Re: Reg file system hash function
On Fri, Jun 15, 2001 at 03:52:52PM +0530, SATHISH.J wrote: > In the vfs layer when we see the lookup_dentry() function code we see that > a part of the code checks whether low level filesystem wants to use its > own hash. the part odf the code that calls the filesystem dependant > hashing is "error = base->d_op->d_hash->(base,);". Why should it > callfilesystem dependant hashing. What is the main purpose of hashing > here. > Please help me with these details. It is used in two cases. If a filesystem has: 1. case-insensitive filenames (its much better to have the names 'FOO' and 'foo' refer to the same dentry, since they refer to the same file) 2. a limited filename length and your filesystem truncates names (on a non-vfat filesystem 'dosfilen.ame' and 'dosfilename.ame' would be the same file and the same dentry structure). -- Russell King ([EMAIL PROTECTED])The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Reg file system hash function
Hi, In the vfs layer when we see the lookup_dentry() function code we see that a part of the code checks whether low level filesystem wants to use its own hash. the part odf the code that calls the filesystem dependant hashing is "error = base->d_op->d_hash->(base,);". Why should it callfilesystem dependant hashing. What is the main purpose of hashing here. Please help me with these details. Thanks in advance, Regards, sathish.j - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Reg file system hash function
Hi, In the vfs layer when we see the lookup_dentry() function code we see that a part of the code checks whether low level filesystem wants to use its own hash. the part odf the code that calls the filesystem dependant hashing is error = base-d_op-d_hash-(base,this);. Why should it callfilesystem dependant hashing. What is the main purpose of hashing here. Please help me with these details. Thanks in advance, Regards, sathish.j - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: Reg file system hash function
On Fri, Jun 15, 2001 at 03:52:52PM +0530, SATHISH.J wrote: In the vfs layer when we see the lookup_dentry() function code we see that a part of the code checks whether low level filesystem wants to use its own hash. the part odf the code that calls the filesystem dependant hashing is error = base-d_op-d_hash-(base,this);. Why should it callfilesystem dependant hashing. What is the main purpose of hashing here. Please help me with these details. It is used in two cases. If a filesystem has: 1. case-insensitive filenames (its much better to have the names 'FOO' and 'foo' refer to the same dentry, since they refer to the same file) 2. a limited filename length and your filesystem truncates names (on a non-vfat filesystem 'dosfilen.ame' and 'dosfilename.ame' would be the same file and the same dentry structure). -- Russell King ([EMAIL PROTECTED])The developer of ARM Linux http://www.arm.linux.org.uk/personal/aboutme.html - To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
