>
---
 man/man2/mount.2 | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/man/man2/mount.2 b/man/man2/mount.2
index d5a68cb836b2..bebd3c1792ba 100644
--- a/man/man2/mount.2
+++ b/man/man2/mount.2
@@ -793,6 +793,19 @@ A pathname was empty or had a nonexistent component.
 .B ENOMEM
 The kernel could not allocate a free page to copy filenames or data into.
 .TP
+.B ENOSPC
+Number of mounts will exceed the limit after this syscall in some mount
+namespaces. This limit is controlled by
+.IR /proc/sys/fs/mount-max ,
+see
+.BR proc_sys_fs (5)
+for details of this limit.
+Note that this limit applies both to the mount namespace where the mount
+operation occurs and to any mount namespaces to which the mount will propagate.
+See
+.BR mount_namespaces (7)
+for details for mount namespace and mount propagation.
+.TP
 .B ENOTBLK
 .I source
 is not a block device (and a device was required).

---
base-commit: 6754bd1a126ed1e9b7d9c2bc1d221681f5182bb3
change-id: 20260130-add-enospc-for-mount-3ea1e87af6ee

Best regards,
-- 
Chen Linxuan <me@black-desk.cn>

Re: [PATCH] man/man2/mount.2: add ENOSPC

[Alejandro Colomar]

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[CC += CAI, Eric]

Hi Chen,

On 2026-01-30T16:13:54+0800, Chen Linxuan via B4 Relay wrote:
> From: Chen Linxuan <me@black-desk.cn>
> 
> After linux commit d29216842a85 ("mnt: Add a per mount namespace limit
> on the number of mounts"), mount(2) might return ENOSPC.
> 
> ---
> Signed-off-by: Chen Linxuan <me@black-desk.cn>

The sign-off should be in the commit message (above the '---').

> ---
>  man/man2/mount.2 | 13 +++++++++++++
>  1 file changed, 13 insertions(+)
> 
> diff --git a/man/man2/mount.2 b/man/man2/mount.2
> index d5a68cb836b2..bebd3c1792ba 100644
> --- a/man/man2/mount.2
> +++ b/man/man2/mount.2
> @@ -793,6 +793,19 @@ A pathname was empty or had a nonexistent component.
>  .B ENOMEM
>  The kernel could not allocate a free page to copy filenames or data into.
>  .TP
> +.B ENOSPC
> +Number of mounts will exceed the limit after this syscall in some mount
> +namespaces. This limit is controlled by

Please use semantic newlines.  See man-pages(7):

$ MANWIDTH=72 man man-pages | awk '/Use semantic newlines/,/^$/'
   Use semantic newlines
     In the source of a manual page, new sentences should be started on
     new lines, long sentences should be split  into  lines  at  clause
     breaks  (commas,  semicolons, colons, and so on), and long clauses
     should be split at phrase boundaries.  This convention,  sometimes
     known as "semantic newlines", makes it easier to see the effect of
     patches, which often operate at the level of individual sentences,
     clauses, or phrases.


Have a lovely day!
Alex

> +.IR /proc/sys/fs/mount-max ,
> +see
> +.BR proc_sys_fs (5)
> +for details of this limit.
> +Note that this limit applies both to the mount namespace where the mount
> +operation occurs and to any mount namespaces to which the mount will propagate.
> +See
> +.BR mount_namespaces (7)
> +for details for mount namespace and mount propagation.
> +.TP
>  .B ENOTBLK
>  .I source
>  is not a block device (and a device was required).
> 
> ---
> base-commit: 6754bd1a126ed1e9b7d9c2bc1d221681f5182bb3
> change-id: 20260130-add-enospc-for-mount-3ea1e87af6ee
> 
> Best regards,
> -- 
> Chen Linxuan <me@black-desk.cn>
> 
> 
> 

-- 
<https://www.alejandro-colomar.es>

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