[PATCH 2/2] path_resolution.7: document read-only mounts, ACLs, and immutable files

[Simon Essien <champbreed1@gmail.com>]

Address several FIXMEs by adding brief mentions of:
- EROFS errors on read-only filesystems.
- Access restrictions from filesystem ACLs.
- Access restrictions from immutable file attributes.

Signed-off-by: Simon Essien <champbreed1@gmail.com>
---
 man/man7/path_resolution.7 | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/man/man7/path_resolution.7 b/man/man7/path_resolution.7
index cdf21e1f7..78573f3c2 100644
--- a/man/man7/path_resolution.7
+++ b/man/man7/path_resolution.7
@@ -225,7 +225,12 @@ Similarly, Linux uses the fsgid ("filesystem group ID")
 instead of the effective group ID.
 See
 .BR setfsgid (2).
-.\" FIXME . say something about filesystem mounted read-only ?
+.P
+Even if a process has the necessary permissions to access or
+modify a file, an attempt to modify any part of the filesystem
+will fail with the error
+.B EROFS
+if the filesystem is currently mounted read-only.
 .SS Bypassing permission checks: superuser and capabilities
 On a traditional UNIX system, the superuser
 .RI ( root ,
@@ -256,8 +261,15 @@ The
 .B CAP_DAC_READ_SEARCH
 capability grants read and search permission
 on directories, and read permission on ordinary files.
-.\" FIXME . say something about immutable files
-.\" FIXME . say something about ACLs
+.P
+Beyond the standard permissions, access may also be restricted by
+filesystem-specific ACLs (Access Control Lists) or by
+immutable file attributes.
+See
+.BR acl (5)
+and
+.BR chattr (1)
+for more details.
 .SH SEE ALSO
 .BR readlink (2),
 .BR capabilities (7),
-- 
2.51.0